1 files changed, 195 insertions, 0 deletions
diff --git a/hal/android/AndroidPerformanceHintManager.cpp b/hal/android/AndroidPerformanceHintManager.cpp
new file mode 100644
index 0000000000..a9507a8272
--- /dev/null
+++ b/hal/android/AndroidPerformanceHintManager.cpp
@@ -0,0 +1,195 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+#include "Hal.h"
+#include "HalLog.h"
+#include "HalTypes.h"
+
+#include "AndroidBuild.h"
+
+#include <dlfcn.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+typedef struct APerformanceHintManager APerformanceHintManager;
+typedef struct APerformanceHintSession APerformanceHintSession;
+
+namespace mozilla {
+namespace hal_impl {
+
+#define LOAD_FN(api, lib, name)                                      \
+  do {                                                               \
+    api->m##name = reinterpret_cast<Fn##name>(dlsym(handle, #name)); \
+    if (!api->m##name) {                                             \
+      HAL_ERR("Failed to load %s", #name);                           \
+      return nullptr;                                                \
+    }                                                                \
+  } while (false)
+
+class PerformanceHintManagerApi final {
+ public:
+  static PerformanceHintManagerApi* Get() {
+    // C++ guarantees local static variable initialization is thread safe
+    static UniquePtr<PerformanceHintManagerApi> api = Create();
+    return api.get();
+  }
+
+  APerformanceHintManager* APerformanceHint_getManager() const {
+    return mAPerformanceHint_getManager();
+  }
+
+  APerformanceHintSession* APerformanceHint_createSession(
+      APerformanceHintManager* manager, const int32_t* threadIds, size_t size,
+      int64_t initialTargetWorkDurationNanos) const {
+    return mAPerformanceHint_createSession(manager, threadIds, size,
+                                           initialTargetWorkDurationNanos);
+  }
+
+  int APerformanceHint_updateTargetWorkDuration(
+      APerformanceHintSession* session, int64_t targetDurationNanos) const {
+    return mAPerformanceHint_updateTargetWorkDuration(session,
+                                                      targetDurationNanos);
+  }
+
+  int APerformanceHint_reportActualWorkDuration(
+      APerformanceHintSession* session, int64_t actualDurationNanos) const {
+    return mAPerformanceHint_reportActualWorkDuration(session,
+                                                      actualDurationNanos);
+  }
+
+  void APerformanceHint_closeSession(APerformanceHintSession* session) const {
+    mAPerformanceHint_closeSession(session);
+  }
+
+ private:
+  PerformanceHintManagerApi() = default;
+
+  static UniquePtr<PerformanceHintManagerApi> Create() {
+    if (mozilla::jni::GetAPIVersion() < __ANDROID_API_T__) {
+      return nullptr;
+    }
+
+    void* const handle = dlopen("libandroid.so", RTLD_LAZY | RTLD_LOCAL);
+    if (!handle) {
+      HAL_ERR("Failed to open libandroid.so");
+      return nullptr;
+    }
+
+    auto api = WrapUnique(new PerformanceHintManagerApi());
+    LOAD_FN(api, handle, APerformanceHint_getManager);
+    LOAD_FN(api, handle, APerformanceHint_createSession);
+    LOAD_FN(api, handle, APerformanceHint_updateTargetWorkDuration);
+    LOAD_FN(api, handle, APerformanceHint_reportActualWorkDuration);
+    LOAD_FN(api, handle, APerformanceHint_closeSession);
+
+    return api;
+  }
+
+  using FnAPerformanceHint_getManager = APerformanceHintManager* (*)();
+  using FnAPerformanceHint_createSession =
+      APerformanceHintSession* (*)(APerformanceHintManager* manager,
+                                   const int32_t* threadIds, size_t size,
+                                   int64_t initialTargetWorkDurationNanos);
+  using FnAPerformanceHint_updateTargetWorkDuration =
+      int (*)(APerformanceHintSession* session, int64_t targetDurationNanos);
+  using FnAPerformanceHint_reportActualWorkDuration =
+      int (*)(APerformanceHintSession* session, int64_t actualDurationNanos);
+  using FnAPerformanceHint_closeSession =
+      void (*)(APerformanceHintSession* session);
+
+  FnAPerformanceHint_getManager mAPerformanceHint_getManager = nullptr;
+  FnAPerformanceHint_createSession mAPerformanceHint_createSession = nullptr;
+  FnAPerformanceHint_updateTargetWorkDuration
+      mAPerformanceHint_updateTargetWorkDuration = nullptr;
+  FnAPerformanceHint_reportActualWorkDuration
+      mAPerformanceHint_reportActualWorkDuration = nullptr;
+  FnAPerformanceHint_closeSession mAPerformanceHint_closeSession = nullptr;
+};
+
+class AndroidPerformanceHintSession final : public hal::PerformanceHintSession {
+ public:
+  // Creates a PerformanceHintSession wrapping the provided NDK
+  // APerformanceHintSession instance. This assumes ownership of aSession,
+  // therefore the caller must not close the session itself.
