From 1295093170c4c6e44fde1d58797b01e73b77f557 Mon Sep 17 00:00:00 2001
From: Jon Coppeard <jcoppeard@mozilla.com>
Date: Thu, 22 Sep 2016 13:02:40 +0100
Subject: [PATCH] Bug 1301496 - Simplify runtime check when tracing helper
 threads r=terrence a=decoder

---
 js/src/jit-test/tests/gc/bug-1301496.js | 7 +++++++
 js/src/jit/CompileWrappers.cpp          | 6 ++++++
 js/src/jit/CompileWrappers.h            | 2 ++
 js/src/jit/IonBuilder.cpp               | 2 +-
 js/src/jscntxt.h                        | 4 ++++
 js/src/vm/HelperThreads.cpp             | 2 +-
 js/src/vm/HelperThreads.h               | 2 +-
 7 files changed, 22 insertions(+), 3 deletions(-)
 create mode 100644 js/src/jit-test/tests/gc/bug-1301496.js

diff --git a/js/src/jit-test/tests/gc/bug-1301496.js b/js/src/jit-test/tests/gc/bug-1301496.js
new file mode 100644
index 000000000000..7200ab98c952
--- /dev/null
+++ b/js/src/jit-test/tests/gc/bug-1301496.js
@@ -0,0 +1,7 @@
+if (helperThreadCount() == 0)
+    quit();
+startgc(1, 'shrinking');
+offThreadCompileScript("");
+// Adapted from randomly chosen test: js/src/jit-test/tests/parser/bug-1263355-13.js
+gczeal(9);
+newGlobal();
diff --git a/js/src/jit/CompileWrappers.cpp b/js/src/jit/CompileWrappers.cpp
index 286bd17c51ba..9402efcbd96c 100644
--- a/js/src/jit/CompileWrappers.cpp
+++ b/js/src/jit/CompileWrappers.cpp
@@ -188,6 +188,12 @@ CompileRuntime::setMinorGCShouldCancelIonCompilations()
     runtime()->gc.storeBuffer.setShouldCancelIonCompilations();
 }
 
+bool
+CompileRuntime::runtimeMatches(JSRuntime* rt)
+{
+    return rt == runtime();
+}
+
 Zone*
 CompileZone::zone()
 {
diff --git a/js/src/jit/CompileWrappers.h b/js/src/jit/CompileWrappers.h
index ae42d8602c94..bbec9ffa34bd 100644
--- a/js/src/jit/CompileWrappers.h
+++ b/js/src/jit/CompileWrappers.h
@@ -86,6 +86,8 @@ class CompileRuntime
 
     const Nursery& gcNursery();
     void setMinorGCShouldCancelIonCompilations();
+
+    bool runtimeMatches(JSRuntime* rt);
 };
 
 class CompileZone
diff --git a/js/src/jit/IonBuilder.cpp b/js/src/jit/IonBuilder.cpp
index 3d02994f58e8..a4aa7405a7e6 100644
--- a/js/src/jit/IonBuilder.cpp
+++ b/js/src/jit/IonBuilder.cpp
@@ -14622,7 +14622,7 @@ IonBuilder::convertToBoolean(MDefinition* input)
 void
 IonBuilder::trace(JSTracer* trc)
 {
-    if (script_->zoneFromAnyThread()->runtimeFromAnyThread() != trc->runtime())
+    if (!compartment->runtime()->runtimeMatches(trc->runtime()))
         return;
 
     TraceManuallyBarrieredEdge(trc, &script_, "IonBuiler::script_");
diff --git a/js/src/jscntxt.h b/js/src/jscntxt.h
index b96ae9d2ace1..1702660dee4a 100644
--- a/js/src/jscntxt.h
+++ b/js/src/jscntxt.h
@@ -162,6 +162,10 @@ class ExclusiveContext : public ContextFriendFields,
         return options_;
     }
 
+    bool runtimeMatches(JSRuntime* rt) const {
+        return runtime_ == rt;
+    }
+
   protected:
     js::gc::ArenaLists* arenas_;
 
diff --git a/js/src/vm/HelperThreads.cpp b/js/src/vm/HelperThreads.cpp
index 625157869958..91da8329cbb1 100644
--- a/js/src/vm/HelperThreads.cpp
+++ b/js/src/vm/HelperThreads.cpp
@@ -345,7 +345,7 @@ ParseTask::~ParseTask()
 void
 ParseTask::trace(JSTracer* trc)
 {
-    if (exclusiveContextGlobal->zoneFromAnyThread()->runtimeFromAnyThread() != trc->runtime())
+    if (!cx->runtimeMatches(trc->runtime()))
         return;
 
     TraceManuallyBarrieredEdge(trc, &exclusiveContextGlobal, "ParseTask::exclusiveContextGlobal");
diff --git a/js/src/vm/HelperThreads.h b/js/src/vm/HelperThreads.h
index b300099dda64..e9cfa90a8091 100644
--- a/js/src/vm/HelperThreads.h
+++ b/js/src/vm/HelperThreads.h
@@ -568,7 +568,7 @@ struct ParseTask
     bool finish(JSContext* cx);
 
     bool runtimeMatches(JSRuntime* rt) {
-        return exclusiveContextGlobal->runtimeFromAnyThread() == rt;
+        return cx->runtimeMatches(rt);
     }
 
     virtual ~ParseTask();