/*
* Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "code/codeCache.hpp"
#include "code/compiledIC.hpp"
#include "code/dependencies.hpp"
#include "code/nmethod.hpp"
#include "code/scopeDesc.hpp"
#include "compiler/abstractCompiler.hpp"
#include "compiler/compileBroker.hpp"
#include "compiler/compileLog.hpp"
#include "compiler/compilerOracle.hpp"
#include "compiler/disassembler.hpp"
#include "interpreter/bytecode.hpp"
#include "oops/methodDataOop.hpp"
#include "prims/jvmtiRedefineClassesTrace.hpp"
#include "prims/jvmtiImpl.hpp"
#include "runtime/sharedRuntime.hpp"
#include "runtime/sweeper.hpp"
#include "utilities/dtrace.hpp"
#include "utilities/events.hpp"
#include "utilities/xmlstream.hpp"
#ifdef SHARK
#include "shark/sharkCompiler.hpp"
#endif
#ifdef DTRACE_ENABLED
// Only bother with this argument setup if dtrace is available
#ifndef USDT2
HS_DTRACE_PROBE_DECL8(hotspot, compiled__method__load,
const char*, int, const char*, int, const char*, int, void*, size_t);
HS_DTRACE_PROBE_DECL6(hotspot, compiled__method__unload,
char*, int, char*, int, char*, int);
#define DTRACE_METHOD_UNLOAD_PROBE(method) \
{ \
methodOop m = (method); \
if (m != NULL) { \
Symbol* klass_name = m->klass_name(); \
Symbol* name = m->name(); \
Symbol* signature = m->signature(); \
HS_DTRACE_PROBE6(hotspot, compiled__method__unload, \
klass_name->bytes(), klass_name->utf8_length(), \
name->bytes(), name->utf8_length(), \
signature->bytes(), signature->utf8_length()); \
} \
}
#else /* USDT2 */
#define DTRACE_METHOD_UNLOAD_PROBE(method) \
{ \
methodOop m = (method); \
if (m != NULL) { \
Symbol* klass_name = m->klass_name(); \
Symbol* name = m->name(); \
Symbol* signature = m->signature(); \
HOTSPOT_COMPILED_METHOD_UNLOAD( \
(char *) klass_name->bytes(), klass_name->utf8_length(), \
(char *) name->bytes(), name->utf8_length(), \
(char *) signature->bytes(), signature->utf8_length()); \
} \
}
#endif /* USDT2 */
#else // ndef DTRACE_ENABLED
#define DTRACE_METHOD_UNLOAD_PROBE(method)
#endif
bool nmethod::is_compiled_by_c1() const {
if (compiler() == NULL || method() == NULL) return false; // can happen during debug printing
if (is_native_method()) return false;
return compiler()->is_c1();
}
bool nmethod::is_compiled_by_c2() const {
if (compiler() == NULL || method() == NULL) return false; // can happen during debug printing
if (is_native_method()) return false;
return compiler()->is_c2();
}
bool nmethod::is_compiled_by_shark() const {
if (is_native_method()) return false;
assert(compiler() != NULL, "must be");
return compiler()->is_shark();
}
//---------------------------------------------------------------------------------
// NMethod statistics
// They are printed under various flags, including:
// PrintC1Statistics, PrintOptoStatistics, LogVMOutput, and LogCompilation.
// (In the latter two cases, they like other stats are printed to the log only.)
#ifndef PRODUCT
// These variables are put into one block to reduce relocations
// and make it simpler to print from the debugger.
static
struct nmethod_stats_struct {
int nmethod_count;
int total_size;
int relocation_size;
int consts_size;
int insts_size;
int stub_size;
int scopes_data_size;
int scopes_pcs_size;
int dependencies_size;
int handler_table_size;
int nul_chk_table_size;
int oops_size;
void note_nmethod(nmethod* nm) {
nmethod_count += 1;
total_size += nm->size();
relocation_size += nm->relocation_size();
consts_size += nm->consts_size();
insts_size += nm->insts_size();
stub_size += nm->stub_size();
oops_size += nm->oops_size();
scopes_data_size += nm->scopes_data_size();
scopes_pcs_size += nm->scopes_pcs_size();
dependencies_size += nm->dependencies_size();
handler_table_size += nm->handler_table_size();
nul_chk_table_size += nm->nul_chk_table_size();
}
void print_nmethod_stats() {
if (nmethod_count == 0) return;
tty->print_cr("Statistics for %d bytecoded nmethods:", nmethod_count);
if (total_size != 0) tty->print_cr(" total in heap = %d", total_size);
if (relocation_size != 0) tty->print_cr(" relocation = %d", relocation_size);
if (consts_size != 0) tty->print_cr(" constants = %d", consts_size);
if (insts_size != 0) tty->print_cr(" main code = %d", insts_size);
if (stub_size != 0) tty->print_cr(" stub code = %d", stub_size);
if (oops_size != 0) tty->print_cr(" oops = %d", oops_size);
if (scopes_data_size != 0) tty->print_cr(" scopes data = %d", scopes_data_size);
if (scopes_pcs_size != 0) tty->print_cr(" scopes pcs = %d", scopes_pcs_size);
if (dependencies_size != 0) tty->print_cr(" dependencies = %d", dependencies_size);
if (handler_table_size != 0) tty->print_cr(" handler table = %d", handler_table_size);
if (nul_chk_table_size != 0) tty->print_cr(" nul chk table = %d", nul_chk_table_size);
}
int native_nmethod_count;
int native_total_size;
int native_relocation_size;
int native_insts_size;
int native_oops_size;
void note_native_nmethod(nmethod* nm) {
native_nmethod_count += 1;
native_total_size += nm->size();
native_relocation_size += nm->relocation_size();
native_insts_size += nm->insts_size();
native_oops_size += nm->oops_size();
}
void print_native_nmethod_stats() {
if (native_nmethod_count == 0) return;
tty->print_cr("Statistics for %d native nmethods:", native_nmethod_count);
if (native_total_size != 0) tty->print_cr(" N. total size = %d", native_total_size);
if (native_relocation_size != 0) tty->print_cr(" N. relocation = %d", native_relocation_size);
if (native_insts_size != 0) tty->print_cr(" N. main code = %d", native_insts_size);
if (native_oops_size != 0) tty->print_cr(" N. oops = %d", native_oops_size);
}
int pc_desc_resets; // number of resets (= number of caches)
int pc_desc_queries; // queries to nmethod::find_pc_desc
int pc_desc_approx; // number of those which have approximate true
int pc_desc_repeats; // number of _pc_descs[0] hits
int pc_desc_hits; // number of LRU cache hits
int pc_desc_tests; // total number of PcDesc examinations
int pc_desc_searches; // total number of quasi-binary search steps
int pc_desc_adds; // number of LUR cache insertions
void print_pc_stats() {
tty->print_cr("PcDesc Statistics: %d queries, %.2f comparisons per query",
pc_desc_queries,
(double)(pc_desc_tests + pc_desc_searches)
/ pc_desc_queries);
tty->print_cr(" caches=%d queries=%d/%d, hits=%d+%d, tests=%d+%d, adds=%d",
pc_desc_resets,
pc_desc_queries, pc_desc_approx,
pc_desc_repeats, pc_desc_hits,
pc_desc_tests, pc_desc_searches, pc_desc_adds);
}
} nmethod_stats;
#endif //PRODUCT
//---------------------------------------------------------------------------------
ExceptionCache::ExceptionCache(Handle exception, address pc, address handler) {
assert(pc != NULL, "Must be non null");
assert(exception.not_null(), "Must be non null");
assert(handler != NULL, "Must be non null");
_count = 0;
_exception_type = exception->klass();
_next = NULL;
add_address_and_handler(pc,handler);
}
address ExceptionCache::match(Handle exception, address pc) {
assert(pc != NULL,"Must be non null");
assert(exception.not_null(),"Must be non null");
if (exception->klass() == exception_type()) {
return (test_address(pc));
}
return NULL;
}
bool ExceptionCache::match_exception_with_space(Handle exception) {
assert(exception.not_null(),"Must be non null");
if (exception->klass() == exception_type() && count() < cache_size) {
return true;
}
return false;
}
address ExceptionCache::test_address(address addr) {
for (int i=0; i<count(); i++) {
if (pc_at(i) == addr) {
return handler_at(i);
}
}
return NULL;
}
bool ExceptionCache::add_address_and_handler(address addr, address handler) {
if (test_address(addr) == handler) return true;
if (count() < cache_size) {
set_pc_at(count(),addr);
set_handler_at(count(), handler);
increment_count();
return true;
}
return false;
}
// private method for handling exception cache
// These methods are private, and used to manipulate the exception cache
// directly.
ExceptionCache* nmethod::exception_cache_entry_for_exception(Handle exception) {
ExceptionCache* ec = exception_cache();
while (ec != NULL) {
if (ec->match_exception_with_space(exception)) {
return ec;
}
ec = ec->next();
}
return NULL;
}
//-----------------------------------------------------------------------------
// Helper used by both find_pc_desc methods.
static inline bool match_desc(PcDesc* pc, int pc_offset, bool approximate) {
NOT_PRODUCT(++nmethod_stats.pc_desc_tests);
if (!approximate)
return pc->pc_offset() == pc_offset;
else
return (pc-1)->pc_offset() < pc_offset && pc_offset <= pc->pc_offset();
}
void PcDescCache::reset_to(PcDesc* initial_pc_desc) {
if (initial_pc_desc == NULL) {
_pc_descs[0] = NULL; // native method; no PcDescs at all
return;
}
NOT_PRODUCT(++nmethod_stats.pc_desc_resets);
// reset the cache by filling it with benign (non-null) values
assert(initial_pc_desc->pc_offset() < 0, "must be sentinel");
for (int i = 0; i < cache_size; i++)
_pc_descs[i] = initial_pc_desc;
}
PcDesc* PcDescCache::find_pc_desc(int pc_offset, bool approximate) {
NOT_PRODUCT(++nmethod_stats.pc_desc_queries);
NOT_PRODUCT(if (approximate) ++nmethod_stats.pc_desc_approx);
// Note: one might think that caching the most recently
// read value separately would be a win, but one would be
// wrong. When many threads are updating it, the cache
// line it's in would bounce between caches, negating
// any benefit.
// In order to prevent race conditions do not load cache elements
// repeatedly, but use a local copy:
PcDesc* res;
// Step one: Check the most recently added value.
res = _pc_descs[0];
if (res == NULL) return NULL; // native method; no PcDescs at all
if (match_desc(res, pc_offset, approximate)) {
NOT_PRODUCT(++nmethod_stats.pc_desc_repeats);
return res;
}
// Step two: Check the rest of the LRU cache.
for (int i = 1; i < cache_size; ++i) {
res = _pc_descs[i];
if (res->pc_offset() < 0) break; // optimization: skip empty cache
if (match_desc(res, pc_offset, approximate)) {
NOT_PRODUCT(++nmethod_stats.pc_desc_hits);
return res;
}
}
// Report failure.
return NULL;
}
void PcDescCache::add_pc_desc(PcDesc* pc_desc) {
NOT_PRODUCT(++nmethod_stats.pc_desc_adds);
// Update the LRU cache by shifting pc_desc forward.
for (int i = 0; i < cache_size; i++) {
PcDesc* next = _pc_descs[i];
_pc_descs[i] = pc_desc;
pc_desc = next;
}
}
// adjust pcs_size so that it is a multiple of both oopSize and
// sizeof(PcDesc) (assumes that if sizeof(PcDesc) is not a multiple
// of oopSize, then 2*sizeof(PcDesc) is)
static int adjust_pcs_size(int pcs_size) {
int nsize = round_to(pcs_size, oopSize);
if ((nsize % sizeof(PcDesc)) != 0) {
nsize = pcs_size + sizeof(PcDesc);
}
assert((nsize % oopSize) == 0, "correct alignment");
return nsize;
}
//-----------------------------------------------------------------------------
void nmethod::add_exception_cache_entry(ExceptionCache* new_entry) {
assert(ExceptionCache_lock->owned_by_self(),"Must hold the ExceptionCache_lock");
assert(new_entry != NULL,"Must be non null");
assert(new_entry->next() == NULL, "Must be null");
if (exception_cache() != NULL) {
new_entry->set_next(exception_cache());
}
set_exception_cache(new_entry);
}
void nmethod::remove_from_exception_cache(ExceptionCache* ec) {
ExceptionCache* prev = NULL;
ExceptionCache* curr = exception_cache();
assert(curr != NULL, "nothing to remove");
// find the previous and next entry of ec
while (curr != ec) {
prev = curr;
curr = curr->next();
assert(curr != NULL, "ExceptionCache not found");
}
// now: curr == ec
ExceptionCache* next = curr->next();
if (prev == NULL) {
set_exception_cache(next);
} else {
prev->set_next(next);
}
delete curr;
}
// public method for accessing the exception cache
// These are the public access methods.
address nmethod::handler_for_exception_and_pc(Handle exception, address pc) {
// We never grab a lock to read the exception cache, so we may
// have false negatives. This is okay, as it can only happen during
// the first few exception lookups for a given nmethod.
