mt.patch

diff --git src/modbus-private.h src/modbus-private.h
index 7994459..799eccd 100644
--- src/modbus-private.h
+++ src/modbus-private.h
@@ -109,6 +109,7 @@ typedef struct _modbus_backend {
                                    const uint8_t *rsp, int rsp_length);
     int (*connect) (modbus_t *ctx);
     void (*close) (modbus_t *ctx);
+    void (*close_mt) (modbus_t *ctx);
     int (*flush) (modbus_t *ctx);
     int (*select) (modbus_t *ctx, fd_set *rset, struct timeval *tv, int msg_length);
 } modbus_backend_t;
@@ -124,6 +125,7 @@ struct _modbus {
     struct timeval byte_timeout;
     const modbus_backend_t *backend;
     void *backend_data;
+    void *mt_data;
 };
 
 void _modbus_init_common(modbus_t *ctx);
diff --git src/modbus-rtu-private.h src/modbus-rtu-private.h
index c8fdeab..4f20db4 100644
--- src/modbus-rtu-private.h
+++ src/modbus-rtu-private.h
@@ -94,4 +94,10 @@ typedef struct _modbus_rtu {
     int confirmation_to_ignore;
 } modbus_rtu_t;
 
+typedef struct _modbus_rtu_mt {
+	/* Pipes for control in multithread */
+    int mtp_r;
+    int mtp_w;
+} modbus_rtu_mt_t;
+
 #endif /* _MODBUS_RTU_PRIVATE_H_ */
diff --git src/modbus-rtu.c src/modbus-rtu.c
index c41110e..60e7456 100644
--- src/modbus-rtu.c
+++ src/modbus-rtu.c
@@ -937,6 +937,20 @@ void _modbus_rtu_close(modbus_t *ctx)
 #endif
 }
 
+void _modbus_rtu_close_mt(modbus_t *ctx)
+{
+  ssize_t size;
+	_modbus_rtu_close(ctx);
+	
+	modbus_rtu_mt_t *ctx_mt = ctx->mt_data;
+	size = write(ctx_mt->mtp_w, "q", 1);
+  if (size == -1)
+    fprintf(stderr, "ERROR returned by write() (%s)\n",
+      strerror(errno));
+  close(ctx_mt->mtp_w);
+  close(ctx_mt->mtp_r);
+}
+
 int _modbus_rtu_flush(modbus_t *ctx)
 {
 #if defined(_WIN32)
@@ -964,7 +978,13 @@ int _modbus_rtu_select(modbus_t *ctx, fd_set *rset,
         return -1;
     }
 #else
-    while ((s_rc = select(ctx->s+1, rset, NULL, NULL, tv)) == -1) {
+	/* Add pipe descriptor to select */
+	modbus_rtu_mt_t *ctx_mt = ctx->mt_data;
+	FD_SET(ctx_mt->mtp_r, rset);
+	
+	int max_n = (ctx->s > ctx_mt->mtp_r) ? ctx->s : ctx_mt->mtp_r;
+	
+    while ((s_rc = select(max_n+1, rset, NULL, NULL, tv)) == -1) {
         if (errno == EINTR) {
             if (ctx->debug) {
                 fprintf(stderr, "A non blocked signal was caught\n");
@@ -972,6 +992,7 @@ int _modbus_rtu_select(modbus_t *ctx, fd_set *rset,
             /* Necessary after an error */
             FD_ZERO(rset);
             FD_SET(ctx->s, rset);
+            FD_SET(ctx_mt->mtp_r, rset);
         } else {
             return -1;
         }
@@ -983,7 +1004,12 @@ int _modbus_rtu_select(modbus_t *ctx, fd_set *rset,
         return -1;
     }
 #endif
-
+	if (FD_ISSET(ctx_mt->mtp_r, rset)) {
+		/* Connection reset. */
+		errno = ECONNRESET;
+		return -1;
+	}
+	
     return s_rc;
 }
 
