Changeset 65440 in vbox for trunk/src/libs/xpcom18a4/xpcom/base

Timestamp:

Jan 25, 2017 10:06:46 AM (8 years ago)

Author:

vboxsync

svn:sync-xref-src-repo-rev:

113053

Message:

XPCOM: Previous change broke the shutdown detection in nsExceptionService, causing races with creating new exception manager instances when XPCOM shutdown has begun. The race happened when XPCOM shutdown was destroying all object instances for the known components. With "enough luck" nsExceptionService::GetCurrentExceptionManager created a new manager which by the time the AddRef call at the end was reached would've been already freed (which happens regardless of refcounts for obvious reasons).

File:

• trunk/src/libs/xpcom18a4/xpcom/base/nsExceptionService.cpp (modified) (2 diffs)

trunk/src/libs/xpcom18a4/xpcom/base/nsExceptionService.cpp

@@ -45 +45 @@
 static const PRUintn BAD_TLS_INDEX = (PRUintn) -1;
 
-#define CHECK_SERVICE_USE_OK() if (!lock) return NS_ERROR_NOT_INITIALIZED
-#define CHECK_MANAGER_USE_OK() if (!mService || !nsExceptionService::lock) return NS_ERROR_NOT_INITIALIZED
+#define CHECK_SERVICE_USE_OK() if (tlsIndex == BAD_TLS_INDEX) return NS_ERROR_NOT_INITIALIZED
+#define CHECK_MANAGER_USE_OK() if (!mService || nsExceptionService::tlsIndex == BAD_TLS_INDEX) return NS_ERROR_NOT_INITIALIZED
 
 // A key for our registered module providers hashtable
@@ -225 +225 @@
 void nsExceptionService::Shutdown()
 {
-  PR_SetThreadPrivate(tlsIndex, nsnull);
+  PRUintn tmp = tlsIndex;
+  tlsIndex = BAD_TLS_INDEX;
+  PR_SetThreadPrivate(tmp, nsnull);
   mProviders.Reset();
   if (lock) {