ExceptionCache* ec = exception_cache();
while (ec != NULL) {
address ret_val;
if ((ret_val = ec->match(exception,pc)) != NULL) {
return ret_val;
}
ec = ec->next();
}
return NULL;
}
void nmethod::add_handler_for_exception_and_pc(Handle exception, address pc, address handler) {
// There are potential race conditions during exception cache updates, so we
// must own the ExceptionCache_lock before doing ANY modifications. Because
// we don't lock during reads, it is possible to have several threads attempt
// to update the cache with the same data. We need to check for already inserted
// copies of the current data before adding it.
MutexLocker ml(ExceptionCache_lock);
ExceptionCache* target_entry = exception_cache_entry_for_exception(exception);
if (target_entry == NULL || !target_entry->add_address_and_handler(pc,handler)) {
target_entry = new ExceptionCache(exception,pc,handler);
add_exception_cache_entry(target_entry);
}
}
//-------------end of code for ExceptionCache--------------
int nmethod::total_size() const {
return
consts_size() +
insts_size() +
stub_size() +
scopes_data_size() +
scopes_pcs_size() +
handler_table_size() +
nul_chk_table_size();
}
const char* nmethod::compile_kind() const {
if (is_osr_method()) return "osr";
if (method() != NULL && is_native_method()) return "c2n";
return NULL;
}
// Fill in default values for various flag fields
void nmethod::init_defaults() {
_state = alive;
_marked_for_reclamation = 0;
_has_flushed_dependencies = 0;
_speculatively_disconnected = 0;
_has_unsafe_access = 0;
_has_method_handle_invokes = 0;
_lazy_critical_native = 0;
_has_wide_vectors = 0;
_marked_for_deoptimization = 0;
_lock_count = 0;
_stack_traversal_mark = 0;
_unload_reported = false; // jvmti state
#ifdef ASSERT
_oops_are_stale = false;
#endif
_oops_do_mark_link = NULL;
_jmethod_id = NULL;
_osr_link = NULL;
_scavenge_root_link = NULL;
_scavenge_root_state = 0;
_saved_nmethod_link = NULL;
_compiler = NULL;
#ifdef HAVE_DTRACE_H
_trap_offset = 0;
#endif // def HAVE_DTRACE_H
}
nmethod* nmethod::new_native_nmethod(methodHandle method,
int compile_id,
CodeBuffer *code_buffer,
int vep_offset,
int frame_complete,
int frame_size,
ByteSize basic_lock_owner_sp_offset,
ByteSize basic_lock_sp_offset,
OopMapSet* oop_maps) {
// create nmethod
nmethod* nm = NULL;
{
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
int native_nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
CodeOffsets offsets;
offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
nm = new (native_nmethod_size)
nmethod(method(), native_nmethod_size, compile_id, &offsets,
code_buffer, frame_size,
basic_lock_owner_sp_offset, basic_lock_sp_offset,
oop_maps);
NOT_PRODUCT(if (nm != NULL) nmethod_stats.note_native_nmethod(nm));
if (PrintAssembly && nm != NULL)
Disassembler::decode(nm);
}
// verify nmethod
debug_only(if (nm) nm->verify();) // might block
if (nm != NULL) {
nm->log_new_nmethod();
}
return nm;
}
#ifdef HAVE_DTRACE_H
nmethod* nmethod::new_dtrace_nmethod(methodHandle method,
CodeBuffer *code_buffer,
int vep_offset,
int trap_offset,
int frame_complete,
int frame_size) {
// create nmethod
nmethod* nm = NULL;
{
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
int nmethod_size = allocation_size(code_buffer, sizeof(nmethod));
CodeOffsets offsets;
offsets.set_value(CodeOffsets::Verified_Entry, vep_offset);
offsets.set_value(CodeOffsets::Dtrace_trap, trap_offset);
offsets.set_value(CodeOffsets::Frame_Complete, frame_complete);
nm = new (nmethod_size) nmethod(method(), nmethod_size, &offsets, code_buffer, frame_size);
NOT_PRODUCT(if (nm != NULL) nmethod_stats.note_nmethod(nm));
if (PrintAssembly && nm != NULL)
Disassembler::decode(nm);
}
// verify nmethod
debug_only(if (nm) nm->verify();) // might block
if (nm != NULL) {
nm->log_new_nmethod();
}
return nm;
}
#endif // def HAVE_DTRACE_H
nmethod* nmethod::new_nmethod(methodHandle method,
int compile_id,
int entry_bci,
CodeOffsets* offsets,
int orig_pc_offset,
DebugInformationRecorder* debug_info,
Dependencies* dependencies,
CodeBuffer* code_buffer, int frame_size,
OopMapSet* oop_maps,
ExceptionHandlerTable* handler_table,
ImplicitExceptionTable* nul_chk_table,
AbstractCompiler* compiler,
int comp_level
)
{
assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
// create nmethod
nmethod* nm = NULL;
{ MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
int nmethod_size =
allocation_size(code_buffer, sizeof(nmethod))
+ adjust_pcs_size(debug_info->pcs_size())
+ round_to(dependencies->size_in_bytes() , oopSize)
+ round_to(handler_table->size_in_bytes(), oopSize)
+ round_to(nul_chk_table->size_in_bytes(), oopSize)
+ round_to(debug_info->data_size() , oopSize);
nm = new (nmethod_size)
nmethod(method(), nmethod_size, compile_id, entry_bci, offsets,
orig_pc_offset, debug_info, dependencies, code_buffer, frame_size,
oop_maps,
handler_table,
nul_chk_table,
compiler,
comp_level);
if (nm != NULL) {
// To make dependency checking during class loading fast, record
// the nmethod dependencies in the classes it is dependent on.
// This allows the dependency checking code to simply walk the
// class hierarchy above the loaded class, checking only nmethods
// which are dependent on those classes. The slow way is to
// check every nmethod for dependencies which makes it linear in
// the number of methods compiled. For applications with a lot
// classes the slow way is too slow.
for (Dependencies::DepStream deps(nm); deps.next(); ) {
klassOop klass = deps.context_type();
if (klass == NULL) continue; // ignore things like evol_method
// record this nmethod as dependent on this klass
instanceKlass::cast(klass)->add_dependent_nmethod(nm);
}
}
NOT_PRODUCT(if (nm != NULL) nmethod_stats.note_nmethod(nm));
if (PrintAssembly && nm != NULL)
Disassembler::decode(nm);
}
// verify nmethod
debug_only(if (nm) nm->verify();) // might block
if (nm != NULL) {
nm->log_new_nmethod();
}
// done
return nm;
}
// For native wrappers
nmethod::nmethod(
methodOop method,
int nmethod_size,
int compile_id,
CodeOffsets* offsets,
CodeBuffer* code_buffer,
int frame_size,
ByteSize basic_lock_owner_sp_offset,
ByteSize basic_lock_sp_offset,
OopMapSet* oop_maps )
: CodeBlob("native nmethod", code_buffer, sizeof(nmethod),
nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
_native_receiver_sp_offset(basic_lock_owner_sp_offset),
_native_basic_lock_sp_offset(basic_lock_sp_offset)
{
{
debug_only(No_Safepoint_Verifier nsv;)
assert_locked_or_safepoint(CodeCache_lock);
init_defaults();
_method = method;
_entry_bci = InvocationEntryBci;
// We have no exception handler or deopt handler make the
// values something that will never match a pc like the nmethod vtable entry
_exception_offset = 0;
_deoptimize_offset = 0;
_deoptimize_mh_offset = 0;
_orig_pc_offset = 0;
_consts_offset = data_offset();
_stub_offset = data_offset();
_oops_offset = data_offset();
_scopes_data_offset = _oops_offset + round_to(code_buffer->total_oop_size(), oopSize);
_scopes_pcs_offset = _scopes_data_offset;
_dependencies_offset = _scopes_pcs_offset;
_handler_table_offset = _dependencies_offset;
_nul_chk_table_offset = _handler_table_offset;
_nmethod_end_offset = _nul_chk_table_offset;
_compile_id = compile_id;
_comp_level = CompLevel_none;
_entry_point = code_begin() + offsets->value(CodeOffsets::Entry);
_verified_entry_point = code_begin() + offsets->value(CodeOffsets::Verified_Entry);
_osr_entry_point = NULL;
_exception_cache = NULL;
_pc_desc_cache.reset_to(NULL);
code_buffer->copy_oops_to(this);
if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
CodeCache::add_scavenge_root_nmethod(this);
}
debug_only(verify_scavenge_root_oops());
CodeCache::commit(this);
}
if (PrintNativeNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
ttyLocker ttyl; // keep the following output all in one block
// This output goes directly to the tty, not the compiler log.
// To enable tools to match it up with the compilation activity,
// be sure to tag this tty output with the compile ID.
if (xtty != NULL) {
xtty->begin_head("print_native_nmethod");
xtty->method(_method);
xtty->stamp();
xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
}
// print the header part first
print();
// then print the requested information
if (PrintNativeNMethods) {
print_code();
if (oop_maps != NULL) {
oop_maps->print();
}
}
if (PrintRelocations) {
print_relocations();
}
if (xtty != NULL) {
xtty->tail("print_native_nmethod");
}
}
}
// For dtrace wrappers
#ifdef HAVE_DTRACE_H
nmethod::nmethod(
methodOop method,
int nmethod_size,
CodeOffsets* offsets,
CodeBuffer* code_buffer,
int frame_size)
: CodeBlob("dtrace nmethod", code_buffer, sizeof(nmethod),
nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, NULL),
_native_receiver_sp_offset(in_ByteSize(-1)),
_native_basic_lock_sp_offset(in_ByteSize(-1))
{
{
debug_only(No_Safepoint_Verifier nsv;)
assert_locked_or_safepoint(CodeCache_lock);
init_defaults();
_method = method;
_entry_bci = InvocationEntryBci;
// We have no exception handler or deopt handler make the
// values something that will never match a pc like the nmethod vtable entry
_exception_offset = 0;
_deoptimize_offset = 0;
_deoptimize_mh_offset = 0;
_unwind_handler_offset = -1;
_trap_offset = offsets->value(CodeOffsets::Dtrace_trap);
_orig_pc_offset = 0;
_consts_offset = data_offset();
_stub_offset = data_offset();
_oops_offset = data_offset();
_scopes_data_offset = _oops_offset + round_to(code_buffer->total_oop_size(), oopSize);
_scopes_pcs_offset = _scopes_data_offset;
_dependencies_offset = _scopes_pcs_offset;
_handler_table_offset = _dependencies_offset;
_nul_chk_table_offset = _handler_table_offset;
_nmethod_end_offset = _nul_chk_table_offset;
_compile_id = 0; // default
_comp_level = CompLevel_none;
_entry_point = code_begin() + offsets->value(CodeOffsets::Entry);
_verified_entry_point = code_begin() + offsets->value(CodeOffsets::Verified_Entry);
_osr_entry_point = NULL;
_exception_cache = NULL;
_pc_desc_cache.reset_to(NULL);
code_buffer->copy_oops_to(this);
debug_only(verify_scavenge_root_oops());
CodeCache::commit(this);
}
if (PrintNMethods || PrintDebugInfo || PrintRelocations || PrintDependencies) {
ttyLocker ttyl; // keep the following output all in one block
// This output goes directly to the tty, not the compiler log.
