| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #define LOG_TAG "DisplayEventReceiver" |
| |
| //#define LOG_NDEBUG 0 |
| |
| |
| #include "JNIHelp.h" |
| |
| #include <android_runtime/AndroidRuntime.h> |
| #include <utils/Log.h> |
| #include <utils/Looper.h> |
| #include <utils/threads.h> |
| #include <gui/DisplayEventReceiver.h> |
| #include "android_os_MessageQueue.h" |
| |
| namespace android { |
| |
| // Number of events to read at a time from the DisplayEventReceiver pipe. |
| // The value should be large enough that we can quickly drain the pipe |
| // using just a few large reads. |
| static const size_t EVENT_BUFFER_SIZE = 100; |
| |
| static struct { |
| jclass clazz; |
| |
| jmethodID dispatchVsync; |
| } gDisplayEventReceiverClassInfo; |
| |
| |
| class NativeDisplayEventReceiver : public RefBase { |
| public: |
| NativeDisplayEventReceiver(JNIEnv* env, |
| jobject receiverObj, const sp<Looper>& looper); |
| |
| status_t initialize(); |
| status_t scheduleVsync(); |
| static int handleReceiveCallback(int receiveFd, int events, void* data); |
| |
| protected: |
| virtual ~NativeDisplayEventReceiver(); |
| |
| private: |
| jobject mReceiverObjGlobal; |
| sp<Looper> mLooper; |
| DisplayEventReceiver mReceiver; |
| bool mWaitingForVsync; |
| }; |
| |
| |
| NativeDisplayEventReceiver::NativeDisplayEventReceiver(JNIEnv* env, |
| jobject receiverObj, const sp<Looper>& looper) : |
| mReceiverObjGlobal(env->NewGlobalRef(receiverObj)), |
| mLooper(looper), mWaitingForVsync(false) { |
| ALOGV("receiver %p ~ Initializing input event receiver.", this); |
| } |
| |
| NativeDisplayEventReceiver::~NativeDisplayEventReceiver() { |
| ALOGV("receiver %p ~ Disposing display event receiver.", this); |
| |
| if (!mReceiver.initCheck()) { |
| mLooper->removeFd(mReceiver.getFd()); |
| } |
| |
| JNIEnv* env = AndroidRuntime::getJNIEnv(); |
| env->DeleteGlobalRef(mReceiverObjGlobal); |
| } |
| |
| status_t NativeDisplayEventReceiver::initialize() { |
| status_t result = mReceiver.initCheck(); |
| if (result) { |
| ALOGW("Failed to initialize display event receiver, status=%d", result); |
| return result; |
| } |
| |
| int rc = mLooper->addFd(mReceiver.getFd(), 0, ALOOPER_EVENT_INPUT, |
| handleReceiveCallback, this); |
| if (rc < 0) { |
| return UNKNOWN_ERROR; |
| } |
| return OK; |
| } |
| |
| status_t NativeDisplayEventReceiver::scheduleVsync() { |
| if (!mWaitingForVsync) { |
| ALOGV("receiver %p ~ Scheduling vsync.", this); |
| |
| // Drain all pending events. |
| DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE]; |
| ssize_t n; |
| while ((n = mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) { |
| ALOGV("receiver %p ~ Drained %d events.", this, int(n)); |
| } |
| |
| if (n < 0) { |
| ALOGW("Failed to drain events from display event receiver, status=%d", status_t(n)); |
| return status_t(n); |
| } |
| |
| status_t status = mReceiver.requestNextVsync(); |
| if (status) { |
| ALOGW("Failed to request next vsync, status=%d", status); |
| return status; |
| } |
| |
| mWaitingForVsync = true; |
| } |
| return OK; |
| } |
| |
| int NativeDisplayEventReceiver::handleReceiveCallback(int receiveFd, int events, void* data) { |
| sp<NativeDisplayEventReceiver> r = static_cast<NativeDisplayEventReceiver*>(data); |
| |
| if (events & (ALOOPER_EVENT_ERROR | ALOOPER_EVENT_HANGUP)) { |
| ALOGE("Display event receiver pipe was closed or an error occurred. " |
| "events=0x%x", events); |
| return 0; // remove the callback |
| } |
| |
| if (!(events & ALOOPER_EVENT_INPUT)) { |
| ALOGW("Received spurious callback for unhandled poll event. " |
| "events=0x%x", events); |
| return 1; // keep the callback |
| } |
| |
| // Drain all pending events, keep the last vsync. |
| nsecs_t vsyncTimestamp = -1; |
| uint32_t vsyncCount = 0; |
| |
| DisplayEventReceiver::Event buf[EVENT_BUFFER_SIZE]; |
| ssize_t n; |
| while ((n = r->mReceiver.getEvents(buf, EVENT_BUFFER_SIZE)) > 0) { |
