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src/hotspot/share/runtime/objectMonitor.inline.hpp
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rev 57232 : v2.00 -> v2.08 (CR8/v2.08/11-for-jdk14) patches combined into one; merge with jdk-14+25 snapshot; merge with jdk-14+26 snapshot.
rev 57233 : See CR8-to-CR9-changes; merge with 8230876.patch (2019.11.15); merge with jdk-14+25 snapshot; fuzzy merge with jdk-14+26 snapshot.
@@ -23,10 +23,11 @@
*/
#ifndef SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP
#define SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP
+#include "logging/log.hpp"
#include "runtime/atomic.hpp"
inline intptr_t ObjectMonitor::is_entered(TRAPS) const {
if (THREAD == _owner || THREAD->is_lock_owned((address) _owner)) {
return 1;
@@ -49,23 +50,61 @@
inline jint ObjectMonitor::waiters() const {
return _waiters;
}
+// Returns NULL if DEFLATER_MARKER is observed.
inline void* ObjectMonitor::owner() const {
- return _owner;
+ void* owner = _owner;
+ return owner != DEFLATER_MARKER ? owner : NULL;
+}
+
+// Returns true if owner field == DEFLATER_MARKER and false otherwise.
+// This accessor is called when we really need to know if the owner
+// field == DEFLATER_MARKER and any non-NULL value won't do the trick.
+inline bool ObjectMonitor::owner_is_DEFLATER_MARKER() {
+ return _owner == DEFLATER_MARKER;
}
inline void ObjectMonitor::clear() {
assert(Atomic::load(&_header).value() != 0, "must be non-zero");
+ assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
+#ifdef ASSERT
+ jint l_ref_count = ref_count();
+#endif
+ assert(l_ref_count == 0, "must be 0: l_ref_count=%d, ref_count=%d", l_ref_count, ref_count());
+
+ Atomic::store(&_header, markWord::zero());
+
+ clear_using_JT();
+}
+
+inline void ObjectMonitor::clear_using_JT() {
+ // Unlike other *_using_JT() functions, we cannot assert
+ // AsyncDeflateIdleMonitors or Thread::current()->is_Java_thread()
+ // because clear() calls this function for the rest of its checks.
+
+ if (AsyncDeflateIdleMonitors) {
+ // Async deflation protocol uses the header, owner and ref_count
+ // fields. While the ObjectMonitor being deflated is on the global free
+ // list, we leave those three fields alone; owner == DEFLATER_MARKER
+ // and ref_count < 0 will force any racing threads to retry. The
+ // header field is used by install_displaced_markword_in_object()
+ // in the last part of the deflation protocol so we cannot check
+ // its value here.
+ guarantee(_owner == NULL || _owner == DEFLATER_MARKER,
+ "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT,
+ p2i(_owner));
+ jint l_ref_count = ref_count();
+ guarantee(l_ref_count <= 0, "must be <= 0: l_ref_count=%d, ref_count=%d", l_ref_count, ref_count());
+ }
assert(_contentions == 0, "must be 0: contentions=%d", _contentions);
assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
assert(_recursions == 0, "must be 0: recursions=" INTX_FORMAT, _recursions);
assert(_object != NULL, "must be non-NULL");
- assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
- Atomic::store(&_header, markWord::zero());
+ set_allocation_state(Free);
_object = NULL;
}
inline void* ObjectMonitor::object() const {
return _object;
@@ -82,10 +121,124 @@
// return number of threads contending for this monitor
inline jint ObjectMonitor::contentions() const {
return _contentions;
}
-inline void ObjectMonitor::set_owner(void* owner) {
- _owner = owner;
+// Clear _owner field; current value must match old_value.
+// If needs_fence is true, we issue a fence() after the release_store().
+// Otherwise, a storeload() is good enough. See the callers for more info.
+inline void ObjectMonitor::release_clear_owner_with_barrier(void* old_value,
+ bool needs_fence) {
+ void* prev = _owner;
+ ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
+ ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
+ Atomic::release_store(&_owner, (void*)NULL);
+ if (needs_fence) {
+ OrderAccess::fence();
+ } else {
+ OrderAccess::storeload();
+ }
+ log_trace(monitorinflation, owner)("release_clear_owner_with_barrier(): mid="
+ INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+ ", needs_fence=%d", p2i(this), p2i(prev),
+ needs_fence);
+}
+
+// Simply set _owner field to new_value; current value must match old_value.
