lib/magma/src/magma_util/platform/platform_trace.h

// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef PLATFORM_TRACE_H
#define PLATFORM_TRACE_H

#include <functional>

#include <lib/fit/function.h>

#if MAGMA_ENABLE_TRACING
#include "trace-vthread/event_vthread.h"
#include <trace/event.h>
#define TRACE_NONCE_DECLARE(x) uint64_t x = TRACE_NONCE()
#else
#define TRACE_NONCE() 0
#define TRACE_NONCE_DECLARE(x)
#define TRACE_ASYNC_BEGIN(category, name, id, args...)
#define TRACE_ASYNC_END(category, name, id, args...)
#define TRACE_SCOPE_GLOBAL 0
#define TRACE_INSTANT(category, name, id, args...)
#define TRACE_DURATION(category, name, args...)
#define TRACE_DURATION_BEGIN(category, name, args...)
#define TRACE_DURATION_END(category, name, args...)
#define TRACE_FLOW_BEGIN(category, name, id, args...)
#define TRACE_FLOW_STEP(category, name, id, args...)
#define TRACE_FLOW_END(category, name, id, args...)
#define TRACE_VTHREAD_DURATION_BEGIN(category, name, vthread_name, vthread_id, timestamp, args...)
#define TRACE_VTHREAD_DURATION_END(category, name, vthread_name, vthread_id, timestamp, args...)
#endif

namespace magma {

class PlatformTrace {
public:
    virtual ~PlatformTrace() {}

    virtual bool Initialize() = 0;

    // Returns the current time in ticks.
    static uint64_t GetCurrentTicks();

    // Returns null if tracing is not enabled.
    static PlatformTrace* Get();
};

class PlatformTraceObserver {
public:
    virtual ~PlatformTraceObserver() {}

    static std::unique_ptr<PlatformTraceObserver> Create();

    virtual bool Initialize() = 0;

    // Invokes the given |callback| (on a different thread) when the tracing state changes.
    virtual void SetObserver(fit::function<void(bool trace_enabled)> callback) = 0;
};

} // namespace magma

#endif // PLATFORM_TRACE_H