// To enable tools to match it up with the compilation activity,
// be sure to tag this tty output with the compile ID.
if (xtty != NULL) {
xtty->begin_head("print_dtrace_nmethod");
xtty->method(_method);
xtty->stamp();
xtty->end_head(" address='" INTPTR_FORMAT "'", (intptr_t) this);
}
// print the header part first
print();
// then print the requested information
if (PrintNMethods) {
print_code();
}
if (PrintRelocations) {
print_relocations();
}
if (xtty != NULL) {
xtty->tail("print_dtrace_nmethod");
}
}
}
#endif // def HAVE_DTRACE_H
void* nmethod::operator new(size_t size, int nmethod_size) {
// Always leave some room in the CodeCache for I2C/C2I adapters
if (CodeCache::largest_free_block() < CodeCacheMinimumFreeSpace) return NULL;
return CodeCache::allocate(nmethod_size);
}
nmethod::nmethod(
methodOop method,
int nmethod_size,
int compile_id,
int entry_bci,
CodeOffsets* offsets,
int orig_pc_offset,
DebugInformationRecorder* debug_info,
Dependencies* dependencies,
CodeBuffer *code_buffer,
int frame_size,
OopMapSet* oop_maps,
ExceptionHandlerTable* handler_table,
ImplicitExceptionTable* nul_chk_table,
AbstractCompiler* compiler,
int comp_level
)
: CodeBlob("nmethod", code_buffer, sizeof(nmethod),
nmethod_size, offsets->value(CodeOffsets::Frame_Complete), frame_size, oop_maps),
_native_receiver_sp_offset(in_ByteSize(-1)),
_native_basic_lock_sp_offset(in_ByteSize(-1))
{
assert(debug_info->oop_recorder() == code_buffer->oop_recorder(), "shared OR");
{
debug_only(No_Safepoint_Verifier nsv;)
assert_locked_or_safepoint(CodeCache_lock);
init_defaults();
_method = method;
_entry_bci = entry_bci;
_compile_id = compile_id;
_comp_level = comp_level;
_compiler = compiler;
_orig_pc_offset = orig_pc_offset;
// Section offsets
_consts_offset = content_offset() + code_buffer->total_offset_of(code_buffer->consts());
_stub_offset = content_offset() + code_buffer->total_offset_of(code_buffer->stubs());
// Exception handler and deopt handler are in the stub section
assert(offsets->value(CodeOffsets::Exceptions) != -1, "must be set");
assert(offsets->value(CodeOffsets::Deopt ) != -1, "must be set");
_exception_offset = _stub_offset + offsets->value(CodeOffsets::Exceptions);
_deoptimize_offset = _stub_offset + offsets->value(CodeOffsets::Deopt);
if (offsets->value(CodeOffsets::DeoptMH) != -1) {
_deoptimize_mh_offset = _stub_offset + offsets->value(CodeOffsets::DeoptMH);
} else {
_deoptimize_mh_offset = -1;
}
if (offsets->value(CodeOffsets::UnwindHandler) != -1) {
_unwind_handler_offset = code_offset() + offsets->value(CodeOffsets::UnwindHandler);
} else {
_unwind_handler_offset = -1;
}
_oops_offset = data_offset();
_scopes_data_offset = _oops_offset + round_to(code_buffer->total_oop_size (), oopSize);
_scopes_pcs_offset = _scopes_data_offset + round_to(debug_info->data_size (), oopSize);
_dependencies_offset = _scopes_pcs_offset + adjust_pcs_size(debug_info->pcs_size());
_handler_table_offset = _dependencies_offset + round_to(dependencies->size_in_bytes (), oopSize);
_nul_chk_table_offset = _handler_table_offset + round_to(handler_table->size_in_bytes(), oopSize);
_nmethod_end_offset = _nul_chk_table_offset + round_to(nul_chk_table->size_in_bytes(), oopSize);
_entry_point = code_begin() + offsets->value(CodeOffsets::Entry);
_verified_entry_point = code_begin() + offsets->value(CodeOffsets::Verified_Entry);
_osr_entry_point = code_begin() + offsets->value(CodeOffsets::OSR_Entry);
_exception_cache = NULL;
_pc_desc_cache.reset_to(scopes_pcs_begin());
// Copy contents of ScopeDescRecorder to nmethod
code_buffer->copy_oops_to(this);
debug_info->copy_to(this);
dependencies->copy_to(this);
if (ScavengeRootsInCode && detect_scavenge_root_oops()) {
CodeCache::add_scavenge_root_nmethod(this);
}
debug_only(verify_scavenge_root_oops());
CodeCache::commit(this);
// Copy contents of ExceptionHandlerTable to nmethod
handler_table->copy_to(this);
nul_chk_table->copy_to(this);
// we use the information of entry points to find out if a method is
// static or non static
assert(compiler->is_c2() ||
_method->is_static() == (entry_point() == _verified_entry_point),
" entry points must be same for static methods and vice versa");
}
bool printnmethods = PrintNMethods
|| CompilerOracle::should_print(_method)
|| CompilerOracle::has_option_string(_method, "PrintNMethods");
if (printnmethods || PrintDebugInfo || PrintRelocations || PrintDependencies || PrintExceptionHandlers) {
print_nmethod(printnmethods);
}
}
// Print a short set of xml attributes to identify this nmethod. The
// output should be embedded in some other element.
void nmethod::log_identity(xmlStream* log) const {
log->print(" compile_id='%d'", compile_id());
const char* nm_kind = compile_kind();
if (nm_kind != NULL) log->print(" compile_kind='%s'", nm_kind);
if (compiler() != NULL) {
log->print(" compiler='%s'", compiler()->name());
}
if (TieredCompilation) {
log->print(" level='%d'", comp_level());
}
}
#define LOG_OFFSET(log, name) \
if ((intptr_t)name##_end() - (intptr_t)name##_begin()) \
log->print(" " XSTR(name) "_offset='%d'" , \
(intptr_t)name##_begin() - (intptr_t)this)
void nmethod::log_new_nmethod() const {
if (LogCompilation && xtty != NULL) {
ttyLocker ttyl;
HandleMark hm;
xtty->begin_elem("nmethod");
log_identity(xtty);
xtty->print(" entry='" INTPTR_FORMAT "' size='%d'", code_begin(), size());
xtty->print(" address='" INTPTR_FORMAT "'", (intptr_t) this);
LOG_OFFSET(xtty, relocation);
LOG_OFFSET(xtty, consts);
LOG_OFFSET(xtty, insts);
LOG_OFFSET(xtty, stub);
LOG_OFFSET(xtty, scopes_data);
LOG_OFFSET(xtty, scopes_pcs);
LOG_OFFSET(xtty, dependencies);
LOG_OFFSET(xtty, handler_table);
LOG_OFFSET(xtty, nul_chk_table);
LOG_OFFSET(xtty, oops);
xtty->method(method());
xtty->stamp();
xtty->end_elem();
}
}
#undef LOG_OFFSET
// Print out more verbose output usually for a newly created nmethod.
void nmethod::print_on(outputStream* st, const char* msg) const {
if (st != NULL) {
ttyLocker ttyl;
if (WizardMode) {
CompileTask::print_compilation(st, this, msg, /*short_form:*/ true);
st->print_cr(" (" INTPTR_FORMAT ")", this);
} else {
CompileTask::print_compilation(st, this, msg, /*short_form:*/ false);
}
}
}
void nmethod::print_nmethod(bool printmethod) {
ttyLocker ttyl; // keep the following output all in one block
if (xtty != NULL) {
xtty->begin_head("print_nmethod");
xtty->stamp();
xtty->end_head();
}
// print the header part first
print();
// then print the requested information
if (printmethod) {
print_code();
print_pcs();
if (oop_maps()) {
oop_maps()->print();
}
}
if (PrintDebugInfo) {
print_scopes();
}
if (PrintRelocations) {
print_relocations();
}
if (PrintDependencies) {
print_dependencies();
}
if (PrintExceptionHandlers) {
print_handler_table();
print_nul_chk_table();
}
if (xtty != NULL) {
xtty->tail("print_nmethod");
}
}
// Promote one word from an assembly-time handle to a live embedded oop.
inline void nmethod::initialize_immediate_oop(oop* dest, jobject handle) {
if (handle == NULL ||
// As a special case, IC oops are initialized to 1 or -1.
handle == (jobject) Universe::non_oop_word()) {
(*dest) = (oop) handle;
} else {
(*dest) = JNIHandles::resolve_non_null(handle);
}
}
void nmethod::copy_oops(GrowableArray<jobject>* array) {
//assert(oops_size() == 0, "do this handshake just once, please");
int length = array->length();
assert((address)(oops_begin() + length) <= data_end(), "oops big enough");
oop* dest = oops_begin();
for (int index = 0 ; index < length; index++) {
initialize_immediate_oop(&dest[index], array->at(index));
}
// Now we can fix up all the oops in the code. We need to do this
// in the code because the assembler uses jobjects as placeholders.
// The code and relocations have already been initialized by the
// CodeBlob constructor, so it is valid even at this early point to
// iterate over relocations and patch the code.
fix_oop_relocations(NULL, NULL, /*initialize_immediates=*/ true);
}
bool nmethod::is_at_poll_return(address pc) {
RelocIterator iter(this, pc, pc+1);
while (iter.next()) {
if (iter.type() == relocInfo::poll_return_type)
return true;
}
return false;
}
bool nmethod::is_at_poll_or_poll_return(address pc) {
RelocIterator iter(this, pc, pc+1);
while (iter.next()) {
relocInfo::relocType t = iter.type();
if (t == relocInfo::poll_return_type || t == relocInfo::poll_type)
return true;
}
return false;
}
void nmethod::fix_oop_relocations(address begin, address end, bool initialize_immediates) {
// re-patch all oop-bearing instructions, just in case some oops moved
RelocIterator iter(this, begin, end);
while (iter.next()) {
if (iter.type() == relocInfo::oop_type) {
oop_Relocation* reloc = iter.oop_reloc();
if (initialize_immediates && reloc->oop_is_immediate()) {
oop* dest = reloc->oop_addr();
initialize_immediate_oop(dest, (jobject) *dest);
}
// Refresh the oop-related bits of this instruction.
reloc->fix_oop_relocation();
}
// There must not be any interfering patches or breakpoints.
assert(!(iter.type() == relocInfo::breakpoint_type
&& iter.breakpoint_reloc()->active()),
"no active breakpoint");
}
}
void nmethod::verify_oop_relocations() {
// Ensure sure that the code matches the current oop values
RelocIterator iter(this, NULL, NULL);
while (iter.next()) {
if (iter.type() == relocInfo::oop_type) {
oop_Relocation* reloc = iter.oop_reloc();
if (!reloc->oop_is_immediate()) {
reloc->verify_oop_relocation();
}
}
}
}
ScopeDesc* nmethod::scope_desc_at(address pc) {
PcDesc* pd = pc_desc_at(pc);
guarantee(pd != NULL, "scope must be present");
return new ScopeDesc(this, pd->scope_decode_offset(),
pd->obj_decode_offset(), pd->should_reexecute(),
pd->return_oop());
}
void nmethod::clear_inline_caches() {
assert(SafepointSynchronize::is_at_safepoint(), "cleaning of IC's only allowed at safepoint");
if (is_zombie()) {
return;
}
RelocIterator iter(this);
while (iter.next()) {
iter.reloc()->clear_inline_cache();
}
}
void nmethod::cleanup_inline_caches() {
assert_locked_or_safepoint(CompiledIC_lock);
// If the method is not entrant or zombie then a JMP is plastered over the
// first few bytes. If an oop in the old code was there, that oop
// should not get GC'd. Skip the first few bytes of oops on
// not-entrant methods.
address low_boundary = verified_entry_point();
if (!is_in_use()) {
low_boundary += NativeJump::instruction_size;
// %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
// This means that the low_boundary is going to be a little too high.
