xan/awips2
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Issue #3248 ensure that a locking file output streams obtains the lock

Browse source 
before calling the FileOutputStream constructor

Change-Id: I210ac789322c975cb93584facb3eec417f5097f2

Former-commit-id: 599f2598f711ce2ae6ac69ed78a90502a84d2716
This commit is contained in:
Nate Jensen 2014-06-19 09:51:10 -05:00
parent 9946f78241
commit 845483346f
1 changed files with 43 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

46
edexOsgi/com.raytheon.uf.common.localization/src/com/raytheon/uf/common/localization/LockingFileOutputStream.java
View file

@ -36,6 +36,8 @@ import com.raytheon.uf.common.localization.FileLocker.Type;
* Date Ticket# Engineer Description
* ------------ ---------- ----------- --------------------------
* Jun 23, 2011 mschenke Initial creation
* Jun 05, 2014 3248 njensen Fix constructors so lock is obtained
* before super constructor called
*
* </pre>
*
@ -47,6 +49,8 @@ public class LockingFileOutputStream extends FileOutputStream {
private File file;
private final Object locker;
/**
* Create a new LockingFileOuputStream, creates an exclusive lock on the
* file
@ -55,9 +59,7 @@ public class LockingFileOutputStream extends FileOutputStream {
* @throws FileNotFoundException
*/
public LockingFileOutputStream(File file) throws FileNotFoundException {
super(file);
this.file = file;
FileLocker.lock(this, file, Type.WRITE);
this(file, false);
}
/**
@ -70,9 +72,40 @@ public class LockingFileOutputStream extends FileOutputStream {
*/
public LockingFileOutputStream(File file, boolean isAppending)
throws FileNotFoundException {
this(file, isAppending, new Object());
}
/**
* Intentionally private constructor that takes a locker object to provide a
* unique lock tied to this stream instance. This constructor enforces that
* the FileLocker lock will be obtained before the super constructor is
* called. Otherwise, if isAppending is false, the super constructor will
* set the file length to zero, wiping out the contents, and we absolutely
* must have the write lock before that.
*
* @param file
* @param isAppending
* @param locker
* @throws FileNotFoundException
*/
private LockingFileOutputStream(File file, boolean isAppending, Object locker) throws FileNotFoundException {
this(file, isAppending, locker, FileLocker.lock(locker, file, Type.WRITE));
}
/**
* Intentionally private constructor that should be called after the file
* lock is obtained.
*
* @param file
* @param isAppending
* @param locker
* @param gotLock
* @throws FileNotFoundException
*/
private LockingFileOutputStream(File file, boolean isAppending, Object locker, boolean gotLock) throws FileNotFoundException {
super(file, isAppending);
this.file = file;
FileLocker.lock(this, file, Type.WRITE);
this.locker = locker;
}
@Override
@ -106,7 +139,10 @@ public class LockingFileOutputStream extends FileOutputStream {
}
}
/**
* Unlocks the file lock associated with the stream.
*/
public void unlock() {
FileLocker.unlock(this, file);
FileLocker.unlock(locker, file);
}
}