Merge "Replace epoll() with poll() and rename PollLoop to Looper." into gingerbread

5 files changed, 217 insertions, 227 deletions

diff --git a/include/gui/SensorEventQueue.h b/include/gui/SensorEventQueue.h
index 6581ae3..97dd391 100644
--- a/include/gui/SensorEventQueue.h
+++ b/include/gui/SensorEventQueue.h
@@ -42,7 +42,7 @@ namespace android {
 
 class ISensorEventConnection;
 class Sensor;
-class PollLoop;
+class Looper;
 
 // ----------------------------------------------------------------------------
 
@@ -69,11 +69,11 @@ public:
     status_t disableSensor(int32_t handle) const;
 
 private:
-    sp<PollLoop> getPollLoop() const;
+    sp<Looper> getLooper() const;
     sp<ISensorEventConnection> mSensorEventConnection;
     sp<SensorChannel> mSensorChannel;
     mutable Mutex mLock;
-    mutable sp<PollLoop> mPollLoop;
+    mutable sp<Looper> mLooper;
 };
 
 // ----------------------------------------------------------------------------
diff --git a/include/ui/InputDispatcher.h b/include/ui/InputDispatcher.h
index a06208a..d7e6254 100644
--- a/include/ui/InputDispatcher.h
+++ b/include/ui/InputDispatcher.h
@@ -25,7 +25,7 @@
 #include <utils/Timers.h>
 #include <utils/RefBase.h>
 #include <utils/String8.h>
-#include <utils/PollLoop.h>
+#include <utils/Looper.h>
 #include <utils/Pool.h>
 
 #include <stddef.h>
@@ -826,7 +826,7 @@ private:
     Mutex mLock;
 
     Allocator mAllocator;
-    sp<PollLoop> mPollLoop;
+    sp<Looper> mLooper;
 
     EventEntry* mPendingEvent;
     Queue<EventEntry> mInboundQueue;
@@ -837,7 +837,7 @@ private:
     void dispatchOnceInnerLocked(nsecs_t keyRepeatTimeout, nsecs_t keyRepeatDelay,
             nsecs_t* nextWakeupTime);
 
-    // Enqueues an inbound event.  Returns true if mPollLoop->wake() should be called.
+    // Enqueues an inbound event.  Returns true if mLooper->wake() should be called.
     bool enqueueInboundEventLocked(EventEntry* entry);
 
     // App switch latency optimization.
@@ -1010,7 +1010,7 @@ private:
     void abortDispatchCycleLocked(nsecs_t currentTime, const sp<Connection>& connection,
             bool broken);
     void drainOutboundQueueLocked(Connection* connection, DispatchEntry* firstDispatchEntryToDrain);
-    static bool handleReceiveCallback(int receiveFd, int events, void* data);
+    static int handleReceiveCallback(int receiveFd, int events, void* data);
 
