Add ScopedSurfaceRequestManager

content/browser/android/scoped_surface_request_manager.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/browser/android/scoped_surface_request_manager.h"
+
+#include "base/base64.h"
+#include "content/public/browser/browser_thread.h"
+#include "crypto/random.h"
+
+namespace content {
+
+const int kRequestTokenSize = 16;
+// 128 bits / (6 bits per base64 char) = 22.33 chars, or 24 chars with padding.
+const size_t kPaddedStringTokenSize = 24;
+
+// static
+ScopedSurfaceRequestManager* ScopedSurfaceRequestManager::GetInstance() {
+  return base::Singleton<
+      ScopedSurfaceRequestManager,
+      base::LeakySingletonTraits<ScopedSurfaceRequestManager>>::get();
+}
+
+base::Nonce ScopedSurfaceRequestManager::RegisterScopedSurfaceRequest(
+    ScopedSurfaceRequestCB request_cb) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  DCHECK(!request_cb.is_null());
+
+  base::Nonce request_token = base::Nonce::Generate();
+
+  DCHECK(!request_callbacks_.count(request_token));
+  request_callbacks_.insert(std::make_pair(request_token, request_cb));
+
+  return request_token;
+}
+
+void ScopedSurfaceRequestManager::UnregisterScopedSurfaceRequest(
+    base::Nonce request_token) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  GetAndUnregisterInternal(request_token);
+}
+
+ScopedSurfaceRequestManager::ScopedSurfaceRequestCB
+ScopedSurfaceRequestManager::GetAndUnregisterInternal(
+    base::Nonce request_token) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  ScopedSurfaceRequestManager::ScopedSurfaceRequestCB request;
+
+  auto it = request_callbacks_.find(request_token);
+  if (it != request_callbacks_.end()) {
+    request = it->second;
+    request_callbacks_.erase(it);
+  }
+
+  return request;
+}
+
+void ScopedSurfaceRequestManager::ForwardSurfaceTextureForSurfaceRequest(
+    base::Nonce request_token,
+    gl::SurfaceTexture* surface_texture) {

[no sievers, 2016/09/13 23:25:56]

nit: should be |const gl::SurfaceTexture*|

[tguilbert, 2016/09/20 03:08:40]

Done.

+  gl::ScopedJavaSurface surface(surface_texture);
+  FulfillScopedSurfaceRequest(request_token, std::move(surface));
+}
+
+void ScopedSurfaceRequestManager::FulfillScopedSurfaceRequest(
+    base::Nonce request_token,
+    gl::ScopedJavaSurface surface) {
+  if (!BrowserThread::CurrentlyOn(BrowserThread::UI)) {

[no sievers, 2016/09/13 23:25:56]

You might want to DCHECK() that this is *not* called on the UI thread.
That could cause deadlocks if the GPU process synchronously calls back onto the
UI thread.

[tguilbert, 2016/09/20 03:08:40]

I changed this to always post onto the UI thread, and then to complete the
request.

+    // base::Unretained is safe because the lifetime of this object is tied to
+    // the lifetime of the browser process.
+    BrowserThread::PostTask(
+        BrowserThread::UI, FROM_HERE,
+        base::Bind(&ScopedSurfaceRequestManager::FulfillScopedSurfaceRequest,
+                   base::Unretained(this), request_token,
+                   base::Passed(std::move(surface))));
+    return;
+  }
+
+  ScopedSurfaceRequestManager::ScopedSurfaceRequestCB request =
+      GetAndUnregisterInternal(request_token);
+
+  if (!request.is_null())
+    request.Run(std::move(surface));
+}
+
+ScopedSurfaceRequestManager::ScopedSurfaceRequestManager() {}
+
+ScopedSurfaceRequestManager::~ScopedSurfaceRequestManager() {}
+
+}  // namespace content