Fix alignment issues in FD passing code

[free-sw/xcb/libxcb] / src / xcb_out.c

diff --git a/src/xcb_out.c b/src/xcb_out.c
index fe71193..1a3aca5 100644 (file)
--- a/src/xcb_out.c
+++ b/src/xcb_out.c
@@ -25,6 +25,10 @@
 
 /* Stuff that sends stuff to the server. */
 
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
 #include <assert.h>
 #include <stdlib.h>
 #include <unistd.h>
@@ -82,21 +86,24 @@ static void send_sync(xcb_connection_t *c)
 
 static void get_socket_back(xcb_connection_t *c)
 {
-    while(c->out.return_socket && c->out.socket_moving)
-        pthread_cond_wait(&c->out.socket_cond, &c->iolock);
-    if(!c->out.return_socket)
-        return;
-
-    c->out.socket_moving = 1;
-    pthread_mutex_unlock(&c->iolock);
-    c->out.return_socket(c->out.socket_closure);
-    pthread_mutex_lock(&c->iolock);
-    c->out.socket_moving = 0;
-
-    pthread_cond_broadcast(&c->out.socket_cond);
-    c->out.return_socket = 0;
-    c->out.socket_closure = 0;
-    _xcb_in_replies_done(c);
+    while (c->out.return_socket) {
+        /* we are about to release the lock,
+           so make a copy of the current status */
+        xcb_return_socket_func_t return_socket = c->out.return_socket;
+        void *socket_closure = c->out.socket_closure;
+        int socket_seq = c->out.socket_seq;
+
+        pthread_mutex_unlock(&c->iolock);
+        return_socket(socket_closure);
+        pthread_mutex_lock(&c->iolock);
+
+        /* make sure nobody else has acquired the socket */
+        if (socket_seq == c->out.socket_seq) {
+            c->out.return_socket = 0;
+            c->out.socket_closure = 0;
+            _xcb_in_replies_done(c);
+        }
+    }
 }
 
 /* Public interface */
@@ -173,7 +180,7 @@ unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vect
             const xcb_query_extension_reply_t *extension = xcb_get_extension_data(c, req->ext);
             if(!(extension && extension->present))
             {
-                _xcb_conn_shutdown(c);
+                _xcb_conn_shutdown(c, XCB_CONN_CLOSED_EXT_NOTSUPPORTED);
                 return 0;
             }
             ((uint8_t *) vector[0].iov_base)[0] = extension->major_opcode;
@@ -203,7 +210,7 @@ unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vect
         }
         else if(longlen > xcb_get_maximum_request_length(c))
         {
-            _xcb_conn_shutdown(c);
+            _xcb_conn_shutdown(c, XCB_CONN_CLOSED_REQ_LEN_EXCEED);
             return 0; /* server can't take this; maybe need BIGREQUESTS? */
         }
 
@@ -256,6 +263,24 @@ unsigned int xcb_send_request(xcb_connection_t *c, int flags, struct iovec *vect
     return request;
 }
 
+void
+xcb_send_fd(xcb_connection_t *c, int fd)
+{
+#if HAVE_SENDMSG
+    if (c->has_error)
+        return;
+    pthread_mutex_lock(&c->iolock);
+    while (c->out.out_fd.nfd == XCB_MAX_PASS_FD) {
+        _xcb_out_flush_to(c, c->out.request);
+        if (c->has_error)
+            break;
+    }
+    if (!c->has_error)
+        c->out.out_fd.fd[c->out.out_fd.nfd++] = fd;
+    pthread_mutex_unlock(&c->iolock);
+#endif
+}
+
 int xcb_take_socket(xcb_connection_t *c, void (*return_socket)(void *closure), void *closure, int flags, uint64_t *sent)
 {
     int ret;
@@ -263,11 +288,18 @@ int xcb_take_socket(xcb_connection_t *c, void (*return_socket)(void *closure), v
         return 0;
     pthread_mutex_lock(&c->iolock);
     get_socket_back(c);
-    ret = _xcb_out_flush_to(c, c->out.request);
+
+    /* _xcb_out_flush may drop the iolock allowing other threads to
+     * write requests, so keep flushing until we're done
+     */
+    do
+        ret = _xcb_out_flush_to(c, c->out.request);
+    while (ret && c->out.request != c->out.request_written);
     if(ret)
     {
         c->out.return_socket = return_socket;
         c->out.socket_closure = closure;
+        ++c->out.socket_seq;
         if(flags)
             _xcb_in_expect_reply(c, c->out.request, WORKAROUND_EXTERNAL_SOCKET_OWNER, flags);
         assert(c->out.request == c->out.request_written);
@@ -304,11 +336,9 @@ int xcb_flush(xcb_connection_t *c)
 
 int _xcb_out_init(_xcb_out *out)
 {
-    if(pthread_cond_init(&out->socket_cond, 0))
-        return 0;
     out->return_socket = 0;
     out->socket_closure = 0;
-    out->socket_moving = 0;
+    out->socket_seq = 0;
 
     if(pthread_cond_init(&out->cond, 0))
         return 0;
@@ -343,6 +373,15 @@ int _xcb_out_send(xcb_connection_t *c, struct iovec *vector, int count)
     return ret;
 }
 
+void _xcb_out_send_sync(xcb_connection_t *c)
+{
+    /* wait for other writing threads to get out of my way. */
+    while(c->out.writing)
+        pthread_cond_wait(&c->out.cond, &c->iolock);
+    get_socket_back(c);
+    send_sync(c);
+}
+
 int _xcb_out_flush_to(xcb_connection_t *c, uint64_t request)
 {
     assert(XCB_SEQUENCE_COMPARE(request, <=, c->out.request));