stan/jdk-24
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

8211176: Initialize ObjectMonitor eagerly

Browse Source 
Reviewed-by: dholmes, adinn, redestad
This commit is contained in:
Mikael Vidstedt 2018-09-28 14:11:21 -07:00
parent 7ef28cb2bc
commit f4b9613346
2 changed files with 14 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
src/hotspot/share/runtime/objectMonitor.cpp
View File

@ -110,7 +110,7 @@ static int Knob_Poverty = 1000;
static int Knob_FixedSpin = 0;
static int Knob_PreSpin = 10; // 20-100 likely better
static volatile int InitDone = 0;
DEBUG_ONLY(static volatile bool InitDone = false;)
// -----------------------------------------------------------------------------
// Theory of operations -- Monitors lists, thread residency, etc:
@ -428,7 +428,7 @@ void ObjectMonitor::EnterI(TRAPS) {
return;
}
DeferredInitialize();
assert(InitDone, "Unexpectedly not initialized");
// We try one round of spinning *before* enqueueing Self.
//
@ -1102,7 +1102,7 @@ intptr_t ObjectMonitor::complete_exit(TRAPS) {
assert(Self->is_Java_thread(), "Must be Java thread!");
JavaThread *jt = (JavaThread *)THREAD;
DeferredInitialize();
assert(InitDone, "Unexpectedly not initialized");
if (THREAD != _owner) {
if (THREAD->is_lock_owned ((address)_owner)) {
@ -1186,7 +1186,7 @@ void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
assert(Self->is_Java_thread(), "Must be Java thread!");
JavaThread *jt = (JavaThread *)THREAD;
DeferredInitialize();
assert(InitDone, "Unexpectedly not initialized");
// Throw IMSX or IEX.
CHECK_OWNER();
@ -1888,9 +1888,14 @@ PerfLongVariable * ObjectMonitor::_sync_MonExtant = NULL;
// be protected - like so many things - by the MonitorCache_lock.
void ObjectMonitor::Initialize() {
static int InitializationCompleted = 0;
assert(InitializationCompleted == 0, "invariant");
InitializationCompleted = 1;
assert(!InitDone, "invariant");
if (!os::is_MP()) {
Knob_SpinLimit = 0;
Knob_PreSpin = 0;
Knob_FixedSpin = -1;
}
if (UsePerfData) {
EXCEPTION_MARK;
#define NEWPERFCOUNTER(n) \
@ -1913,26 +1918,6 @@ void ObjectMonitor::Initialize() {
#undef NEWPERFCOUNTER
#undef NEWPERFVARIABLE
}
DEBUG_ONLY(InitDone = true;)
}
void ObjectMonitor::DeferredInitialize() {
if (InitDone > 0) return;
if (Atomic::cmpxchg (-1, &InitDone, 0) != 0) {
while (InitDone != 1) /* empty */;
return;
}
// One-shot global initialization ...
// The initialization is idempotent, so we don't need locks.
// In the future consider doing this via os::init_2().
if (!os::is_MP()) {
Knob_SpinLimit = 0;
Knob_PreSpin = 0;
Knob_FixedSpin = -1;
}
OrderAccess::fence();
InitDone = 1;
}

1
src/hotspot/share/runtime/objectMonitor.hpp
View File

@ -302,7 +302,6 @@ class ObjectMonitor {
private:
void AddWaiter(ObjectWaiter * waiter);
static void DeferredInitialize();
void INotify(Thread * Self);
ObjectWaiter * DequeueWaiter();
void DequeueSpecificWaiter(ObjectWaiter * waiter);