Author: j16sdiz
Date: 2008-05-04 13:12:16 +0000 (Sun, 04 May 2008)
New Revision: 19734
Modified:
branches/saltedhashstore/freenet/src/freenet/store/SaltedHashFreenetStore.java
Log:
proper locking
Modified:
branches/saltedhashstore/freenet/src/freenet/store/SaltedHashFreenetStore.java
===================================================================
---
branches/saltedhashstore/freenet/src/freenet/store/SaltedHashFreenetStore.java
2008-05-04 13:11:55 UTC (rev 19733)
+++
branches/saltedhashstore/freenet/src/freenet/store/SaltedHashFreenetStore.java
2008-05-04 13:12:16 UTC (rev 19734)
@@ -12,6 +12,8 @@
import java.nio.channels.FileChannel;
import java.text.DecimalFormat;
import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
import java.util.Random;
import freenet.crypt.Digest;
@@ -107,7 +109,10 @@
Entry entry;
long offset = getOffsetFromPlainKey(routingKey, probeStoreSize);
- lockEntry(offset);
+ if (!lockEntry(offset)) {
+ Logger.error(this, "can't lock entry: " + offset);
+ return null;
+ }
try {
entry = readEntry(offset, routingKey);
} catch (EOFException e) {
@@ -140,7 +145,11 @@
}
Entry entry = new Entry(routingKey, header, data);
- lockEntry(entry.getOffset());
+ if (!lockEntry(entry.getOffset())) {
+ Logger.error(this, "can't lock entry: " +
entry.getOffset());
+ incMisses();
+ return;
+ }
try {
writeEntry(entry);
incWrites();
@@ -399,6 +408,7 @@
storeRAF[i].setLength(entryTotalLength *
(storeSize / FILE_SPLIT + 1));
}
storeFC[i] = storeRAF[i].getChannel();
+ storeFC[i].lock();
}
}
@@ -581,6 +591,10 @@
}
// ------------- Locking
+ private boolean shutdown = false;
+ private boolean lockGlobal = false;
+ private Map lockMap = new HashMap();
+
/**
* Lock the entry // TODO locking
*
@@ -588,6 +602,29 @@
* then one lock at a time (or deadlock may occur).
*/
private boolean lockEntry(long offset) {
+ if (logDEBUG)
+ Logger.debug(this, "try locking " + offset, new
Exception());
+
+ Long lxr = new Long(offset);
+
+ try {
+ synchronized (lockMap) {
+ while (lockMap.containsKey(lxr) || lockGlobal)
{ // while someone hold the lock
+ if (shutdown)
+ return false;
+
+ lockMap.wait();
+ }
+
+ lockMap.put(lxr, Thread.currentThread());
+ }
+ } catch (InterruptedException e) {
+ Logger.error(this, "lock interrupted", e);
+ return false;
+ }
+
+ if (logDEBUG)
+ Logger.debug(this, "locked " + offset, new Exception());
return true;
}
@@ -595,8 +632,56 @@
* Unlock the entry // TODO locking
*/
private void unlockEntry(long offset) {
+ if (logDEBUG)
+ Logger.debug(this, "unlocking " + offset);
+ Long lxr = new Long(offset);
+
+ synchronized (lockMap) {
+ Object o = lockMap.remove(lxr);
+ assert o == Thread.currentThread();
+
+ lockMap.notifyAll();
+ }
}
+ /**
+ * Lock all entries.
+ *
+ * Use this method to stop all read / write before database shutdown.
+ *
+ * @param timeout
+ * the maximum time to wait in milliseconds.
+ */
+ private boolean lockGlobal(long timeout) {
+ synchronized (lockMap) {
+ try {
+ long startTime = System.currentTimeMillis();
+
+ while (!lockMap.isEmpty() || lockGlobal) {
+ lockMap.wait(timeout);
+
+ if (System.currentTimeMillis() -
startTime > timeout)
+ return false;
+ }
+
+ lockGlobal = true;
+ return true;
+ } catch (InterruptedException e) {
+ return false;
+ }
+ }
+ }
+
+ /**
+ * Unlock the global lock
+ */
+ private void unlockGlobal() {
+ synchronized (lockMap) {
+ lockGlobal = false;
+ lockMap.notifyAll();
+ }
+ }
+
// ------------- Hashing
/**
* <tt>0x10</tt> bytes of salt for better digestion, not too salty.
