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106 lines (82 loc) · 2.99 KB
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// Copied from upstream cefclient with minor modifications.
// 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 "main_message_loop_external_pump.h"
#include <climits>
#include "include/cef_app.h"
#include "include/wrapper/cef_helpers.h"
#include "main_message_loop.h"
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
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_;
}