< prev index next >
src/share/vm/runtime/safepoint.cpp
Print this page
@@ -30,10 +30,11 @@
#include "code/nmethod.hpp"
#include "code/pcDesc.hpp"
#include "code/scopeDesc.hpp"
#include "gc_interface/collectedHeap.hpp"
#include "interpreter/interpreter.hpp"
+#include "jfr/jfrEvents.hpp"
#include "memory/resourceArea.hpp"
#include "memory/universe.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "runtime/compilationPolicy.hpp"
@@ -81,10 +82,77 @@
#include "c1/c1_globals.hpp"
#endif
PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
+template <typename E>
+static void set_current_safepoint_id(E* event, int adjustment = 0) {
+ assert(event != NULL, "invariant");
+ event->set_safepointId(SafepointSynchronize::safepoint_counter() + adjustment);
+}
+
+static void post_safepoint_begin_event(EventSafepointBegin* event,
+ int thread_count,
+ int critical_thread_count) {
+ assert(event != NULL, "invariant");
+ assert(event->should_commit(), "invariant");
+ set_current_safepoint_id(event);
+ event->set_totalThreadCount(thread_count);
+ event->set_jniCriticalThreadCount(critical_thread_count);
+ event->commit();
+}
+
+static void post_safepoint_cleanup_event(EventSafepointCleanup* event) {
+ assert(event != NULL, "invariant");
+ assert(event->should_commit(), "invariant");
+ set_current_safepoint_id(event);
+ event->commit();
+}
+
+static void post_safepoint_synchronize_event(EventSafepointStateSynchronization* event,
+ int initial_number_of_threads,
+ int threads_waiting_to_block,
+ unsigned int iterations) {
+ assert(event != NULL, "invariant");
+ if (event->should_commit()) {
+ // Group this event together with the ones committed after the counter is increased
+ set_current_safepoint_id(event, 1);
+ event->set_initialThreadCount(initial_number_of_threads);
+ event->set_runningThreadCount(threads_waiting_to_block);
+ event->set_iterations(iterations);
+ event->commit();
+ }
+}
+
+static void post_safepoint_wait_blocked_event(EventSafepointWaitBlocked* event,
+ int initial_threads_waiting_to_block) {
+ assert(event != NULL, "invariant");
+ assert(event->should_commit(), "invariant");
+ set_current_safepoint_id(event);
+ event->set_runningThreadCount(initial_threads_waiting_to_block);
+ event->commit();
+}
+
+static void post_safepoint_cleanup_task_event(EventSafepointCleanupTask* event,
+ const char* name) {
+ assert(event != NULL, "invariant");
+ if (event->should_commit()) {
+ set_current_safepoint_id(event);
+ event->set_name(name);
+ event->commit();
+ }
+}
+
+static void post_safepoint_end_event(EventSafepointEnd* event) {
+ assert(event != NULL, "invariant");
+ if (event->should_commit()) {
+ // Group this event together with the ones committed before the counter increased
+ set_current_safepoint_id(event, -1);
+ event->commit();
+ }
+}
+
// --------------------------------------------------------------------------------------------------
// Implementation of Safepoint begin/end
SafepointSynchronize::SynchronizeState volatile SafepointSynchronize::_state = SafepointSynchronize::_not_synchronized;
volatile int SafepointSynchronize::_waiting_to_block = 0;
@@ -95,11 +163,11 @@
static volatile int TryingToBlock = 0 ; // proximate value -- for advisory use only
static bool timeout_error_printed = false;
// Roll all threads forward to a safepoint and suspend them all
void SafepointSynchronize::begin() {
-
+ EventSafepointBegin begin_event;
Thread* myThread = Thread::current();
assert(myThread->is_VM_thread(), "Only VM thread may execute a safepoint");
if (PrintSafepointStatistics || PrintSafepointStatisticsTimeout > 0) {
_safepoint_begin_time = os::javaTimeNanos();
@@ -187,10 +255,13 @@
// 5. In VM or Transitioning between states
// If a Java thread is currently running in the VM or transitioning
// between states, the safepointing code will wait for the thread to
// block itself when it attempts transitions to a new state.
