Merge pull request pocoproject#2088 from Burgch/tcpserverdispatcher-race

obiltschnig · web-flow · commit fe40ea901b73 · 2018-03-05T15:22:54.000+01:00
Fix race condition in TCPServerDispatcher.cpp
diff --git a/Net/src/TCPServerDispatcher.cpp b/Net/src/TCPServerDispatcher.cpp
@@ -92,7 +92,7 @@ void TCPServerDispatcher::release()
 
 void TCPServerDispatcher::run()
 {
-	AutoPtr<TCPServerDispatcher> guard(this, true); // ensure object stays alive
+	AutoPtr<TCPServerDispatcher> guard(this, false); // ensure _rc is decreased when function exits
 
 	int idleTime = (int) _pParams->getThreadIdleTime().totalMilliseconds();
 
@@ -144,6 +144,10 @@ void TCPServerDispatcher::enqueue(const StreamSocket& socket)
 			{
 				_threadPool.startWithPriority(_pParams->getThreadPriority(), *this, threadName);
 				++_currentThreads;
+				// Ensure this object lives at least until run() starts
+				// Small chance of leaking if threadpool is stopped before this
+				// work runs, but better than a dangling pointer and crash!
+				duplicate();
 			}
 			catch (Poco::Exception&)
 			{

Original file line number	Diff line number	Diff line change
`@@ -92,7 +92,7 @@ void TCPServerDispatcher::release()`
`92`	`92`
`93`	`93`	`void TCPServerDispatcher::run()`
`94`	`94`	`{`
`95`		`- AutoPtr<TCPServerDispatcher> guard(this, true); // ensure object stays alive`
	`95`	`+ AutoPtr<TCPServerDispatcher> guard(this, false); // ensure _rc is decreased when function exits`
`96`	`96`
`97`	`97`	`int idleTime = (int) _pParams->getThreadIdleTime().totalMilliseconds();`
`98`	`98`
`@@ -144,6 +144,10 @@ void TCPServerDispatcher::enqueue(const StreamSocket& socket)`
`144`	`144`	`{`
`145`	`145`	`_threadPool.startWithPriority(_pParams->getThreadPriority(), *this, threadName);`
`146`	`146`	`++_currentThreads;`
	`147`	`+ // Ensure this object lives at least until run() starts`
	`148`	`+ // Small chance of leaking if threadpool is stopped before this`
	`149`	`+ // work runs, but better than a dangling pointer and crash!`
	`150`	`+ duplicate();`
`147`	`151`	`}`
`148`	`152`	`catch (Poco::Exception&)`
`149`	`153`	`{`