Bug 510461 - Database.giveUpExclusiveLock is a severe bottleneck
Change-Id: I24f57186dea252309e7b199fdf67ff44cd55578a
diff --git a/org.eclipse.jdt.core/search/org/eclipse/jdt/internal/core/nd/db/Database.java b/org.eclipse.jdt.core/search/org/eclipse/jdt/internal/core/nd/db/Database.java
index 64c7da0..8847cc4 100644
--- a/org.eclipse.jdt.core/search/org/eclipse/jdt/internal/core/nd/db/Database.java
+++ b/org.eclipse.jdt.core/search/org/eclipse/jdt/internal/core/nd/db/Database.java
@@ -23,6 +23,8 @@
import java.nio.channels.ClosedChannelException;
import java.nio.channels.FileChannel;
import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.Iterator;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.OperationCanceledException;
@@ -109,6 +111,7 @@
public static final int WRITE_NUMBER_OFFSET = FREE_BLOCK_OFFSET + PTR_SIZE;
public static final int MALLOC_STATS_OFFSET = WRITE_NUMBER_OFFSET + LONG_SIZE;
public static final int DATA_AREA_OFFSET = MALLOC_STATS_OFFSET + MemoryStats.SIZE;
+ private static final int NUM_HEADER_CHUNKS = 1;
// Malloc pool IDs (used for classifying memory allocations and recording statistics about them)
/** Misc pool -- may be used for any purpose that doesn't fit the IDs below. */
@@ -132,7 +135,16 @@
private int fVersion;
private final Chunk fHeaderChunk;
+ /**
+ * Stores the {@link Chunk} associated with each page number or null if the chunk isn't loaded. Synchronize on
+ * {@link #fCache} before accessing.
+ */
private Chunk[] fChunks;
+
+ /**
+ * Holds all the non-null entries from {@link #fChunks}. Synchronize on {@link #fCache} before accessing.
+ */
+ private HashSet<Chunk> allocatedChunks = new HashSet<>();
private int fChunksUsed;
private ChunkCache fCache;
@@ -328,11 +340,12 @@
private void removeChunksFromCache() {
synchronized (this.fCache) {
- for (int i= 1; i < this.fChunks.length; i++) {
- Chunk chunk= this.fChunks[i];
- if (chunk != null) {
+ for (Iterator<Chunk> next = this.allocatedChunks.iterator(); next.hasNext();) {
+ Chunk chunk = next.next();
+ if (chunk.fSequenceNumber >= NUM_HEADER_CHUNKS) {
this.fCache.remove(chunk);
- this.fChunks[i]= null;
+ this.fChunks[chunk.fSequenceNumber] = null;
+ next.remove();
}
}
}
@@ -362,6 +375,7 @@
chunk = new Chunk(this, index);
chunk.read();
this.fChunks[index] = chunk;
+ this.allocatedChunks.add(chunk);
} else {
this.cacheHits++;
}
@@ -831,6 +845,7 @@
this.fChunksUsed = lastChunkIndex + 1;
this.fChunks[lastChunkIndex] = lastChunk;
+ this.allocatedChunks.add(lastChunk);
this.fCache.add(lastChunk, true);
long result = (long) firstChunkIndex * CHUNK_SIZE;
@@ -1182,6 +1197,7 @@
void releaseChunk(final Chunk chunk) {
if (!chunk.fLocked) {
this.fChunks[chunk.fSequenceNumber]= null;
+ this.allocatedChunks.remove(chunk);
}
}
@@ -1212,16 +1228,17 @@
try {
ArrayList<Chunk> dirtyChunks= new ArrayList<>();
synchronized (this.fCache) {
- for (int i= 1; i < this.fChunksUsed; i++) {
- Chunk chunk= this.fChunks[i];
- if (chunk != null) {
+ for (Iterator<Chunk> iter = this.allocatedChunks.iterator(); iter.hasNext();) {
+ Chunk chunk = iter.next();
+ if (chunk.fSequenceNumber >= NUM_HEADER_CHUNKS) {
if (chunk.fCacheIndex < 0) {
// Locked chunk that has been removed from cache.
if (chunk.fDirty) {
dirtyChunks.add(chunk); // Keep in fChunks until it is flushed.
} else {
chunk.fLocked= false;
- this.fChunks[i]= null;
+ this.fChunks[chunk.fSequenceNumber]= null;
+ iter.remove();
}
} else if (chunk.fLocked) {
// Locked chunk, still in cache.
@@ -1238,6 +1255,7 @@
}
}
}
+ sortBySequenceNumber(dirtyChunks);
// Also handles header chunk.
wasInterrupted = flushAndUnlockChunks(dirtyChunks, flush) || wasInterrupted;
} finally {
@@ -1247,6 +1265,10 @@
return wasInterrupted;
}
+ private void sortBySequenceNumber(ArrayList<Chunk> dirtyChunks) {
+ dirtyChunks.sort((a, b) -> {return a.fSequenceNumber - b.fSequenceNumber;});
+ }
+
public boolean flush() throws IndexException {
boolean wasInterrupted = false;
assert this.fLocked;
@@ -1262,14 +1284,15 @@
// Be careful as other readers may access chunks concurrently.
ArrayList<Chunk> dirtyChunks= new ArrayList<>();
synchronized (this.fCache) {
- for (int i= 1; i < this.fChunksUsed ; i++) {
- Chunk chunk= this.fChunks[i];
- if (chunk != null && chunk.fDirty) {
+ for (Chunk chunk : this.allocatedChunks) {
+ if (chunk.fSequenceNumber >= 1 && chunk.fDirty) {
dirtyChunks.add(chunk);
}
}
}
+ sortBySequenceNumber(dirtyChunks);
+
// Also handles header chunk.
return flushAndUnlockChunks(dirtyChunks, true) || wasInterrupted;
}
@@ -1301,6 +1324,7 @@
chunk.fLocked= false;
if (chunk.fCacheIndex < 0) {
this.fChunks[chunk.fSequenceNumber]= null;
+ this.allocatedChunks.remove(chunk);
}
}
}
