@NoInline
@NoNullCheck
@Unpreemptible
public static void unlock(Object o, Offset lockOffset) {
Word threadId = Word.fromIntZeroExtend(RVMThread.getCurrentThread().getLockingId());
for (int cnt = 0; ; cnt++) {
Word old = Magic.getWordAtOffset(o, lockOffset);
Word stat = old.and(TL_STAT_MASK);
if (stat.EQ(TL_STAT_BIASABLE)) {
Word id = old.and(TL_THREAD_ID_MASK);
if (id.EQ(threadId)) {
if (old.and(TL_LOCK_COUNT_MASK).isZero()) {
RVMThread.raiseIllegalMonitorStateException(
"biased unlocking: we own this object but the count is already zero", o);
}
setDedicatedU16(o, lockOffset, old.minus(TL_LOCK_COUNT_UNIT));
return;
} else {
RVMThread.raiseIllegalMonitorStateException(
"biased unlocking: we don't own this object", o);
}
} else if (stat.EQ(TL_STAT_THIN)) {
Magic.sync();
Word id = old.and(TL_THREAD_ID_MASK);
if (id.EQ(threadId)) {
Word changed;
if (old.and(TL_LOCK_COUNT_MASK).isZero()) {
changed = old.and(TL_UNLOCK_MASK).or(TL_STAT_THIN);
} else {
changed = old.minus(TL_LOCK_COUNT_UNIT);
}
if (Synchronization.tryCompareAndSwap(o, lockOffset, old, changed)) {
return;
}
} else {
if (false) {
VM.sysWriteln("threadId = ", threadId);
VM.sysWriteln("id = ", id);
}
RVMThread.raiseIllegalMonitorStateException(
"thin unlocking: we don't own this object", o);
}
} else {
if (VM.VerifyAssertions) VM._assert(stat.EQ(TL_STAT_FAT));
// fat unlock
Lock.getLock(getLockIndex(old)).unlockHeavy(o);
return;
}
}
}
/**
* Prepare for a new collection increment. For the mark-sweep collector we must flip the state of
* the mark bit between collections.
*/
public void prepare(boolean fullHeap) {
if (fullHeap) {
if (VM.VERIFY_ASSERTIONS) {
VM.assertions._assert(treadmill.fromSpaceEmpty());
}
markState = MARK_BIT.minus(markState);
}
treadmill.flip(fullHeap);
inNurseryGC = !fullHeap;
}
@Inline
@NoNullCheck
@Unpreemptible
public static void inlineUnlockHelper(Object o, Offset lockOffset) {
Word old = Magic.prepareWord(o, lockOffset); // FIXME: bad for PPC?
Word id = old.and(TL_THREAD_ID_MASK.or(TL_STAT_MASK));
Word tid = Word.fromIntSignExtend(RVMThread.getCurrentThread().getLockingId());
if (id.EQ(tid)) {
if (!old.and(TL_LOCK_COUNT_MASK).isZero()) {
setDedicatedU16(o, lockOffset, old.minus(TL_LOCK_COUNT_UNIT));
return;
}
} else if (old.xor(tid).rshl(TL_LOCK_COUNT_SHIFT).EQ(TL_STAT_THIN.rshl(TL_LOCK_COUNT_SHIFT))) {
Magic.sync();
if (Magic.attemptWord(o, lockOffset, old, old.and(TL_UNLOCK_MASK).or(TL_STAT_THIN))) {
return;
}
}
unlock(o, lockOffset);
}
