Bug 956899 - Convert exclusive access lock from PRLock to Mutex; r=jandem

--HG--
extra : rebase_source : b13f0ea577d947e5192d16181ac14051490de741

js/src/jscntxt.h

@@ -762,7 +762,7 @@ class MOZ_RAII AutoLockForExclusiveAccess
         runtime = rt;
         if (runtime->numExclusiveThreads) {
             runtime->assertCanLock(ExclusiveAccessLock);
-            PR_Lock(runtime->exclusiveAccessLock);
+            runtime->exclusiveAccessLock.lock();
 #ifdef DEBUG
             runtime->exclusiveAccessOwner = PR_GetCurrentThread();
 #endif
@@ -789,7 +789,7 @@ class MOZ_RAII AutoLockForExclusiveAccess
             MOZ_ASSERT(runtime->exclusiveAccessOwner == PR_GetCurrentThread());
             runtime->exclusiveAccessOwner = nullptr;
 #endif
-            PR_Unlock(runtime->exclusiveAccessLock);
+            runtime->exclusiveAccessLock.unlock();
         } else {
             MOZ_ASSERT(runtime->mainThreadHasExclusiveAccess);
 #ifdef DEBUG

js/src/vm/Runtime.cpp

@@ -151,7 +151,6 @@ JSRuntime::JSRuntime(JSRuntime* parentRuntime)
     handlingSegFault(false),
     handlingJitInterrupt_(false),
     interruptCallback(nullptr),
-    exclusiveAccessLock(nullptr),
 #ifdef DEBUG
     exclusiveAccessOwner(nullptr),
     mainThreadHasExclusiveAccess(false),
@@ -287,10 +286,6 @@ JSRuntime::init(uint32_t maxbytes, uint32_t maxNurseryBytes)
     ownerThreadNative_ = (size_t)pthread_self();
 #endif
 
-    exclusiveAccessLock = PR_NewLock();
-    if (!exclusiveAccessLock)
-        return false;
-
     if (!mainThread.init())
         return false;
 
@@ -428,8 +423,6 @@ JSRuntime::~JSRuntime()
     finishSelfHosting();
 
     MOZ_ASSERT(!exclusiveAccessOwner);
-    if (exclusiveAccessLock)
-        PR_DestroyLock(exclusiveAccessLock);
 
     // Avoid bogus asserts during teardown.
     MOZ_ASSERT(!numExclusiveThreads);

js/src/vm/Runtime.h

@@ -919,7 +919,7 @@ struct JSRuntime : public JS::shadow::Runtime,
      * Locking this only occurs if there is actually a thread other than the
      * main thread with an ExclusiveContext which could access such data.
      */
-    PRLock* exclusiveAccessLock;
+    js::Mutex exclusiveAccessLock;
 #ifdef DEBUG
     PRThread* exclusiveAccessOwner;
     bool mainThreadHasExclusiveAccess;