0N/A

1879N/A#ifndef SHARE_VM_RUNTIME_SAFEPOINT_HPP

1879N/A#define SHARE_VM_RUNTIME_SAFEPOINT_HPP

1879N/A

1879N/A#include "asm/assembler.hpp"

1879N/A#include "code/nmethod.hpp"

1879N/A#include "memory/allocation.hpp"

1879N/A#include "runtime/extendedPC.hpp"

3152N/A#include "runtime/mutexLocker.hpp"

1879N/A#include "runtime/os.hpp"

1879N/A#include "utilities/ostream.hpp"

1879N/A

0N/A

0N/A

0N/Aclass ThreadSafepointState;

0N/Aclass SnippetCache;

0N/Aclass nmethod;

0N/A

0N/Aclass SafepointSynchronize : AllStatic {

0N/A public:

0N/A enum SynchronizeState {

0N/A _not_synchronized = 0, // Threads not synchronized at a safepoint

0N/A // Keep this value 0. See the coment in do_call_back()

0N/A _synchronizing = 1, // Synchronizing in progress

0N/A _synchronized = 2 // All Java threads are stopped at a safepoint. Only VM thread is running

0N/A };

0N/A

0N/A enum SafepointingThread {

0N/A _null_thread = 0,

0N/A _vm_thread = 1,

0N/A _other_thread = 2

0N/A };

0N/A

0N/A enum SafepointTimeoutReason {

0N/A _spinning_timeout = 0,

0N/A _blocking_timeout = 1

0N/A };

0N/A

0N/A typedef struct {

1291N/A float _time_stamp; // record when the current safepoint occurs in seconds

0N/A int _vmop_type; // type of VM operation triggers the safepoint

0N/A int _nof_total_threads; // total number of Java threads

0N/A int _nof_initial_running_threads; // total number of initially seen running threads

0N/A int _nof_threads_wait_to_block; // total number of threads waiting for to block

0N/A bool _page_armed; // true if polling page is armed, false otherwise

0N/A int _nof_threads_hit_page_trap; // total number of threads hitting the page trap

0N/A jlong _time_to_spin; // total time in millis spent in spinning

0N/A jlong _time_to_wait_to_block; // total time in millis spent in waiting for to block

1291N/A jlong _time_to_do_cleanups; // total time in millis spent in performing cleanups

0N/A jlong _time_to_sync; // total time in millis spent in getting to _synchronized

0N/A jlong _time_to_exec_vmop; // total time in millis spent in vm operation itself

0N/A } SafepointStats;

0N/A

0N/A private:

0N/A static volatile SynchronizeState _state; // Threads might read this flag directly, without acquireing the Threads_lock

1291N/A static volatile int _waiting_to_block; // number of threads we are waiting for to block

3152N/A static int _current_jni_active_count; // Counts the number of active critical natives during the safepoint

0N/A

0N/A // This counter is used for fast versions of jni_Get<Primitive>Field.

0N/A // An even value means there is no ongoing safepoint operations.

0N/A // The counter is incremented ONLY at the beginning and end of each

0N/A // safepoint. The fact that Threads_lock is held throughout each pair of

0N/A // increments (at the beginning and end of each safepoint) guarantees

0N/A // race freedom.

0N/Apublic:

0N/A static volatile int _safepoint_counter;

0N/Aprivate:

1291N/A static long _end_of_last_safepoint; // Time of last safepoint in milliseconds

0N/A

0N/A // statistics

1291N/A static jlong _safepoint_begin_time; // time when safepoint begins

1291N/A static SafepointStats* _safepoint_stats; // array of SafepointStats struct

1291N/A static int _cur_stat_index; // current index to the above array

1291N/A static julong _safepoint_reasons[]; // safepoint count for each VM op

1291N/A static julong _coalesced_vmop_count; // coalesced vmop count

1291N/A static jlong _max_sync_time; // maximum sync time in nanos

1291N/A static jlong _max_vmop_time; // maximum vm operation time in nanos

1291N/A static float _ts_of_current_safepoint; // time stamp of current safepoint in seconds

0N/A

0N/A static void begin_statistics(int nof_threads, int nof_running);

0N/A static void update_statistics_on_spin_end();

0N/A static void update_statistics_on_sync_end(jlong end_time);

1291N/A static void update_statistics_on_cleanup_end(jlong end_time);

0N/A static void end_statistics(jlong end_time);

0N/A static void print_statistics();

0N/A inline static void inc_page_trap_count() {

0N/A Atomic::inc(&_safepoint_stats[_cur_stat_index]._nof_threads_hit_page_trap);

0N/A }

0N/A

0N/A // For debug long safepoint

0N/A static void print_safepoint_timeout(SafepointTimeoutReason timeout_reason);

0N/A

0N/Apublic:

0N/A

0N/A // Main entry points

0N/A

0N/A // Roll all threads forward to safepoint. Must be called by the

0N/A // VMThread or CMS_thread.

