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// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CHROME_BROWSER_WEB_APPLICATIONS_LOCKS_NOOP_LOCK_H_
#define CHROME_BROWSER_WEB_APPLICATIONS_LOCKS_NOOP_LOCK_H_
#include "base/memory/weak_ptr.h"
#include "chrome/browser/web_applications/locks/lock.h"
namespace web_app {
class WebAppLockManager;
// This lock essentially doesn't lock anything in the system. However, if a
// `AllAppsLock` is used, then that will block the acquisition of this lock.
//
// Locks can be acquired by using the `WebAppLockManager`.
class NoopLockDescription : public LockDescription {
public:
NoopLockDescription();
~NoopLockDescription();
NoopLockDescription(NoopLockDescription&&);
};
// Holding a NoopLock is required when a locked operation needs to be executed,
// but there is no explicit resource to be locked yet. If a resource shows up in
// the middle of the command, an upgrade from a NoopLock to an AppLock or
// SharedWebContentsWithAppLock may occur.
//
// See `WebAppLockManager` for how to use locks. Destruction of this class will
// release the lock or cancel the lock request if it is not acquired yet.
//
// Note: Accessing a lock before it is granted or after the WebAppProvider
// system has shutdown (or the profile has shut down) will CHECK-fail.
class NoopLock : public Lock {
public:
using LockDescription = NoopLockDescription;
NoopLock();
~NoopLock();
base::WeakPtr<NoopLock> AsWeakPtr() { return weak_factory_.GetWeakPtr(); }
private:
friend WebAppLockManager;
void GrantLock(WebAppLockManager& lock_manager);
base::WeakPtrFactory<NoopLock> weak_factory_{this};
};
} // namespace web_app
#endif // CHROME_BROWSER_WEB_APPLICATIONS_LOCKS_NOOP_LOCK_H_
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