+// (Simple means no memory sync needed.)
+inline void ObjectMonitor::simply_set_owner_from(void* new_value, void* old_value) {
+ void* prev = _owner;
+ ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
+ ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
+ _owner = new_value;
+ log_trace(monitorinflation, owner)("simply_set_owner_from(): mid="
+ INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+ ", new=" INTPTR_FORMAT, p2i(this),
+ p2i(prev), p2i(new_value));
+}
+
+// Simply set _owner field to new_value; current value must match old_value1 or old_value2.
+// (Simple means no memory sync needed.)
+inline void ObjectMonitor::simply_set_owner_from(void* new_value, void* old_value1, void* old_value2) {
+ void* prev = _owner;
+ ADIM_guarantee(prev == old_value1 || prev == old_value2,
+ "unexpected prev owner=" INTPTR_FORMAT ", expected1="
+ INTPTR_FORMAT " or expected2=" INTPTR_FORMAT, p2i(prev),
+ p2i(old_value1), p2i(old_value2));
+ _owner = new_value;
+ log_trace(monitorinflation, owner)("simply_set_owner_from(old1=" INTPTR_FORMAT
+ ", old2=" INTPTR_FORMAT "): mid="
+ INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+ ", new=" INTPTR_FORMAT, p2i(old_value1),
+ p2i(old_value2), p2i(this), p2i(prev),
+ p2i(new_value));
+}
+
+// Simply set _owner field to self; current value must match basic_lock_p.
+inline void ObjectMonitor::simply_set_owner_from_BasicLock(Thread* self, void* basic_lock_p) {
+ void* prev = _owner;
+ ADIM_guarantee(prev == basic_lock_p, "unexpected prev owner=" INTPTR_FORMAT
+ ", expected=" INTPTR_FORMAT, p2i(prev), p2i(basic_lock_p));
+ // Non-null owner field to non-null owner field is safe without
+ // cmpxchg() as long as all readers can tolerate either flavor.
+ _owner = self;
+ log_trace(monitorinflation, owner)("simply_set_owner_from_BasicLock(): mid="
+ INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+ ", new=" INTPTR_FORMAT ", basic_lock_p="
+ INTPTR_FORMAT, p2i(this), p2i(prev),
+ p2i(self), p2i(basic_lock_p));
+}
+
+// Try to set _owner field to new_value if the current value matches
+// old_value. Otherwise, does not change the _owner field.
+inline void* ObjectMonitor::try_set_owner_from(void* new_value, void* old_value) {
+ void* prev = Atomic::cmpxchg(&_owner, old_value, new_value);
+ if (prev == old_value) {
+ log_trace(monitorinflation, owner)("try_set_owner_from(): mid="
+ INTPTR_FORMAT ", prev=" INTPTR_FORMAT
+ ", new=" INTPTR_FORMAT, p2i(this),
+ p2i(prev), p2i(new_value));
+ }
+ return prev;
+}
+
+inline void ObjectMonitor::set_allocation_state(ObjectMonitor::AllocationState s) {
+ _allocation_state = s;
+}
+
+inline ObjectMonitor::AllocationState ObjectMonitor::allocation_state() const {
+ return _allocation_state;
+}
+
+inline bool ObjectMonitor::is_free() const {
+ return _allocation_state == Free;
+}
+
+inline bool ObjectMonitor::is_old() const {
+ return _allocation_state == Old;
+}
+
+inline bool ObjectMonitor::is_new() const {
+ return _allocation_state == New;
+}
+
+inline void ObjectMonitor::dec_ref_count() {
+ Atomic::dec(&_ref_count);
+ // Can be negative as part of async deflation protocol.
+ jint l_ref_count = ref_count();
+ ADIM_guarantee(AsyncDeflateIdleMonitors || l_ref_count >= 0,
+ "sanity check: l_ref_count=%d, ref_count=%d", l_ref_count, ref_count());
+}
+
+inline void ObjectMonitor::inc_ref_count() {
+ Atomic::inc(&_ref_count);
+ // Can be negative as part of async deflation protocol.
+ jint l_ref_count = ref_count();
+ ADIM_guarantee(AsyncDeflateIdleMonitors || l_ref_count > 0,
+ "sanity check: l_ref_count=%d, ref_count=%d", l_ref_count, ref_count());
+}
+
+inline jint ObjectMonitor::ref_count() const {
+ return Atomic::load(&_ref_count);
}
#endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP
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