User: biorn_steedom
Date: 01/04/20 16:16:52
Modified: src/main/org/jboss/util Semaphore.java
Log:
Generalized the implementation for better subclass reuse.
Revision Changes Path
1.2 +46 -22 jboss/src/main/org/jboss/util/Semaphore.java
Index: Semaphore.java
===================================================================
RCS file: /cvsroot/jboss/jboss/src/main/org/jboss/util/Semaphore.java,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- Semaphore.java 2000/12/12 09:56:05 1.1
+++ Semaphore.java 2001/04/20 23:16:52 1.2
@@ -19,30 +19,40 @@
* and can be used instead of synchronized blocks
*
* @author Simone Bordet ([EMAIL PROTECTED])
- * @version $Revision: 1.1 $
+ * @version $Revision: 1.2 $
*/
public class Semaphore
implements Sync
{
// Constants -----------------------------------------------------
+ private static final long DEADLOCK_TIMEOUT = 5*60*1000;
// Attributes ----------------------------------------------------
- private boolean m_debug;
+ private final static boolean m_debug = true;
private int m_users;
+ private int m_allowed;
private Map m_logMap;
// Static --------------------------------------------------------
// Constructors --------------------------------------------------
- public Semaphore(int users)
+ public Semaphore(int allowed)
{
- if (users < 1) throw new IllegalArgumentException();
- m_users = users;
+ if (allowed < 1) throw new IllegalArgumentException();
+
+ m_users = 0;
+ m_allowed = allowed;
m_logMap = new HashMap();
- m_debug = false;
}
// Public --------------------------------------------------------
+ public int getUsers()
+ {
+ synchronized (this)
+ {
+ return m_users;
+ }
+ }
// Sync implementation ----------------------------------------------
public void acquire() throws InterruptedException
@@ -51,34 +61,32 @@
{
logAcquire();
- while (m_users <= 0)
+ // One user more called acquire, increase users
+ ++m_users;
+ boolean waitSuccessful = false;
+ while (m_allowed <= 0)
{
- // Wait (forever) until notified. To discover
deadlocks,
- // turn on debugging of this class
- long start = System.currentTimeMillis();
- wait(30000);
- long end = System.currentTimeMillis();
-
- if ((end - start) > 29000)
+ waitSuccessful = waitImpl(this);
+ if (!waitSuccessful)
{
- logDeadlock();
+ // Dealock was detected, restore status,
'cause it's like a release()
+ // that will probably be never called
+ --m_users;
+ ++m_allowed;
}
}
- --m_users;
+ --m_allowed;
}
- }
- public boolean attempt(long msecs) throws InterruptedException
- {
- // TODO...
- return false;
}
+
public void release()
{
synchronized (this)
{
logRelease();
- ++m_users;
+ --m_users;
+ ++m_allowed;
notify();
}
}
@@ -92,6 +100,22 @@
// Package protected ---------------------------------------------
// Protected -----------------------------------------------------
+ protected boolean waitImpl(Object lock) throws InterruptedException
+ {
+ // Wait (forever) until notified. To discover deadlocks,
+ // turn on debugging of this class
+ long start = System.currentTimeMillis();
+ lock.wait(DEADLOCK_TIMEOUT);
+ long end = System.currentTimeMillis();
+
+ if ((end - start) > (DEADLOCK_TIMEOUT - 1000))
+ {
+ logDeadlock();
+ return false;
+ }
+ return true;
+ }
+
protected void logAcquire()
{
if (m_debug)
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