make the socket non-blocking, explicitly wait for data using poll()

diff --git a/libubus.c b/libubus.c
index aed615d184c666b4d96801e4eed3fda387a8997b..af8cc469bec8f0cc5c519fa115b5b77a55738a08 100644 (file)
--- a/libubus.c
+++ b/libubus.c
@@ -16,6 +16,7 @@
 #include <sys/socket.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <poll.h>
 
 #include <libubox/blob.h>
 #include <libubox/blobmsg.h>
@@ -88,6 +89,14 @@ out:
        return err;
 }
 
+static void wait_data(int fd, bool write)
+{
+       struct pollfd pfd = { .fd = fd };
+
+       pfd.events = write ? POLLOUT : POLLIN;
+       poll(&pfd, 1, 0);
+}
+
 static int writev_retry(int fd, struct iovec *iov, int iov_len)
 {
        int len = 0;
@@ -97,9 +106,7 @@ static int writev_retry(int fd, struct iovec *iov, int iov_len)
                if (cur_len < 0) {
                        switch(errno) {
                        case EAGAIN:
-                               /* turn off non-blocking mode */
-                               fcntl(fd, F_SETFL, fcntl(fd, F_GETFL) &
-                                     ~O_NONBLOCK);
+                               wait_data(fd, true);
                                break;
                        case EINTR:
                                break;
@@ -165,6 +172,9 @@ static bool recv_retry(int fd, struct iovec *iov, bool wait)
        int bytes;
 
        while (iov->iov_len > 0) {
+               if (wait)
+                       wait_data(fd, false);
+
                bytes = read(fd, iov->iov_base, iov->iov_len);
                if (bytes < 0) {
                        bytes = 0;
@@ -860,6 +870,8 @@ struct ubus_context *ubus_connect(const char *path)
        if (!ctx->local_id)
                goto error_close;
 
+       fcntl(ctx->sock.fd, F_SETFL, fcntl(ctx->sock.fd, F_GETFL) | O_NONBLOCK);
+
        return ctx;
 
 error_free_buf: