Bug 1755316 - Move AsyncBlockers outside of media r=nika,alwu

Differential Revision: https://phabricator.services.mozilla.com/D141797

dom/media/ipc/RDDParent.h

@@ -8,7 +8,7 @@
 #include "mozilla/PRDDParent.h"
 
 #include "mozilla/RefPtr.h"
-#include "mozilla/media/MediaUtils.h"
+#include "mozilla/ipc/AsyncBlockers.h"
 
 namespace mozilla {
 
@@ -22,7 +22,7 @@ class RDDParent final : public PRDDParent {
 
   static RDDParent* GetSingleton();
 
-  AsyncBlockers& AsyncShutdownService() { return mShutdownBlockers; }
+  ipc::AsyncBlockers& AsyncShutdownService() { return mShutdownBlockers; }
 
   bool Init(base::ProcessId aParentPid, const char* aParentBuildID,
             mozilla::ipc::ScopedPort aPort);
@@ -67,7 +67,7 @@ class RDDParent final : public PRDDParent {
  private:
   const TimeStamp mLaunchTime;
   RefPtr<ChildProfilerController> mProfilerController;
-  AsyncBlockers mShutdownBlockers;
+  ipc::AsyncBlockers mShutdownBlockers;
 };
 
 }  // namespace mozilla

dom/media/systemservices/MediaUtils.h

@@ -324,88 +324,6 @@ AwaitAll(already_AddRefed<nsIEventTarget> aPool,
 
 }  // namespace media
 
-/**
- * AsyncBlockers provide a simple registration service that allows to suspend
- * completion of a particular task until all registered entries have been
- * cleared. This can be used to implement a similar service to
- * nsAsyncShutdownService in processes where it wouldn't normally be available.
- * This class is thread-safe.
- */
-class AsyncBlockers {
- public:
-  AsyncBlockers()
-      : mLock("AsyncRegistrar"),
-        mPromise(new GenericPromise::Private(__func__)) {}
-  void Register(void* aBlocker) {
-    MutexAutoLock lock(mLock);
-    if (mResolved) {
-      // Too late.
-      return;
-    }
-    mBlockers.insert({aBlocker, true});
-  }
-  void Deregister(void* aBlocker) {
-    MutexAutoLock lock(mLock);
-    if (mResolved) {
-      // Too late.
-      return;
-    }
-    auto it = mBlockers.find(aBlocker);
-    MOZ_ASSERT(it != mBlockers.end());
-
-    mBlockers.erase(it);
-    MaybeResolve();
-  }
-  RefPtr<GenericPromise> WaitUntilClear(uint32_t aTimeOutInMs = 0) {
-    if (!aTimeOutInMs) {
-      // We don't need to wait, resolve the promise right away.
-      MutexAutoLock lock(mLock);
-      if (!mResolved) {
-        mPromise->Resolve(true, __func__);
-        mResolved = true;
-      }
-    } else {
-      GetCurrentEventTarget()->DelayedDispatch(
-          NS_NewRunnableFunction("AsyncBlockers::WaitUntilClear",
-                                 [promise = mPromise]() {
-                                   // The AsyncBlockers object may have been
-                                   // deleted by now and the object isn't
-                                   // refcounted (nor do we want it to be). We
-                                   // can unconditionally resolve the promise
-                                   // even it has already been resolved as
-                                   // MozPromise are thread-safe and will just
-                                   // ignore the action if already resolved.
-                                   promise->Resolve(true, __func__);
-                                 }),
-          aTimeOutInMs);
-    }
-    return mPromise;
-  }
-
-  virtual ~AsyncBlockers() {
-    if (!mResolved) {
-      mPromise->Resolve(true, __func__);
-    }
-  }
-
- private:
-  void MaybeResolve() {
-    mLock.AssertCurrentThreadOwns();
-    if (mResolved) {
-      return;
-    }
-    if (!mBlockers.empty()) {
-      return;
-    }
-    mPromise->Resolve(true, __func__);
-    mResolved = true;
-  }
-  Mutex mLock MOZ_UNANNOTATED;  // protects mBlockers and mResolved.
-  std::map<void*, bool> mBlockers;
-  bool mResolved = false;
-  const RefPtr<GenericPromise::Private> mPromise;
-};
-
 }  // namespace mozilla
 
 #endif  // mozilla_MediaUtils_h

gfx/ipc/GPUParent.h

@@ -8,7 +8,7 @@
 
 #include "mozilla/RefPtr.h"
 #include "mozilla/gfx/PGPUParent.h"
-#include "mozilla/media/MediaUtils.h"
+#include "mozilla/ipc/AsyncBlockers.h"
 
 namespace mozilla {
 
@@ -26,7 +26,7 @@ class GPUParent final : public PGPUParent {
 
   static GPUParent* GetSingleton();
 