     // Preempting input dispatch.
     bool preemptInputDispatchInnerLocked();
diff --git a/include/ui/InputTransport.h b/include/ui/InputTransport.h
index 82831e2..dc9e27a 100644
--- a/include/ui/InputTransport.h
+++ b/include/ui/InputTransport.h
@@ -33,7 +33,6 @@
 #include <semaphore.h>
 #include <ui/Input.h>
 #include <utils/Errors.h>
-#include <utils/PollLoop.h>
 #include <utils/Timers.h>
 #include <utils/RefBase.h>
 #include <utils/String8.h>
diff --git a/include/utils/Looper.h b/include/utils/Looper.h
new file mode 100644
index 0000000..92e4b0a
--- /dev/null
+++ b/include/utils/Looper.h
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#ifndef UTILS_LOOPER_H
+#define UTILS_LOOPER_H
+
+#include <utils/threads.h>
+#include <utils/RefBase.h>
+#include <utils/KeyedVector.h>
+
+#include <android/looper.h>
+
+/*
+ * Declare a concrete type for the NDK's looper forward declaration.
+ */
+struct ALooper {
+};
+
+namespace android {
+
+/**
+ * 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 {
+protected:
+    virtual ~Looper();
+
+public:
+    /**
+     * Creates a looper.
+     *
+     * If allowNonCallbaks is true, the looper will allow file descriptors to be
+     * registered without associated callbacks.  This assumes that the caller of
+     * pollOnce() is prepared to handle callback-less events itself.
+     */
+    Looper(bool allowNonCallbacks);
+
+    /**
+     * Returns whether this looper instance allows the registration of file descriptors
+     * using identifiers instead of callbacks.
+     */
+    bool getAllowNonCallbacks() const;
+
+    /**
+     * Waits for events to be available, with optional timeout in milliseconds.
+     * Invokes callbacks for all file descriptors on which an event occurred.
+     *
+     * 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
+     * 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 ALOOPER_POLL_TIMEOUT if there was no data before the given
+     * timeout expired.
+     *
+     * Returns ALOOPER_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).
+     * In this (and only this) case outFd, outEvents and outData will contain the poll
+     * events and data associated with the fd, otherwise they will be set to NULL.
+     *
+     * This method does not return until it has finished invoking the appropriate callbacks
+     * for all file descriptors that were signalled.
+     */
+    int pollOnce(int timeoutMillis,
+            int* outFd = NULL, int* outEvents = NULL, void** outData = NULL);
+
+    /**
+     * 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.
+     */
+    int pollAll(int timeoutMillis,
+            int* outFd = NULL, int* outEvents = NULL, void** outData = NULL);
+
+    /**
+     * Wakes the poll asynchronously.
+     *
+     * This method can be called on any thread.
+     * This method returns immediately.
+     */
+    void wake();
+
+    /**
+     * Adds a new file descriptor to be polled by the looper.
+     * If the same file descriptor was previously added, it is replaced.
+     *
+     * "fd" is the file descriptor to be added.
+     * "ident" is an identifier for this event, which is returned from ALooper_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.
+     * "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.
+     *
+     * There are two main uses of this function:
+     *
+     * (1) If "callback" is non-NULL, then this function will be called when there is
+     * 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
+     * when its file descriptor has data available, requiring the caller to take
+     * care of processing it.
+     *
+     * Returns 1 if the file descriptor was added, 0 if the arguments were invalid.
+     *
+     * This method can be called on any thread.
+     * This method may block briefly if it needs to wake the poll.
+     */
+    int addFd(int fd, int ident,
+            int events, ALooper_callbackFunc callback, void* data = NULL);
+
+    /**
+     * Removes a previously added file descriptor from the looper.
+     *
+     * When this method returns, it is safe to close the file descriptor since the looper
+     * will no longer have a reference to it.  However, it is possible for the callback to
+     * already be running or for it to run one last time if the file descriptor was already
+     * signalled.  Calling code is responsible for ensuring that this case is safely handled.
+     * For example, if the callback takes care of removing itself during its own execution either
+     * by returning 0 or by calling this method, then it can be guaranteed to not be invoked
+     * again at any later time unless registered anew.
+     *
