Use InheritableThreadLocal instead of ThreadLocal in TransactionSynchronizationManager [SPR-1514]

[spring-projects-issues]

Jeff Badorek opened SPR-1514 and commented

It would be nice if a bound resource in TransactionSynchronizationManager was visible to child threads. I think this could be accomplished using InheritableThreadLocal.

Here is a test case that recreates the problem. (Changing to InheritableThreadLocal works.)

public void testTransactionSynchronizationManager() throws InterruptedException {
	final ArrayList actual = new ArrayList();
	final ArrayList expected = new ArrayList();
	final Object key = new Object();
	
	TransactionSynchronizationManager.bindResource(key, "value");
	
	actual.add(TransactionSynchronizationManager.getResource(key));
	
	Thread thread = new Thread() {
		/* (non-Javadoc)
		 * @see java.lang.Thread#run()
		 */
		public void run() {
			expected.add(TransactionSynchronizationManager.getResource(key));
		}
	};
	
	thread.start();
	
	thread.join();
	
	assertEquals(actual, expected);
}

---

Affects: 1.2.6

Referenced from: commits spring-projects/spring-batch@d203f2a

[spring-projects-issues]

Juergen Hoeller commented

The question is whether thread-bound resources should be visible to child threads in the first place. Such resources are usually not thread-safe, so they shouldn't be used by multiple threads in parallel...

Juergen

[spring-projects-issues]

Juergen Hoeller commented

Closed for the time being, since there doesn't seem to be a compelling use case for child threads to inherit transactional resources - while keeping thread-safe resource access.

Juergen