Make libutils Looper independent of frameworks/native (1693d7e4) · Commits · e / os / android_system_core

include/utils/Looper.h

+112 −23

Original line number	Diff line number	Diff line
		@@ -22,17 +22,27 @@
		#include <utils/KeyedVector.h>
		#include <utils/Timers.h>

		#include <android/looper.h>

		#include <sys/epoll.h>

		namespace android {

		/*
		* Declare a concrete type for the NDK's looper forward declaration.
		* NOTE: Since Looper is used to implement the NDK ALooper, the Looper
		* enums and the signature of Looper_callbackFunc need to align with
		* that implementation.
		*/
		struct ALooper {
		};

		namespace android {
		/**
		* For callback-based event loops, this is the prototype of the function
		* that is called when a file descriptor event occurs.
		* It is given the file descriptor it is associated with,
		* a bitmask of the poll events that were triggered (typically EVENT_INPUT),
		* and the data pointer that was originally supplied.
		*
		* Implementations should return 1 to continue receiving callbacks, or 0
		* to have this file descriptor and callback unregistered from the looper.
		*/
		typedef int (Looper_callbackFunc)(int fd, int events, void data);

		/**
		* A message that can be posted to a Looper.
		@@ -93,7 +103,7 @@ public:
		/**
		* Handles a poll event for the given file descriptor.
		* It is given the file descriptor it is associated with,
		* a bitmask of the poll events that were triggered (typically ALOOPER_EVENT_INPUT),
		* a bitmask of the poll events that were triggered (typically EVENT_INPUT),
		* and the data pointer that was originally supplied.
		*
		* Implementations should return 1 to continue receiving callbacks, or 0
		@@ -102,34 +112,113 @@ public:
		virtual int handleEvent(int fd, int events, void* data) = 0;
		};


		/**
		* Wraps a ALooper_callbackFunc function pointer.
		* Wraps a Looper_callbackFunc function pointer.
		*/
		class SimpleLooperCallback : public LooperCallback {
		protected:
		virtual ~SimpleLooperCallback();

		public:
		SimpleLooperCallback(ALooper_callbackFunc callback);
		SimpleLooperCallback(Looper_callbackFunc callback);
		virtual int handleEvent(int fd, int events, void* data);

		private:
		ALooper_callbackFunc mCallback;
		Looper_callbackFunc mCallback;
		};


		/**
		* A polling loop that supports monitoring file descriptor events, optionally
		* using callbacks. The implementation uses epoll() internally.
		*
		* A looper can be associated with a thread although there is no requirement that it must be.
		*/
		class Looper : public ALooper, public RefBase {
		class Looper : public RefBase {
		protected:
		virtual ~Looper();

		public:
		enum {
		/**
		* Result from Looper_pollOnce() and Looper_pollAll():
		* The poll was awoken using wake() before the timeout expired
		* and no callbacks were executed and no other file descriptors were ready.
		*/
		POLL_WAKE = -1,

		/**
		* Result from Looper_pollOnce() and Looper_pollAll():
		* One or more callbacks were executed.
		*/
		POLL_CALLBACK = -2,

		/**
		* Result from Looper_pollOnce() and Looper_pollAll():
		* The timeout expired.
		*/
		POLL_TIMEOUT = -3,

		/**
		* Result from Looper_pollOnce() and Looper_pollAll():
		* An error occurred.
		*/
		POLL_ERROR = -4,
		};

		/**
		* Flags for file descriptor events that a looper can monitor.
		*
		* These flag bits can be combined to monitor multiple events at once.
		*/
		enum {
		/**
		* The file descriptor is available for read operations.
		*/
		EVENT_INPUT = 1 << 0,

		/**
		* The file descriptor is available for write operations.
		*/
		EVENT_OUTPUT = 1 << 1,

		/**
		* The file descriptor has encountered an error condition.
		*
		* The looper always sends notifications about errors; it is not necessary
		* to specify this event flag in the requested event set.
		*/
		EVENT_ERROR = 1 << 2,

		/**
		* The file descriptor was hung up.
		* For example, indicates that the remote end of a pipe or socket was closed.
		*
		* The looper always sends notifications about hangups; it is not necessary
		* to specify this event flag in the requested event set.
		*/
		EVENT_HANGUP = 1 << 3,

		/**
		* The file descriptor is invalid.
		* For example, the file descriptor was closed prematurely.
		*
		* The looper always sends notifications about invalid file descriptors; it is not necessary
		* to specify this event flag in the requested event set.
		*/
		EVENT_INVALID = 1 << 4,
		};

		enum {
		/**
		* Option for Looper_prepare: this looper will accept calls to
		* Looper_addFd() that do not have a callback (that is provide NULL
		* for the callback). In this case the caller of Looper_pollOnce()
		* or Looper_pollAll() MUST check the return from these functions to
		* discover when data is available on such fds and process it.
		*/
		PREPARE_ALLOW_NON_CALLBACKS = 1<<0
		};