//
+ EventSafepointStateSynchronization sync_event;
+ int initial_running = 0;
+
_state = _synchronizing;
OrderAccess::fence();
// Flush all thread states to memory
if (!UseMembar) {
@@ -241,13 +312,16 @@
}
if (TraceSafepoint && Verbose) cur_state->print();
}
}
- if (PrintSafepointStatistics && iterations == 0) {
+ if (iterations == 0) {
+ initial_running = still_running;
+ if (PrintSafepointStatistics) {
begin_statistics(nof_threads, still_running);
}
+ }
if (still_running > 0) {
// Check for if it takes to long
if (SafepointTimeout && safepoint_limit_time < os::javaTimeNanos()) {
print_safepoint_timeout(_spinning_timeout);
@@ -334,11 +408,19 @@
if (PrintSafepointStatistics) {
update_statistics_on_spin_end();
}
+ if (sync_event.should_commit()) {
+ post_safepoint_synchronize_event(&sync_event, initial_running, _waiting_to_block, iterations);
+ }
+
// wait until all threads are stopped
+ {
+ EventSafepointWaitBlocked wait_blocked_event;
+ int initial_waiting_to_block = _waiting_to_block;
+
while (_waiting_to_block > 0) {
if (TraceSafepoint) tty->print_cr("Waiting for %d thread(s) to block", _waiting_to_block);
if (!SafepointTimeout || timeout_error_printed) {
Safepoint_lock->wait(true); // true, means with no safepoint checks
} else {
@@ -372,10 +454,15 @@
// Record state
_state = _synchronized;
OrderAccess::fence();
+ if (wait_blocked_event.should_commit()) {
+ post_safepoint_wait_blocked_event(&wait_blocked_event, initial_waiting_to_block);
+ }
+ }
+
#ifdef ASSERT
for (JavaThread *cur = Threads::first(); cur != NULL; cur = cur->next()) {
// make sure all the threads were visited
assert(cur->was_visited_for_critical_count(), "missed a thread");
}
@@ -393,24 +480,35 @@
if (PrintSafepointStatistics) {
update_statistics_on_sync_end(os::javaTimeNanos());
}
// Call stuff that needs to be run when a safepoint is just about to be completed
+ {
+ EventSafepointCleanup cleanup_event;
do_cleanup_tasks();
+ if (cleanup_event.should_commit()) {
+ post_safepoint_cleanup_event(&cleanup_event);
+ }
+ }
if (PrintSafepointStatistics) {
// Record how much time spend on the above cleanup tasks
update_statistics_on_cleanup_end(os::javaTimeNanos());
}
+
+ if (begin_event.should_commit()) {
+ post_safepoint_begin_event(&begin_event, nof_threads, _current_jni_active_count);
+ }
}
// Wake up all threads, so they are ready to resume execution after the safepoint
// operation has been carried out
void SafepointSynchronize::end() {
assert(Threads_lock->owned_by_self(), "must hold Threads_lock");
assert((_safepoint_counter & 0x1) == 1, "must be odd");
+ EventSafepointEnd event;
_safepoint_counter ++;
// memory fence isn't required here since an odd _safepoint_counter
// value can do no harm and a fence is issued below anyway.
DEBUG_ONLY(Thread* myThread = Thread::current();)
@@ -492,10 +590,13 @@
}
#endif // INCLUDE_ALL_GCS
// record this time so VMThread can keep track how much time has elasped
// since last safepoint.
_end_of_last_safepoint = os::javaTimeMillis();
+ if (event.should_commit()) {
+ post_safepoint_end_event(&event);
+ }
}
bool SafepointSynchronize::is_cleanup_needed() {
// Need a safepoint if some inline cache buffers is non-empty
if (!InlineCacheBuffer::is_empty()) return true;
@@ -505,36 +606,66 @@
// Various cleaning tasks that should be done periodically at safepoints
void SafepointSynchronize::do_cleanup_tasks() {
{
- TraceTime t1("deflating idle monitors", TraceSafepointCleanupTime);
+ const char* name = "deflating idle monitors";
+ EventSafepointCleanupTask event;
+ TraceTime t1(name, TraceSafepointCleanupTime);
ObjectSynchronizer::deflate_idle_monitors();
+ if (event.should_commit()) {
+ post_safepoint_cleanup_task_event(&event, name);
+ }
}
{
- TraceTime t2("updating inline caches", TraceSafepointCleanupTime);
+ const char* name = "updating inline caches";
+ EventSafepointCleanupTask event;
+ TraceTime t2(name, TraceSafepointCleanupTime);
InlineCacheBuffer::update_inline_caches();
+ if (event.should_commit()) {
+ post_safepoint_cleanup_task_event(&event, name);
+ }
}
{
- TraceTime t3("compilation policy safepoint handler", TraceSafepointCleanupTime);
+ const char* name = "compilation policy safepoint handler";
+ EventSafepointCleanupTask event;
+ TraceTime t3(name, TraceSafepointCleanupTime);
CompilationPolicy::policy()->do_safepoint_work();
+ if (event.should_commit()) {
+ post_safepoint_cleanup_task_event(&event, name);
+ }
}
{
- TraceTime t4("mark nmethods", TraceSafepointCleanupTime);
+ const char* name = "mark nmethods";
+ EventSafepointCleanupTask event;
+ TraceTime t4(name, TraceSafepointCleanupTime);
NMethodSweeper::mark_active_nmethods();
+ if (event.should_commit()) {
+ post_safepoint_cleanup_task_event(&event, name);
+ }
}
if (SymbolTable::needs_rehashing()) {
- TraceTime t5("rehashing symbol table", TraceSafepointCleanupTime);
+ const char* name = "rehashing symbol table";
+ EventSafepointCleanupTask event;
+ TraceTime t5(name, TraceSafepointCleanupTime);
SymbolTable::rehash_table();
+ if (event.should_commit()) {
+ post_safepoint_cleanup_task_event(&event, name);
+ }
}
if (StringTable::needs_rehashing()) {
- TraceTime t6("rehashing string table", TraceSafepointCleanupTime);
+ const char* name = "rehashing string table";
+ EventSafepointCleanupTask event;
+ TraceTime t6(name, TraceSafepointCleanupTime);
StringTable::rehash_table();
+ if (event.should_commit()) {
+ post_safepoint_cleanup_task_event(&event, name);
+ }
}
// rotate log files?
if (UseGCLogFileRotation) {
gclog_or_tty->rotate_log(false);
< prev index next >