From 935011733c7d4025fd2fc0cf63b2763eabb499fa Mon Sep 17 00:00:00 2001
From: Jan Oravec <jan@fb.com>
Date: Tue, 28 May 2013 15:10:03 -0700
Subject: [PATCH] Make AsioExternalThreadEvent::abandon() not hit assertion
 error

Destructor of AsioExternalThreadEvent uses assert() to check whether the
state is legal. Introduction of abandon() mechanism makes it possible to
destroy the AsioExternalThreadEvent in the Waiting state and hit the
assertion error.

This diff solves the problem by introducing Abandoned state.
---
 .../ext/asio/asio_external_thread_event.cpp        |  3 ++-
 hphp/runtime/ext/asio/asio_external_thread_event.h | 14 +++++++++++++-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/hphp/runtime/ext/asio/asio_external_thread_event.cpp b/hphp/runtime/ext/asio/asio_external_thread_event.cpp
index 56d40f0eb..c519b143a 100644
--- a/hphp/runtime/ext/asio/asio_external_thread_event.cpp
+++ b/hphp/runtime/ext/asio/asio_external_thread_event.cpp
@@ -15,9 +15,9 @@
    +----------------------------------------------------------------------+
 */
 
+#include "hphp/runtime/ext/asio/asio_external_thread_event.h"
 #include <thread>
 #include "hphp/runtime/ext/ext_asio.h"
-#include "hphp/runtime/ext/asio/asio_external_thread_event.h"
 #include "hphp/runtime/ext/asio/asio_session.h"
 
 namespace HPHP {
@@ -32,6 +32,7 @@ AsioExternalThreadEvent::AsioExternalThreadEvent(ObjectData* priv_data)
 void AsioExternalThreadEvent::abandon() {
   assert(m_state.load() == Waiting);
   assert(m_waitHandle->getCount() == 1);
+  m_state.store(Abandoned);
   m_waitHandle->abandon(false);
 }
 
diff --git a/hphp/runtime/ext/asio/asio_external_thread_event.h b/hphp/runtime/ext/asio/asio_external_thread_event.h
index 6c067a45c..00a628d43 100644
--- a/hphp/runtime/ext/asio/asio_external_thread_event.h
+++ b/hphp/runtime/ext/asio/asio_external_thread_event.h
@@ -214,7 +214,11 @@ class AsioExternalThreadEvent {
      * is eventually called.
      */
     virtual ~AsioExternalThreadEvent() {
-      assert(m_state.load() == Finished || m_state.load() == Canceled);
+      assert(
+        m_state.load() == Finished ||
+        m_state.load() == Canceled ||
+        m_state.load() == Abandoned
+      );
     };
 
     /**
@@ -267,6 +271,14 @@ class AsioExternalThreadEvent {
        * eventually calling markAsFinished() that will destruct this object.
        */
       Canceled,
+
+      /**
+       * Web request thread abandoned event before passing to processing thread.
+       *
+       * This object is owned by web request thread, which is trying to abandon
+       * it prior to passing ownership to processing thread.
+       */
+      Abandoned,
     };
 
     AsioSession* m_session;