Bug 1519397 - Factor GC locking RAII classes out of vm/Runtime.h r=pbone

js/src/gc/Allocator.h

@@ -7,6 +7,7 @@
 #ifndef gc_Allocator_h
 #define gc_Allocator_h
 
+#include "gc/GCLock.h"
 #include "gc/Heap.h"
 #include "js/RootingAPI.h"
 

js/src/gc/GC.cpp

@@ -216,6 +216,7 @@
 #include "gc/FindSCCs.h"
 #include "gc/FreeOp.h"
 #include "gc/GCInternals.h"
+#include "gc/GCLock.h"
 #include "gc/GCTrace.h"
 #include "gc/Memory.h"
 #include "gc/Policy.h"

js/src/gc/GCLock.h

@@ -0,0 +1,118 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=8 sts=2 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * GC-internal classes for acquiring and releasing the GC lock.
+ */
+
+#ifndef gc_GCLock_h
+#define gc_GCLock_h
+
+#include "vm/Runtime.h"
+
+namespace js {
+
+class AutoUnlockGC;
+
+/*
+ * RAII class that takes the GC lock while it is live.
+ *
+ * Usually functions will pass const references of this class.  However
+ * non-const references can be used to either temporarily release the lock by
+ * use of AutoUnlockGC or to start background allocation when the lock is
+ * released.
+ */
+class MOZ_RAII AutoLockGC {
+ public:
+  explicit AutoLockGC(JSRuntime* rt MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
+      : runtime_(rt) {
+    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
+    lock();
+  }
+
+  ~AutoLockGC() { lockGuard_.reset(); }
+
+  void lock() {
+    MOZ_ASSERT(lockGuard_.isNothing());
+    lockGuard_.emplace(runtime_->gc.lock);
+  }
+
+  void unlock() {
+    MOZ_ASSERT(lockGuard_.isSome());
+    lockGuard_.reset();
+  }
+
+ protected:
+  js::LockGuard<js::Mutex>& guard() { return lockGuard_.ref(); }
+
+  JSRuntime* runtime() const { return runtime_; }
+
+ private:
+  JSRuntime* runtime_;
+  mozilla::Maybe<js::LockGuard<js::Mutex>> lockGuard_;
+  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
+
+  AutoLockGC(const AutoLockGC&) = delete;
+  AutoLockGC& operator=(const AutoLockGC&) = delete;
+};
+
+/*
+ * Same as AutoLockGC except it can optionally start a background chunk
+ * allocation task when the lock is released.
+ */
+class MOZ_RAII AutoLockGCBgAlloc : public AutoLockGC {
+ public:
+  explicit AutoLockGCBgAlloc(JSRuntime* rt)
+      : AutoLockGC(rt), startBgAlloc(false) {}
+
+  ~AutoLockGCBgAlloc() {
+    unlock();
+
+    /*
+     * We have to do this after releasing the lock because it may acquire
+     * the helper lock which could cause lock inversion if we still held
+     * the GC lock.
+     */
+    if (startBgAlloc) {
+      runtime()->gc.startBackgroundAllocTaskIfIdle();  // Ignore failure.
+    }
+  }
+
+  /*
+   * This can be used to start a background allocation task (if one isn't
+   * already running) that allocates chunks and makes them available in the
+   * free chunks list.  This happens after the lock is released in order to
+   * avoid lock inversion.
+   */
+  void tryToStartBackgroundAllocation() { startBgAlloc = true; }
+
+ private:
+  // true if we should start a background chunk allocation task after the
+  // lock is released.
+  bool startBgAlloc;
+};
+
+class MOZ_RAII AutoUnlockGC {
+ public:
+  explicit AutoUnlockGC(AutoLockGC& lock MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
+      : lock(lock) {
+    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
+    lock.unlock();
+  }
+
+  ~AutoUnlockGC() { lock.lock(); }
+
+ private:
+  AutoLockGC& lock;
+  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
+
+  AutoUnlockGC(const AutoUnlockGC&) = delete;
+  AutoUnlockGC& operator=(const AutoUnlockGC&) = delete;
+};
+
+} // namespace js
+
+#endif /* gc_GCLock_h */

js/src/gc/Verifier.cpp

@@ -13,6 +13,7 @@
 #endif
 
 #include "gc/GCInternals.h"
+#include "gc/GCLock.h"
 #include "gc/PublicIterators.h"
 #include "gc/WeakMap.h"
 #include "gc/Zone.h"

js/src/jsapi-tests/testGCChunkPool.cpp

@@ -7,6 +7,7 @@
 
 #include "mozilla/Move.h"
 