// This shouldn't matter, since oops of non-entrant methods are never used.
// In fact, why are we bothering to look at oops in a non-entrant method??
}
// Find all calls in an nmethod, and clear the ones that points to zombie methods
ResourceMark rm;
RelocIterator iter(this, low_boundary);
while(iter.next()) {
switch(iter.type()) {
case relocInfo::virtual_call_type:
case relocInfo::opt_virtual_call_type: {
CompiledIC *ic = CompiledIC_at(iter.reloc());
// Ok, to lookup references to zombies here
CodeBlob *cb = CodeCache::find_blob_unsafe(ic->ic_destination());
if( cb != NULL && cb->is_nmethod() ) {
nmethod* nm = (nmethod*)cb;
// Clean inline caches pointing to both zombie and not_entrant methods
if (!nm->is_in_use() || (nm->method()->code() != nm)) ic->set_to_clean();
}
break;
}
case relocInfo::static_call_type: {
CompiledStaticCall *csc = compiledStaticCall_at(iter.reloc());
CodeBlob *cb = CodeCache::find_blob_unsafe(csc->destination());
if( cb != NULL && cb->is_nmethod() ) {
nmethod* nm = (nmethod*)cb;
// Clean inline caches pointing to both zombie and not_entrant methods
if (!nm->is_in_use() || (nm->method()->code() != nm)) csc->set_to_clean();
}
break;
}
}
}
}
// This is a private interface with the sweeper.
void nmethod::mark_as_seen_on_stack() {
assert(is_not_entrant(), "must be a non-entrant method");
// Set the traversal mark to ensure that the sweeper does 2
// cleaning passes before moving to zombie.
set_stack_traversal_mark(NMethodSweeper::traversal_count());
}
// Tell if a non-entrant method can be converted to a zombie (i.e.,
// there are no activations on the stack, not in use by the VM,
// and not in use by the ServiceThread)
bool nmethod::can_not_entrant_be_converted() {
assert(is_not_entrant(), "must be a non-entrant method");
// Since the nmethod sweeper only does partial sweep the sweeper's traversal
// count can be greater than the stack traversal count before it hits the
// nmethod for the second time.
return stack_traversal_mark()+1 < NMethodSweeper::traversal_count() &&
!is_locked_by_vm();
}
void nmethod::inc_decompile_count() {
if (!is_compiled_by_c2()) return;
// Could be gated by ProfileTraps, but do not bother...
methodOop m = method();
if (m == NULL) return;
methodDataOop mdo = m->method_data();
if (mdo == NULL) return;
// There is a benign race here. See comments in methodDataOop.hpp.
mdo->inc_decompile_count();
}
void nmethod::make_unloaded(BoolObjectClosure* is_alive, oop cause) {
post_compiled_method_unload();
// Since this nmethod is being unloaded, make sure that dependencies
// recorded in instanceKlasses get flushed and pass non-NULL closure to
// indicate that this work is being done during a GC.
assert(Universe::heap()->is_gc_active(), "should only be called during gc");
assert(is_alive != NULL, "Should be non-NULL");
// A non-NULL is_alive closure indicates that this is being called during GC.
flush_dependencies(is_alive);
// Break cycle between nmethod & method
if (TraceClassUnloading && WizardMode) {
tty->print_cr("[Class unloading: Making nmethod " INTPTR_FORMAT
" unloadable], methodOop(" INTPTR_FORMAT
"), cause(" INTPTR_FORMAT ")",
this, (address)_method, (address)cause);
if (!Universe::heap()->is_gc_active())
cause->klass()->print();
}
// Unlink the osr method, so we do not look this up again
if (is_osr_method()) {
invalidate_osr_method();
}
// If _method is already NULL the methodOop is about to be unloaded,
// so we don't have to break the cycle. Note that it is possible to
// have the methodOop live here, in case we unload the nmethod because
// it is pointing to some oop (other than the methodOop) being unloaded.
if (_method != NULL) {
// OSR methods point to the methodOop, but the methodOop does not
// point back!
if (_method->code() == this) {
_method->clear_code(); // Break a cycle
}
_method = NULL; // Clear the method of this dead nmethod
}
// Make the class unloaded - i.e., change state and notify sweeper
assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
if (is_in_use()) {
// Transitioning directly from live to unloaded -- so
// we need to force a cache clean-up; remember this
// for later on.
CodeCache::set_needs_cache_clean(true);
}
_state = unloaded;
// Log the unloading.
log_state_change();
// The methodOop is gone at this point
assert(_method == NULL, "Tautology");
set_osr_link(NULL);
//set_scavenge_root_link(NULL); // done by prune_scavenge_root_nmethods
NMethodSweeper::notify(this);
}
void nmethod::invalidate_osr_method() {
assert(_entry_bci != InvocationEntryBci, "wrong kind of nmethod");
// Remove from list of active nmethods
if (method() != NULL)
instanceKlass::cast(method()->method_holder())->remove_osr_nmethod(this);
// Set entry as invalid
_entry_bci = InvalidOSREntryBci;
}
void nmethod::log_state_change() const {
if (LogCompilation) {
if (xtty != NULL) {
ttyLocker ttyl; // keep the following output all in one block
if (_state == unloaded) {
xtty->begin_elem("make_unloaded thread='" UINTX_FORMAT "'",
os::current_thread_id());
} else {
xtty->begin_elem("make_not_entrant thread='" UINTX_FORMAT "'%s",
os::current_thread_id(),
(_state == zombie ? " zombie='1'" : ""));
}
log_identity(xtty);
xtty->stamp();
xtty->end_elem();
}
}
if (PrintCompilation && _state != unloaded) {
print_on(tty, _state == zombie ? "made zombie" : "made not entrant");
}
}
// Common functionality for both make_not_entrant and make_zombie
bool nmethod::make_not_entrant_or_zombie(unsigned int state) {
assert(state == zombie || state == not_entrant, "must be zombie or not_entrant");
assert(!is_zombie(), "should not already be a zombie");
// Make sure neither the nmethod nor the method is flushed in case of a safepoint in code below.
nmethodLocker nml(this);
methodHandle the_method(method());
No_Safepoint_Verifier nsv;
{
// invalidate osr nmethod before acquiring the patching lock since
// they both acquire leaf locks and we don't want a deadlock.
// This logic is equivalent to the logic below for patching the
// verified entry point of regular methods.
if (is_osr_method()) {
// this effectively makes the osr nmethod not entrant
invalidate_osr_method();
}
// Enter critical section. Does not block for safepoint.
MutexLockerEx pl(Patching_lock, Mutex::_no_safepoint_check_flag);
if (_state == state) {
// another thread already performed this transition so nothing
// to do, but return false to indicate this.
return false;
}
// The caller can be calling the method statically or through an inline
// cache call.
if (!is_osr_method() && !is_not_entrant()) {
NativeJump::patch_verified_entry(entry_point(), verified_entry_point(),
SharedRuntime::get_handle_wrong_method_stub());
}
if (is_in_use()) {
// It's a true state change, so mark the method as decompiled.
// Do it only for transition from alive.
inc_decompile_count();
}
// Change state
_state = state;
// Log the transition once
log_state_change();
// Remove nmethod from method.
// We need to check if both the _code and _from_compiled_code_entry_point
// refer to this nmethod because there is a race in setting these two fields
// in methodOop as seen in bugid 4947125.
// If the vep() points to the zombie nmethod, the memory for the nmethod
// could be flushed and the compiler and vtable stubs could still call
// through it.
if (method() != NULL && (method()->code() == this ||
method()->from_compiled_entry() == verified_entry_point())) {
HandleMark hm;
method()->clear_code();
}
if (state == not_entrant) {
mark_as_seen_on_stack();
}
} // leave critical region under Patching_lock
// When the nmethod becomes zombie it is no longer alive so the
// dependencies must be flushed. nmethods in the not_entrant
// state will be flushed later when the transition to zombie
// happens or they get unloaded.
if (state == zombie) {
{
// Flushing dependecies must be done before any possible
// safepoint can sneak in, otherwise the oops used by the
// dependency logic could have become stale.
MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
flush_dependencies(NULL);
}
// zombie only - if a JVMTI agent has enabled the CompiledMethodUnload
// event and it hasn't already been reported for this nmethod then
// report it now. The event may have been reported earilier if the GC
// marked it for unloading). JvmtiDeferredEventQueue support means
// we no longer go to a safepoint here.
post_compiled_method_unload();
#ifdef ASSERT
// It's no longer safe to access the oops section since zombie
// nmethods aren't scanned for GC.
_oops_are_stale = true;
#endif
} else {
assert(state == not_entrant, "other cases may need to be handled differently");
}
if (TraceCreateZombies) {
tty->print_cr("nmethod <" INTPTR_FORMAT "> code made %s", this, (state == not_entrant) ? "not entrant" : "zombie");
}
// Make sweeper aware that there is a zombie method that needs to be removed
NMethodSweeper::notify(this);
return true;
}
void nmethod::flush() {
// Note that there are no valid oops in the nmethod anymore.
assert(is_zombie() || (is_osr_method() && is_unloaded()), "must be a zombie method");
assert(is_marked_for_reclamation() || (is_osr_method() && is_unloaded()), "must be marked for reclamation");
assert (!is_locked_by_vm(), "locked methods shouldn't be flushed");
assert_locked_or_safepoint(CodeCache_lock);
// completely deallocate this method
Events::log(JavaThread::current(), "flushing nmethod " INTPTR_FORMAT, this);
if (PrintMethodFlushing) {
tty->print_cr("*flushing nmethod %3d/" INTPTR_FORMAT ". Live blobs:" UINT32_FORMAT "/Free CodeCache:" SIZE_FORMAT "Kb",
_compile_id, this, CodeCache::nof_blobs(), CodeCache::unallocated_capacity()/1024);
}
// We need to deallocate any ExceptionCache data.
// Note that we do not need to grab the nmethod lock for this, it
// better be thread safe if we're disposing of it!
ExceptionCache* ec = exception_cache();
set_exception_cache(NULL);
while(ec != NULL) {
ExceptionCache* next = ec->next();
delete ec;
ec = next;
}
if (on_scavenge_root_list()) {
CodeCache::drop_scavenge_root_nmethod(this);
}
if (is_speculatively_disconnected()) {
CodeCache::remove_saved_code(this);
}
#ifdef SHARK
((SharkCompiler *) compiler())->free_compiled_method(insts_begin());
#endif // SHARK
((CodeBlob*)(this))->flush();
CodeCache::free(this);
}
//
// Notify all classes this nmethod is dependent on that it is no
// longer dependent. This should only be called in two situations.
// First, when a nmethod transitions to a zombie all dependents need
// to be clear. Since zombification happens at a safepoint there's no
// synchronization issues. The second place is a little more tricky.
