Files
oemcrypto/util/test/test_sleep.h
2024-11-26 20:50:11 +00:00

92 lines
3.4 KiB
C++

// Copyright 2019 Google LLC. All Rights Reserved. This file and proprietary
// source code may only be used and distributed under the Widevine License
// Agreement.
//
// TestSleep - Controls sleep and clock adjustment during tests.
//
#ifndef WVCDM_UTIL_TEST_SLEEP_H_
#define WVCDM_UTIL_TEST_SLEEP_H_
#include <stdint.h>
#include <unordered_set>
namespace wvutil {
class TestSleep {
public:
// The callback is called when the test clock should be advanced. If the
// system uses a real clock, it is used to sync the real and test
// clock. Otherwise it is used to simulate sleep in the test clock.
class CallBack {
public:
virtual void ElapseTime(int64_t milliseconds) = 0;
protected:
virtual ~CallBack(){};
};
// If real_sleep_ is true, then this sleeps for |seconds| of time. If
// real_sleep_ is false, then the fake clock is advanced by |seconds|. If the
// callback exists, this calls the callback.
static void Sleep(unsigned int seconds);
// Like sleep, above, except it sleeps until the specified time.
static void SleepUntil(int64_t desired_time);
// If we are using a real clock and a fake clock, then the real clock advances
// a little while we are doing work, but the fake one only advances when we
// sleep. This function advances the fake clock to be in sync with the real
// clock. This function should be called to prevent a slow flaky test from
// failing due to this drift.
static void SyncFakeClock();
// Roll the system clock back by |seconds|. Returns true on success. A well
// mannered test will call CanChangeSystemTime before attempting to call this
// function and then assert that this is true. This function should *NOT* roll
// back the clock used by OEMCrypto -- in fact, there are several tests that
// verify this function does not roll back the clock used by OEMCrypto.
static bool RollbackSystemTime(int seconds);
// Set the system clock to the specified time. This is only expected to work
// when real_sleep is false.
static void SetFakeClock(int64_t time_seconds);
// Roll the system clock forward to undo all previous calls to
// RollBackSystemTime. Returns true on success.
static bool ResetRollback() {
return total_clock_rollback_seconds_ == 0 ||
RollbackSystemTime(-total_clock_rollback_seconds_);
}
// Returns true if the system time can be rolled back. This is true on some
// devices if the tests are run as root. It is also true when using a fake
// clock with the reference version of OEMCrypto. This function is about the
// system clock, *NOT* the clock used by OEMCrypto.
static bool CanChangeSystemTime();
static void set_real_sleep(bool real_sleep) { real_sleep_ = real_sleep; }
static bool real_sleep() { return real_sleep_; }
// The callback is notified whenever sleep is called.
static void AddCallback(CallBack* callback) {
callbacks_.insert(callback);
}
static void RemoveCallback(CallBack* callback) {
callbacks_.erase(callback);
}
private:
// Controls if the test sleep should use real sleep.
static bool real_sleep_;
// Called when the clock should advance.
static std::unordered_set<CallBack*> callbacks_;
// The sum of all calls to RollBackSystemTime. Kept so we can undo all changes
// at the end of a test.
static int total_clock_rollback_seconds_;
};
} // namespace wvutil
#endif // WVCDM_UTIL_TEST_SLEEP_H_