FTL: Yield futures without overhead
ftl::yield, which lifts T to std::future<T>, incurs the cost of
allocating, ref counting, and locking the latter's shared state.
Consolidate the existing std::future extensions into ftl::Future,
and optimize ftl::yield by including static storage for T within.
Bug: 232436803
Test: simpleperf (-31% cycles in postFramebuffer)
Change-Id: I9a7ca7de17e7af10515de97d2f6a0dfa24e35d7a
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.cpp b/services/surfaceflinger/DisplayHardware/HWC2.cpp
index adf4be3..c52e96d 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWC2.cpp
@@ -27,7 +27,6 @@
#include "HWC2.h"
#include <android/configuration.h>
-#include <ftl/future.h>
#include <ui/Fence.h>
#include <ui/FloatRect.h>
#include <ui/GraphicBuffer.h>
@@ -543,7 +542,7 @@
return error;
}
-std::future<Error> Display::setDisplayBrightness(
+ftl::Future<Error> Display::setDisplayBrightness(
float brightness, float brightnessNits,
const Hwc2::Composer::DisplayBrightnessOptions& options) {
return ftl::defer([composer = &mComposer, id = mId, brightness, brightnessNits, options] {
diff --git a/services/surfaceflinger/DisplayHardware/HWC2.h b/services/surfaceflinger/DisplayHardware/HWC2.h
index cca20bd..24aef9b 100644
--- a/services/surfaceflinger/DisplayHardware/HWC2.h
+++ b/services/surfaceflinger/DisplayHardware/HWC2.h
@@ -18,6 +18,7 @@
#include <android-base/expected.h>
#include <android-base/thread_annotations.h>
+#include <ftl/future.h>
#include <gui/HdrMetadata.h>
#include <math/mat4.h>
#include <ui/HdrCapabilities.h>
@@ -28,7 +29,6 @@
#include <utils/Timers.h>
#include <functional>
-#include <future>
#include <string>
#include <unordered_map>
#include <unordered_set>
@@ -147,7 +147,7 @@
uint32_t* outNumRequests,
android::sp<android::Fence>* outPresentFence,
uint32_t* state) = 0;
- [[nodiscard]] virtual std::future<hal::Error> setDisplayBrightness(
+ [[nodiscard]] virtual ftl::Future<hal::Error> setDisplayBrightness(
float brightness, float brightnessNits,
const Hwc2::Composer::DisplayBrightnessOptions& options) = 0;
[[nodiscard]] virtual hal::Error setActiveConfigWithConstraints(
@@ -229,7 +229,7 @@
uint32_t* outNumRequests,
android::sp<android::Fence>* outPresentFence,
uint32_t* state) override;
- std::future<hal::Error> setDisplayBrightness(
+ ftl::Future<hal::Error> setDisplayBrightness(
float brightness, float brightnessNits,
const Hwc2::Composer::DisplayBrightnessOptions& options) override;
hal::Error setActiveConfigWithConstraints(hal::HWConfigId configId,
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.cpp b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
index 79e4c75..0da8ece 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.cpp
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.cpp
@@ -30,7 +30,6 @@
#include <compositionengine/Output.h>
#include <compositionengine/OutputLayer.h>
#include <compositionengine/impl/OutputLayerCompositionState.h>
-#include <ftl/future.h>
#include <log/log.h>
#include <ui/DebugUtils.h>
#include <ui/GraphicBuffer.h>
@@ -720,13 +719,13 @@
return NO_ERROR;
}
-std::future<status_t> HWComposer::setDisplayBrightness(
+ftl::Future<status_t> HWComposer::setDisplayBrightness(
PhysicalDisplayId displayId, float brightness, float brightnessNits,
const Hwc2::Composer::DisplayBrightnessOptions& options) {
RETURN_IF_INVALID_DISPLAY(displayId, ftl::yield<status_t>(BAD_INDEX));
auto& display = mDisplayData[displayId].hwcDisplay;
- return ftl::chain(display->setDisplayBrightness(brightness, brightnessNits, options))
+ return display->setDisplayBrightness(brightness, brightnessNits, options)
.then([displayId](hal::Error error) -> status_t {
if (error == hal::Error::UNSUPPORTED) {
RETURN_IF_HWC_ERROR(error, displayId, INVALID_OPERATION);
diff --git a/services/surfaceflinger/DisplayHardware/HWComposer.h b/services/surfaceflinger/DisplayHardware/HWComposer.h
index 7dc10ea..4c0ecd8 100644
--- a/services/surfaceflinger/DisplayHardware/HWComposer.h
+++ b/services/surfaceflinger/DisplayHardware/HWComposer.h
@@ -17,7 +17,6 @@
#pragma once
#include <cstdint>
-#include <future>
#include <memory>
#include <mutex>
#include <optional>
@@ -26,6 +25,7 @@
#include <vector>
#include <android-base/thread_annotations.h>
+#include <ftl/future.h>
#include <ui/DisplayIdentification.h>
#include <ui/FenceTime.h>
@@ -195,7 +195,7 @@
DisplayedFrameStats* outStats) = 0;
// Sets the brightness of a display.
- virtual std::future<status_t> setDisplayBrightness(
+ virtual ftl::Future<status_t> setDisplayBrightness(
PhysicalDisplayId, float brightness, float brightnessNits,
const Hwc2::Composer::DisplayBrightnessOptions&) = 0;
@@ -372,7 +372,7 @@
uint64_t maxFrames) override;
status_t getDisplayedContentSample(HalDisplayId, uint64_t maxFrames, uint64_t timestamp,
DisplayedFrameStats* outStats) override;
- std::future<status_t> setDisplayBrightness(
+ ftl::Future<status_t> setDisplayBrightness(
PhysicalDisplayId, float brightness, float brightnessNits,
const Hwc2::Composer::DisplayBrightnessOptions&) override;