// During phase 1 of mark sweep class unloading may happen and as a
// result some nmethods may get unloaded. In this case the flushing
// of dependencies must happen during phase 1 since after GC any
// dependencies in the unloaded nmethod won't be updated, so
// traversing the dependency information in unsafe. In that case this
// function is called with a non-NULL argument and this function only
// notifies instanceKlasses that are reachable
void nmethod::flush_dependencies(BoolObjectClosure* is_alive) {
assert_locked_or_safepoint(CodeCache_lock);
assert(Universe::heap()->is_gc_active() == (is_alive != NULL),
"is_alive is non-NULL if and only if we are called during GC");
if (!has_flushed_dependencies()) {
set_has_flushed_dependencies();
for (Dependencies::DepStream deps(this); deps.next(); ) {
klassOop klass = deps.context_type();
if (klass == NULL) continue; // ignore things like evol_method
// During GC the is_alive closure is non-NULL, and is used to
// determine liveness of dependees that need to be updated.
if (is_alive == NULL || is_alive->do_object_b(klass)) {
instanceKlass::cast(klass)->remove_dependent_nmethod(this);
}
}
}
}
// If this oop is not live, the nmethod can be unloaded.
bool nmethod::can_unload(BoolObjectClosure* is_alive,
OopClosure* keep_alive,
oop* root, bool unloading_occurred) {
assert(root != NULL, "just checking");
oop obj = *root;
if (obj == NULL || is_alive->do_object_b(obj)) {
return false;
}
if (obj->is_compiledICHolder()) {
compiledICHolderOop cichk_oop = compiledICHolderOop(obj);
if (is_alive->do_object_b(
cichk_oop->holder_method()->method_holder()) &&
is_alive->do_object_b(cichk_oop->holder_klass())) {
// The oop should be kept alive
keep_alive->do_oop(root);
return false;
}
}
// If ScavengeRootsInCode is true, an nmethod might be unloaded
// simply because one of its constant oops has gone dead.
// No actual classes need to be unloaded in order for this to occur.
assert(unloading_occurred || ScavengeRootsInCode, "Inconsistency in unloading");
make_unloaded(is_alive, obj);
return true;
}
// ------------------------------------------------------------------
// post_compiled_method_load_event
// new method for install_code() path
// Transfer information from compilation to jvmti
void nmethod::post_compiled_method_load_event() {
methodOop moop = method();
#ifndef USDT2
HS_DTRACE_PROBE8(hotspot, compiled__method__load,
moop->klass_name()->bytes(),
moop->klass_name()->utf8_length(),
moop->name()->bytes(),
moop->name()->utf8_length(),
moop->signature()->bytes(),
moop->signature()->utf8_length(),
insts_begin(), insts_size());
#else /* USDT2 */
HOTSPOT_COMPILED_METHOD_LOAD(
(char *) moop->klass_name()->bytes(),
moop->klass_name()->utf8_length(),
(char *) moop->name()->bytes(),
moop->name()->utf8_length(),
(char *) moop->signature()->bytes(),
moop->signature()->utf8_length(),
insts_begin(), insts_size());
#endif /* USDT2 */
if (JvmtiExport::should_post_compiled_method_load() ||
JvmtiExport::should_post_compiled_method_unload()) {
get_and_cache_jmethod_id();
}
if (JvmtiExport::should_post_compiled_method_load()) {
// Let the Service thread (which is a real Java thread) post the event
MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
JvmtiDeferredEventQueue::enqueue(
JvmtiDeferredEvent::compiled_method_load_event(this));
}
}
jmethodID nmethod::get_and_cache_jmethod_id() {
if (_jmethod_id == NULL) {
// Cache the jmethod_id since it can no longer be looked up once the
// method itself has been marked for unloading.
_jmethod_id = method()->jmethod_id();
}
return _jmethod_id;
}
void nmethod::post_compiled_method_unload() {
if (unload_reported()) {
// During unloading we transition to unloaded and then to zombie
// and the unloading is reported during the first transition.
return;
}
assert(_method != NULL && !is_unloaded(), "just checking");
DTRACE_METHOD_UNLOAD_PROBE(method());
// If a JVMTI agent has enabled the CompiledMethodUnload event then
// post the event. Sometime later this nmethod will be made a zombie
// by the sweeper but the methodOop will not be valid at that point.
// If the _jmethod_id is null then no load event was ever requested
// so don't bother posting the unload. The main reason for this is
// that the jmethodID is a weak reference to the methodOop so if
// it's being unloaded there's no way to look it up since the weak
// ref will have been cleared.
if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) {
assert(!unload_reported(), "already unloaded");
JvmtiDeferredEvent event =
JvmtiDeferredEvent::compiled_method_unload_event(this,
_jmethod_id, insts_begin());
if (SafepointSynchronize::is_at_safepoint()) {
// Don't want to take the queueing lock. Add it as pending and
// it will get enqueued later.
JvmtiDeferredEventQueue::add_pending_event(event);
} else {
MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
JvmtiDeferredEventQueue::enqueue(event);
}
}
// The JVMTI CompiledMethodUnload event can be enabled or disabled at
// any time. As the nmethod is being unloaded now we mark it has
// having the unload event reported - this will ensure that we don't
// attempt to report the event in the unlikely scenario where the
// event is enabled at the time the nmethod is made a zombie.
set_unload_reported();
}
// This is called at the end of the strong tracing/marking phase of a
// GC to unload an nmethod if it contains otherwise unreachable
// oops.
void nmethod::do_unloading(BoolObjectClosure* is_alive,
OopClosure* keep_alive, bool unloading_occurred) {
// Make sure the oop's ready to receive visitors
assert(!is_zombie() && !is_unloaded(),
"should not call follow on zombie or unloaded nmethod");
// If the method is not entrant then a JMP is plastered over the
// first few bytes. If an oop in the old code was there, that oop
// should not get GC'd. Skip the first few bytes of oops on
// not-entrant methods.
address low_boundary = verified_entry_point();
if (is_not_entrant()) {
low_boundary += NativeJump::instruction_size;
// %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
// (See comment above.)
}
// The RedefineClasses() API can cause the class unloading invariant
// to no longer be true. See jvmtiExport.hpp for details.
// Also, leave a debugging breadcrumb in local flag.
bool a_class_was_redefined = JvmtiExport::has_redefined_a_class();
if (a_class_was_redefined) {
// This set of the unloading_occurred flag is done before the
// call to post_compiled_method_unload() so that the unloading
// of this nmethod is reported.
unloading_occurred = true;
}
// Follow methodOop
if (can_unload(is_alive, keep_alive, (oop*)&_method, unloading_occurred)) {
return;
}
// Exception cache
ExceptionCache* ec = exception_cache();
while (ec != NULL) {
oop* ex_addr = (oop*)ec->exception_type_addr();
oop ex = *ex_addr;
ExceptionCache* next_ec = ec->next();
if (ex != NULL && !is_alive->do_object_b(ex)) {
assert(!ex->is_compiledICHolder(), "Possible error here");
remove_from_exception_cache(ec);
}
ec = next_ec;
}
// If class unloading occurred we first iterate over all inline caches and
// clear ICs where the cached oop is referring to an unloaded klass or method.
// The remaining live cached oops will be traversed in the relocInfo::oop_type
// iteration below.
if (unloading_occurred) {
RelocIterator iter(this, low_boundary);
while(iter.next()) {
if (iter.type() == relocInfo::virtual_call_type) {
CompiledIC *ic = CompiledIC_at(iter.reloc());
oop ic_oop = ic->cached_oop();
if (ic_oop != NULL && !is_alive->do_object_b(ic_oop)) {
// The only exception is compiledICHolder oops which may
// yet be marked below. (We check this further below).
if (ic_oop->is_compiledICHolder()) {
compiledICHolderOop cichk_oop = compiledICHolderOop(ic_oop);
if (is_alive->do_object_b(
cichk_oop->holder_method()->method_holder()) &&
is_alive->do_object_b(cichk_oop->holder_klass())) {
continue;
}
}
ic->set_to_clean();
assert(ic->cached_oop() == NULL,
"cached oop in IC should be cleared");
}
}
}
}
// Compiled code
RelocIterator iter(this, low_boundary);
while (iter.next()) {
if (iter.type() == relocInfo::oop_type) {
oop_Relocation* r = iter.oop_reloc();
// In this loop, we must only traverse those oops directly embedded in
// the code. Other oops (oop_index>0) are seen as part of scopes_oops.
assert(1 == (r->oop_is_immediate()) +
(r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
"oop must be found in exactly one place");
if (r->oop_is_immediate() && r->oop_value() != NULL) {
if (can_unload(is_alive, keep_alive, r->oop_addr(), unloading_occurred)) {
return;
}
}
}
}
// Scopes
for (oop* p = oops_begin(); p < oops_end(); p++) {
if (*p == Universe::non_oop_word()) continue; // skip non-oops
if (can_unload(is_alive, keep_alive, p, unloading_occurred)) {
return;
}
}
#ifndef PRODUCT
// This nmethod was not unloaded; check below that all CompiledICs
// refer to marked oops.
{
RelocIterator iter(this, low_boundary);
while (iter.next()) {
if (iter.type() == relocInfo::virtual_call_type) {
CompiledIC *ic = CompiledIC_at(iter.reloc());
oop ic_oop = ic->cached_oop();
assert(ic_oop == NULL || is_alive->do_object_b(ic_oop),
"Found unmarked ic_oop in reachable nmethod");
}
}
}
#endif // !PRODUCT
}
// This method is called twice during GC -- once while
// tracing the "active" nmethods on thread stacks during
// the (strong) marking phase, and then again when walking
// the code cache contents during the weak roots processing
// phase. The two uses are distinguished by means of the
// 'do_strong_roots_only' flag, which is true in the first
// case. We want to walk the weak roots in the nmethod
// only in the second case. The weak roots in the nmethod
// are the oops in the ExceptionCache and the InlineCache
// oops.
void nmethod::oops_do(OopClosure* f, bool do_strong_roots_only) {
// make sure the oops ready to receive visitors
assert(!is_zombie() && !is_unloaded(),
"should not call follow on zombie or unloaded nmethod");
// If the method is not entrant or zombie then a JMP is plastered over the
// first few bytes. If an oop in the old code was there, that oop
// should not get GC'd. Skip the first few bytes of oops on
// not-entrant methods.
address low_boundary = verified_entry_point();
if (is_not_entrant()) {
low_boundary += NativeJump::instruction_size;
// %%% Note: On SPARC we patch only a 4-byte trap, not a full NativeJump.
// (See comment above.)
}
// Compiled code
f->do_oop((oop*) &_method);
if (!do_strong_roots_only) {
// weak roots processing phase -- update ExceptionCache oops
ExceptionCache* ec = exception_cache();
while(ec != NULL) {
f->do_oop((oop*)ec->exception_type_addr());
ec = ec->next();
}
} // Else strong roots phase -- skip oops in ExceptionCache
RelocIterator iter(this, low_boundary);
while (iter.next()) {
if (iter.type() == relocInfo::oop_type ) {
oop_Relocation* r = iter.oop_reloc();
// In this loop, we must only follow those oops directly embedded in
// the code. Other oops (oop_index>0) are seen as part of scopes_oops.
assert(1 == (r->oop_is_immediate()) +
(r->oop_addr() >= oops_begin() && r->oop_addr() < oops_end()),
"oop must be found in exactly one place");
if (r->oop_is_immediate() && r->oop_value() != NULL) {
f->do_oop(r->oop_addr());
}
}
}
// Scopes
// This includes oop constants not inlined in the code stream.
for (oop* p = oops_begin(); p < oops_end(); p++) {
if (*p == Universe::non_oop_word()) continue; // skip non-oops
f->do_oop(p);
}
}
#define NMETHOD_SENTINEL ((nmethod*)badAddress)
nmethod* volatile nmethod::_oops_do_mark_nmethods;
// An nmethod is "marked" if its _mark_link is set non-null.