@@ -1004,6 +1030,7 @@ const modbus_backend_t _modbus_rtu_backend = {
     _modbus_rtu_pre_check_confirmation,
     _modbus_rtu_connect,
     _modbus_rtu_close,
+    _modbus_rtu_close_mt,
     _modbus_rtu_flush,
     _modbus_rtu_select
 };
@@ -1014,6 +1041,7 @@ modbus_t* modbus_new_rtu(const char *device,
 {
     modbus_t *ctx;
     modbus_rtu_t *ctx_rtu;
+    modbus_rtu_mt_t *ctx_mt;
     size_t dest_size;
     size_t ret_size;
 
@@ -1062,6 +1090,20 @@ modbus_t* modbus_new_rtu(const char *device,
 #endif
 
     ctx_rtu->confirmation_to_ignore = FALSE;
+    
+    /* Create pipe chanel */
+    ctx->mt_data = (modbus_rtu_mt_t *) malloc(sizeof(modbus_rtu_mt_t));
+    ctx_mt = (modbus_rtu_mt_t *)ctx->mt_data;
+    
+    int mtp[2];
+    if (pipe(mtp) == -1) {
+        fprintf(stderr, "ERROR Can't create pipe (%s)\n",
+			strerror(errno));
+		modbus_free(ctx);
+        return NULL;
+    }
+    ctx_mt->mtp_r = mtp[0];
+    ctx_mt->mtp_w = mtp[1];
 
     return ctx;
 }
diff --git src/modbus-tcp-private.h src/modbus-tcp-private.h
index 408d08a..8a2b43b 100644
--- src/modbus-tcp-private.h
+++ src/modbus-tcp-private.h
@@ -53,4 +53,10 @@ typedef struct _modbus_tcp_pi {
     char service[_MODBUS_TCP_PI_SERVICE_LENGTH];
 } modbus_tcp_pi_t;
 
+
+typedef struct _modbus_tcp_mt {
+	/* Main listen socket */
+    int lst_socket;
+} modbus_tcp_mt_t;
+
 #endif /* _MODBUS_TCP_PRIVATE_H_ */
diff --git src/modbus-tcp.c src/modbus-tcp.c
index b3eae81..928b850 100644
--- src/modbus-tcp.c
+++ src/modbus-tcp.c
@@ -404,6 +404,17 @@ void _modbus_tcp_close(modbus_t *ctx)
     close(ctx->s);
 }
 
+void _modbus_tcp_close_mt(modbus_t *ctx)
+{
+	_modbus_tcp_close(ctx);
+	
+	modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
+	if (ctx_mt->lst_socket != -1) {
+		shutdown(ctx_mt->lst_socket, SHUT_RDWR);
+		close(ctx_mt->lst_socket);
+	}
+}
+
 int _modbus_tcp_flush(modbus_t *ctx)
 {
     int rc;
@@ -448,6 +459,7 @@ int modbus_tcp_listen(modbus_t *ctx, int nb_connection)
     int yes;
     struct sockaddr_in addr;
     modbus_tcp_t *ctx_tcp = ctx->backend_data;
+    modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
 
 #ifdef OS_WIN32
     if (_modbus_tcp_init_win32() == -1) {
@@ -481,6 +493,8 @@ int modbus_tcp_listen(modbus_t *ctx, int nb_connection)
         close(new_socket);
         return -1;
     }
+    
+    ctx_mt->lst_socket = new_socket;
 
     return new_socket;
 }
@@ -495,6 +509,7 @@ int modbus_tcp_pi_listen(modbus_t *ctx, int nb_connection)
     const char *service;
     int new_socket;
     modbus_tcp_pi_t *ctx_tcp_pi = ctx->backend_data;
+    modbus_tcp_mt_t *ctx_mt = ctx->mt_data;
 
     if (ctx_tcp_pi->node[0] == 0)
         node = NULL; /* == any */
@@ -577,6 +592,8 @@ int modbus_tcp_pi_listen(modbus_t *ctx, int nb_connection)
     if (new_socket < 0) {
         return -1;
     }
+    
+    ctx_mt->lst_socket = new_socket;
 
