[asterisk-scf-commits] asterisk-scf/integration/media_operations_core.git branch "retry_deux" updated.

[Commits to the Asterisk SCF project code repositories]

branch "retry_deux" has been updated
       via  b0bd266487b0f665edcac1cc784b7a09e2654e52 (commit)
      from  1d23331df6c10c92fa72e11e911acaa16a626bdd (commit)

Summary of changes:
 src/InbandTelephonyEvents.cpp   |   14 ++++++++++++--
 src/MediaOperationFactoryImpl.h |   12 ++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)


- Log -----------------------------------------------------------------
commit b0bd266487b0f665edcac1cc784b7a09e2654e52
Author: David M. Lee <dlee at digium.com>
Date:   Thu Mar 22 10:43:11 2012 -0500

    Thread safety for createMediaOperation

diff --git a/src/InbandTelephonyEvents.cpp b/src/InbandTelephonyEvents.cpp
index 5b5524a..bf4174b 100644
--- a/src/InbandTelephonyEvents.cpp
+++ b/src/InbandTelephonyEvents.cpp
@@ -362,13 +362,23 @@ MediaOperationPrx InbandTelephonyEventOperationFactory::createMediaOperation(
             const StreamSinkPrx& sink,
             const Ice::Current&)
 {
-    const CreateMediaOperationCookiePtr cookie(new CreateMediaOperationCookie);
+    // The factory itself doesn't need a lock, so we'll lock the cookie instead to reduce needless
+    // contention.
+    const CreateMediaOperationCookieWithLockPtr cookie(new CreateMediaOperationCookieWithLock);
+    // lock this cookie so that no one will get our results prematurely
+    boost::lock_guard<boost::mutex> lock(cookie->getMutex());
     OperationContextCookiePtr existingCookie;
     mOperationContextCache->addOperationContext(operationContext, cookie, existingCookie);
 
     if (existingCookie)
     {
-        CreateMediaOperationCookiePtr c = boost::dynamic_pointer_cast<CreateMediaOperationCookie>(existingCookie);
+        // retry detected!
+        CreateMediaOperationCookieWithLockPtr c =
+            boost::dynamic_pointer_cast<CreateMediaOperationCookieWithLock>(existingCookie);
+        assert(c);
+        // Even though we're holding a lock on cookie, it's never left this function; no one can be waiting on it.
+        // There's no danger of deadlocking while waiting on the lock for existingCookie.
+        boost::lock_guard<boost::mutex> lockExistingCookie(c->getMutex());
         return c->get();
     }
 
diff --git a/src/MediaOperationFactoryImpl.h b/src/MediaOperationFactoryImpl.h
index 61715bd..b7db27a 100644
--- a/src/MediaOperationFactoryImpl.h
+++ b/src/MediaOperationFactoryImpl.h
@@ -77,5 +77,17 @@ typedef IceUtil::Handle<MediaOperationFactoryImpl> MediaOperationFactoryImplPtr;
 typedef Operations::ValueOperationContextCookie<AsteriskSCF::Media::V1::MediaOperationPrx> CreateMediaOperationCookie;
 typedef boost::shared_ptr<CreateMediaOperationCookie> CreateMediaOperationCookiePtr;
 
+/**
+ * CreateMediaOperationCookie with a mutex.
+ */
+class CreateMediaOperationCookieWithLock : public CreateMediaOperationCookie {
+public:
+    boost::mutex &getMutex() { return mMutex; }
+private:
+    boost::mutex mMutex;
+};
+
+typedef boost::shared_ptr<CreateMediaOperationCookieWithLock> CreateMediaOperationCookieWithLockPtr;
+
 } //end namespace MediaOperationsCore
 } //end namespace AsteriskSCF

-----------------------------------------------------------------------


-- 
asterisk-scf/integration/media_operations_core.git