Package org.eclipse.persistence.internal.helper

Class ConcurrencySemaphore

java.lang.Object

org.eclipse.persistence.internal.helper.ConcurrencySemaphore

public class ConcurrencySemaphore
extends Object

Constructor Summary

Constructors

Constructor	Description
ConcurrencySemaphore(ThreadLocal<Boolean> threadLocalVarControlIfCurrentThreadHasAcquiredSemaphore, int noOfThreadsAllowedToExecuteInParallel, Semaphore semaphoreOfThreadsAllowedToExecuteInParallel, Object outerObject, String logMessageKey)	Constructor to create ConcurrencySemaphore(java.lang.ThreadLocal<java.lang.Boolean>, int, java.util.concurrent.Semaphore, java.lang.Object, java.lang.String)

Method Summary

Modifier and Type	Method	Description
boolean	acquireSemaphoreIfAppropriate(boolean useSemaphore)	Do nothing if the semaphore has already been acquired by this thread in a higher recursive call or if the configuration to acquire the slow down semaphore is not active.
void	releaseSemaphoreAllowOtherThreadsToStartDoingObjectBuilding(boolean semaphoreWasAcquired)	If the call to acquireSemaphoreIfAppropriate(boolean) returned true implying the current thread acquire the semaphore, the same thread on the same method is mandated to release the semaphore.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ConcurrencySemaphore

public ConcurrencySemaphore(ThreadLocal<Boolean> threadLocalVarControlIfCurrentThreadHasAcquiredSemaphore,
                            int noOfThreadsAllowedToExecuteInParallel,
                            Semaphore semaphoreOfThreadsAllowedToExecuteInParallel,
                            Object outerObject,
                            String logMessageKey)

Constructor to create ConcurrencySemaphore(java.lang.ThreadLocal<java.lang.Boolean>, int, java.util.concurrent.Semaphore, java.lang.Object, java.lang.String)

Parameters:

threadLocalVarControlIfCurrentThreadHasAcquiredSemaphore - Thread local variable that the code to acquire a semaphore can check to make sure it does not try to acquire twice the same semaphore (e.g. in case the object building algorithm is recursive).

noOfThreadsAllowedToExecuteInParallel - Max number of threads to acquire semaphore.

semaphoreOfThreadsAllowedToExecuteInParallel - Semaphore used to control.

outerObject - Reference to outer object where is this semaphore used.

logMessageKey - Log message key from TraceLocalization

Method Detail

acquireSemaphoreIfAppropriate

public boolean acquireSemaphoreIfAppropriate(boolean useSemaphore)

Do nothing if the semaphore has already been acquired by this thread in a higher recursive call or if the configuration to acquire the slow down semaphore is not active. Otherwise, try to acquire the semaphore

Parameters:

useSemaphore - TRUE to use semaphore, FALSE don't use it.

Returns:

FALSE is returned if we do not want to be using the semaphore. FALSE is also returned if the current thread has acquire the semaphore in an upper level recursive stack call. TRUE is returned if and only using the semaphore is desired and we succeed acquiring the semaphore.

releaseSemaphoreAllowOtherThreadsToStartDoingObjectBuilding

public void releaseSemaphoreAllowOtherThreadsToStartDoingObjectBuilding(boolean semaphoreWasAcquired)

If the call to acquireSemaphoreIfAppropriate(boolean) returned true implying the current thread acquire the semaphore, the same thread on the same method is mandated to release the semaphore.

Parameters:

semaphoreWasAcquired - flag that tells us if the current thread had successfully acquired semaphore if the flag is true then the semaphore will be released and given resources again.