0N/A static void begin();

0N/A static void end(); // Start all suspended threads again...

0N/A

0N/A static bool safepoint_safe(JavaThread *thread, JavaThreadState state);

0N/A

3158N/A static void check_for_lazy_critical_native(JavaThread *thread, JavaThreadState state);

3158N/A

0N/A // Query

0N/A inline static bool is_at_safepoint() { return _state == _synchronized; }

0N/A inline static bool is_synchronizing() { return _state == _synchronizing; }

0N/A

0N/A inline static bool do_call_back() {

0N/A return (_state != _not_synchronized);

0N/A }

0N/A

3152N/A inline static void increment_jni_active_count() {

3152N/A assert_locked_or_safepoint(Safepoint_lock);

3152N/A _current_jni_active_count++;

3152N/A }

3152N/A

0N/A // Called when a thread volantary blocks

0N/A static void block(JavaThread *thread);

0N/A static void signal_thread_at_safepoint() { _waiting_to_block--; }

0N/A

0N/A // Exception handling for page polling

0N/A static void handle_polling_page_exception(JavaThread *thread);

0N/A

0N/A // VM Thread interface for determining safepoint rate

1291N/A static long last_non_safepoint_interval() {

1291N/A return os::javaTimeMillis() - _end_of_last_safepoint;

1291N/A }

1703N/A static long end_of_last_safepoint() {

1703N/A return _end_of_last_safepoint;

1703N/A }

0N/A static bool is_cleanup_needed();

0N/A static void do_cleanup_tasks();

0N/A

0N/A // debugging

0N/A static void print_state() PRODUCT_RETURN;

0N/A static void safepoint_msg(const char* format, ...) PRODUCT_RETURN;

0N/A

0N/A static void deferred_initialize_stat();

0N/A static void print_stat_on_exit();

0N/A inline static void inc_vmop_coalesced_count() { _coalesced_vmop_count++; }

0N/A

0N/A static void set_is_at_safepoint() { _state = _synchronized; }

0N/A static void set_is_not_at_safepoint() { _state = _not_synchronized; }

0N/A

0N/A // assembly support

0N/A static address address_of_state() { return (address)&_state; }

0N/A

0N/A static address safepoint_counter_addr() { return (address)&_safepoint_counter; }

0N/A};

0N/A

3863N/Aclass ThreadSafepointState: public CHeapObj<mtInternal> {

0N/A public:

0N/A // These states are maintained by VM thread while threads are being brought

0N/A // to a safepoint. After SafepointSynchronize::end(), they are reset to

0N/A // _running.

0N/A enum suspend_type {

0N/A _running = 0, // Thread state not yet determined (i.e., not at a safepoint yet)

0N/A _at_safepoint = 1, // Thread at a safepoint (f.ex., when blocked on a lock)

0N/A _call_back = 2 // Keep executing and wait for callback (if thread is in interpreted or vm)

0N/A };

0N/A private:

0N/A volatile bool _at_poll_safepoint; // At polling page safepoint (NOT a poll return safepoint)

0N/A // Thread has called back the safepoint code (for debugging)

0N/A bool _has_called_back;

0N/A

0N/A JavaThread * _thread;

0N/A volatile suspend_type _type;

1647N/A JavaThreadState _orig_thread_state;

0N/A

0N/A

0N/A public:

0N/A ThreadSafepointState(JavaThread *thread);

0N/A

0N/A // examine/roll-forward/restart

0N/A void examine_state_of_thread();

0N/A void roll_forward(suspend_type type);

0N/A void restart();

0N/A

0N/A // Query

0N/A JavaThread* thread() const { return _thread; }

0N/A suspend_type type() const { return _type; }

0N/A bool is_running() const { return (_type==_running); }

1647N/A JavaThreadState orig_thread_state() const { return _orig_thread_state; }

0N/A

0N/A // Support for safepoint timeout (debugging)

0N/A bool has_called_back() const { return _has_called_back; }

0N/A void set_has_called_back(bool val) { _has_called_back = val; }

0N/A bool is_at_poll_safepoint() { return _at_poll_safepoint; }

0N/A void set_at_poll_safepoint(bool val) { _at_poll_safepoint = val; }

0N/A

0N/A void handle_polling_page_exception();

0N/A

0N/A // debugging

0N/A void print_on(outputStream* st) const;

0N/A void print() const { print_on(tty); }

0N/A

0N/A // Initialize

0N/A static void create(JavaThread *thread);

0N/A static void destroy(JavaThread *thread);

0N/A

0N/A void safepoint_msg(const char* format, ...) {

0N/A if (ShowSafepointMsgs) {

0N/A va_list ap;

0N/A va_start(ap, format);

0N/A tty->vprint_cr(format, ap);

0N/A va_end(ap);

0N/A }

0N/A }

0N/A};

0N/A

1703N/A

1879N/A

1879N/A#endif // SHARE_VM_RUNTIME_SAFEPOINT_HPP