-  AsyncBlockers& AsyncShutdownService() { return mShutdownBlockers; }
+  ipc::AsyncBlockers& AsyncShutdownService() { return mShutdownBlockers; }
 
   // Gets the name of the GPU process, in the format expected by about:memory.
   // There must be a GPU process active, and the caller must be either in that
@@ -111,7 +111,7 @@ class GPUParent final : public PGPUParent {
   const TimeStamp mLaunchTime;
   RefPtr<VsyncBridgeParent> mVsyncBridge;
   RefPtr<ChildProfilerController> mProfilerController;
-  AsyncBlockers mShutdownBlockers;
+  ipc::AsyncBlockers mShutdownBlockers;
 };
 
 }  // namespace gfx

ipc/glue/AsyncBlockers.h

@@ -0,0 +1,98 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set sw=2 ts=8 et ft=cpp : */
+/* 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/. */
+
+#ifndef mozilla_ipc_AsyncBlockers_h
+#define mozilla_ipc_AsyncBlockers_h
+
+// FIXME: when bug 1760855 is fixed, it should not be required anymore
+
+namespace mozilla::ipc {
+
+/**
+ * AsyncBlockers provide a simple registration service that allows to suspend
+ * completion of a particular task until all registered entries have been
+ * cleared. This can be used to implement a similar service to
+ * nsAsyncShutdownService in processes where it wouldn't normally be available.
+ * This class is thread-safe.
+ */
+class AsyncBlockers {
+ public:
+  AsyncBlockers()
+      : mLock("AsyncRegistrar"),
+        mPromise(new GenericPromise::Private(__func__)) {}
+  void Register(void* aBlocker) {
+    MutexAutoLock lock(mLock);
+    if (mResolved) {
+      // Too late.
+      return;
+    }
+    mBlockers.insert({aBlocker, true});
+  }
+  void Deregister(void* aBlocker) {
+    MutexAutoLock lock(mLock);
+    if (mResolved) {
+      // Too late.
+      return;
+    }
+    auto it = mBlockers.find(aBlocker);
+    MOZ_ASSERT(it != mBlockers.end());
+
+    mBlockers.erase(it);
+    MaybeResolve();
+  }
+  RefPtr<GenericPromise> WaitUntilClear(uint32_t aTimeOutInMs = 0) {
+    if (!aTimeOutInMs) {
+      // We don't need to wait, resolve the promise right away.
+      MutexAutoLock lock(mLock);
+      if (!mResolved) {
+        mPromise->Resolve(true, __func__);
+        mResolved = true;
+      }
+    } else {
+      GetCurrentEventTarget()->DelayedDispatch(
+          NS_NewRunnableFunction("AsyncBlockers::WaitUntilClear",
+                                 [promise = mPromise]() {
+                                   // The AsyncBlockers object may have been
+                                   // deleted by now and the object isn't
+                                   // refcounted (nor do we want it to be). We
+                                   // can unconditionally resolve the promise
+                                   // even it has already been resolved as
+                                   // MozPromise are thread-safe and will just
+                                   // ignore the action if already resolved.
+                                   promise->Resolve(true, __func__);
+                                 }),
+          aTimeOutInMs);
+    }
+    return mPromise;
+  }
+
+  virtual ~AsyncBlockers() {
+    if (!mResolved) {
+      mPromise->Resolve(true, __func__);
+    }
+  }
+
+ private:
+  void MaybeResolve() {
+    mLock.AssertCurrentThreadOwns();
+    if (mResolved) {
+      return;
+    }
+    if (!mBlockers.empty()) {
+      return;
+    }
+    mPromise->Resolve(true, __func__);
+    mResolved = true;
+  }
+  Mutex mLock MOZ_UNANNOTATED;  // protects mBlockers and mResolved.
+  std::map<void*, bool> mBlockers;
+  bool mResolved = false;
+  const RefPtr<GenericPromise::Private> mPromise;
+};
+
+}  // namespace mozilla::ipc
+
+#endif  // mozilla_ipc_AsyncBlockers_h

ipc/glue/moz.build

@@ -10,6 +10,7 @@ EXPORTS += [
 ]
 
 EXPORTS.mozilla.ipc += [
+    "AsyncBlockers.h",
     "BackgroundChild.h",
     "BackgroundParent.h",
     "BackgroundStarterChild.h",