// Even if it is the end of the linked list, it will have a non-null link value,
// as long as it is on the list.
// This code must be MP safe, because it is used from parallel GC passes.
bool nmethod::test_set_oops_do_mark() {
assert(nmethod::oops_do_marking_is_active(), "oops_do_marking_prologue must be called");
nmethod* observed_mark_link = _oops_do_mark_link;
if (observed_mark_link == NULL) {
// Claim this nmethod for this thread to mark.
observed_mark_link = (nmethod*)
Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_link, NULL);
if (observed_mark_link == NULL) {
// Atomically append this nmethod (now claimed) to the head of the list:
nmethod* observed_mark_nmethods = _oops_do_mark_nmethods;
for (;;) {
nmethod* required_mark_nmethods = observed_mark_nmethods;
_oops_do_mark_link = required_mark_nmethods;
observed_mark_nmethods = (nmethod*)
Atomic::cmpxchg_ptr(this, &_oops_do_mark_nmethods, required_mark_nmethods);
if (observed_mark_nmethods == required_mark_nmethods)
break;
}
// Mark was clear when we first saw this guy.
NOT_PRODUCT(if (TraceScavenge) print_on(tty, "oops_do, mark"));
return false;
}
}
// On fall through, another racing thread marked this nmethod before we did.
return true;
}
void nmethod::oops_do_marking_prologue() {
NOT_PRODUCT(if (TraceScavenge) tty->print_cr("[oops_do_marking_prologue"));
assert(_oops_do_mark_nmethods == NULL, "must not call oops_do_marking_prologue twice in a row");
// We use cmpxchg_ptr instead of regular assignment here because the user
// may fork a bunch of threads, and we need them all to see the same state.
void* observed = Atomic::cmpxchg_ptr(NMETHOD_SENTINEL, &_oops_do_mark_nmethods, NULL);
guarantee(observed == NULL, "no races in this sequential code");
}
void nmethod::oops_do_marking_epilogue() {
assert(_oops_do_mark_nmethods != NULL, "must not call oops_do_marking_epilogue twice in a row");
nmethod* cur = _oops_do_mark_nmethods;
while (cur != NMETHOD_SENTINEL) {
assert(cur != NULL, "not NULL-terminated");
nmethod* next = cur->_oops_do_mark_link;
cur->_oops_do_mark_link = NULL;
cur->fix_oop_relocations();
NOT_PRODUCT(if (TraceScavenge) cur->print_on(tty, "oops_do, unmark"));
cur = next;
}
void* required = _oops_do_mark_nmethods;
void* observed = Atomic::cmpxchg_ptr(NULL, &_oops_do_mark_nmethods, required);
guarantee(observed == required, "no races in this sequential code");
NOT_PRODUCT(if (TraceScavenge) tty->print_cr("oops_do_marking_epilogue]"));
}
class DetectScavengeRoot: public OopClosure {
bool _detected_scavenge_root;
public:
DetectScavengeRoot() : _detected_scavenge_root(false)
{ NOT_PRODUCT(_print_nm = NULL); }
bool detected_scavenge_root() { return _detected_scavenge_root; }
virtual void do_oop(oop* p) {
if ((*p) != NULL && (*p)->is_scavengable()) {
NOT_PRODUCT(maybe_print(p));
_detected_scavenge_root = true;
}
}
virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
#ifndef PRODUCT
nmethod* _print_nm;
void maybe_print(oop* p) {
if (_print_nm == NULL) return;
if (!_detected_scavenge_root) _print_nm->print_on(tty, "new scavenge root");
tty->print_cr(""PTR_FORMAT"[offset=%d] detected scavengable oop "PTR_FORMAT" (found at "PTR_FORMAT")",
_print_nm, (int)((intptr_t)p - (intptr_t)_print_nm),
(intptr_t)(*p), (intptr_t)p);
(*p)->print();
}
#endif //PRODUCT
};
bool nmethod::detect_scavenge_root_oops() {
DetectScavengeRoot detect_scavenge_root;
NOT_PRODUCT(if (TraceScavenge) detect_scavenge_root._print_nm = this);
oops_do(&detect_scavenge_root);
return detect_scavenge_root.detected_scavenge_root();
}
// Method that knows how to preserve outgoing arguments at call. This method must be
// called with a frame corresponding to a Java invoke
void nmethod::preserve_callee_argument_oops(frame fr, const RegisterMap *reg_map, OopClosure* f) {
#ifndef SHARK
if (!method()->is_native()) {
SimpleScopeDesc ssd(this, fr.pc());
Bytecode_invoke call(ssd.method(), ssd.bci());
// compiled invokedynamic call sites have an implicit receiver at
// resolution time, so make sure it gets GC'ed.
bool has_receiver = !call.is_invokestatic();
Symbol* signature = call.signature();
fr.oops_compiled_arguments_do(signature, has_receiver, reg_map, f);
}
#endif // !SHARK
}
oop nmethod::embeddedOop_at(u_char* p) {
RelocIterator iter(this, p, p + 1);
while (iter.next())
if (iter.type() == relocInfo::oop_type) {
return iter.oop_reloc()->oop_value();
}
return NULL;
}
inline bool includes(void* p, void* from, void* to) {
return from <= p && p < to;
}
void nmethod::copy_scopes_pcs(PcDesc* pcs, int count) {
assert(count >= 2, "must be sentinel values, at least");
#ifdef ASSERT
// must be sorted and unique; we do a binary search in find_pc_desc()
int prev_offset = pcs[0].pc_offset();
assert(prev_offset == PcDesc::lower_offset_limit,
"must start with a sentinel");
for (int i = 1; i < count; i++) {
int this_offset = pcs[i].pc_offset();
assert(this_offset > prev_offset, "offsets must be sorted");
prev_offset = this_offset;
}
assert(prev_offset == PcDesc::upper_offset_limit,
"must end with a sentinel");
#endif //ASSERT
// Search for MethodHandle invokes and tag the nmethod.
for (int i = 0; i < count; i++) {
if (pcs[i].is_method_handle_invoke()) {
set_has_method_handle_invokes(true);
break;
}
}
assert(has_method_handle_invokes() == (_deoptimize_mh_offset != -1), "must have deopt mh handler");
int size = count * sizeof(PcDesc);
assert(scopes_pcs_size() >= size, "oob");
memcpy(scopes_pcs_begin(), pcs, size);
// Adjust the final sentinel downward.
PcDesc* last_pc = &scopes_pcs_begin()[count-1];
assert(last_pc->pc_offset() == PcDesc::upper_offset_limit, "sanity");
last_pc->set_pc_offset(content_size() + 1);
for (; last_pc + 1 < scopes_pcs_end(); last_pc += 1) {
// Fill any rounding gaps with copies of the last record.
last_pc[1] = last_pc[0];
}
// The following assert could fail if sizeof(PcDesc) is not
// an integral multiple of oopSize (the rounding term).
// If it fails, change the logic to always allocate a multiple
// of sizeof(PcDesc), and fill unused words with copies of *last_pc.
assert(last_pc + 1 == scopes_pcs_end(), "must match exactly");
}
void nmethod::copy_scopes_data(u_char* buffer, int size) {
assert(scopes_data_size() >= size, "oob");
memcpy(scopes_data_begin(), buffer, size);
}
#ifdef ASSERT
static PcDesc* linear_search(nmethod* nm, int pc_offset, bool approximate) {
PcDesc* lower = nm->scopes_pcs_begin();
PcDesc* upper = nm->scopes_pcs_end();
lower += 1; // exclude initial sentinel
PcDesc* res = NULL;
for (PcDesc* p = lower; p < upper; p++) {
NOT_PRODUCT(--nmethod_stats.pc_desc_tests); // don't count this call to match_desc
if (match_desc(p, pc_offset, approximate)) {
if (res == NULL)
res = p;
else
res = (PcDesc*) badAddress;
}
}
return res;
}
#endif
// Finds a PcDesc with real-pc equal to "pc"
PcDesc* nmethod::find_pc_desc_internal(address pc, bool approximate) {
address base_address = code_begin();
if ((pc < base_address) ||
(pc - base_address) >= (ptrdiff_t) PcDesc::upper_offset_limit) {
return NULL; // PC is wildly out of range
}
int pc_offset = (int) (pc - base_address);
// Check the PcDesc cache if it contains the desired PcDesc
// (This as an almost 100% hit rate.)
PcDesc* res = _pc_desc_cache.find_pc_desc(pc_offset, approximate);
if (res != NULL) {
assert(res == linear_search(this, pc_offset, approximate), "cache ok");
return res;
}
// Fallback algorithm: quasi-linear search for the PcDesc
// Find the last pc_offset less than the given offset.
// The successor must be the required match, if there is a match at all.
// (Use a fixed radix to avoid expensive affine pointer arithmetic.)
PcDesc* lower = scopes_pcs_begin();
PcDesc* upper = scopes_pcs_end();
upper -= 1; // exclude final sentinel
if (lower >= upper) return NULL; // native method; no PcDescs at all
#define assert_LU_OK \
/* invariant on lower..upper during the following search: */ \
assert(lower->pc_offset() < pc_offset, "sanity"); \
assert(upper->pc_offset() >= pc_offset, "sanity")
assert_LU_OK;
// Use the last successful return as a split point.
PcDesc* mid = _pc_desc_cache.last_pc_desc();
NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
if (mid->pc_offset() < pc_offset) {
lower = mid;
} else {
upper = mid;
}
// Take giant steps at first (4096, then 256, then 16, then 1)
const int LOG2_RADIX = 4 /*smaller steps in debug mode:*/ debug_only(-1);
const int RADIX = (1 << LOG2_RADIX);
for (int step = (1 << (LOG2_RADIX*3)); step > 1; step >>= LOG2_RADIX) {
while ((mid = lower + step) < upper) {
assert_LU_OK;
NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
if (mid->pc_offset() < pc_offset) {
lower = mid;
} else {
upper = mid;
break;
}
}
assert_LU_OK;
}
// Sneak up on the value with a linear search of length ~16.
while (true) {
assert_LU_OK;
mid = lower + 1;
NOT_PRODUCT(++nmethod_stats.pc_desc_searches);
if (mid->pc_offset() < pc_offset) {
lower = mid;
} else {
upper = mid;
break;
}
}
#undef assert_LU_OK
if (match_desc(upper, pc_offset, approximate)) {
assert(upper == linear_search(this, pc_offset, approximate), "search ok");
_pc_desc_cache.add_pc_desc(upper);
return upper;
} else {
assert(NULL == linear_search(this, pc_offset, approximate), "search ok");
return NULL;
}
}
bool nmethod::check_all_dependencies() {
bool found_check = false;
// wholesale check of all dependencies
for (Dependencies::DepStream deps(this); deps.next(); ) {
if (deps.check_dependency() != NULL) {
found_check = true;
NOT_DEBUG(break);
}
}
return found_check; // tell caller if we found anything
}
bool nmethod::check_dependency_on(DepChange& changes) {
// What has happened:
// 1) a new class dependee has been added
// 2) dependee and all its super classes have been marked
bool found_check = false; // set true if we are upset
for (Dependencies::DepStream deps(this); deps.next(); ) {
// Evaluate only relevant dependencies.
