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7129164: JNI Get/ReleasePrimitiveArrayCritical doesn't scale

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Reviewed-by: kvn, iveresov, dholmes
This commit is contained in:
Tom Rodriguez 2012-01-29 16:46:04 -08:00
parent e27deedf24
commit 5721fa222a
6 changed files with 182 additions and 81 deletions
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22
hotspot/src/share/vm/runtime/safepoint.cpp
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@ -1,5 +1,5 @@
/*
* Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
* 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
@ -95,6 +95,7 @@
SafepointSynchronize::SynchronizeState volatile SafepointSynchronize::_state = SafepointSynchronize::_not_synchronized;
volatile int SafepointSynchronize::_waiting_to_block = 0;
volatile int SafepointSynchronize::_safepoint_counter = 0;
int SafepointSynchronize::_current_jni_active_count = 0;
long SafepointSynchronize::_end_of_last_safepoint = 0;
static volatile int PageArmed = 0 ; // safepoint polling page is RO|RW vs PROT_NONE
static volatile int TryingToBlock = 0 ; // proximate value -- for advisory use only
@ -138,6 +139,9 @@ void SafepointSynchronize::begin() {
{
MutexLocker mu(Safepoint_lock);
// Reset the count of active JNI critical threads
_current_jni_active_count = 0;
// Set number of threads to wait for, before we initiate the callbacks
_waiting_to_block = nof_threads;
TryingToBlock = 0 ;
@ -375,6 +379,9 @@ void SafepointSynchronize::begin() {
OrderAccess::fence();
// Update the count of active JNI critical regions
GC_locker::set_jni_lock_count(_current_jni_active_count);
if (TraceSafepoint) {
VM_Operation *op = VMThread::vm_operation();
tty->print_cr("Entering safepoint region: %s", (op != NULL) ? op->name() : "no vm operation");
@ -585,6 +592,11 @@ void SafepointSynchronize::block(JavaThread *thread) {
_waiting_to_block--;
thread->safepoint_state()->set_has_called_back(true);
if (thread->in_critical()) {
// Notice that this thread is in a critical section
increment_jni_active_count();
}
// Consider (_waiting_to_block < 2) to pipeline the wakeup of the VM thread
if (_waiting_to_block == 0) {
Safepoint_lock->notify_all();
@ -861,8 +873,12 @@ void ThreadSafepointState::examine_state_of_thread() {
// running, but are actually at a safepoint. We will happily
// agree and update the safepoint state here.
if (SafepointSynchronize::safepoint_safe(_thread, state)) {
roll_forward(_at_safepoint);
return;
roll_forward(_at_safepoint);
if (_thread->in_critical()) {
// Notice that this thread is in a critical section
SafepointSynchronize::increment_jni_active_count();
}
return;
}
if (state == _thread_in_vm) {