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Merge changes Ibb3467f7,I2af99903 

* changes:
  Always use try/finally around DfsBlockCache.clockLock
  DfsBlockCache: Fix NPE when evicting empty cell
This commit is contained in:
Robin Rosenberg 2011-11-10 02:07:04 -05:00 committed by Code Review
parent 45c714456b 9652f16a47
commit c0392381ee
1 changed files with 42 additions and 36 deletions
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78
org.eclipse.jgit/src/org/eclipse/jgit/storage/dfs/DfsBlockCache.java
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@ -206,7 +206,7 @@ else if (eb < 4)
blockSizeShift = Integer.numberOfTrailingZeros(blockSize);
clockLock = new ReentrantLock(true /* fair */);
clockHand = new Ref<Object>(null, -1, 0, null);
clockHand = new Ref<Object>(new DfsPackKey(), -1, 0, null);
clockHand.next = clockHand;
readAheadLimit = cfg.getReadAheadLimit();
@ -389,36 +389,39 @@ DfsBlock getOrLoad(DfsPackFile pack, long position, DfsReader ctx)
@SuppressWarnings("unchecked")
private void reserveSpace(int reserve) {
clockLock.lock();
long live = liveBytes + reserve;
if (maxBytes < live) {
Ref prev = clockHand;
Ref hand = clockHand.next;
do {
if (hand.hot) {
// Value was recently touched. Clear
// hot and give it another chance.
hand.hot = false;
prev = hand;
hand = hand.next;
continue;
} else if (prev == hand)
break;
try {
long live = liveBytes + reserve;
if (maxBytes < live) {
Ref prev = clockHand;
Ref hand = clockHand.next;
do {
if (hand.hot) {
// Value was recently touched. Clear
// hot and give it another chance.
hand.hot = false;
prev = hand;
hand = hand.next;
continue;
} else if (prev == hand)
break;
// No recent access since last scan, kill
// value and remove from clock.
Ref dead = hand;
hand = hand.next;
prev.next = hand;
dead.next = null;
dead.value = null;
live -= dead.size;
dead.pack.cachedSize.addAndGet(-dead.size);
statEvict++;
} while (maxBytes < live);
clockHand = prev;
// No recent access since last scan, kill
// value and remove from clock.
Ref dead = hand;
hand = hand.next;
prev.next = hand;
dead.next = null;
dead.value = null;
live -= dead.size;
dead.pack.cachedSize.addAndGet(-dead.size);
statEvict++;
} while (maxBytes < live);
clockHand = prev;
}
liveBytes = live;
} finally {
clockLock.unlock();
}
liveBytes = live;
clockLock.unlock();
}
private void creditSpace(int credit) {
@ -429,13 +432,16 @@ private void creditSpace(int credit) {
private void addToClock(Ref ref, int credit) {
clockLock.lock();
if (credit != 0)
liveBytes -= credit;
Ref ptr = clockHand;
ref.next = ptr.next;
ptr.next = ref;
clockHand = ref;
clockLock.unlock();
try {
if (credit != 0)
liveBytes -= credit;
Ref ptr = clockHand;
ref.next = ptr.next;
ptr.next = ref;
clockHand = ref;
} finally {
clockLock.unlock();
}
}
void put(DfsBlock v) {