		/**
		* Creates a looper.
		*
		@@ -152,16 +241,16 @@ public:
		* If the timeout is zero, returns immediately without blocking.
		* If the timeout is negative, waits indefinitely until an event appears.
		*
		* Returns ALOOPER_POLL_WAKE if the poll was awoken using wake() before
		* Returns POLL_WAKE if the poll was awoken using wake() before
		* the timeout expired and no callbacks were invoked and no other file
		* descriptors were ready.
		*
		* Returns ALOOPER_POLL_CALLBACK if one or more callbacks were invoked.
		* Returns POLL_CALLBACK if one or more callbacks were invoked.
		*
		* Returns ALOOPER_POLL_TIMEOUT if there was no data before the given
		* Returns POLL_TIMEOUT if there was no data before the given
		* timeout expired.
		*
		* Returns ALOOPER_POLL_ERROR if an error occurred.
		* Returns POLL_ERROR if an error occurred.
		*
		* Returns a value >= 0 containing an identifier if its file descriptor has data
		* and it has no callback function (requiring the caller here to handle it).
		@@ -179,7 +268,7 @@ public:
		/**
		* Like pollOnce(), but performs all pending callbacks until all
		* data has been consumed or a file descriptor is available with no callback.
		* This function will never return ALOOPER_POLL_CALLBACK.
		* This function will never return POLL_CALLBACK.
		*/
		int pollAll(int timeoutMillis, int* outFd, int* outEvents, void** outData);
		inline int pollAll(int timeoutMillis) {
		@@ -200,8 +289,8 @@ public:
		*
		* "fd" is the file descriptor to be added.
		* "ident" is an identifier for this event, which is returned from pollOnce().
		* The identifier must be >= 0, or ALOOPER_POLL_CALLBACK if providing a non-NULL callback.
		* "events" are the poll events to wake up on. Typically this is ALOOPER_EVENT_INPUT.
		* The identifier must be >= 0, or POLL_CALLBACK if providing a non-NULL callback.
		* "events" are the poll events to wake up on. Typically this is EVENT_INPUT.
		* "callback" is the function to call when there is an event on the file descriptor.
		* "data" is a private data pointer to supply to the callback.
		*
		@@ -211,7 +300,7 @@ public:
		* data on the file descriptor. It should execute any events it has pending,
		* appropriately reading from the file descriptor. The 'ident' is ignored in this case.
		*
		* (2) If "callback" is NULL, the 'ident' will be returned by ALooper_pollOnce
		* (2) If "callback" is NULL, the 'ident' will be returned by Looper_pollOnce
		* when its file descriptor has data available, requiring the caller to take
		* care of processing it.
		*
		@@ -225,7 +314,7 @@ public:
		* easier to avoid races when the callback is removed from a different thread.
		* See removeFd() for details.
		*/
		int addFd(int fd, int ident, int events, ALooper_callbackFunc callback, void* data);
		int addFd(int fd, int ident, int events, Looper_callbackFunc callback, void* data);
		int addFd(int fd, int ident, int events, const sp<LooperCallback>& callback, void* data);

		/**
		@@ -308,7 +397,7 @@ public:
		* If the thread already has a looper, it is returned. Otherwise, a new
		* one is created, associated with the thread, and returned.
		*
		* The opts may be ALOOPER_PREPARE_ALLOW_NON_CALLBACKS or 0.
		* The opts may be PREPARE_ALLOW_NON_CALLBACKS or 0.
		*/
		static sp<Looper> prepare(int opts);

libutils/Looper.cpp

+20 −20

Original line number	Diff line number	Diff line
		@@ -43,7 +43,7 @@ void WeakMessageHandler::handleMessage(const Message& message) {

		// --- SimpleLooperCallback ---

		SimpleLooperCallback::SimpleLooperCallback(ALooper_callbackFunc callback) :
		SimpleLooperCallback::SimpleLooperCallback(Looper_callbackFunc callback) :
		mCallback(callback) {
		}

		@@ -139,7 +139,7 @@ sp<Looper> Looper::getForThread() {
		}

		sp<Looper> Looper::prepare(int opts) {
		bool allowNonCallbacks = opts & ALOOPER_PREPARE_ALLOW_NON_CALLBACKS;
		bool allowNonCallbacks = opts & PREPARE_ALLOW_NON_CALLBACKS;
		sp<Looper> looper = Looper::getForThread();
		if (looper == NULL) {
		looper = new Looper(allowNonCallbacks);
		@@ -147,7 +147,7 @@ sp<Looper> Looper::prepare(int opts) {
		}
		if (looper->getAllowNonCallbacks() != allowNonCallbacks) {
		ALOGW("Looper already prepared for this thread with a different value for the "
		"ALOOPER_PREPARE_ALLOW_NON_CALLBACKS option.");
		"LOOPER_PREPARE_ALLOW_NON_CALLBACKS option.");
		}
		return looper;
		}
		@@ -212,7 +212,7 @@ int Looper::pollInner(int timeoutMillis) {
		}

		// Poll.
		int result = ALOOPER_POLL_WAKE;
		int result = POLL_WAKE;
		mResponses.clear();
		mResponseIndex = 0;

