Version: 2020.3
  • C#


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public static void FlowEvent(uint flowId, Unity.Profiling.ProfilerFlowEventType flowEventType);


flowId Profiler flow identifier.
flowEventType Flow event type.


Add flow event to a Profiler sample.

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.

See Also: CreateFlow, CPU Usage Profiler module.