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8246476: remove AsyncDeflateIdleMonitors option and the safepoint based deflation mechanism

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Reviewed-by: dholmes, pchilanomate, coleenp
This commit is contained in:
Daniel D. Daugherty 2020-07-13 16:36:01 -04:00
parent 231a8408b2
commit 7436ef236e
14 changed files with 144 additions and 630 deletions
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37
src/hotspot/share/runtime/objectMonitor.cpp
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@ -290,8 +290,6 @@ bool ObjectMonitor::enter(TRAPS) {
JavaThread * jt = (JavaThread *) Self;
assert(!SafepointSynchronize::is_at_safepoint(), "invariant");
assert(jt->thread_state() != _thread_blocked, "invariant");
assert(AsyncDeflateIdleMonitors || this->object() != NULL, "invariant");
assert(AsyncDeflateIdleMonitors || contentions() >= 0, "must not be negative: contentions=%d", contentions());
// Keep track of contention for JVM/TI and M&M queries.
add_to_contentions(1);
@ -455,12 +453,12 @@ void ObjectMonitor::install_displaced_markword_in_object(const oop obj) {
// deflation so we're done here.
return;
}
ADIM_guarantee(l_object == obj, "object=" INTPTR_FORMAT " must equal obj="
INTPTR_FORMAT, p2i(l_object), p2i(obj));
assert(l_object == obj, "object=" INTPTR_FORMAT " must equal obj="
INTPTR_FORMAT, p2i(l_object), p2i(obj));
markWord dmw = header();
// The dmw has to be neutral (not NULL, not locked and not marked).
ADIM_guarantee(dmw.is_neutral(), "must be neutral: dmw=" INTPTR_FORMAT, dmw.value());
assert(dmw.is_neutral(), "must be neutral: dmw=" INTPTR_FORMAT, dmw.value());
// Install displaced mark word if the object's header still points
// to this ObjectMonitor. More than one racing caller to this function
@ -487,22 +485,17 @@ void ObjectMonitor::install_displaced_markword_in_object(const oop obj) {
// used for diagnostic output.
const char* ObjectMonitor::is_busy_to_string(stringStream* ss) {
ss->print("is_busy: waiters=%d, ", _waiters);
if (!AsyncDeflateIdleMonitors) {
if (contentions() > 0) {
ss->print("contentions=%d, ", contentions());
} else {
ss->print("contentions=0");
}
if (_owner != DEFLATER_MARKER) {
ss->print("owner=" INTPTR_FORMAT, p2i(_owner));
} else {
if (contentions() > 0) {
ss->print("contentions=%d, ", contentions());
} else {
ss->print("contentions=0");
}
if (_owner != DEFLATER_MARKER) {
ss->print("owner=" INTPTR_FORMAT, p2i(_owner));
} else {
// We report NULL instead of DEFLATER_MARKER here because is_busy()
// ignores DEFLATER_MARKER values.
ss->print("owner=" INTPTR_FORMAT, NULL);
}
// We report NULL instead of DEFLATER_MARKER here because is_busy()
// ignores DEFLATER_MARKER values.
ss->print("owner=" INTPTR_FORMAT, NULL);
}
ss->print(", cxq=" INTPTR_FORMAT ", EntryList=" INTPTR_FORMAT, p2i(_cxq),
p2i(_EntryList));
@ -524,8 +517,7 @@ void ObjectMonitor::EnterI(TRAPS) {
return;
}
if (AsyncDeflateIdleMonitors &&
try_set_owner_from(DEFLATER_MARKER, Self) == DEFLATER_MARKER) {
if (try_set_owner_from(DEFLATER_MARKER, Self) == DEFLATER_MARKER) {
// Cancelled the in-progress async deflation by changing owner from
// DEFLATER_MARKER to Self. As part of the contended enter protocol,
// contentions was incremented to a positive value before EnterI()
@ -659,8 +651,7 @@ void ObjectMonitor::EnterI(TRAPS) {
if (TryLock(Self) > 0) break;
if (AsyncDeflateIdleMonitors &&
try_set_owner_from(DEFLATER_MARKER, Self) == DEFLATER_MARKER) {
if (try_set_owner_from(DEFLATER_MARKER, Self) == DEFLATER_MARKER) {
// Cancelled the in-progress async deflation by changing owner from
// DEFLATER_MARKER to Self. As part of the contended enter protocol,
// contentions was incremented to a positive value before EnterI()
@ -1007,8 +998,8 @@ void ObjectMonitor::exit(bool not_suspended, TRAPS) {
" is exiting an ObjectMonitor it does not own.", p2i(THREAD));
lsh.print_cr("The imbalance is possibly caused by JNI locking.");
print_debug_style_on(&lsh);
#endif
assert(false, "Non-balanced monitor enter/exit!");
#endif
return;
}
}