skia2/tools/gpu/GpuTimer.h
2016-10-05 08:42:03 -07:00

78 lines
2.2 KiB
C++

/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef GpuTimer_DEFINED
#define GpuTimer_DEFINED
#include "SkTypes.h"
#include "SkExchange.h"
#include <chrono>
namespace sk_gpu_test {
using PlatformTimerQuery = uint64_t;
static constexpr PlatformTimerQuery kInvalidTimerQuery = 0;
/**
* Platform-independent interface for timing operations on the GPU.
*/
class GpuTimer {
public:
GpuTimer(bool disjointSupport)
: fDisjointSupport(disjointSupport)
, fActiveTimer(kInvalidTimerQuery) {
}
virtual ~GpuTimer() { SkASSERT(!fActiveTimer); }
/**
* Returns whether this timer can detect disjoint GPU operations while timing. If false, a query
* has less confidence when it completes with QueryStatus::kAccurate.
*/
bool disjointSupport() const { return fDisjointSupport; }
/**
* Inserts a "start timing" command in the GPU command stream.
*/
void queueStart() {
SkASSERT(!fActiveTimer);
fActiveTimer = this->onQueueTimerStart();
}
/**
* Inserts a "stop timing" command in the GPU command stream.
*
* @return a query object that can retrieve the time elapsed once the timer has completed.
*/
PlatformTimerQuery SK_WARN_UNUSED_RESULT queueStop() {
SkASSERT(fActiveTimer);
this->onQueueTimerStop(fActiveTimer);
return skstd::exchange(fActiveTimer, kInvalidTimerQuery);
}
enum class QueryStatus {
kInvalid, //<! the timer query is invalid.
kPending, //<! the timer is still running on the GPU.
kDisjoint, //<! the query is complete, but dubious due to disjoint GPU operations.
kAccurate //<! the query is complete and reliable.
};
virtual QueryStatus checkQueryStatus(PlatformTimerQuery) = 0;
virtual std::chrono::nanoseconds getTimeElapsed(PlatformTimerQuery) = 0;
virtual void deleteQuery(PlatformTimerQuery) = 0;
private:
virtual PlatformTimerQuery onQueueTimerStart() const = 0;
virtual void onQueueTimerStop(PlatformTimerQuery) const = 0;
bool const fDisjointSupport;
PlatformTimerQuery fActiveTimer;
};
} // namespace sk_gpu_test
#endif