Prevent uxr_read_*_data_platform() from blocking too long

This commit sets the timeout in uxr_read_*_data_platform() to 0 after the first
occurrence of an EINTR interrupt. This ensures that the function will never
block longer than the specified timeout. But it may return early if an
interrupt occurs.

Signed-off-by: J. S. Seldenthuis <jseldenthuis@lely.com>

Author: jseldent

src/c/profile/transport/ip/tcp/tcp_transport_posix.c

@@ -126,6 +126,7 @@ size_t uxr_read_tcp_data_platform(
     {
         errno = errsv;
         poll_rv = poll(&platform->poll_fd, 1, timeout);
+        timeout = 0;
     } while (-1 == poll_rv && EINTR == errno);
     if (0 < poll_rv)
     {

src/c/profile/transport/ip/tcp/tcp_transport_posix_nopoll.c

@@ -123,19 +123,22 @@ size_t uxr_read_tcp_data_platform(
     size_t rv = 0;
     int errsv = errno;
 
-    timeout = (timeout <= 0) ? 1 : timeout;
-
-    struct timeval tv;
-    tv.tv_sec = timeout / 1000;
-    tv.tv_usec = (timeout % 1000) * 1000;
-
-    setsockopt(platform->fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
-
     ssize_t bytes_received;
     do
     {
         errno = errsv;
+
+        timeout = (timeout <= 0) ? 1 : timeout;
+
+        struct timeval tv;
+        tv.tv_sec = timeout / 1000;
+        tv.tv_usec = (timeout % 1000) * 1000;
+
+        setsockopt(platform->fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
+
         bytes_received = recv(platform->fd, (void*)buf, len, 0);
+
+        timeout = 0;
     } while (-1 == bytes_received && EINTR == errno);
     if (-1 != bytes_received)
     {

src/c/profile/transport/ip/udp/udp_transport_posix.c

@@ -113,6 +113,7 @@ size_t uxr_read_udp_data_platform(
     {
         errno = errsv;
         poll_rv = poll(&platform->poll_fd, 1, timeout);
+        timeout = 0;
     } while (-1 == poll_rv && EINTR == errno);
     if (0 < poll_rv)
     {

src/c/profile/transport/ip/udp/udp_transport_posix_nopoll.c

@@ -110,19 +110,22 @@ size_t uxr_read_udp_data_platform(
     size_t rv = 0;
     int errsv = errno;
 
-    timeout = (timeout <= 0) ? 1 : timeout;
-
-    struct timeval tv;
-    tv.tv_sec = timeout / 1000;
-    tv.tv_usec = (timeout % 1000) * 1000;
-
-    setsockopt(platform->fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
-
     ssize_t bytes_received;
     do
     {
         errno = errsv;
+
+        timeout = (timeout <= 0) ? 1 : timeout;
+
+        struct timeval tv;
+        tv.tv_sec = timeout / 1000;
+        tv.tv_usec = (timeout % 1000) * 1000;
+
+        setsockopt(platform->fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
+
         bytes_received = recv(platform->fd, (void*)buf, len, 0);
+
+        timeout = 0;
     } while (-1 == bytes_received && EINTR == errno);
     if (-1 != bytes_received)
     {