+     * Returns 1 if the file descriptor was removed, 0 if none was previously registered.
+     *
+     * This method can be called on any thread.
+     * This method may block briefly if it needs to wake the poll.
+     */
+    int removeFd(int fd);
+
+    /**
+     * Prepares a looper associated with the calling thread, and returns it.
+     * 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.
+     */
+    static sp<Looper> prepare(int opts);
+
+    /**
+     * Sets the given looper to be associated with the calling thread.
+     * If another looper is already associated with the thread, it is replaced.
+     *
+     * If "looper" is NULL, removes the currently associated looper.
+     */
+    static void setForThread(const sp<Looper>& looper);
+
+    /**
+     * Returns the looper associated with the calling thread, or NULL if
+     * there is not one.
+     */
+    static sp<Looper> getForThread();
+
+private:
+    struct Request {
+        int fd;
+        int ident;
+        ALooper_callbackFunc callback;
+        void* data;
+    };
+
+    struct Response {
+        int events;
+        Request request;
+    };
+
+    const bool mAllowNonCallbacks; // immutable
+
+    int mEpollFd; // immutable
+    int mWakeReadPipeFd;  // immutable
+    int mWakeWritePipeFd; // immutable
+
+    // Locked list of file descriptor monitoring requests.
+    Mutex mLock;
+    KeyedVector<int, Request> mRequests;
+
+    // This state is only used privately by pollOnce and does not require a lock since
+    // it runs on a single thread.
+    Vector<Response> mResponses;
+    size_t mResponseIndex;
+
+    int pollInner(int timeoutMillis);
+
+    static void threadDestructor(void *st);
+};
+
+} // namespace android
+
+#endif // UTILS_LOOPER_H
diff --git a/include/utils/PollLoop.h b/include/utils/PollLoop.h
deleted file mode 100644
index c2dfe5d..0000000
--- a/include/utils/PollLoop.h
+++ /dev/null
@@ -1,219 +0,0 @@
-/*
- * Copyright (C) 2010 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.
- */
-
-#ifndef UTILS_POLL_LOOP_H
-#define UTILS_POLL_LOOP_H
-
-#include <utils/Vector.h>
-#include <utils/threads.h>
-
-#include <sys/poll.h>
-
-#include <android/looper.h>
-
-struct ALooper : public android::RefBase {
-protected:
-    virtual ~ALooper() { }
-
-public:
-    ALooper() { }
-};
-
-namespace android {
-
-/**
- * A basic file descriptor polling loop based on poll() with callbacks.
- */
-class PollLoop : public ALooper {
-protected:
-    virtual ~PollLoop();
-
-public:
-    PollLoop(bool allowNonCallbacks);
-
-    /**
-     * A callback that it to be invoked when an event occurs on a file descriptor.
-     * Specifies the events that were triggered and the user data provided when the
-     * callback was set.
-     *
-     * Returns true if the callback should be kept, false if it should be removed automatically
-     * after the callback returns.
-     */
-    typedef bool (*Callback)(int fd, int events, void* data);
-
-    enum {
-        POLL_CALLBACK = ALOOPER_POLL_CALLBACK,
-        POLL_TIMEOUT = ALOOPER_POLL_TIMEOUT,
-        POLL_ERROR = ALOOPER_POLL_ERROR,
-    };
-    
-    /**
-     * Performs a single call to poll() with optional timeout in milliseconds.
-     * Invokes callbacks for all file descriptors on which an event occurred.
-     *
-     * If the timeout is zero, returns immediately without blocking.
-     * If the timeout is negative, waits indefinitely until awoken.
-     *
-     * Returns ALOOPER_POLL_CALLBACK if a callback was invoked.
-     *
-     * Returns ALOOPER_POLL_TIMEOUT if there was no data before the given
-     * timeout expired.
-     *
-     * Returns ALOPER_POLL_ERROR if an error occurred.
-     *
-     * Returns a value >= 0 containing a file descriptor if it has data
-     * and it has no callback function (requiring the caller here to handle it).
-     * In this (and only this) case outEvents and outData will contain the poll
-     * events and data associated with the fd.
-     *
-     * This method must only be called on the thread owning the PollLoop.
-     * This method blocks until either a file descriptor is signalled, a timeout occurs,
-     * or wake() is called.
-     * This method does not return until it has finished invoking the appropriate callbacks
-     * for all file descriptors that were signalled.
-     */
-    int32_t pollOnce(int timeoutMillis, int* outEvents = NULL, void** outData = NULL);
-
-    /**
-     * Wakes the loop asynchronously.
-     *
-     * This method can be called on any thread.
-     * This method returns immediately.
-     */
-    void wake();
-
-    /**
-     * Control whether this PollLoop instance allows using IDs instead
-     * of callbacks.
-     */
-    bool getAllowNonCallbacks() const;
