Bug 1005375 - Add an API that allows CryptoTasks to be created without being dispatched

security/manager/ssl/src/CryptoTask.h

@@ -29,6 +29,17 @@ namespace mozilla {
  * except CalculateResult might be skipped if NSS is shut down before it can
  * be called; in that case ReleaseNSSResources will be called and then
  * CallCallback will be called with an error code.
+ *
+ * That sequence of events is what happens if you call Dispatch.  If for
+ * some reason, you decide not to run the task (e.g., due to an error in the
+ * constructor), you may call Skip, in which case the task is cleaned up and
+ * not run.  In that case, only ReleaseNSSResources is called.  (So a
+ * subclass must be prepared for ReleaseNSSResources to be run without
+ * CalculateResult having been called first.)
+ *
+ * Once a CryptoTask is created, the calling code must call either
+ * Dispatch or Skip.
+ *
  */
 class CryptoTask : public nsRunnable,
                    public nsNSSShutDownObject
@@ -48,6 +59,11 @@ public:
     return rv;
   }
 
+  void Skip()
+  {
+    virtualDestroyNSSReference();
+  }
+
 protected:
   CryptoTask()
     : mRv(NS_ERROR_NOT_INITIALIZED),