241 lock->set_displaced_header(markWord::unused_mark());
242
243 if (owner == NULL && Atomic::replace_if_null(Self, &(m->_owner))) {
244 assert(m->_recursions == 0, "invariant");
245 return true;
246 }
247 }
248
249 // Note that we could inflate in quick_enter.
250 // This is likely a useful optimization
251 // Critically, in quick_enter() we must not:
252 // -- perform bias revocation, or
253 // -- block indefinitely, or
254 // -- reach a safepoint
255
256 return false; // revert to slow-path
257 }
258
259 // -----------------------------------------------------------------------------
260 // Monitor Enter/Exit
261 // The interpreter and compiler use some assembly copies of this code. Make sure
262 // update those code if the following function is changed. The implementation
263 // is extremely sensitive to race condition. Be careful.
264
265 void ObjectSynchronizer::enter(Handle obj, BasicLock* lock, TRAPS) {
266 if (UseBiasedLocking) {
267 if (!SafepointSynchronize::is_at_safepoint()) {
268 BiasedLocking::revoke(obj, THREAD);
269 } else {
270 BiasedLocking::revoke_at_safepoint(obj);
271 }
272 }
273
274 markWord mark = obj->mark();
275 assert(!mark.has_bias_pattern(), "should not see bias pattern here");
276
277 if (mark.is_neutral()) {
278 // Anticipate successful CAS -- the ST of the displaced mark must
279 // be visible <= the ST performed by the CAS.
280 lock->set_displaced_header(mark);
281 if (mark == obj()->cas_set_mark(markWord::from_pointer(lock), mark)) {
282 return;
283 }
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241 lock->set_displaced_header(markWord::unused_mark());
242
243 if (owner == NULL && Atomic::replace_if_null(Self, &(m->_owner))) {
244 assert(m->_recursions == 0, "invariant");
245 return true;
246 }
247 }
248
249 // Note that we could inflate in quick_enter.
250 // This is likely a useful optimization
251 // Critically, in quick_enter() we must not:
252 // -- perform bias revocation, or
253 // -- block indefinitely, or
254 // -- reach a safepoint
255
256 return false; // revert to slow-path
257 }
258
259 // -----------------------------------------------------------------------------
260 // Monitor Enter/Exit
261 // The interpreter and compiler assembly code tries to lock using the fast path
262 // of this algorithm. Make sure to update that code if the following function is
263 // changed. The implementation is extremely sensitive to race condition. Be careful.
264
265 void ObjectSynchronizer::enter(Handle obj, BasicLock* lock, TRAPS) {
266 if (UseBiasedLocking) {
267 if (!SafepointSynchronize::is_at_safepoint()) {
268 BiasedLocking::revoke(obj, THREAD);
269 } else {
270 BiasedLocking::revoke_at_safepoint(obj);
271 }
272 }
273
274 markWord mark = obj->mark();
275 assert(!mark.has_bias_pattern(), "should not see bias pattern here");
276
277 if (mark.is_neutral()) {
278 // Anticipate successful CAS -- the ST of the displaced mark must
279 // be visible <= the ST performed by the CAS.
280 lock->set_displaced_header(mark);
281 if (mark == obj()->cas_set_mark(markWord::from_pointer(lock), mark)) {
282 return;
283 }
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