blob: 6ebd7afa503ce66d6b12c36fe5bfb9d1dbb80103 [file] [log] [blame]
// Copyright (c) 2012 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 "base/callback.h"
#include "base/macros.h"
#include "build/build_config.h"
#if defined(OS_IOS)
#include "base/bind.h"
#include "base/ios/scoped_critical_action.h"
namespace base {
namespace internal {
#if defined(OS_IOS)
// Returns true if multi-tasking is supported on this iOS device.
bool IsMultiTaskingSupported();
// This class wraps a closure so it can continue to run for a period of time
// when the application goes to the background by using
// |ios::ScopedCriticalAction|.
template <typename R>
class CriticalClosure {
explicit CriticalClosure(const Callback<R(void)>& closure)
: closure_(closure) {}
~CriticalClosure() {}
R Run() {
return closure_.Run();
ios::ScopedCriticalAction critical_action_;
Callback<R(void)> closure_;
#endif // defined(OS_IOS)
} // namespace internal
// Returns a closure (which may return a result, but must not require any extra
// arguments) that will continue to run for a period of time when the
// application goes to the background if possible on platforms where
// applications don't execute while backgrounded, otherwise the original task is
// returned.
// Example:
// file_task_runner_->PostTask(
// MakeCriticalClosure(base::Bind(&WriteToDiskTask, path_, data)));
// Note new closures might be posted in this closure. If the new closures need
// background running time, |MakeCriticalClosure| should be applied on them
// before posting.
#if defined(OS_IOS)
template <typename R>
Callback<R(void)> MakeCriticalClosure(const Callback<R(void)>& closure) {
return base::Bind(&internal::CriticalClosure<R>::Run,
Owned(new internal::CriticalClosure<R>(closure)));
#else // defined(OS_IOS)
template <typename R>
inline Callback<R(void)> MakeCriticalClosure(const Callback<R(void)>& closure) {
// No-op for platforms where the application does not need to acquire
// background time for closures to finish when it goes into the background.
return closure;
#endif // defined(OS_IOS)
} // namespace base