Add new glue code for writing native apps.

This factors out the boiler-plate code from the sample
app to a common glue code that can be used for everyone
writing this style of app: a dedicated app thread that
takes care of waiting for events and processing them.

As part of doing this, ALooper has a new facility to allow
registration of fds that cause ALooper_pollOnce() to return
the fd that has data, allowing the app to drive the loop
without callbacks.  Hopefully this makes some people feel better. :)

Also do some other cleanup of the ALooper API, plus some
actual documentation.

Change-Id: Ic53bd56bdf627e3ba28a3c093faa06a92be522b8

1 files changed, 25 insertions, 6 deletions

diff --git a/native/android/looper.cpp b/native/android/looper.cpp
index 6e78bbd03d12..1564c477d29e 100644
--- a/native/android/looper.cpp
+++ b/native/android/looper.cpp
@@ -27,22 +27,41 @@ ALooper* ALooper_forThread() {
     return PollLoop::getForThread().get();
 }
 
-ALooper* ALooper_prepare() {
+ALooper* ALooper_prepare(int32_t opts) {
+    bool allowFds = (opts&ALOOPER_PREPARE_ALLOW_NON_CALLBACKS) != 0;
     sp<PollLoop> loop = PollLoop::getForThread();
     if (loop == NULL) {
-        loop = new PollLoop();
+        loop = new PollLoop(allowFds);
         PollLoop::setForThread(loop);
     }
+    if (loop->getAllowNonCallbacks() != allowFds) {
+        LOGW("ALooper_prepare again with different ALOOPER_PREPARE_ALLOW_NON_CALLBACKS");
+    }
     return loop.get();
 }
 
-int32_t ALooper_pollOnce(int timeoutMillis) {
+int32_t ALooper_pollOnce(int timeoutMillis, int* outEvents, void** outData) {
     sp<PollLoop> loop = PollLoop::getForThread();
     if (loop == NULL) {
         LOGW("ALooper_pollOnce: No looper for this thread!");
         return -1;
     }
-    return loop->pollOnce(timeoutMillis) ? 1 : 0;
+    return loop->pollOnce(timeoutMillis, outEvents, outData);
+}
+
+int32_t ALooper_pollAll(int timeoutMillis, int* outEvents, void** outData) {
+    sp<PollLoop> loop = PollLoop::getForThread();
+    if (loop == NULL) {
+        LOGW("ALooper_pollOnce: No looper for this thread!");
+        return -1;
+    }
+    
+    int32_t result;
+    while ((result = loop->pollOnce(timeoutMillis, outEvents, outData)) == ALOOPER_POLL_CALLBACK) {
+        ;
+    }
+    
+    return result;
 }
 
 void ALooper_acquire(ALooper* looper) {
@@ -53,11 +72,11 @@ void ALooper_release(ALooper* looper) {
     static_cast<PollLoop*>(looper)->decStrong((void*)ALooper_acquire);
 }
 
-void ALooper_setCallback(ALooper* looper, int fd, int events,
+void ALooper_addFd(ALooper* looper, int fd, int events,
         ALooper_callbackFunc* callback, void* data) {
     static_cast<PollLoop*>(looper)->setLooperCallback(fd, events, callback, data);
 }
 
-int32_t ALooper_removeCallback(ALooper* looper, int fd) {
+int32_t ALooper_removeFd(ALooper* looper, int fd) {
     return static_cast<PollLoop*>(looper)->removeCallback(fd) ? 1 : 0;
 }