--- /dev/null
+// Copyright (c) 2016 The Chromium Embedded Framework 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 "tests/shared/browser/main_message_loop_external_pump.h"
+
+#include <climits>
+
+#include "include/cef_app.h"
+#include "include/wrapper/cef_helpers.h"
+#include "tests/shared/browser/main_message_loop.h"
+
+namespace client {
+
+namespace {
+
+// Special timer delay placeholder value. Intentionally 32-bit for Windows and
+// OS X platform API compatibility.
+const int32 kTimerDelayPlaceholder = INT_MAX;
+
+// The maximum number of milliseconds we're willing to wait between calls to
+// DoWork().
+const int64 kMaxTimerDelay = 1000 / 30; // 30fps
+
+client::MainMessageLoopExternalPump* g_external_message_pump = NULL;
+
+} // namespace
+
+MainMessageLoopExternalPump::MainMessageLoopExternalPump()
+ : is_active_(false),
+ reentrancy_detected_(false) {
+ DCHECK(!g_external_message_pump);
+ g_external_message_pump = this;
+}
+
+MainMessageLoopExternalPump::~MainMessageLoopExternalPump() {
+ g_external_message_pump = NULL;
+}
+
+MainMessageLoopExternalPump* MainMessageLoopExternalPump::Get() {
+ return g_external_message_pump;
+}
+
+void MainMessageLoopExternalPump::OnScheduleWork(int64 delay_ms) {
+ REQUIRE_MAIN_THREAD();
+
+ if (delay_ms == kTimerDelayPlaceholder && IsTimerPending()) {
+ // Don't set the maximum timer requested from DoWork() if a timer event is
+ // currently pending.
+ return;
+ }
+
+ KillTimer();
+
+ if (delay_ms <= 0) {
+ // Execute the work immediately.
+ DoWork();
+ } else {
+ // Never wait longer than the maximum allowed time.
+ if (delay_ms > kMaxTimerDelay)
+ delay_ms = kMaxTimerDelay;
+
+ // Results in call to OnTimerTimeout() after the specified delay.
+ SetTimer(delay_ms);
+ }
+}
+
+void MainMessageLoopExternalPump::OnTimerTimeout() {
+ REQUIRE_MAIN_THREAD();
+
+ KillTimer();
+ DoWork();
+}
+
+void MainMessageLoopExternalPump::DoWork() {
+ const bool was_reentrant = PerformMessageLoopWork();
+ if (was_reentrant) {
+ // Execute the remaining work as soon as possible.
+ OnScheduleMessagePumpWork(0);
+ } else if (!IsTimerPending()) {
+ // Schedule a timer event at the maximum allowed time. This may be dropped
+ // in OnScheduleWork() if another timer event is already in-flight.
+ OnScheduleMessagePumpWork(kTimerDelayPlaceholder);
+ }
+}
+
+bool MainMessageLoopExternalPump::PerformMessageLoopWork() {
+ if (is_active_) {
+ // When CefDoMessageLoopWork() is called there may be various callbacks
+ // (such as paint and IPC messages) that result in additional calls to this
+ // method. If re-entrancy is detected we must repost a request again to the
+ // owner thread to ensure that the discarded call is executed in the future.
+ reentrancy_detected_ = true;
+ return false;
+ }
+
+ reentrancy_detected_ = false;
+
+ is_active_ = true;
+ CefDoMessageLoopWork();
+ is_active_ = false;
+
+ // |reentrancy_detected_| may have changed due to re-entrant calls to this
+ // method.
+ return reentrancy_detected_;
+}
+
+} // namespace client