| ALOGV("receiver %p ~ Read %d events.", data, int(n)); |
| while (n-- > 0) { |
| if (buf[n].header.type == DisplayEventReceiver::DISPLAY_EVENT_VSYNC) { |
| vsyncTimestamp = buf[n].header.timestamp; |
| vsyncCount = buf[n].vsync.count; |
| break; // stop at last vsync in the buffer |
| } |
| } |
| } |
| |
| if (vsyncTimestamp < 0) { |
| ALOGV("receiver %p ~ Woke up but there was no vsync pulse!", data); |
| return 1; // keep the callback, did not obtain a vsync pulse |
| } |
| |
| ALOGV("receiver %p ~ Vsync pulse: timestamp=%lld, count=%d", |
| data, vsyncTimestamp, vsyncCount); |
| r->mWaitingForVsync = false; |
| |
| JNIEnv* env = AndroidRuntime::getJNIEnv(); |
| |
| ALOGV("receiver %p ~ Invoking vsync handler.", data); |
| env->CallVoidMethod(r->mReceiverObjGlobal, |
| gDisplayEventReceiverClassInfo.dispatchVsync, vsyncTimestamp, vsyncCount); |
| ALOGV("receiver %p ~ Returned from vsync handler.", data); |
| |
| if (env->ExceptionCheck()) { |
| ALOGE("An exception occurred while dispatching a vsync event."); |
| LOGE_EX(env); |
| env->ExceptionClear(); |
| } |
| |
| return 1; // keep the callback |
| } |
| |
| |
| static jint nativeInit(JNIEnv* env, jclass clazz, jobject receiverObj, |
| jobject messageQueueObj) { |
| sp<Looper> looper = android_os_MessageQueue_getLooper(env, messageQueueObj); |
| if (looper == NULL) { |
| jniThrowRuntimeException(env, "MessageQueue is not initialized."); |
| return 0; |
| } |
| |
| sp<NativeDisplayEventReceiver> receiver = new NativeDisplayEventReceiver(env, |
| receiverObj, looper); |
| status_t status = receiver->initialize(); |
| if (status) { |
| String8 message; |
| message.appendFormat("Failed to initialize display event receiver. status=%d", status); |
| jniThrowRuntimeException(env, message.string()); |
| return 0; |
| } |
| |
| receiver->incStrong(gDisplayEventReceiverClassInfo.clazz); // retain a reference for the object |
| return reinterpret_cast<jint>(receiver.get()); |
| } |
| |
| static void nativeDispose(JNIEnv* env, jclass clazz, jint receiverPtr) { |
| sp<NativeDisplayEventReceiver> receiver = |
| reinterpret_cast<NativeDisplayEventReceiver*>(receiverPtr); |
| receiver->decStrong(gDisplayEventReceiverClassInfo.clazz); // drop reference held by the object |
| } |
| |
| static void nativeScheduleVsync(JNIEnv* env, jclass clazz, jint receiverPtr) { |
| sp<NativeDisplayEventReceiver> receiver = |
| reinterpret_cast<NativeDisplayEventReceiver*>(receiverPtr); |
| status_t status = receiver->scheduleVsync(); |
| if (status) { |
| String8 message; |
| message.appendFormat("Failed to schedule next vertical sync pulse. status=%d", status); |
| jniThrowRuntimeException(env, message.string()); |
| } |
| } |
| |
| |
| static JNINativeMethod gMethods[] = { |
| /* name, signature, funcPtr */ |
| { "nativeInit", |
| "(Landroid/view/DisplayEventReceiver;Landroid/os/MessageQueue;)I", |
| (void*)nativeInit }, |
| { "nativeDispose", |
| "(I)V", |
| (void*)nativeDispose }, |
| { "nativeScheduleVsync", "(I)V", |
| (void*)nativeScheduleVsync } |
| }; |
| |
| #define FIND_CLASS(var, className) \ |
| var = env->FindClass(className); \ |
| LOG_FATAL_IF(! var, "Unable to find class " className); \ |
| var = jclass(env->NewGlobalRef(var)); |
| |
| #define GET_METHOD_ID(var, clazz, methodName, methodDescriptor) \ |
| var = env->GetMethodID(clazz, methodName, methodDescriptor); \ |
| LOG_FATAL_IF(! var, "Unable to find method " methodName); |
| |
| int register_android_view_DisplayEventReceiver(JNIEnv* env) { |
| int res = jniRegisterNativeMethods(env, "android/view/DisplayEventReceiver", |
| gMethods, NELEM(gMethods)); |
| LOG_FATAL_IF(res < 0, "Unable to register native methods."); |
| |
| FIND_CLASS(gDisplayEventReceiverClassInfo.clazz, "android/view/DisplayEventReceiver"); |
| |
| GET_METHOD_ID(gDisplayEventReceiverClassInfo.dispatchVsync, |
| gDisplayEventReceiverClassInfo.clazz, |
| "dispatchVsync", "(JI)V"); |
| return 0; |
| } |
| |
| } // namespace android |