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Unity Engine

FlowEvent(uint, ProfilerFlowEventType)

Add flow event to a Profiler sample.
Read time 2 minutesLast updated 13 days ago

Definition

public static void FlowEvent(uint flowId, ProfilerFlowEventType flowEventType)

Parameters

flowId

uint
Profiler flow identifier.

flowEventType

ProfilerFlowEventType
Flow event type.

Remarks

Use Profiler flow events to highlight the dependencies between task execution on different threads.
Flow event works in conjunction with ProfilerMarker.
using System;using System.Threading;using Unity.Profiling;using Unity.Profiling.LowLevel;using Unity.Profiling.LowLevel.Unsafe;public class Example{    public const int k_NumberOfTasks = 4;    static readonly ProfilerMarker k_ScheduleParallelTasksMarker = new ProfilerMarker("Schedule Parallel Tasks");    static readonly ProfilerMarker k_ParallelTaskMarker = new ProfilerMarker("Parallel Task");    static readonly ProfilerMarker k_TaskSyncMarker = new ProfilerMarker("Sync Task");    static void EmitFlowEventAndChainThread(uint flowId)    {        // Mark the next k_ParallelTaskMarker as a beginning of the flow        ProfilerUnsafeUtility.FlowEvent(flowId, ProfilerFlowEventType.ParallelNext);        using (k_ParallelTaskMarker.Auto())        {            // Do work        }    }    static void ScheduleParallelTask()    {        uint flowId;        var threads = new Thread[k_NumberOfTasks];        using (k_ScheduleParallelTasksMarker.Auto())        {            flowId = ProfilerUnsafeUtility.CreateFlow(ProfilerUnsafeUtility.CategoryScripts);            // Mark the parent k_ScheduleParallelTasksMarker as a beginning of the flow            ProfilerUnsafeUtility.FlowEvent(flowId, ProfilerFlowEventType.Begin);            for (var i = 0; i < k_NumberOfTasks; ++i)            {                var thread = new Thread(() => EmitFlowEventAndChainThread(flowId));                thread.Start();                threads[i] = thread;            }        }        using (k_TaskSyncMarker.Auto())        {            // Mark the parent k_TaskSyncMarker as a beginning of the flow            ProfilerUnsafeUtility.FlowEvent(flowId, ProfilerFlowEventType.End);            for (var i = 0; i < k_NumberOfTasks; ++i)                threads[i].Join();        }    }}
You must use 
FlowEvent
together with a ProfilerMarker.
To mark the sample as a beginning or end of a flow, use 
FlowEvent
with ProfilerFlowEventType.Begin and ProfilerFlowEventType.End events within a scope that is instrumented with ProfilerMarker.Begin and ProfilerMarker.End, or within the 
using
scope of ProfilerMarker.Auto.
To mark the sample as a flow continuation point, use 
FlowEvent
with ProfilerFlowEventType.Next and ProfilerFlowEventType.ParallelNext before a call to ProfilerMarker.Begin or ProfilerMarker.Auto.
Note: Unity Job System automatically marks up job scheduling, execution and wait points.
Additional Resources: ProfilerUnsafeUtility.CreateFlow, CPU Usage Profiler module.