#include "precompiled.hpp"

#include "gc_implementation/shared/cSpaceCounters.hpp"

#include "gc_implementation/shared/vmGCOperations.hpp"

#include "gc_interface/collectedHeap.inline.hpp"

#include "memory/blockOffsetTable.inline.hpp"

#include "memory/compactPermGen.hpp"

#include "memory/gcLocker.hpp"

#include "memory/gcLocker.inline.hpp"

#include "memory/genCollectedHeap.hpp"

#include "memory/generation.inline.hpp"

#include "memory/permGen.hpp"

#include "memory/universe.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/java.hpp"

#include "runtime/vmThread.hpp"

HeapWord* PermGen::request_expand_and_allocate(Generation* gen, size_t size,

GCCause::Cause prev_cause) {

if (gen->capacity() < _capacity_expansion_limit ||

prev_cause != GCCause::_no_gc || UseG1GC) { // last disjunct is a temporary hack for G1

return gen->expand_and_allocate(size, false);

}

// We have reached the limit of capacity expansion where

// we will not expand further until a GC is done; request denied.

return NULL;

}

HeapWord* PermGen::mem_allocate_in_gen(size_t size, Generation* gen) {

GCCause::Cause next_cause = GCCause::_permanent_generation_full;

GCCause::Cause prev_cause = GCCause::_no_gc;

unsigned int gc_count_before, full_gc_count_before;

HeapWord* obj;

for (;;) {

{

MutexLocker ml(Heap_lock);

if ((obj = gen->allocate(size, false)) != NULL) {

return obj;

}

// Attempt to expand and allocate the requested space:

// specific subtypes may use specific policy to either expand

// or not. The default policy (see above) is to expand until

// _capacity_expansion_limit, and no further unless a GC is done.

// Concurrent collectors may decide to kick off a concurrent

// collection under appropriate conditions.

obj = request_expand_and_allocate(gen, size, prev_cause);

if (obj != NULL || prev_cause == GCCause::_last_ditch_collection) {

return obj;

}

if (GC_locker::is_active_and_needs_gc()) {

// If this thread is not in a jni critical section, we stall

// the requestor until the critical section has cleared and

// GC allowed. When the critical section clears, a GC is

// initiated by the last thread exiting the critical section; so

// we retry the allocation sequence from the beginning of the loop,

// rather than causing more, now probably unnecessary, GC attempts.

JavaThread* jthr = JavaThread::current();

if (!jthr->in_critical()) {

MutexUnlocker mul(Heap_lock);

// Wait for JNI critical section to be exited

GC_locker::stall_until_clear();

continue;

} else {

if (CheckJNICalls) {

fatal("Possible deadlock due to allocating while"

" in jni critical section");

}

return NULL;

}

}

// Read the GC count while holding the Heap_lock

gc_count_before = SharedHeap::heap()->total_collections();

full_gc_count_before = SharedHeap::heap()->total_full_collections();

}

// Give up heap lock above, VMThread::execute below gets it back

VM_GenCollectForPermanentAllocation op(size, gc_count_before, full_gc_count_before,

next_cause);

VMThread::execute(&op);

if (!op.prologue_succeeded() || op.gc_locked()) {

assert(op.result() == NULL, "must be NULL if gc_locked() is true");

continue; // retry and/or stall as necessary

}

obj = op.result();

assert(obj == NULL || SharedHeap::heap()->is_in_reserved(obj),

"result not in heap");

if (obj != NULL) {

return obj;

}

prev_cause = next_cause;

next_cause = GCCause::_last_ditch_collection;

}

}

CompactingPermGen::CompactingPermGen(ReservedSpace rs,

ReservedSpace shared_rs,

size_t initial_byte_size,

GenRemSet* remset,

PermanentGenerationSpec* perm_spec)

{

CompactingPermGenGen* g =

new CompactingPermGenGen(rs, shared_rs, initial_byte_size, -1, remset,

NULL, perm_spec);

if (g == NULL)

vm_exit_during_initialization("Could not allocate a CompactingPermGen");

_gen = g;

g->initialize_performance_counters();

_capacity_expansion_limit = g->capacity() + MaxPermHeapExpansion;

}

HeapWord* CompactingPermGen::mem_allocate(size_t size) {

return mem_allocate_in_gen(size, _gen);

}

void CompactingPermGen::compute_new_size() {

size_t desired_capacity = align_size_up(_gen->used(), MinPermHeapExpansion);

if (desired_capacity < PermSize) {

desired_capacity = PermSize;

}

if (_gen->capacity() > desired_capacity) {

_gen->shrink(_gen->capacity() - desired_capacity);

}

set_capacity_expansion_limit(_gen->capacity() + MaxPermHeapExpansion);

}