     return new_socket;
 }
@@ -671,6 +688,7 @@ const modbus_backend_t _modbus_tcp_backend = {
     _modbus_tcp_pre_check_confirmation,
     _modbus_tcp_connect,
     _modbus_tcp_close,
+    _modbus_tcp_close_mt,
     _modbus_tcp_flush,
     _modbus_tcp_select
 };
@@ -693,6 +711,7 @@ const modbus_backend_t _modbus_tcp_pi_backend = {
     _modbus_tcp_pre_check_confirmation,
     _modbus_tcp_pi_connect,
     _modbus_tcp_close,
+    _modbus_tcp_close_mt,
     _modbus_tcp_flush,
     _modbus_tcp_select
 };
@@ -701,6 +720,7 @@ modbus_t* modbus_new_tcp(const char *ip, int port)
 {
     modbus_t *ctx;
     modbus_tcp_t *ctx_tcp;
+    modbus_tcp_mt_t *ctx_mt;
     size_t dest_size;
     size_t ret_size;
 
@@ -727,6 +747,9 @@ modbus_t* modbus_new_tcp(const char *ip, int port)
 
     ctx->backend_data = (modbus_tcp_t *) malloc(sizeof(modbus_tcp_t));
     ctx_tcp = (modbus_tcp_t *)ctx->backend_data;
+    
+    ctx->mt_data = (modbus_tcp_mt_t *) malloc(sizeof(modbus_tcp_mt_t));
+    ctx_mt = (modbus_tcp_mt_t *)ctx->mt_data;
 
     dest_size = sizeof(char) * 16;
     ret_size = strlcpy(ctx_tcp->ip, ip, dest_size);
@@ -746,6 +769,8 @@ modbus_t* modbus_new_tcp(const char *ip, int port)
 
     ctx_tcp->port = port;
     ctx_tcp->t_id = 0;
+    
+    ctx_mt->lst_socket = -1;
 
     return ctx;
 }
@@ -755,6 +780,7 @@ modbus_t* modbus_new_tcp_pi(const char *node, const char *service)
 {
     modbus_t *ctx;
     modbus_tcp_pi_t *ctx_tcp_pi;
+    modbus_tcp_mt_t *ctx_mt;
     size_t dest_size;
     size_t ret_size;
 
@@ -768,6 +794,9 @@ modbus_t* modbus_new_tcp_pi(const char *node, const char *service)
 
     ctx->backend_data = (modbus_tcp_pi_t *) malloc(sizeof(modbus_tcp_pi_t));
     ctx_tcp_pi = (modbus_tcp_pi_t *)ctx->backend_data;
+    
+    ctx->mt_data = (modbus_tcp_mt_t *) malloc(sizeof(modbus_tcp_mt_t));
+    ctx_mt = (modbus_tcp_mt_t *)ctx->mt_data;
 
     dest_size = sizeof(char) * _MODBUS_TCP_PI_NODE_LENGTH;
     ret_size = strlcpy(ctx_tcp_pi->node, node, dest_size);
@@ -802,6 +831,8 @@ modbus_t* modbus_new_tcp_pi(const char *node, const char *service)
     }
 
     ctx_tcp_pi->t_id = 0;
+    
+    ctx_mt->lst_socket = -1;
 
     return ctx;
 }
diff --git src/modbus.c src/modbus.c
index b555913..e08f7ae 100644
--- src/modbus.c
+++ src/modbus.c
@@ -1457,12 +1457,21 @@ void modbus_close(modbus_t *ctx)
     ctx->backend->close(ctx);
 }
 
+void modbus_close_mt(modbus_t *ctx)
+{
+    if (ctx == NULL)
+        return;
+	
+    ctx->backend->close_mt(ctx);
+}
+
 void modbus_free(modbus_t *ctx)
 {
     if (ctx == NULL)
         return;
 
     free(ctx->backend_data);
+    free(ctx->mt_data);
     free(ctx);
 }
 
diff --git src/modbus.h src/modbus.h
index 399c41b..e31faf4 100644
--- src/modbus.h
+++ src/modbus.h
@@ -169,6 +169,7 @@ EXPORT int modbus_get_header_length(modbus_t *ctx);
 
 EXPORT int modbus_connect(modbus_t *ctx);
 EXPORT void modbus_close(modbus_t *ctx);
+EXPORT void modbus_close_mt(modbus_t *ctx);
 
 EXPORT void modbus_free(modbus_t *ctx);