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[OpenWrt-Devel,libubox,1/2] usock: add helper waiting for socket to be ready

Message ID 1421322172-6939-1-git-send-email-zajec5@gmail.com
State Superseded
Headers show

Commit Message

Rafał Miłecki Jan. 15, 2015, 11:42 a.m. UTC
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
---
 usock.c | 30 ++++++++++++++++++++++++++++++
 usock.h | 11 +++++++++++
 2 files changed, 41 insertions(+)

Comments

Felix Fietkau Jan. 15, 2015, 11:49 a.m. UTC | #1
On 2015-01-15 12:42, Rafał Miłecki wrote:
> Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
> ---
>  usock.c | 30 ++++++++++++++++++++++++++++++
>  usock.h | 11 +++++++++++
>  2 files changed, 41 insertions(+)
> 
> diff --git a/usock.c b/usock.c
> index 04ed4ee..39909c1 100644
> --- a/usock.c
> +++ b/usock.c
> @@ -117,3 +117,33 @@ int usock(int type, const char *host, const char *service) {
>  	usock_set_flags(sock, type);
>  	return sock;
>  }
> +
> +int usock_wait_ready(int fd, int msecs) {
> +	fd_set fds;
> +	struct timeval tv;
> +	int res;
> +
> +	FD_ZERO(&fds);
> +	FD_SET(fd, &fds);
> +
> +	tv.tv_sec = msecs / 1000;
> +	tv.tv_usec = (msecs % 1000) * 1000;
> +
> +	res = select(fd + 1, NULL, &fds, NULL, &tv);
Wouldn't it be better to use poll() here? The fd bitmask crap that
select uses is quite ugly.

- Felix
diff mbox

Patch

diff --git a/usock.c b/usock.c
index 04ed4ee..39909c1 100644
--- a/usock.c
+++ b/usock.c
@@ -117,3 +117,33 @@  int usock(int type, const char *host, const char *service) {
 	usock_set_flags(sock, type);
 	return sock;
 }
+
+int usock_wait_ready(int fd, int msecs) {
+	fd_set fds;
+	struct timeval tv;
+	int res;
+
+	FD_ZERO(&fds);
+	FD_SET(fd, &fds);
+
+	tv.tv_sec = msecs / 1000;
+	tv.tv_usec = (msecs % 1000) * 1000;
+
+	res = select(fd + 1, NULL, &fds, NULL, &tv);
+	if (res < 0) {
+		return errno;
+	} else if (res == 0) {
+		return -ETIMEDOUT;
+	} else {
+		int err = 0;
+		socklen_t optlen = sizeof(err);
+
+		res = getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &optlen);
+		if (res)
+			return errno;
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
diff --git a/usock.h b/usock.h
index 8f30add..c97fc40 100644
--- a/usock.h
+++ b/usock.h
@@ -32,4 +32,15 @@ 
 
 int usock(int type, const char *host, const char *service);
 
+/**
+ * Wait for a socket to become ready.
+ *
+ * This may be useful for users of USOCK_NONBLOCK to wait (with a timeout)
+ * for a socket.
+ *
+ * @param fd file descriptor of socket
+ * @param msecs timeout in microseconds
+ */
+int usock_wait_ready(int fd, int msecs);
+
 #endif /* USOCK_H_ */