Bound the ADB connect time with a non-blocking connect

After a disconnect, the initial blocking connect takes
a long time to return, while subsequent calls return
quicks.  Switch to a non-blocking connect to make the
re-connect time more consistent and faster overall.

Change-Id: I21d02b22a8eb9a457c2f1fa95eb17894d5612ccd
Signed-off-by: Ken Lierman <ken.lierman@windriver.com>
Reviewed-by: Gumbel, Matthew K <matthew.k.gumbel@intel.com>
Reviewed-by: Jovanovic, Radivoje <radivoje.jovanovic@intel.com>
Reviewed-by: Boie, Andrew P <andrew.p.boie@intel.com>

adb/services.c

@@ -460,7 +460,7 @@ static void connect_device(char* host, char* buffer, int buffer_size)
 
     snprintf(serial, sizeof(serial), "%s:%d", hostbuf, port);
 
-    fd = socket_network_client(hostbuf, port, SOCK_STREAM);
+    fd = socket_network_client_timeout(hostbuf, port, SOCK_STREAM, 10);
     if (fd < 0) {
         snprintf(buffer, buffer_size, "unable to connect to %s:%d", host, port);
         return;

include/cutils/sockets.h

@@ -86,6 +86,8 @@ static inline int android_get_control_socket(const char *name)
 
 extern int socket_loopback_client(int port, int type);
 extern int socket_network_client(const char *host, int port, int type);
+extern int socket_network_client_timeout(const char *host, int port, int type,
+                                         int timeout);
 extern int socket_loopback_server(int port, int type);
 extern int socket_local_server(const char *name, int namespaceId, int type);
 extern int socket_local_server_bind(int s, const char *name, int namespaceId);

libcutils/socket_network_client.c

@@ -15,6 +15,7 @@
 */
 
 #include <errno.h>
+#include <fcntl.h>
 #include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
@@ -35,28 +36,94 @@
  * return is a file descriptor or -1 on error
  */
 int socket_network_client(const char *host, int port, int type)
+{
+    return socket_network_client_timeout(host, port, type, 0);
+}
+
+/* Connect to port on the IP interface. type is SOCK_STREAM or SOCK_DGRAM.
+ * timeout in seconds return is a file descriptor or -1 on error
+ */
+int socket_network_client_timeout(const char *host, int port, int type, int timeout)
 {
     struct hostent *hp;
     struct sockaddr_in addr;
+    socklen_t alen;
     int s;
+    int flags = 0, error = 0, ret = 0;
+    fd_set rset, wset;
+    socklen_t len = sizeof(error);
+    struct timeval ts;
+
+    ts.tv_sec = timeout;
+    ts.tv_usec = 0;
 
     hp = gethostbyname(host);
-    if(hp == 0) return -1;
-    
+    if (hp == 0) return -1;
+
     memset(&addr, 0, sizeof(addr));
     addr.sin_family = hp->h_addrtype;
     addr.sin_port = htons(port);
     memcpy(&addr.sin_addr, hp->h_addr, hp->h_length);
 
     s = socket(hp->h_addrtype, type, 0);
-    if(s < 0) return -1;
+    if (s < 0) return -1;
 
-    if(connect(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
+    if ((flags = fcntl(s, F_GETFL, 0)) < 0) {
+        close(s);
+        return -1;
+    }
+
+    if (fcntl(s, F_SETFL, flags | O_NONBLOCK) < 0) {
+        close(s);
+        return -1;
+    }
+
+    if ((ret = connect(s, (struct sockaddr *) &addr, sizeof(addr))) < 0) {
+        if (errno != EINPROGRESS) {
+            close(s);
+            return -1;
+        }
+    }
+
+    if (ret == 0)
+        goto done;
+
+    FD_ZERO(&rset);
+    FD_SET(s, &rset);
+    wset = rset;
+
+    if ((ret = select(s + 1, &rset, &wset, NULL, (timeout) ? &ts : NULL)) < 0) {
+        close(s);
+        return -1;
+    }
+    if (ret == 0) {   // we had a timeout
+        errno = ETIMEDOUT;
+        close(s);
+        return -1;
+    }
+
+    if (FD_ISSET(s, &rset) || FD_ISSET(s, &wset)) {
+        if (getsockopt(s, SOL_SOCKET, SO_ERROR, &error, &len) < 0) {
+            close(s);
+            return -1;
+        }
+    } else {
+        close(s);
+        return -1;
+    }
+
+    if (error) {  // check if we had a socket error
+        errno = error;
+        close(s);
+        return -1;
+    }
+
+done:
+    if (fcntl(s, F_SETFL, flags) < 0) {
         close(s);
         return -1;
     }
 
     return s;
-
 }