+  explicit AndroidPerformanceHintSession(APerformanceHintSession* aSession)
+      : mSession(aSession) {}
+
+  AndroidPerformanceHintSession(AndroidPerformanceHintSession& aOther) = delete;
+  AndroidPerformanceHintSession(AndroidPerformanceHintSession&& aOther) {
+    mSession = aOther.mSession;
+    aOther.mSession = nullptr;
+  }
+
+  ~AndroidPerformanceHintSession() {
+    if (mSession) {
+      PerformanceHintManagerApi::Get()->APerformanceHint_closeSession(mSession);
+    }
+  }
+
+  void UpdateTargetWorkDuration(TimeDuration aDuration) override {
+    PerformanceHintManagerApi::Get()->APerformanceHint_updateTargetWorkDuration(
+        mSession, aDuration.ToMicroseconds() * 1000);
+  }
+
+  void ReportActualWorkDuration(TimeDuration aDuration) override {
+    PerformanceHintManagerApi::Get()->APerformanceHint_reportActualWorkDuration(
+        mSession, aDuration.ToMicroseconds() * 1000);
+  }
+
+ private:
+  APerformanceHintSession* mSession;
+};
+
+static APerformanceHintManager* InitManager() {
+  const auto* api = PerformanceHintManagerApi::Get();
+  if (!api) {
+    return nullptr;
+  }
+
+  // At the time of writing we are only aware of PerformanceHintManager being
+  // implemented on Tensor devices (Pixel 6 and 7 families). On most devices
+  // createSession() will simply return null. However, on some devices
+  // createSession() does return a session but scheduling does not appear to be
+  // affected in any way. Rather than pretending to the caller that
+  // PerformanceHintManager is available on such devices, return null allowing
+  // them to use another means of achieving the performance they require.
+  const auto socManufacturer = java::sdk::Build::SOC_MANUFACTURER()->ToString();
+  if (!socManufacturer.EqualsASCII("Google")) {
+    return nullptr;
+  }
+
+  return api->APerformanceHint_getManager();
+}
+
+UniquePtr<hal::PerformanceHintSession> CreatePerformanceHintSession(
+    const nsTArray<PlatformThreadHandle>& aThreads,
+    mozilla::TimeDuration aTargetWorkDuration) {
+  // C++ guarantees local static variable initialization is thread safe
+  static APerformanceHintManager* manager = InitManager();
+
+  if (!manager) {
+    return nullptr;
+  }
+
+  const auto* api = PerformanceHintManagerApi::Get();
+
+  nsTArray<pid_t> tids(aThreads.Length());
+  std::transform(aThreads.cbegin(), aThreads.cend(), MakeBackInserter(tids),
+                 [](pthread_t handle) { return pthread_gettid_np(handle); });
+
+  APerformanceHintSession* session = api->APerformanceHint_createSession(
+      manager, tids.Elements(), tids.Length(),
+      aTargetWorkDuration.ToMicroseconds() * 1000);
+  if (!session) {
+    return nullptr;
+  }
+
+  return MakeUnique<AndroidPerformanceHintSession>(session);
+}
+
+}  // namespace hal_impl
+}  // namespace mozilla