if (deps.spot_check_dependency_at(changes) != NULL) {
found_check = true;
NOT_DEBUG(break);
}
}
return found_check;
}
bool nmethod::is_evol_dependent_on(klassOop dependee) {
instanceKlass *dependee_ik = instanceKlass::cast(dependee);
objArrayOop dependee_methods = dependee_ik->methods();
for (Dependencies::DepStream deps(this); deps.next(); ) {
if (deps.type() == Dependencies::evol_method) {
methodOop method = deps.method_argument(0);
for (int j = 0; j < dependee_methods->length(); j++) {
if ((methodOop) dependee_methods->obj_at(j) == method) {
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x01000000,
("Found evol dependency of nmethod %s.%s(%s) compile_id=%d on method %s.%s(%s)",
_method->method_holder()->klass_part()->external_name(),
_method->name()->as_C_string(),
_method->signature()->as_C_string(), compile_id(),
method->method_holder()->klass_part()->external_name(),
method->name()->as_C_string(),
method->signature()->as_C_string()));
if (TraceDependencies || LogCompilation)
deps.log_dependency(dependee);
return true;
}
}
}
}
return false;
}
// Called from mark_for_deoptimization, when dependee is invalidated.
bool nmethod::is_dependent_on_method(methodOop dependee) {
for (Dependencies::DepStream deps(this); deps.next(); ) {
if (deps.type() != Dependencies::evol_method)
continue;
methodOop method = deps.method_argument(0);
if (method == dependee) return true;
}
return false;
}
bool nmethod::is_patchable_at(address instr_addr) {
assert(insts_contains(instr_addr), "wrong nmethod used");
if (is_zombie()) {
// a zombie may never be patched
return false;
}
return true;
}
address nmethod::continuation_for_implicit_exception(address pc) {
// Exception happened outside inline-cache check code => we are inside
// an active nmethod => use cpc to determine a return address
int exception_offset = pc - code_begin();
int cont_offset = ImplicitExceptionTable(this).at( exception_offset );
#ifdef ASSERT
if (cont_offset == 0) {
Thread* thread = ThreadLocalStorage::get_thread_slow();
ResetNoHandleMark rnm; // Might be called from LEAF/QUICK ENTRY
HandleMark hm(thread);
ResourceMark rm(thread);
CodeBlob* cb = CodeCache::find_blob(pc);
assert(cb != NULL && cb == this, "");
tty->print_cr("implicit exception happened at " INTPTR_FORMAT, pc);
print();
method()->print_codes();
print_code();
print_pcs();
}
#endif
if (cont_offset == 0) {
// Let the normal error handling report the exception
return NULL;
}
return code_begin() + cont_offset;
}
void nmethod_init() {
// make sure you didn't forget to adjust the filler fields
assert(sizeof(nmethod) % oopSize == 0, "nmethod size must be multiple of a word");
}
//-------------------------------------------------------------------------------------------
// QQQ might we make this work from a frame??
nmethodLocker::nmethodLocker(address pc) {
CodeBlob* cb = CodeCache::find_blob(pc);
guarantee(cb != NULL && cb->is_nmethod(), "bad pc for a nmethod found");
_nm = (nmethod*)cb;
lock_nmethod(_nm);
}
// Only JvmtiDeferredEvent::compiled_method_unload_event()
// should pass zombie_ok == true.
void nmethodLocker::lock_nmethod(nmethod* nm, bool zombie_ok) {
if (nm == NULL) return;
Atomic::inc(&nm->_lock_count);
guarantee(zombie_ok || !nm->is_zombie(), "cannot lock a zombie method");
}
void nmethodLocker::unlock_nmethod(nmethod* nm) {
if (nm == NULL) return;
Atomic::dec(&nm->_lock_count);
guarantee(nm->_lock_count >= 0, "unmatched nmethod lock/unlock");
}
// -----------------------------------------------------------------------------
// nmethod::get_deopt_original_pc
//
// Return the original PC for the given PC if:
// (a) the given PC belongs to a nmethod and
// (b) it is a deopt PC
address nmethod::get_deopt_original_pc(const frame* fr) {
if (fr->cb() == NULL) return NULL;
nmethod* nm = fr->cb()->as_nmethod_or_null();
if (nm != NULL && nm->is_deopt_pc(fr->pc()))
return nm->get_original_pc(fr);
return NULL;
}
// -----------------------------------------------------------------------------
// MethodHandle
bool nmethod::is_method_handle_return(address return_pc) {
if (!has_method_handle_invokes()) return false;
PcDesc* pd = pc_desc_at(return_pc);
if (pd == NULL)
return false;
return pd->is_method_handle_invoke();
}
// -----------------------------------------------------------------------------
// Verification
class VerifyOopsClosure: public OopClosure {
nmethod* _nm;
bool _ok;
public:
VerifyOopsClosure(nmethod* nm) : _nm(nm), _ok(true) { }
bool ok() { return _ok; }
virtual void do_oop(oop* p) {
if ((*p) == NULL || (*p)->is_oop()) return;
if (_ok) {
_nm->print_nmethod(true);
_ok = false;
}
tty->print_cr("*** non-oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
(intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
}
virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
};
void nmethod::verify() {
// Hmm. OSR methods can be deopted but not marked as zombie or not_entrant
// seems odd.
if( is_zombie() || is_not_entrant() )
return;
// Make sure all the entry points are correctly aligned for patching.
NativeJump::check_verified_entry_alignment(entry_point(), verified_entry_point());
assert(method()->is_oop(), "must be valid");
ResourceMark rm;
if (!CodeCache::contains(this)) {
fatal(err_msg("nmethod at " INTPTR_FORMAT " not in zone", this));
}
if(is_native_method() )
return;
nmethod* nm = CodeCache::find_nmethod(verified_entry_point());
if (nm != this) {
fatal(err_msg("findNMethod did not find this nmethod (" INTPTR_FORMAT ")",
this));
}
for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
if (! p->verify(this)) {
tty->print_cr("\t\tin nmethod at " INTPTR_FORMAT " (pcs)", this);
}
}
VerifyOopsClosure voc(this);
oops_do(&voc);
assert(voc.ok(), "embedded oops must be OK");
verify_scavenge_root_oops();
verify_scopes();
}
void nmethod::verify_interrupt_point(address call_site) {
// This code does not work in release mode since
// owns_lock only is available in debug mode.
CompiledIC* ic = NULL;
Thread *cur = Thread::current();
if (CompiledIC_lock->owner() == cur ||
((cur->is_VM_thread() || cur->is_ConcurrentGC_thread()) &&
SafepointSynchronize::is_at_safepoint())) {
ic = CompiledIC_at(call_site);
CHECK_UNHANDLED_OOPS_ONLY(Thread::current()->clear_unhandled_oops());
} else {
MutexLocker ml_verify (CompiledIC_lock);
ic = CompiledIC_at(call_site);
}
PcDesc* pd = pc_desc_at(ic->end_of_call());
assert(pd != NULL, "PcDesc must exist");
for (ScopeDesc* sd = new ScopeDesc(this, pd->scope_decode_offset(),
pd->obj_decode_offset(), pd->should_reexecute(),
pd->return_oop());
!sd->is_top(); sd = sd->sender()) {
sd->verify();
}
}
void nmethod::verify_scopes() {
if( !method() ) return; // Runtime stubs have no scope
if (method()->is_native()) return; // Ignore stub methods.
// iterate through all interrupt point
// and verify the debug information is valid.
RelocIterator iter((nmethod*)this);
while (iter.next()) {
address stub = NULL;
switch (iter.type()) {
case relocInfo::virtual_call_type:
verify_interrupt_point(iter.addr());
break;
case relocInfo::opt_virtual_call_type:
stub = iter.opt_virtual_call_reloc()->static_stub();
verify_interrupt_point(iter.addr());
break;
case relocInfo::static_call_type:
stub = iter.static_call_reloc()->static_stub();
//verify_interrupt_point(iter.addr());
break;
case relocInfo::runtime_call_type:
address destination = iter.reloc()->value();
// Right now there is no way to find out which entries support
// an interrupt point. It would be nice if we had this
// information in a table.
break;
}
assert(stub == NULL || stub_contains(stub), "static call stub outside stub section");
}
}
// -----------------------------------------------------------------------------
// Non-product code
#ifndef PRODUCT
class DebugScavengeRoot: public OopClosure {
nmethod* _nm;
bool _ok;
public:
DebugScavengeRoot(nmethod* nm) : _nm(nm), _ok(true) { }
bool ok() { return _ok; }
virtual void do_oop(oop* p) {
if ((*p) == NULL || !(*p)->is_scavengable()) return;
if (_ok) {
_nm->print_nmethod(true);
_ok = false;
}
tty->print_cr("*** scavengable oop "PTR_FORMAT" found at "PTR_FORMAT" (offset %d)",
(intptr_t)(*p), (intptr_t)p, (int)((intptr_t)p - (intptr_t)_nm));
(*p)->print();
}
virtual void do_oop(narrowOop* p) { ShouldNotReachHere(); }
};
void nmethod::verify_scavenge_root_oops() {
if (!on_scavenge_root_list()) {
// Actually look inside, to verify the claim that it's clean.
DebugScavengeRoot debug_scavenge_root(this);
oops_do(&debug_scavenge_root);
if (!debug_scavenge_root.ok())
fatal("found an unadvertised bad scavengable oop in the code cache");
}
assert(scavenge_root_not_marked(), "");
}
#endif // PRODUCT
// Printing operations
void nmethod::print() const {
ResourceMark rm;
ttyLocker ttyl; // keep the following output all in one block
tty->print("Compiled method ");
if (is_compiled_by_c1()) {
tty->print("(c1) ");
} else if (is_compiled_by_c2()) {
tty->print("(c2) ");
} else if (is_compiled_by_shark()) {
tty->print("(shark) ");
} else {
tty->print("(nm) ");
}
print_on(tty, NULL);
if (WizardMode) {
tty->print("((nmethod*) "INTPTR_FORMAT ") ", this);
tty->print(" for method " INTPTR_FORMAT , (address)method());
tty->print(" { ");
if (is_in_use()) tty->print("in_use ");
if (is_not_entrant()) tty->print("not_entrant ");
if (is_zombie()) tty->print("zombie ");
if (is_unloaded()) tty->print("unloaded ");
if (on_scavenge_root_list()) tty->print("scavenge_root ");
tty->print_cr("}:");
}
if (size () > 0) tty->print_cr(" total in heap [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
(address)this,
(address)this + size(),
size());
if (relocation_size () > 0) tty->print_cr(" relocation [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
relocation_begin(),
relocation_end(),
relocation_size());
if (consts_size () > 0) tty->print_cr(" constants [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
consts_begin(),
consts_end(),
consts_size());
if (insts_size () > 0) tty->print_cr(" main code [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
insts_begin(),
insts_end(),
insts_size());
if (stub_size () > 0) tty->print_cr(" stub code [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
stub_begin(),
stub_end(),
stub_size());
if (oops_size () > 0) tty->print_cr(" oops [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
oops_begin(),
oops_end(),
oops_size());
if (scopes_data_size () > 0) tty->print_cr(" scopes data [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
scopes_data_begin(),
scopes_data_end(),
scopes_data_size());
if (scopes_pcs_size () > 0) tty->print_cr(" scopes pcs [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
scopes_pcs_begin(),
scopes_pcs_end(),
scopes_pcs_size());
if (dependencies_size () > 0) tty->print_cr(" dependencies [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
dependencies_begin(),
dependencies_end(),
dependencies_size());
if (handler_table_size() > 0) tty->print_cr(" handler table [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
handler_table_begin(),
handler_table_end(),
handler_table_size());
if (nul_chk_table_size() > 0) tty->print_cr(" nul chk table [" INTPTR_FORMAT "," INTPTR_FORMAT "] = %d",
nul_chk_table_begin(),
nul_chk_table_end(),
nul_chk_table_size());
}
void nmethod::print_code() {
HandleMark hm;
ResourceMark m;
Disassembler::decode(this);
}
#ifndef PRODUCT
void nmethod::print_scopes() {
// Find the first pc desc for all scopes in the code and print it.
