提交 079c91bf authored 作者: Noel Grandin's avatar Noel Grandin

fix concurrency issues in compressed FilePathNioMem

unfortunately I had to hit it with the big synchronization stick. I
could no simple way to rescue the current rather clever code.

This bug was reported by Anatolii K  in this message:
https://groups.google.com/d/msg/h2-database/rhSoRhzeZzk/gc-pNlSpEwAJ
上级 333a5027
......@@ -399,11 +399,13 @@ class FileNioMemData {
private static final int BLOCK_SIZE = 1 << BLOCK_SIZE_SHIFT;
private static final int BLOCK_SIZE_MASK = BLOCK_SIZE - 1;
private static final CompressLZF LZF = new CompressLZF();
private static final byte[] BUFFER = new byte[BLOCK_SIZE * 2];
private static final ByteBuffer COMPRESSED_EMPTY_BLOCK;
private static final CompressLaterCache<CompressItem, CompressItem> COMPRESS_LATER =
private final CompressLZF LZF = new CompressLZF();
/** the output buffer when compressing */
private final byte[] compressOutputBuffer = new byte[BLOCK_SIZE * 2];
private final CompressLaterCache<CompressItem, CompressItem> compressLaterCache =
new CompressLaterCache<CompressItem, CompressItem>(CACHE_SIZE);
private String name;
......@@ -417,10 +419,11 @@ class FileNioMemData {
private int sharedLockCount;
static {
byte[] n = new byte[BLOCK_SIZE];
int len = LZF.compress(n, BLOCK_SIZE, BUFFER, 0);
final byte[] n = new byte[BLOCK_SIZE];
final byte[] output = new byte[BLOCK_SIZE * 2];
int len = new CompressLZF().compress(n, BLOCK_SIZE, output, 0);
COMPRESSED_EMPTY_BLOCK = ByteBuffer.allocateDirect(len);
COMPRESSED_EMPTY_BLOCK.put(BUFFER, 0, len);
COMPRESSED_EMPTY_BLOCK.put(output, 0, len);
}
FileNioMemData(String name, boolean compress) {
......@@ -530,9 +533,7 @@ class FileNioMemData {
private void addToCompressLaterCache(int page) {
CompressItem c = new CompressItem(this, page);
synchronized (LZF) {
COMPRESS_LATER.put(c, c);
}
compressLaterCache.put(c, c);
}
private void expand(int page) {
......@@ -548,10 +549,8 @@ class FileNioMemData {
}
ByteBuffer out = ByteBuffer.allocateDirect(BLOCK_SIZE);
if (d != COMPRESSED_EMPTY_BLOCK) {
synchronized (LZF) {
d.position(0);
CompressLZF.expand(d, out);
}
d.position(0);
CompressLZF.expand(d, out);
}
list[page] = out;
}
......@@ -568,12 +567,10 @@ class FileNioMemData {
return;
}
ByteBuffer d = list[page];
synchronized (LZF) {
int len = LZF.compress(d, 0, BUFFER, 0);
d = ByteBuffer.allocateDirect(len);
d.put(BUFFER, 0, len);
list[page] = d;
}
int len = LZF.compress(d, 0, compressOutputBuffer, 0);
d = ByteBuffer.allocateDirect(len);
d.put(compressOutputBuffer, 0, len);
list[page] = d;
}
/**
......@@ -602,7 +599,7 @@ class FileNioMemData {
*
* @param newLength the new length
*/
void truncate(long newLength) {
synchronized void truncate(long newLength) {
changeLength(newLength);
long end = MathUtils.roundUpLong(newLength, BLOCK_SIZE);
if (end != newLength) {
......@@ -642,7 +639,7 @@ class FileNioMemData {
* @param write true for writing
* @return the new position
*/
long readWrite(long pos, ByteBuffer b, int off, int len, boolean write) {
synchronized long readWrite(long pos, ByteBuffer b, int off, int len, boolean write) {
long end = pos + len;
if (end > length) {
if (write) {
......
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