Make libutils Looper independent of frameworks/native
Change-Id: I1dacca10a3cd7601abc3451b69ed761bf71c38fe
diff --git a/include/utils/Looper.h b/include/utils/Looper.h
index 2e0651a..15c9891 100644
--- a/include/utils/Looper.h
+++ b/include/utils/Looper.h
@@ -22,18 +22,28 @@
#include <utils/KeyedVector.h>
#include <utils/Timers.h>
-#include <android/looper.h>
-
#include <sys/epoll.h>
-/*
- * Declare a concrete type for the NDK's looper forward declaration.
- */
-struct ALooper {
-};
-
namespace android {
+/*
+ * 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.
+ */
+
+/**
+ * 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 @@
/**
* 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 @@
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 @@
* 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 @@
/**
* 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 @@
*
* "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 @@
* 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 @@
* 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 @@
* 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);