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Issue #2056: Update FileLocker to handle release of ACQUIRING locks

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Change-Id: Id1e0f60390775c4143dbbf25070d2efb9ffe2b23

Former-commit-id: 163998df17 [formerly e63f2de395 [formerly 9097197872da18fded96e09d133132872d4dcc27]]
Former-commit-id: e63f2de395
Former-commit-id: c15635bccc
This commit is contained in:
Richard Peter 2013-05-30 17:50:47 -05:00
parent c3e9110e32
commit ba4d97a349
1 changed files with 38 additions and 27 deletions
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65
edexOsgi/com.raytheon.uf.common.localization/src/com/raytheon/uf/common/localization/FileLocker.java
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@ -51,6 +51,7 @@ import com.raytheon.uf.common.status.UFStatus.Priority;
* ------------ ---------- ----------- --------------------------
* Jun 23, 2011 mschenke Initial creation
* Apr 12, 2013 1903 rjpeter Fix allocateLock freezing out other lock requests.
* May 30, 2013 2056 rjpeter Allow ACQUIRING state to be released.
* </pre>
*
* @author mschenke
@ -73,6 +74,8 @@ public class FileLocker {
final List<Object> lockers = new ArrayList<Object>();
long lockTime = System.currentTimeMillis();
File lockFile;
LockState lockState = LockState.ACQUIRING;
@ -210,6 +213,7 @@ public class FileLocker {
// TODO: This is not safe as another thread could have a
// read lock and we may clobber the read
lock.lockers.add(locker);
lock.lockTime = System.currentTimeMillis();
return true;
}
}
@ -265,30 +269,24 @@ public class FileLocker {
return allocateLock(file, lock);
} else if (lock != null) {
synchronized (lock) {
switch (lock.lockState) {
case IN_USE:
if ((type == Type.READ)
&& (type == lock.lockType)) {
// A different waiter grabbed it for
// reading, we can read it also
lock.lockers.add(locker);
return true;
} else {
long curTime = System.currentTimeMillis();
long lastMod = lock.lockFile.lastModified();
if ((curTime - lastMod) > MAX_WAIT) {
System.err
.println("Releasing lock: "
+ "Lock has been allocated for "
+ ((curTime - lastMod) / 1000)
+ "s on file "
+ file.getPath());
locks.remove(file);
}
if ((type == Type.READ) && (type == lock.lockType)
&& LockState.IN_USE.equals(lock.lockState)) {
// A different waiter grabbed it for
// reading, we can read it also
lock.lockers.add(locker);
lock.lockTime = System.currentTimeMillis();
return true;
} else {
long curTime = System.currentTimeMillis();
if ((curTime - lock.lockTime) > MAX_WAIT) {
System.err
.println("Releasing lock: "
+ "Lock has been allocated for "
+ ((curTime - lock.lockTime) / 1000)
+ "s on file "
+ file.getPath());
locks.remove(file);
}
break;
// ACUIRING - NOOP wait for lock to be acquired
// RELEASED - loop again and check if next waiter
}
}
}
@ -309,6 +307,7 @@ public class FileLocker {
try {
boolean fileUnlocked = false;
LockedFile lock = null;
// Get the Lock
synchronized (locks) {
lock = locks.get(file);
@ -319,7 +318,8 @@ public class FileLocker {
}
synchronized (lock) {
if (lock.lockState == LockState.IN_USE) {
if ((lock.lockState == LockState.IN_USE)
|| lock.lockingThread.equals(Thread.currentThread())) {
lock.lockers.remove(locker);
if (lock.lockers.isEmpty()) {
@ -370,14 +370,23 @@ public class FileLocker {
// Get the lock directory, make sure it is not already taken
File parentDir = file.getParentFile();
// If we can't write to the parent directory of the file we are locking,
// can't do any locking
if (!parentDir.exists()) {
parentDir.mkdirs();
}
// If we can't write to the parent directory of the file we are
// locking, can't do any locking
if (parentDir.canWrite() == false) {
UFStatus.getHandler()
.handle(Priority.PROBLEM,
"Cannot write to directory: "
+ parentDir.getAbsolutePath());
return false;
}
boolean gotLock = false;
File lockFile = new File(parentDir, "." + file.getName() + "_LOCK");
try {
// start with a moderate wait
long waitInterval = 100;
@ -409,8 +418,10 @@ public class FileLocker {
"Error obtaining file lock: " + file, e);
} finally {
synchronized (lock) {
long millis = System.currentTimeMillis();
lock.lockFile = lockFile;
lock.lockFile.setLastModified(System.currentTimeMillis());
lock.lockTime = millis;
lock.lockFile.setLastModified(millis);
lock.lockState = LockState.IN_USE;
}
}