anet.c: new API anetSendTimeout().

src/anet.c

@@ -34,6 +34,7 @@
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/un.h>
+#include <sys/time.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <arpa/inet.h>
@@ -178,6 +179,20 @@ int anetTcpKeepAlive(char *err, int fd)
     return ANET_OK;
 }
 
+/* Set the socket send timeout (SO_SNDTIMEO socket option) to the specified
+ * number of milliseconds, or disable it if the 'ms' argument is zero. */
+int anetSendTimeout(char *err, int fd, long long ms) {
+    struct timeval tv;
+
+    tv.tv_sec = ms/1000;
+    tv.tv_usec = (ms%1000)*1000;
+    if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) == -1) {
+        anetSetError(err, "setsockopt SO_SNDTIMEO: %s", strerror(errno));
+        return ANET_ERR;
+    }
+    return ANET_OK;
+}
+
 /* anetGenericResolve() is called by anetResolve() and anetResolveIP() to
  * do the actual work. It resolves the hostname "host" and set the string
  * representation of the IP address into the buffer pointed by "ipbuf".

src/anet.h

@@ -66,6 +66,7 @@ int anetBlock(char *err, int fd);
 int anetEnableTcpNoDelay(char *err, int fd);
 int anetDisableTcpNoDelay(char *err, int fd);
 int anetTcpKeepAlive(char *err, int fd);
+int anetSendTimeout(char *err, int fd, long long ms);
 int anetPeerToString(int fd, char *ip, size_t ip_len, int *port);
 int anetKeepAlive(char *err, int fd, int interval);
 int anetSockName(int fd, char *ip, size_t ip_len, int *port);