		@@ -234,7 +234,7 @@ int Looper::pollInner(int timeoutMillis) {
		goto Done;
		}
		ALOGW("Poll failed with an unexpected error, errno=%d", errno);
		result = ALOOPER_POLL_ERROR;
		result = POLL_ERROR;
		goto Done;
		}

		@@ -243,7 +243,7 @@ int Looper::pollInner(int timeoutMillis) {
		#if DEBUG_POLL_AND_WAKE
		ALOGD("%p ~ pollOnce - timeout", this);
		#endif
		result = ALOOPER_POLL_TIMEOUT;
		result = POLL_TIMEOUT;
		goto Done;
		}

		@@ -265,10 +265,10 @@ int Looper::pollInner(int timeoutMillis) {
		ssize_t requestIndex = mRequests.indexOfKey(fd);
		if (requestIndex >= 0) {
		int events = 0;
		if (epollEvents & EPOLLIN) events \|= ALOOPER_EVENT_INPUT;
		if (epollEvents & EPOLLOUT) events \|= ALOOPER_EVENT_OUTPUT;
		if (epollEvents & EPOLLERR) events \|= ALOOPER_EVENT_ERROR;
		if (epollEvents & EPOLLHUP) events \|= ALOOPER_EVENT_HANGUP;
		if (epollEvents & EPOLLIN) events \|= EVENT_INPUT;
		if (epollEvents & EPOLLOUT) events \|= EVENT_OUTPUT;
		if (epollEvents & EPOLLERR) events \|= EVENT_ERROR;
		if (epollEvents & EPOLLHUP) events \|= EVENT_HANGUP;
		pushResponse(events, mRequests.valueAt(requestIndex));
		} else {
		ALOGW("Ignoring unexpected epoll events 0x%x on fd %d that is "
		@@ -304,7 +304,7 @@ Done: ;

		mLock.lock();
		mSendingMessage = false;
		result = ALOOPER_POLL_CALLBACK;
		result = POLL_CALLBACK;
		} else {
		// The last message left at the head of the queue determines the next wakeup time.
		mNextMessageUptime = messageEnvelope.uptime;
		@@ -318,7 +318,7 @@ Done: ;
		// Invoke all response callbacks.
		for (size_t i = 0; i < mResponses.size(); i++) {
		Response& response = mResponses.editItemAt(i);
		if (response.request.ident == ALOOPER_POLL_CALLBACK) {
		if (response.request.ident == POLL_CALLBACK) {
		int fd = response.request.fd;
		int events = response.events;
		void* data = response.request.data;
		@@ -333,7 +333,7 @@ Done: ;
		// Clear the callback reference in the response structure promptly because we
		// will not clear the response vector itself until the next poll.
		response.request.callback.clear();
		result = ALOOPER_POLL_CALLBACK;
		result = POLL_CALLBACK;
		}
		}
		return result;
		@@ -344,7 +344,7 @@ int Looper::pollAll(int timeoutMillis, int* outFd, int* outEvents, void** outDat
		int result;
		do {
		result = pollOnce(timeoutMillis, outFd, outEvents, outData);
		} while (result == ALOOPER_POLL_CALLBACK);
		} while (result == POLL_CALLBACK);
		return result;
		} else {
		nsecs_t endTime = systemTime(SYSTEM_TIME_MONOTONIC)
		@@ -352,14 +352,14 @@ int Looper::pollAll(int timeoutMillis, int* outFd, int* outEvents, void** outDat

		for (;;) {
		int result = pollOnce(timeoutMillis, outFd, outEvents, outData);
		if (result != ALOOPER_POLL_CALLBACK) {
		if (result != POLL_CALLBACK) {
		return result;
		}

		nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
		timeoutMillis = toMillisecondTimeoutDelay(now, endTime);
		if (timeoutMillis == 0) {
		return ALOOPER_POLL_TIMEOUT;
		return POLL_TIMEOUT;
		}
		}
		}
		@@ -401,7 +401,7 @@ void Looper::pushResponse(int events, const Request& request) {
		mResponses.push(response);
		}

		int Looper::addFd(int fd, int ident, int events, ALooper_callbackFunc callback, void* data) {
		int Looper::addFd(int fd, int ident, int events, Looper_callbackFunc callback, void* data) {
		return addFd(fd, ident, events, callback ? new SimpleLooperCallback(callback) : NULL, data);
		}

		@@ -422,12 +422,12 @@ int Looper::addFd(int fd, int ident, int events, const sp<LooperCallback>& callb
		return -1;
		}
		} else {
		ident = ALOOPER_POLL_CALLBACK;
		ident = POLL_CALLBACK;
		}

		int epollEvents = 0;
		if (events & ALOOPER_EVENT_INPUT) epollEvents \|= EPOLLIN;
		if (events & ALOOPER_EVENT_OUTPUT) epollEvents \|= EPOLLOUT;
		if (events & EVENT_INPUT) epollEvents \|= EPOLLIN;
		if (events & EVENT_OUTPUT) epollEvents \|= EPOLLOUT;

		{ // acquire lock
		AutoMutex _l(mLock);

libutils/tests/Looper_test.cpp

+79 −79

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