From a758f199260b97654afb432834360dbee8c618dd Mon Sep 17 00:00:00 2001
From: Jon Coppeard <jcoppeard@mozilla.com>
Date: Tue, 6 Oct 2015 14:50:50 +0100
Subject: [PATCH] Bug 1209911 - Remove option to simulate OOM on all threads
 r=terrence

--HG--
extra : rebase_source : c03694b314165446ffa3a6ab4d70fea02c202055
---
 js/public/Utility.h                 |  9 ++---
 js/src/builtin/TestingFunctions.cpp | 63 ++++++++++-------------------
 2 files changed, 24 insertions(+), 48 deletions(-)

diff --git a/js/public/Utility.h b/js/public/Utility.h
index 6e635201e476..5b36e5eec0b0 100644
--- a/js/public/Utility.h
+++ b/js/public/Utility.h
@@ -73,7 +73,7 @@ namespace oom {
  * without causing an OOM in the main thread first.
  */
 enum ThreadType {
-    THREAD_TYPE_NONE,           // 0
+    THREAD_TYPE_NONE = 0,       // 0
     THREAD_TYPE_MAIN,           // 1
     THREAD_TYPE_ASMJS,          // 2
     THREAD_TYPE_ION,            // 3
@@ -127,7 +127,7 @@ extern JS_PUBLIC_DATA(uint32_t) targetThread;
 static inline bool
 IsThreadSimulatingOOM()
 {
-    return !js::oom::targetThread || js::oom::targetThread == js::oom::GetThreadType();
+    return js::oom::targetThread && js::oom::targetThread == js::oom::GetThreadType();
 }
 
 static inline bool
@@ -203,11 +203,8 @@ struct MOZ_RAII AutoEnterOOMUnsafeRegion
     }
 
     ~AutoEnterOOMUnsafeRegion() {
-        // TODO: This class is not thread safe.  If another thread has modified
-        // OOM_maxAllocations, don't try to restore it.
-        if (OOM_maxAllocations != UINT32_MAX)
-            return;
         if (oomEnabled_) {
+            MOZ_ASSERT(OOM_maxAllocations == UINT32_MAX);
             int64_t maxAllocations = OOM_counter + oomAfter_;
             MOZ_ASSERT(maxAllocations >= 0 && maxAllocations < UINT32_MAX);
             OOM_maxAllocations = uint32_t(maxAllocations);
diff --git a/js/src/builtin/TestingFunctions.cpp b/js/src/builtin/TestingFunctions.cpp
index 35133f06e24f..edf6e318309f 100644
--- a/js/src/builtin/TestingFunctions.cpp
+++ b/js/src/builtin/TestingFunctions.cpp
@@ -993,25 +993,16 @@ OOMThreadTypes(JSContext* cx, unsigned argc, Value* vp)
 }
 
 static bool
-OOMAfterAllocations(JSContext* cx, unsigned argc, Value* vp)
+SetupOOMFailure(JSContext* cx, bool failAlways, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     if (args.length() < 1) {
-        JS_ReportError(cx, "count argument required");
+        JS_ReportError(cx, "Count argument required");
         return false;
     }
 
     if (args.length() > 2) {
-        JS_ReportError(cx, "too many arguments");
-        return false;
-    }
-
-    uint32_t targetThread = 0;
-    if (!ToUint32(cx, args.get(1), &targetThread))
-        return false;
-
-    if (targetThread >= js::oom::THREAD_TYPE_MAX) {
-        JS_ReportError(cx, "invalid thread type specified");
+        JS_ReportError(cx, "Too many arguments");
         return false;
     }
 
@@ -1019,45 +1010,32 @@ OOMAfterAllocations(JSContext* cx, unsigned argc, Value* vp)
     if (!JS::ToUint32(cx, args.get(0), &count))
         return false;
 
+    uint32_t targetThread = js::oom::THREAD_TYPE_MAIN;
+    if (args.length() > 1 && !ToUint32(cx, args[1], &targetThread))
+        return false;
+
+    if (targetThread == js::oom::THREAD_TYPE_NONE || targetThread >= js::oom::THREAD_TYPE_MAX) {
+        JS_ReportError(cx, "Invalid thread type specified");
+        return false;
+    }
+
     HelperThreadState().waitForAllThreads();
     js::oom::targetThread = targetThread;
     OOM_maxAllocations = OOM_counter + count;
-    OOM_failAlways = true;
+    OOM_failAlways = failAlways;
     return true;
 }
 
+static bool
+OOMAfterAllocations(JSContext* cx, unsigned argc, Value* vp)
+{
+    return SetupOOMFailure(cx, true, argc, vp);
+}
+
 static bool
 OOMAtAllocation(JSContext* cx, unsigned argc, Value* vp)
 {
-    CallArgs args = CallArgsFromVp(argc, vp);
-    if (args.length() < 1) {
-        JS_ReportError(cx, "count argument required");
-        return false;
-    }
-
-    if (args.length() > 2) {
-        JS_ReportError(cx, "too many arguments");
-        return false;
-    }
-
-    uint32_t targetThread = 0;
-    if (!ToUint32(cx, args.get(1), &targetThread))
-        return false;
-
-    if (targetThread >= js::oom::THREAD_TYPE_MAX) {
-        JS_ReportError(cx, "invalid thread type specified");
-        return false;
-    }
-
-    uint32_t count;
-    if (!JS::ToUint32(cx, args.get(0), &count))
-        return false;
-
-    HelperThreadState().waitForAllThreads();
-    js::oom::targetThread = targetThread;
-    OOM_maxAllocations = OOM_counter + count;
-    OOM_failAlways = false;
-    return true;
+    return SetupOOMFailure(cx, false, argc, vp);
 }
 
 static bool
@@ -1065,6 +1043,7 @@ ResetOOMFailure(JSContext* cx, unsigned argc, Value* vp)
 {
     CallArgs args = CallArgsFromVp(argc, vp);
     args.rval().setBoolean(OOM_counter >= OOM_maxAllocations);
+    js::oom::targetThread = js::oom::THREAD_TYPE_NONE;
     OOM_maxAllocations = UINT32_MAX;
     return true;
 }