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8270894: Use acquire semantics in ObjectSynchronizer::read_stable_mark()

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Reviewed-by: dholmes
This commit is contained in:
Roman Kennke 2021-07-23 10:42:00 +00:00
parent ea182b5c6e
commit f22619032d
3 changed files with 11 additions and 5 deletions
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10
src/hotspot/share/runtime/synchronizer.cpp
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@ -681,14 +681,14 @@ struct SharedGlobals {
static SharedGlobals GVars;
static markWord read_stable_mark(oop obj) {
markWord mark = obj->mark();
markWord mark = obj->mark_acquire();
if (!mark.is_being_inflated()) {
return mark; // normal fast-path return
}
int its = 0;
for (;;) {
markWord mark = obj->mark();
markWord mark = obj->mark_acquire();
if (!mark.is_being_inflated()) {
return mark; // normal fast-path return
}
@ -722,7 +722,7 @@ static markWord read_stable_mark(oop obj) {
int YieldThenBlock = 0;
assert(ix >= 0 && ix < NINFLATIONLOCKS, "invariant");
gInflationLocks[ix]->lock();
while (obj->mark() == markWord::INFLATING()) {
while (obj->mark_acquire() == markWord::INFLATING()) {
// Beware: naked_yield() is advisory and has almost no effect on some platforms
// so we periodically call current->_ParkEvent->park(1).
// We use a mixed spin/yield/block mechanism.
@ -1102,7 +1102,7 @@ static void post_monitor_inflate_event(EventJavaMonitorInflate* event,
// Fast path code shared by multiple functions
void ObjectSynchronizer::inflate_helper(oop obj) {
markWord mark = obj->mark();
markWord mark = obj->mark_acquire();
if (mark.has_monitor()) {
ObjectMonitor* monitor = mark.monitor();
markWord dmw = monitor->header();
@ -1117,7 +1117,7 @@ ObjectMonitor* ObjectSynchronizer::inflate(Thread* current, oop object,
EventJavaMonitorInflate event;
for (;;) {
const markWord mark = object->mark();
const markWord mark = object->mark_acquire();
// The mark can be in one of the following states:
// * Inflated - just return