AndroidProfiler.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
 
#include "CoreTypes.h"
#include "CoreMinimal.h"
 
/*
* Invokes android's built-in perfetto capture API.
*
* Usage:
* FString ProfileName = FAndroidProfiler::StartCapture(ArgsString, [](const FAndroidProfiler::FProfileResults& Results)
                { 
                    // lambda to be called when capture completes.
                    // This can be called from a random thread.
                    // params: 
                    // Results.ProfileName  == the tag/name used when initiating the profiling session.
                    // Results.Error        == Any errors or warnings generated during the session
                    // Results.FilePath     == empty on error. otherwise contains the path to the perfetto capture.
                    //                          the file is in the apps internal files folder. it is up to the application
                    //                          to move or delete this file.
                } );
* 
* where ArgsString = "callstack [optional args]"
*       ArgsString = "heap      [optional args]"
*       ArgsString = "system    [optional args]"
*
* optional args can be any of the following (space delimited):
* 
*  duration=x                               (in seconds, default 10)
*  buffersize=x                             (in kb, default 1000)
*  profilename=x                            (unique name for the profile session, default 'profile')
*                                           (you cannot have concurrent sessions with the same name.) 
*  samplingfreq=x                           (callstack profile only. number of samples per second, default 100)
*  samplingintervalbytes=x                  (heap profile only. alloc granularity of heap samples, default 100)
*  bufferfillpolicy=[ringbuffer|discard]    (system profile only. default ringbuffer)
*
* example: callstack samplingfreq=1000 duration=30
*
* to stop an in progress capture:
*   param ProfileName is the name/tag of the profile to cancel (i.e. as returned from StartCapture)
* FAndroidProfiler::StopCapture(ProfileName);
*
*/
 
class FAndroidProfiler
{
public:
 
    struct FProfileResults
    {
        FString ProfileName;// string used to identify the profile session.
        FString Error;      // Any errors or warnings produced
        FString FilePath;   // path to any output produced. empty on error.
    };
 
    // Returns an FString used to identify the profile session.
    static FString StartCapture(const FString& Args, TUniqueFunction<void(const FAndroidProfiler::FProfileResults& Results)> OnFinish);
 
    // stop an in-progress profile session.
    static void StopCapture(const FString& ProfileName);
 
private:
    static inline FCriticalSection ProfilerCS;
 
    // Called when a profile session ends. (either on success or on error)
    static void OnProfileFinish(const FAndroidProfiler::FProfileResults& Results);
 
    struct FActiveSessions
    {
        TUniqueFunction<void(const FProfileResults& Results)> OnFinish;
    };
    static inline TMap<FString, FActiveSessions> ActiveSessions;
 
    friend struct FAndroidProfilerInternal;
};