From 16541ad2049005742da11c29d802311e1796f6c2 Mon Sep 17 00:00:00 2001
From: Luke Wagner <luke@mozilla.com>
Date: Mon, 18 Nov 2013 12:56:32 -0600
Subject: [PATCH] Bug 933807 - Allow easily disabling
 TriggerOperationCallbackFor(Ion|AsmJS)Code (r=bhackett)

--HG--
extra : rebase_source : bcf49d894252af53a24aa08a0db25c99dedd26d9
---
 js/src/vm/Runtime.cpp | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/js/src/vm/Runtime.cpp b/js/src/vm/Runtime.cpp
index d1c4774f155..0d5c6e6a44b 100644
--- a/js/src/vm/Runtime.cpp
+++ b/js/src/vm/Runtime.cpp
@@ -591,6 +591,14 @@ JSRuntime::addSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf, JS::Runtim
         rtSizes->scriptData += mallocSizeOf(r.front());
 }
 
+static bool
+SignalBasedTriggersDisabled()
+{
+  // Don't bother trying to cache the getenv lookup; this should be called
+  // infrequently.
+  return !!getenv("JS_DISABLE_SLOW_SCRIPT_SIGNALS");
+}
+
 void
 JSRuntime::triggerOperationCallback(OperationCallbackTrigger trigger)
 {
@@ -611,8 +619,10 @@ JSRuntime::triggerOperationCallback(OperationCallbackTrigger trigger)
      * asm.js and, optionally, normal Ion code use memory protection and signal
      * handlers to halt running code.
      */
-    TriggerOperationCallbackForAsmJSCode(this);
-    jit::TriggerOperationCallbackForIonCode(this, trigger);
+    if (!SignalBasedTriggersDisabled()) {
+        TriggerOperationCallbackForAsmJSCode(this);
+        jit::TriggerOperationCallbackForIonCode(this, trigger);
+    }
 #endif
 }