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8210513: Obsolete SyncFlags

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Reviewed-by: coleenp, dcubed, dholmes
This commit is contained in:
Mikael Vidstedt 2018-09-11 20:37:47 -07:00
parent 475d422094
commit 72797db95b
3 changed files with 8 additions and 30 deletions
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1
src/hotspot/share/runtime/arguments.cpp
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@ -576,6 +576,7 @@ static SpecialFlag const special_jvm_flags[] = {
{ "ErrorReportServer", JDK_Version::undefined(), JDK_Version::jdk(12), JDK_Version::jdk(13) },
{ "EmitSync", JDK_Version::undefined(), JDK_Version::jdk(12), JDK_Version::jdk(13) },
{ "SyncVerbose", JDK_Version::undefined(), JDK_Version::jdk(12), JDK_Version::jdk(13) },
{ "SyncFlags", JDK_Version::undefined(), JDK_Version::jdk(12), JDK_Version::jdk(13) },
#ifdef TEST_VERIFY_SPECIAL_JVM_FLAGS
{ "dep > obs", JDK_Version::jdk(9), JDK_Version::jdk(8), JDK_Version::undefined() },

3
src/hotspot/share/runtime/globals.hpp
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@ -841,9 +841,6 @@ define_pd_global(uint64_t,MaxRAM, 1ULL*G);
"The check is performed on GuaranteedSafepointInterval.") \
range(0, 100) \
\
experimental(intx, SyncFlags, 0, "(Unsafe, Unstable) " \
"Experimental Sync flags") \
\
experimental(intx, hashCode, 5, \
"(Unstable) select hashCode generation algorithm") \
\

34
src/hotspot/share/runtime/objectMonitor.cpp
View File

@ -529,7 +529,7 @@ void ObjectMonitor::EnterI(TRAPS) {
// timer scalability issues we see on some platforms as we'd only have one thread
// -- the checker -- parked on a timer.
if ((SyncFlags & 16) == 0 && nxt == NULL && _EntryList == NULL) {
if (nxt == NULL && _EntryList == NULL) {
// Try to assume the role of responsible thread for the monitor.
// CONSIDER: ST vs CAS vs { if (Responsible==null) Responsible=Self }
Atomic::replace_if_null(Self, &_Responsible);
@ -554,12 +554,8 @@ void ObjectMonitor::EnterI(TRAPS) {
if (TryLock(Self) > 0) break;
assert(_owner != Self, "invariant");
if ((SyncFlags & 2) && _Responsible == NULL) {
Atomic::replace_if_null(Self, &_Responsible);
}
// park self
if (_Responsible == Self || (SyncFlags & 1)) {
if (_Responsible == Self) {
Self->_ParkEvent->park((jlong) recheckInterval);
// Increase the recheckInterval, but clamp the value.
recheckInterval *= 8;
@ -672,9 +668,6 @@ void ObjectMonitor::EnterI(TRAPS) {
// monitorexit. Recall too, that in 1-0 mode monitorexit does not necessarily
// execute a serializing instruction.
if (SyncFlags & 8) {
OrderAccess::fence();
}
return;
}
@ -714,11 +707,7 @@ void ObjectMonitor::ReenterI(Thread * Self, ObjectWaiter * SelfNode) {
// cleared by handle_special_suspend_equivalent_condition()
// or java_suspend_self()
jt->set_suspend_equivalent();
if (SyncFlags & 1) {
Self->_ParkEvent->park((jlong)MAX_RECHECK_INTERVAL);
} else {
Self->_ParkEvent->park();
}
Self->_ParkEvent->park();
// were we externally suspended while we were waiting?
for (;;) {
@ -927,9 +916,7 @@ void ObjectMonitor::exit(bool not_suspended, TRAPS) {
// Invariant: after setting Responsible=null an thread must execute
// a MEMBAR or other serializing instruction before fetching EntryList|cxq.
if ((SyncFlags & 4) == 0) {
_Responsible = NULL;
}
_Responsible = NULL;
#if INCLUDE_JFR
// get the owner's thread id for the MonitorEnter event
@ -1445,9 +1432,8 @@ void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
AddWaiter(&node);
Thread::SpinRelease(&_WaitSetLock);
if ((SyncFlags & 4) == 0) {
_Responsible = NULL;
}
_Responsible = NULL;
intptr_t save = _recursions; // record the old recursion count
_waiters++; // increment the number of waiters
_recursions = 0; // set the recursion level to be 1
@ -1593,10 +1579,6 @@ void ObjectMonitor::wait(jlong millis, bool interruptible, TRAPS) {
assert(_succ != Self, "invariant");
assert(((oop)(object()))->mark() == markOopDesc::encode(this), "invariant");
if (SyncFlags & 32) {
OrderAccess::fence();
}
// check if the notification happened
if (!WasNotified) {
// no, it could be timeout or Thread.interrupt() or both
@ -1728,9 +1710,7 @@ void ObjectMonitor::INotify(Thread * Self) {
// Note: We can also detect many such problems with a "minimum wait".
// When the "minimum wait" is set to a small non-zero timeout value
// and the program does not hang whereas it did absent "minimum wait",
// that suggests a lost wakeup bug. The '-XX:SyncFlags=1' option uses
// a "minimum wait" for all park() operations; see the recheckInterval
// variable and MAX_RECHECK_INTERVAL.
// that suggests a lost wakeup bug.
void ObjectMonitor::notify(TRAPS) {
CHECK_OWNER();