ResourceMark rm;
for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
if (p->scope_decode_offset() == DebugInformationRecorder::serialized_null)
continue;
ScopeDesc* sd = scope_desc_at(p->real_pc(this));
sd->print_on(tty, p);
}
}
void nmethod::print_dependencies() {
ResourceMark rm;
ttyLocker ttyl; // keep the following output all in one block
tty->print_cr("Dependencies:");
for (Dependencies::DepStream deps(this); deps.next(); ) {
deps.print_dependency();
klassOop ctxk = deps.context_type();
if (ctxk != NULL) {
Klass* k = Klass::cast(ctxk);
if (k->oop_is_instance() && ((instanceKlass*)k)->is_dependent_nmethod(this)) {
tty->print_cr(" [nmethod<=klass]%s", k->external_name());
}
}
deps.log_dependency(); // put it into the xml log also
}
}
void nmethod::print_relocations() {
ResourceMark m; // in case methods get printed via the debugger
tty->print_cr("relocations:");
RelocIterator iter(this);
iter.print();
if (UseRelocIndex) {
jint* index_end = (jint*)relocation_end() - 1;
jint index_size = *index_end;
jint* index_start = (jint*)( (address)index_end - index_size );
tty->print_cr(" index @" INTPTR_FORMAT ": index_size=%d", index_start, index_size);
if (index_size > 0) {
jint* ip;
for (ip = index_start; ip+2 <= index_end; ip += 2)
tty->print_cr(" (%d %d) addr=" INTPTR_FORMAT " @" INTPTR_FORMAT,
ip[0],
ip[1],
header_end()+ip[0],
relocation_begin()-1+ip[1]);
for (; ip < index_end; ip++)
tty->print_cr(" (%d ?)", ip[0]);
tty->print_cr(" @" INTPTR_FORMAT ": index_size=%d", ip, *ip++);
tty->print_cr("reloc_end @" INTPTR_FORMAT ":", ip);
}
}
}
void nmethod::print_pcs() {
ResourceMark m; // in case methods get printed via debugger
tty->print_cr("pc-bytecode offsets:");
for (PcDesc* p = scopes_pcs_begin(); p < scopes_pcs_end(); p++) {
p->print(this);
}
}
#endif // PRODUCT
const char* nmethod::reloc_string_for(u_char* begin, u_char* end) {
RelocIterator iter(this, begin, end);
bool have_one = false;
while (iter.next()) {
have_one = true;
switch (iter.type()) {
case relocInfo::none: return "no_reloc";
case relocInfo::oop_type: {
stringStream st;
oop_Relocation* r = iter.oop_reloc();
oop obj = r->oop_value();
st.print("oop(");
if (obj == NULL) st.print("NULL");
else obj->print_value_on(&st);
st.print(")");
return st.as_string();
}
case relocInfo::virtual_call_type: return "virtual_call";
case relocInfo::opt_virtual_call_type: return "optimized virtual_call";
case relocInfo::static_call_type: return "static_call";
case relocInfo::static_stub_type: return "static_stub";
case relocInfo::runtime_call_type: return "runtime_call";
case relocInfo::external_word_type: return "external_word";
case relocInfo::internal_word_type: return "internal_word";
case relocInfo::section_word_type: return "section_word";
case relocInfo::poll_type: return "poll";
case relocInfo::poll_return_type: return "poll_return";
case relocInfo::type_mask: return "type_bit_mask";
}
}
return have_one ? "other" : NULL;
}
// Return a the last scope in (begin..end]
ScopeDesc* nmethod::scope_desc_in(address begin, address end) {
PcDesc* p = pc_desc_near(begin+1);
if (p != NULL && p->real_pc(this) <= end) {
return new ScopeDesc(this, p->scope_decode_offset(),
p->obj_decode_offset(), p->should_reexecute(),
p->return_oop());
}
return NULL;
}
void nmethod::print_nmethod_labels(outputStream* stream, address block_begin) const {
if (block_begin == entry_point()) stream->print_cr("[Entry Point]");
if (block_begin == verified_entry_point()) stream->print_cr("[Verified Entry Point]");
if (block_begin == exception_begin()) stream->print_cr("[Exception Handler]");
if (block_begin == stub_begin()) stream->print_cr("[Stub Code]");
if (block_begin == deopt_handler_begin()) stream->print_cr("[Deopt Handler Code]");
if (has_method_handle_invokes())
if (block_begin == deopt_mh_handler_begin()) stream->print_cr("[Deopt MH Handler Code]");
if (block_begin == consts_begin()) stream->print_cr("[Constants]");
if (block_begin == entry_point()) {
methodHandle m = method();
if (m.not_null()) {
stream->print(" # ");
m->print_value_on(stream);
stream->cr();
}
if (m.not_null() && !is_osr_method()) {
ResourceMark rm;
int sizeargs = m->size_of_parameters();
BasicType* sig_bt = NEW_RESOURCE_ARRAY(BasicType, sizeargs);
VMRegPair* regs = NEW_RESOURCE_ARRAY(VMRegPair, sizeargs);
{
int sig_index = 0;
if (!m->is_static())
sig_bt[sig_index++] = T_OBJECT; // 'this'
for (SignatureStream ss(m->signature()); !ss.at_return_type(); ss.next()) {
BasicType t = ss.type();
sig_bt[sig_index++] = t;
if (type2size[t] == 2) {
sig_bt[sig_index++] = T_VOID;
} else {
assert(type2size[t] == 1, "size is 1 or 2");
}
}
assert(sig_index == sizeargs, "");
}
const char* spname = "sp"; // make arch-specific?
intptr_t out_preserve = SharedRuntime::java_calling_convention(sig_bt, regs, sizeargs, false);
int stack_slot_offset = this->frame_size() * wordSize;
int tab1 = 14, tab2 = 24;
int sig_index = 0;
int arg_index = (m->is_static() ? 0 : -1);
bool did_old_sp = false;
for (SignatureStream ss(m->signature()); !ss.at_return_type(); ) {
bool at_this = (arg_index == -1);
bool at_old_sp = false;
BasicType t = (at_this ? T_OBJECT : ss.type());
assert(t == sig_bt[sig_index], "sigs in sync");
if (at_this)
stream->print(" # this: ");
else
stream->print(" # parm%d: ", arg_index);
stream->move_to(tab1);
VMReg fst = regs[sig_index].first();
VMReg snd = regs[sig_index].second();
if (fst->is_reg()) {
stream->print("%s", fst->name());
if (snd->is_valid()) {
stream->print(":%s", snd->name());
}
} else if (fst->is_stack()) {
int offset = fst->reg2stack() * VMRegImpl::stack_slot_size + stack_slot_offset;
if (offset == stack_slot_offset) at_old_sp = true;
stream->print("[%s+0x%x]", spname, offset);
} else {
stream->print("reg%d:%d??", (int)(intptr_t)fst, (int)(intptr_t)snd);
}
stream->print(" ");
stream->move_to(tab2);
stream->print("= ");
if (at_this) {
m->method_holder()->print_value_on(stream);
} else {
bool did_name = false;
if (!at_this && ss.is_object()) {
Symbol* name = ss.as_symbol_or_null();
if (name != NULL) {
name->print_value_on(stream);
did_name = true;
}
}
if (!did_name)
stream->print("%s", type2name(t));
}
if (at_old_sp) {
stream->print(" (%s of caller)", spname);
did_old_sp = true;
}
stream->cr();
sig_index += type2size[t];
arg_index += 1;
if (!at_this) ss.next();
}
if (!did_old_sp) {
stream->print(" # ");
stream->move_to(tab1);
stream->print("[%s+0x%x]", spname, stack_slot_offset);
stream->print(" (%s of caller)", spname);
stream->cr();
}
}
}
}
void nmethod::print_code_comment_on(outputStream* st, int column, u_char* begin, u_char* end) {
// First, find an oopmap in (begin, end].
// We use the odd half-closed interval so that oop maps and scope descs
// which are tied to the byte after a call are printed with the call itself.
address base = code_begin();
OopMapSet* oms = oop_maps();
if (oms != NULL) {
for (int i = 0, imax = oms->size(); i < imax; i++) {
OopMap* om = oms->at(i);
address pc = base + om->offset();
if (pc > begin) {
if (pc <= end) {
st->move_to(column);
st->print("; ");
om->print_on(st);
}
break;
}
}
}
// Print any debug info present at this pc.
ScopeDesc* sd = scope_desc_in(begin, end);
if (sd != NULL) {
st->move_to(column);
if (sd->bci() == SynchronizationEntryBCI) {
st->print(";*synchronization entry");
} else {
if (sd->method().is_null()) {
st->print("method is NULL");
} else if (sd->method()->is_native()) {
st->print("method is native");
} else {
Bytecodes::Code bc = sd->method()->java_code_at(sd->bci());
st->print(";*%s", Bytecodes::name(bc));
switch (bc) {
case Bytecodes::_invokevirtual:
case Bytecodes::_invokespecial:
case Bytecodes::_invokestatic:
case Bytecodes::_invokeinterface:
{
Bytecode_invoke invoke(sd->method(), sd->bci());
st->print(" ");
if (invoke.name() != NULL)
invoke.name()->print_symbol_on(st);
else
st->print("<UNKNOWN>");
break;
}
case Bytecodes::_getfield:
case Bytecodes::_putfield:
case Bytecodes::_getstatic:
case Bytecodes::_putstatic:
{
Bytecode_field field(sd->method(), sd->bci());
st->print(" ");
if (field.name() != NULL)
field.name()->print_symbol_on(st);
else
st->print("<UNKNOWN>");
}
}
}
}
// Print all scopes
for (;sd != NULL; sd = sd->sender()) {
st->move_to(column);
st->print("; -");
if (sd->method().is_null()) {
st->print("method is NULL");
} else {
sd->method()->print_short_name(st);
}
int lineno = sd->method()->line_number_from_bci(sd->bci());
if (lineno != -1) {
st->print("@%d (line %d)", sd->bci(), lineno);
} else {
st->print("@%d", sd->bci());
}
st->cr();
}
}
// Print relocation information
const char* str = reloc_string_for(begin, end);
if (str != NULL) {
if (sd != NULL) st->cr();
st->move_to(column);
st->print("; {%s}", str);
}
int cont_offset = ImplicitExceptionTable(this).at(begin - code_begin());
if (cont_offset != 0) {
st->move_to(column);
st->print("; implicit exception: dispatches to " INTPTR_FORMAT, code_begin() + cont_offset);
}
}
#ifndef PRODUCT
void nmethod::print_value_on(outputStream* st) const {
st->print("nmethod");
print_on(st, NULL);
}
void nmethod::print_calls(outputStream* st) {
RelocIterator iter(this);
while (iter.next()) {
switch (iter.type()) {
case relocInfo::virtual_call_type:
case relocInfo::opt_virtual_call_type: {
VerifyMutexLocker mc(CompiledIC_lock);
CompiledIC_at(iter.reloc())->print();
break;
}
case relocInfo::static_call_type:
st->print_cr("Static call at " INTPTR_FORMAT, iter.reloc()->addr());
compiledStaticCall_at(iter.reloc())->print();
break;
}
}
}
void nmethod::print_handler_table() {
ExceptionHandlerTable(this).print();
}
void nmethod::print_nul_chk_table() {
ImplicitExceptionTable(this).print(code_begin());
}
void nmethod::print_statistics() {
ttyLocker ttyl;
if (xtty != NULL) xtty->head("statistics type='nmethod'");
nmethod_stats.print_native_nmethod_stats();
nmethod_stats.print_nmethod_stats();
DebugInformationRecorder::print_statistics();
nmethod_stats.print_pc_stats();
Dependencies::print_statistics();
if (xtty != NULL) xtty->tail("statistics");
}
#endif // PRODUCT