MAINT-6336: Put the timeout upstream of the suspending pump and fire the timeout it. Also some cleanup on LLSD construction in vivox.

4 files changed, 40 insertions, 6 deletions

diff --git a/indra/llcommon/lleventcoro.cpp b/indra/llcommon/lleventcoro.cpp
index 44291eb711..c8c43dc334 100755
--- a/indra/llcommon/lleventcoro.cpp
+++ b/indra/llcommon/lleventcoro.cpp
@@ -229,13 +229,26 @@ LLSD llcoro::postAndSuspend(const LLSD& event, const LLEventPumpOrPumpName& requ
     return value;
 }
 
-LLSD llcoro::suspendUntilEventOnWithTimeout(const LLEventPumpOrPumpName& pump, F32 timeoutin, const LLSD &timeoutResult)
+LLSD llcoro::suspendUntilEventOnWithTimeout(const LLEventPumpOrPumpName& suspendPumpOrName, 
+        F32 timeoutin, const LLSD &timeoutResult)
 {
-    LLEventTimeout timeoutPump(pump);
+    /**
+     * The timeout pump is attached upstream of of the waiting pump and will 
+     * pass the timeout event through it.  We CAN NOT attach downstream since
+     * doing so will cause the suspendPump to fire any waiting events immediately 
+     * and they will be lost.  This becomes especially problematic with the 
+     * LLEventTimeout(pump) constructor which will also attempt to fire those
+     * events using the virtual listen_impl method in the not yet fully constructed
+     * timeoutPump.
+     */
+    LLEventTimeout timeoutPump;
+    LLEventPump &suspendPump = suspendPumpOrName.getPump();
+
+    LLTempBoundListener timeoutListener = timeoutPump.listen(suspendPump.getName(), 
+            boost::bind(&LLEventPump::post, &suspendPump, _1));
 
     timeoutPump.eventAfter(timeoutin, timeoutResult);
-    return llcoro::suspendUntilEventOn(timeoutPump);
-
+    return llcoro::suspendUntilEventOn(suspendPump);
 }
 
 namespace
diff --git a/indra/llcommon/lleventcoro.h b/indra/llcommon/lleventcoro.h
index 19c68e1f35..87926c692d 100755
--- a/indra/llcommon/lleventcoro.h
+++ b/indra/llcommon/lleventcoro.h
@@ -147,7 +147,10 @@ LLSD suspendUntilEventOn(const LLEventPumpOrPumpName& pump)
     return postAndSuspend(LLSD(), LLEventPumpOrPumpName(), pump);
 }
 
-LLSD suspendUntilEventOnWithTimeout(const LLEventPumpOrPumpName& pump, F32 timeoutin, const LLSD &timeoutResult);
+/// Suspend the coroutine until an event is fired on the identified pump
+/// or the timeout duration has elapsed.  If the timeout duration 
+/// elapses the specified LLSD is returned.
+LLSD suspendUntilEventOnWithTimeout(const LLEventPumpOrPumpName& suspendPumpOrName, F32 timeoutin, const LLSD &timeoutResult);
 
 } // namespace llcoro
 
diff --git a/indra/llcommon/lleventfilter.h b/indra/llcommon/lleventfilter.h
index 15bac5fd73..66f3c14869 100755
--- a/indra/llcommon/lleventfilter.h
+++ b/indra/llcommon/lleventfilter.h
@@ -188,7 +188,19 @@ private:
     Action mAction;
 };
 
-/// Production implementation of LLEventTimoutBase
+/**
+ * Production implementation of LLEventTimoutBase.
+ * 
+ * @NOTE: Caution should be taken when using the LLEventTimeout(LLEventPump &) 
+ * constructor to ensure that the upstream event pump is not an LLEventMaildrop
+ * or any other kind of store and forward pump which may have events outstanding.
+ * Using this constructor will cause the upstream event pump to fire any pending
+ * events and could result in the invocation of a virtual method before the timeout
+ * has been fully constructed. The timeout should instead be connected upstream
+ * from the event pump and attached using the listen method.
+ * See llcoro::suspendUntilEventOnWithTimeout() for an example.
+ */
+ 
 class LL_COMMON_API LLEventTimeout: public LLEventTimeoutBase
 {
 public:
diff --git a/indra/llcommon/llevents.h b/indra/llcommon/llevents.h
index 6175329a9d..ba4fcd766e 100755
--- a/indra/llcommon/llevents.h
+++ b/indra/llcommon/llevents.h
@@ -616,6 +616,12 @@ public:
  * a queue. Subsequent attaching listeners will receive stored events from the queue 
  * until a listener indicates that the event has been handled.  In order to receive 
  * multiple events from a mail drop the listener must disconnect and reconnect.
+ * 
+ * @NOTE: When using an LLEventMailDrop (or LLEventQueue) with a LLEventTimeout or
+ * LLEventFilter attaching the filter downstream using Timeout's constructor will
+ * cause the MailDrop to discharge any of it's stored events. The timeout should 
+ * instead be connected upstream using its listen() method.  
+ * See llcoro::suspendUntilEventOnWithTimeout() for an example.
  */
 class LL_COMMON_API LLEventMailDrop : public LLEventStream
 {