+#include "gc/GCLock.h"
 #include "gc/GCRuntime.h"
 #include "gc/Heap.h"
 

js/src/vm/Runtime.h

@@ -1012,104 +1012,6 @@ struct JSRuntime : public js::MallocProvider<JSRuntime> {
 
 namespace js {
 
-/*
- * RAII class that takes the GC lock while it is live.
- *
- * Usually functions will pass const references of this class.  However
- * non-const references can be used to either temporarily release the lock by
- * use of AutoUnlockGC or to start background allocation when the lock is
- * released.
- */
-class MOZ_RAII AutoLockGC {
- public:
-  explicit AutoLockGC(JSRuntime* rt MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
-      : runtime_(rt) {
-    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
-    lock();
-  }
-
-  ~AutoLockGC() { lockGuard_.reset(); }
-
-  void lock() {
-    MOZ_ASSERT(lockGuard_.isNothing());
-    lockGuard_.emplace(runtime_->gc.lock);
-  }
-
-  void unlock() {
-    MOZ_ASSERT(lockGuard_.isSome());
-    lockGuard_.reset();
-  }
-
-  js::LockGuard<js::Mutex>& guard() { return lockGuard_.ref(); }
-
- protected:
-  JSRuntime* runtime() const { return runtime_; }
-
- private:
-  JSRuntime* runtime_;
-  mozilla::Maybe<js::LockGuard<js::Mutex>> lockGuard_;
-  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
-
-  AutoLockGC(const AutoLockGC&) = delete;
-  AutoLockGC& operator=(const AutoLockGC&) = delete;
-};
-
-/*
- * Same as AutoLockGC except it can optionally start a background chunk
- * allocation task when the lock is released.
- */
-class MOZ_RAII AutoLockGCBgAlloc : public AutoLockGC {
- public:
-  explicit AutoLockGCBgAlloc(JSRuntime* rt)
-      : AutoLockGC(rt), startBgAlloc(false) {}
-
-  ~AutoLockGCBgAlloc() {
-    unlock();
-
-    /*
-     * We have to do this after releasing the lock because it may acquire
-     * the helper lock which could cause lock inversion if we still held
-     * the GC lock.
-     */
-    if (startBgAlloc) {
-      runtime()->gc.startBackgroundAllocTaskIfIdle();  // Ignore failure.
-    }
-  }
-
-  /*
-   * This can be used to start a background allocation task (if one isn't
-   * already running) that allocates chunks and makes them available in the
-   * free chunks list.  This happens after the lock is released in order to
-   * avoid lock inversion.
-   */
-  void tryToStartBackgroundAllocation() { startBgAlloc = true; }
-
- private:
-  // true if we should start a background chunk allocation task after the
-  // lock is released.
-  bool startBgAlloc;
-};
-
-class MOZ_RAII AutoUnlockGC {
- public:
-  explicit AutoUnlockGC(AutoLockGC& lock MOZ_GUARD_OBJECT_NOTIFIER_PARAM)
-      : lock(lock) {
-    MOZ_GUARD_OBJECT_NOTIFIER_INIT;
-    lock.unlock();
-  }
-
-  ~AutoUnlockGC() { lock.lock(); }
-
- private:
-  AutoLockGC& lock;
-  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
-
-  AutoUnlockGC(const AutoUnlockGC&) = delete;
-  AutoUnlockGC& operator=(const AutoUnlockGC&) = delete;
-};
-
-/************************************************************************/
-
 static MOZ_ALWAYS_INLINE void MakeRangeGCSafe(Value* vec, size_t len) {
   // Don't PodZero here because JS::Value is non-trivial.
   for (size_t i = 0; i < len; i++) {