-    
-    /**
-     * Sets the callback for a file descriptor, replacing the existing one, if any.
-     * It is an error to call this method with events == 0 or callback == NULL.
-     *
-     * Note that a callback can be invoked with the POLLERR, POLLHUP or POLLNVAL events
-     * even if it is not explicitly requested when registered.
-     *
-     * This method can be called on any thread.
-     * This method may block briefly if it needs to wake the poll loop.
-     */
-    void setCallback(int fd, int ident, int events, Callback callback, void* data = NULL);
-
-    /**
-     * Convenience for above setCallback when ident is not used.  In this case
-     * the ident is set to POLL_CALLBACK.
-     */
-    void setCallback(int fd, int events, Callback callback, void* data = NULL);
-    
-    /**
-     * Like setCallback(), but for the NDK callback function.
-     */
-    void setLooperCallback(int fd, int ident, int events, ALooper_callbackFunc* callback,
-            void* data);
-    
-    /**
-     * Removes the callback for a file descriptor, if one exists.
-     *
-     * When this method returns, it is safe to close the file descriptor since the poll loop
-     * will no longer have a reference to it.  However, it is possible for the callback to
-     * already be running or for it to run one last time if the file descriptor was already
-     * signalled.  Calling code is responsible for ensuring that this case is safely handled.
-     * For example, if the callback takes care of removing itself during its own execution either
-     * by returning false or calling this method, then it can be guaranteed to not be invoked
-     * again at any later time unless registered anew.
-     *
-     * This method can be called on any thread.
-     * This method may block briefly if it needs to wake the poll loop.
-     *
-     * Returns true if a callback was actually removed, false if none was registered.
-     */
-    bool removeCallback(int fd);
-
-    /**
-     * Set the given PollLoop to be associated with the
-     * calling thread.  There must be a 1:1 relationship between
-     * PollLoop and thread.
-     */
-    static void setForThread(const sp<PollLoop>& pollLoop);
-    
-    /**
-     * Return the PollLoop associated with the calling thread.
-     */
-    static sp<PollLoop> getForThread();
-    
-private:
-    struct RequestedCallback {
-        Callback callback;
-        ALooper_callbackFunc* looperCallback;
-        int ident;
-        void* data;
-    };
-
-    struct PendingCallback {
-        int fd;
-        int ident;
-        int events;
-        Callback callback;
-        ALooper_callbackFunc* looperCallback;
-        void* data;
-    };
-    
-    const bool mAllowNonCallbacks; // immutable
-
-    int mWakeReadPipeFd;  // immutable
-    int mWakeWritePipeFd; // immutable
-
-    // The lock guards state used to track whether there is a poll() in progress and whether
-    // there are any other threads waiting in wakeAndLock().  The condition variables
-    // are used to transfer control among these threads such that all waiters are
-    // serviced before a new poll can begin.
-    // The wakeAndLock() method increments mWaiters, wakes the poll, blocks on mAwake
-    // until mPolling becomes false, then decrements mWaiters again.
-    // The poll() method blocks on mResume until mWaiters becomes 0, then sets
-    // mPolling to true, blocks until the poll completes, then resets mPolling to false
-    // and signals mResume if there are waiters.
-    Mutex mLock;
-    bool mPolling;      // guarded by mLock
-    uint32_t mWaiters;  // guarded by mLock
-    Condition mAwake;   // guarded by mLock
-    Condition mResume;  // guarded by mLock
-
-    // The next two vectors are only mutated when mPolling is false since they must
-    // not be changed while the poll() system call is in progress.  To mutate these
-    // vectors, the poll() must first be awoken then the lock acquired.
-    Vector<struct pollfd> mRequestedFds;
-    Vector<RequestedCallback> mRequestedCallbacks;
-
-    // This state is only used privately by pollOnce and does not require a lock since
-    // it runs on a single thread.
-    Vector<PendingCallback> mPendingCallbacks;
-    Vector<PendingCallback> mPendingFds;
-    size_t mPendingFdsPos;
-    
-    void openWakePipe();
-    void closeWakePipe();
-
-    void setCallbackCommon(int fd, int ident, int events, Callback callback,
-            ALooper_callbackFunc* looperCallback, void* data);
-    ssize_t getRequestIndexLocked(int fd);
-    void wakeAndLock();
-    static void threadDestructor(void *st);
-};
-
-} // namespace android
-
-#endif // UTILS_POLL_LOOP_H