Implementation of event loop abstraction.

This patch adds "android/looper.h" which provides an

abstraction for event loops:
 - android/looper-qemu.c implements it on top of the QEMU main event loop.
 - android/looper-generic.c implements it on top of an IoLooper object.

The main idea is to move the UI-related code to use the abstraction
to handle timers and asynchronous (network) i/o.

NOTE: Code compiles but has not been heavily tested.

Change-Id: Ib6820c1b9a9950dc22449a332bc1b066a07af203

1 files changed, 23 insertions, 0 deletions

diff --git a/iolooper-select.c b/iolooper-select.c
index dbb18dd..dc5257c 100644
--- a/iolooper-select.c
+++ b/iolooper-select.c
@@ -57,6 +57,29 @@ iolooper_del_fd( IoLooper*  iol, int fd )
         iol->max_fd_valid = 0;
 }
 
+void
+iolooper_modify( IoLooper* iol, int fd, int oldflags, int newflags )
+{
+    if (fd < 0)
+        return;
+
+    int changed = oldflags ^ newflags;
+
+    if ((changed & IOLOOPER_READ) != 0) {
+        if ((newflags & IOLOOPER_READ) != 0)
+            FD_SET(fd, iol->reads);
+        else
+            FD_CLR(fd, iol->reads);
+    }
+    if ((changed & IOLOOPER_WRITE) != 0) {
+        if ((newflags & IOLOOPER_WRITE) != 0)
+            FD_SET(fd, iol->writes);
+        else
+            FD_CLR(fd, iol->writes);
+    }
+}
+
+
 static int
 iolooper_fd_count( IoLooper*  iol )
 {