- Eliminated a race condition on deletion of PollerHandles

* Added DeletionManager class to delete handles
* Used to stop PollerHandles being deleted whilst still in use


git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@599390 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 16 insertions, 3 deletions

diff --git a/cpp/src/qpid/sys/epoll/EpollPoller.cpp b/cpp/src/qpid/sys/epoll/EpollPoller.cpp
index 57acafd928..0e984d49ee 100644
--- a/cpp/src/qpid/sys/epoll/EpollPoller.cpp
+++ b/cpp/src/qpid/sys/epoll/EpollPoller.cpp
@@ -21,6 +21,7 @@
 
 #include "qpid/sys/Poller.h"
 #include "qpid/sys/Mutex.h"
+#include "qpid/sys/DeletionManager.h"
 #include "qpid/sys/posix/check.h"
 #include "qpid/sys/posix/PrivatePosix.h"
 
@@ -34,6 +35,13 @@
 namespace qpid {
 namespace sys {
 
+// Deletion manager to handle deferring deletion of PollerHandles to when they definitely aren't being used 
+DeletionManager<PollerHandle> PollerHandleDeletionManager;
+
+//  Instantiate (and define) class static for DeletionManager
+template <>
+DeletionManager<PollerHandle>::AllThreadsStatuses DeletionManager<PollerHandle>::allThreadsStatuses(0);
+
 class PollerHandlePrivate {
     friend class Poller;
     friend class PollerHandle;
@@ -98,6 +106,10 @@ PollerHandle::~PollerHandle() {
     delete impl;
 }
 
+void PollerHandle::deferDelete() {
+    PollerHandleDeletionManager.markForDeletion(this);
+}
+
 /**
  * Concrete implementation of Poller to use the Linux specific epoll
  * interface
@@ -239,9 +251,9 @@ void Poller::rearmFd(PollerHandle& handle) {
 }
 
 void Poller::shutdown() {
-	// Allow sloppy code to shut us down more than once
-	if (impl->isShutdown)
-		return;
+    // Allow sloppy code to shut us down more than once
+    if (impl->isShutdown)
+        return;
 
     // Don't use any locking here - isshutdown will be visible to all
     // after the epoll_ctl() anyway (it's a memory barrier)
@@ -261,6 +273,7 @@ Poller::Event Poller::wait(Duration timeout) {
 
     // Repeat until we weren't interupted
     do {
+        PollerHandleDeletionManager.markAllUnusedInThisThread();
         int rc = ::epoll_wait(impl->epollFd, &epe, 1, timeoutMs);
         
         if (impl->isShutdown) {