impeller::GPUTracerMTL Class Reference

Approximate the GPU frame time by computing a difference between the smallest GPUStartTime and largest GPUEndTime for all command buffers submitted in a frame workload. More...

#include <gpu_tracer_mtl.h>

Inheritance diagram for impeller::GPUTracerMTL:

Public Member Functions
	GPUTracerMTL ()=default
	~GPUTracerMTL ()=default
void	MarkFrameEnd ()
	Record that the current frame has ended. Any additional cmd buffers will be attributed to the "next" frame.
void	RecordCmdBuffer (id< MTLCommandBuffer > buffer)
	Record the current cmd buffer GPU execution timestamps into an aggregate frame workload metric.

Detailed Description

Approximate the GPU frame time by computing a difference between the smallest GPUStartTime and largest GPUEndTime for all command buffers submitted in a frame workload.

Definition at line 23 of file gpu_tracer_mtl.h.

Constructor & Destructor Documentation

GPUTracerMTL()

impeller::GPUTracerMTL::GPUTracerMTL ( )

default

~GPUTracerMTL()

impeller::GPUTracerMTL::~GPUTracerMTL ( )

default

Member Function Documentation

MarkFrameEnd()

void impeller::GPUTracerMTL::MarkFrameEnd

(

)

Record that the current frame has ended. Any additional cmd buffers will be attributed to the "next" frame.

Definition at line 16 of file gpu_tracer_mtl.mm.

                                {
  if (@available(ios 10.3, tvos 10.2, macos 10.15, macCatalyst 13.0, *)) {
    Lock lock(trace_state_mutex_);
    current_state_ = (current_state_ + 1) % 16;
  }
}

RecordCmdBuffer()

void impeller::GPUTracerMTL::RecordCmdBuffer

(

id< MTLCommandBuffer >

buffer

)

Record the current cmd buffer GPU execution timestamps into an aggregate frame workload metric.

Definition at line 23 of file gpu_tracer_mtl.mm.

                                                              {
  if (@available(ios 10.3, tvos 10.2, macos 10.15, macCatalyst 13.0, *)) {
    Lock lock(trace_state_mutex_);
    auto current_state = current_state_;
    trace_states_[current_state].pending_buffers += 1;
 
    auto weak_self = weak_from_this();
    [buffer addCompletedHandler:^(id<MTLCommandBuffer> buffer) {
      auto self = weak_self.lock();
      if (!self) {
        return;
      }
      Lock lock(self->trace_state_mutex_);
      auto& state = self->trace_states_[current_state];
      state.pending_buffers--;
      state.smallest_timestamp = std::min(
          state.smallest_timestamp, static_cast<Scalar>(buffer.GPUStartTime));
      state.largest_timestamp = std::max(
          state.largest_timestamp, static_cast<Scalar>(buffer.GPUEndTime));
 
      if (state.pending_buffers == 0) {
        auto gpu_ms =
            (state.largest_timestamp - state.smallest_timestamp) * 1000;
        state.smallest_timestamp = std::numeric_limits<float>::max();
        state.largest_timestamp = 0;
        FML_TRACE_COUNTER("flutter", "GPUTracer",
                          reinterpret_cast<int64_t>(this),  // Trace Counter ID
                          "FrameTimeMS", gpu_ms);
      }
    }];
  }
}

References FML_TRACE_COUNTER, and self.

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The documentation for this class was generated from the following files:

• impeller/renderer/backend/metal/gpu_tracer_mtl.h
• impeller/renderer/backend/metal/gpu_tracer_mtl.mm