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src/hotspot/share/runtime/objectMonitor.inline.hpp

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rev 59077 : 8153224.v2.09b.patch combined with 8153224.v2.10.patch; merge with jdk-15+21.
rev 59078 : eosterlund v2.10 CR: reorganize deflate_monitor_using_JT() to use "early exit" style; dcubed - clarify/fix/rearrange a few comments in deflate_monitor_using_JT(); eosterlund v2.10 CR: simplify install_displaced_markword_in_object() and save_om_ptr(); save_om_ptr()'s call to install_displaced_markword_in_object() can race with the deflater thread's clearing of the object field so handle that; fold 8153224.OMHandle_experiment into 8153224.v2.11.patch; merge with jdk-15+21.

*** 50,72 **** inline jint ObjectMonitor::waiters() const { return _waiters; } inline void* ObjectMonitor::owner() const { ! return _owner; } inline void ObjectMonitor::clear() { assert(Atomic::load(&_header).value() != 0, "must be non-zero"); ! 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()); _object = NULL; } inline void* ObjectMonitor::object() const { return _object; --- 50,108 ---- inline jint ObjectMonitor::waiters() const { return _waiters; } + // Returns NULL if DEFLATER_MARKER is observed. inline void* ObjectMonitor::owner() const { ! 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; ! } ! ! // Returns true if 'this' is being async deflated and false otherwise. ! inline bool ObjectMonitor::is_being_async_deflated() { ! return owner_is_DEFLATER_MARKER() && contentions() < 0; } 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)); ! ! 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 contentions ! // fields. While the ObjectMonitor being deflated is on the global free ! // list, we leave those three fields alone; owner == DEFLATER_MARKER ! // and contentions < 0 will force any racing threads to retry. The ! // header field is used by install_displaced_markword_in_object() ! // to restore the object's header so we cannot check its value here. ! guarantee(_owner == NULL || _owner == DEFLATER_MARKER, ! "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT, ! p2i(_owner)); ! } ! assert(contentions() <= 0, "must not be positive: 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"); ! set_allocation_state(Free); _object = NULL; } inline void* ObjectMonitor::object() const { return _object;
*** 78,120 **** inline void ObjectMonitor::set_object(void* obj) { _object = obj; } ! // return number of threads contending for this monitor inline jint ObjectMonitor::contentions() const { ! return _contentions; } // Clear _owner field; current value must match old_value. inline void ObjectMonitor::release_clear_owner(void* old_value) { ! DEBUG_ONLY(void* prev = Atomic::load(&_owner);) ! assert(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value)); Atomic::release_store(&_owner, (void*)NULL); log_trace(monitorinflation, owner)("release_clear_owner(): mid=" INTPTR_FORMAT ", old_value=" INTPTR_FORMAT, p2i(this), p2i(old_value)); } // Simply set _owner field to new_value; current value must match old_value. // (Simple means no memory sync needed.) inline void ObjectMonitor::set_owner_from(void* old_value, void* new_value) { ! DEBUG_ONLY(void* prev = Atomic::load(&_owner);) ! assert(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value)); Atomic::store(&_owner, new_value); log_trace(monitorinflation, owner)("set_owner_from(): mid=" INTPTR_FORMAT ", old_value=" INTPTR_FORMAT ", new_value=" INTPTR_FORMAT, p2i(this), p2i(old_value), p2i(new_value)); } // Simply set _owner field to self; current value must match basic_lock_p. inline void ObjectMonitor::set_owner_from_BasicLock(void* basic_lock_p, Thread* self) { ! DEBUG_ONLY(void* prev = Atomic::load(&_owner);) ! assert(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. Atomic::store(&_owner, self); log_trace(monitorinflation, owner)("set_owner_from_BasicLock(): mid=" --- 114,173 ---- inline void ObjectMonitor::set_object(void* obj) { _object = obj; } ! // Return number of threads contending for this monitor. inline jint ObjectMonitor::contentions() const { ! return Atomic::load(&_contentions); } // Clear _owner field; current value must match old_value. inline void ObjectMonitor::release_clear_owner(void* old_value) { ! void* prev = Atomic::load(&_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); log_trace(monitorinflation, owner)("release_clear_owner(): mid=" INTPTR_FORMAT ", old_value=" INTPTR_FORMAT, p2i(this), p2i(old_value)); } // Simply set _owner field to new_value; current value must match old_value. // (Simple means no memory sync needed.) inline void ObjectMonitor::set_owner_from(void* old_value, void* new_value) { ! void* prev = Atomic::load(&_owner); ! ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT ", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value)); Atomic::store(&_owner, new_value); log_trace(monitorinflation, owner)("set_owner_from(): mid=" INTPTR_FORMAT ", old_value=" INTPTR_FORMAT ", new_value=" INTPTR_FORMAT, p2i(this), p2i(old_value), 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::set_owner_from(void* old_value1, void* old_value2, void* new_value) { + void* prev = Atomic::load(&_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)("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::set_owner_from_BasicLock(void* basic_lock_p, Thread* self) { ! void* prev = Atomic::load(&_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. Atomic::store(&_owner, self); log_trace(monitorinflation, owner)("set_owner_from_BasicLock(): mid="
*** 135,144 **** --- 188,217 ---- 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; + } + // The _next_om field can be concurrently read and modified so we // use Atomic operations to disable compiler optimizations that // might try to elide loading and/or storing this field. inline ObjectMonitor* ObjectMonitor::next_om() const {
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