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// Copyright 2013 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_SYNC_TEST_INTEGRATION_STATUS_CHANGE_CHECKER_H_
#define CHROME_BROWSER_SYNC_TEST_INTEGRATION_STATUS_CHANGE_CHECKER_H_
#include <iosfwd>
#include "base/location.h"
#include "base/run_loop.h"
#include "base/time/time.h"
namespace switches {
inline constexpr char kStatusChangeCheckerTimeoutInSeconds[] =
"sync-status-change-checker-timeout";
} // namespace switches
// Interface for a helper class that can pump the message loop while waiting
// for a certain state transition to take place.
//
// This is a template that should be filled in by child classes so they can
// observe specific kinds of changes and await specific conditions.
//
// The instances of this class are intended to be single-use. It doesn't make
// sense to call StartBlockingWait() more than once.
//
// |switches::kStatusChangeCheckerTimeoutInSeconds| can be passed to the command
// line to override the timeout used by instances of this class.
class StatusChangeChecker {
public:
StatusChangeChecker();
// Block if IsExitConditionSatisfied() is currently false until TimedOut()
// becomes true. Checkers should call CheckExitCondition upon changes, which
// can cause Wait() to immediately return true if IsExitConditionSatisfied(),
// and continue to block if not. Returns false if and only if timeout occurs.
bool Wait(const base::Location& location = FROM_HERE);
// Returns true if the blocking wait was exited because of a timeout.
bool TimedOut() const;
protected:
virtual ~StatusChangeChecker();
// Allows subclasses to run custom logic when Wait() is invoked.
virtual void WillStartWaiting();
// Returns whether the state the checker is currently in is its desired
// configuration. |os| must not be null and allows subclasses to provide
// details about why the condition was not satisfied. |os| must not be null.
virtual bool IsExitConditionSatisfied(std::ostream* os) = 0;
// Checks IsExitConditionSatisfied() and calls StopWaiting() if it returns
// true.
virtual void CheckExitCondition();
// Called when Wait() is done, i.e. from StopWaiting(). Subclasses can
// override this to capture state at exactly the time that the exit condition
// is satisfied. This does *not* get called in the timeout case.
// If the exit condition is already satisfied at the time Wait() is called,
// then this is called immediately.
virtual void WaitDone() {}
private:
// Helper function to start running the nested run loop (run_loop_).
//
// Will exit if IsExitConditionSatisfied() returns true when called from
// CheckExitCondition(), if a timeout occurs, or if StopWaiting() is called.
//
// The timeout length is specified with GetTimeoutDuration().
void StartBlockingWait(const base::Location& location);
// Stop the nested running of the message loop started in StartBlockingWait().
void StopWaiting();
// Called when the blocking wait timeout is exceeded.
void OnTimeout(const base::Location& location);
const base::TimeDelta timeout_;
base::RunLoop run_loop_;
bool timed_out_ = false;
bool wait_done_called_ = false;
};
#endif // CHROME_BROWSER_SYNC_TEST_INTEGRATION_STATUS_CHANGE_CHECKER_H_
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