1 files changed, 441 insertions, 410 deletions
diff --git a/libxcb/src/xcb_conn.c b/libxcb/src/xcb_conn.c
index 84a9917d6..725502af6 100644
--- a/libxcb/src/xcb_conn.c
+++ b/libxcb/src/xcb_conn.c
@@ -1,410 +1,441 @@
-/* Copyright (C) 2001-2004 Bart Massey and Jamey Sharp.
- *
- * Permission is hereby granted, free of charge, to any person obtaining a
- * copy of this software and associated documentation files (the "Software"),
- * to deal in the Software without restriction, including without limitation
- * the rights to use, copy, modify, merge, publish, distribute, sublicense,
- * and/or sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following conditions:
- * 
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
- * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
- * 
- * Except as contained in this notice, the names of the authors or their
- * institutions shall not be used in advertising or otherwise to promote the
- * sale, use or other dealings in this Software without prior written
- * authorization from the authors.
- */
-
-/* Connection management: the core of XCB. */
-
-#include <assert.h>
-#include <string.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <errno.h>
-
-#include "xcb.h"
-#include "xcbint.h"
-#if USE_POLL
-#include <poll.h>
-#elif !defined _WIN32
-#include <sys/select.h>
-#endif
-
-#ifdef _WIN32
-#include "xcb_windefs.h"
-#else
-#include <sys/socket.h>
-#include <netinet/in.h>
-#endif /* _WIN32 */
-
-/* SHUT_RDWR is fairly recent and is not available on all platforms */
-#if !defined(SHUT_RDWR)
-#define SHUT_RDWR 2
-#endif
-
-typedef struct {
-    uint8_t  status;
-    uint8_t  pad0[5];
-    uint16_t length;
-} xcb_setup_generic_t;
-
-const int error_connection = 1;
-
-static int set_fd_flags(const int fd)
-{
-/* Win32 doesn't have file descriptors and the fcntl function. This block sets the socket in non-blocking mode */
-
-#ifdef _WIN32
-   u_long iMode = 1; /* non-zero puts it in non-blocking mode, 0 in blocking mode */   
-   int ret = 0;
-
-   ret = ioctlsocket(fd, FIONBIO, &iMode);
-   if(ret != 0) 
-       return 0;
-   return 1;
-#else
-    int flags = fcntl(fd, F_GETFL, 0);
-    if(flags == -1)
-        return 0;
-    flags |= O_NONBLOCK;
-    if(fcntl(fd, F_SETFL, flags) == -1)
-        return 0;
-    if(fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
-        return 0;
-    return 1;
-#endif /* _WIN32 */
-}
-
-static int write_setup(xcb_connection_t *c, xcb_auth_info_t *auth_info)
-{
-    static const char pad[3];
-    xcb_setup_request_t out;
-    struct iovec parts[6];
-    int count = 0;
-    static const uint32_t endian = 0x01020304;
-    int ret;
-
-    memset(&out, 0, sizeof(out));
-
-    /* B = 0x42 = MSB first, l = 0x6c = LSB first */
-    if(htonl(endian) == endian)
-        out.byte_order = 0x42;
-    else
-        out.byte_order = 0x6c;
-    out.protocol_major_version = X_PROTOCOL;
-    out.protocol_minor_version = X_PROTOCOL_REVISION;
-    out.authorization_protocol_name_len = 0;
-    out.authorization_protocol_data_len = 0;
-    parts[count].iov_len = sizeof(xcb_setup_request_t);
-    parts[count++].iov_base = &out;
-    parts[count].iov_len = XCB_PAD(sizeof(xcb_setup_request_t));
-    parts[count++].iov_base = (char *) pad;
-
-    if(auth_info)
-    {
-        parts[count].iov_len = out.authorization_protocol_name_len = auth_info->namelen;
-        parts[count++].iov_base = auth_info->name;
-        parts[count].iov_len = XCB_PAD(out.authorization_protocol_name_len);
-        parts[count++].iov_base = (char *) pad;
-        parts[count].iov_len = out.authorization_protocol_data_len = auth_info->datalen;
-        parts[count++].iov_base = auth_info->data;
-        parts[count].iov_len = XCB_PAD(out.authorization_protocol_data_len);
-        parts[count++].iov_base = (char *) pad;
-    }
-    assert(count <= (int) (sizeof(parts) / sizeof(*parts)));
-
-    pthread_mutex_lock(&c->iolock);
-    ret = _xcb_out_send(c, parts, count);
-    pthread_mutex_unlock(&c->iolock);
-    return ret;
-}
-
-static int read_setup(xcb_connection_t *c)
-{
-    /* Read the server response */
-    c->setup = malloc(sizeof(xcb_setup_generic_t));
-    if(!c->setup)
-        return 0;
-
-    if(_xcb_in_read_block(c, c->setup, sizeof(xcb_setup_generic_t)) != sizeof(xcb_setup_generic_t))
-        return 0;
-
-    {
-        void *tmp = realloc(c->setup, c->setup->length * 4 + sizeof(xcb_setup_generic_t));
-        if(!tmp)
-            return 0;
-        c->setup = tmp;
-    }
-
-    if(_xcb_in_read_block(c, (char *) c->setup + sizeof(xcb_setup_generic_t), c->setup->length * 4) <= 0)
-        return 0;
-
-    /* 0 = failed, 2 = authenticate, 1 = success */
-    switch(c->setup->status)
-    {
-    case 0: /* failed */
-        {
-            xcb_setup_failed_t *setup = (xcb_setup_failed_t *) c->setup;
-            write(STDERR_FILENO, xcb_setup_failed_reason(setup), xcb_setup_failed_reason_length(setup));
-            return 0;
-        }
-
-    case 2: /* authenticate */
-        {
-            xcb_setup_authenticate_t *setup = (xcb_setup_authenticate_t *) c->setup;
-            write(STDERR_FILENO, xcb_setup_authenticate_reason(setup), xcb_setup_authenticate_reason_length(setup));
-            return 0;
-        }
-    }
-
-    return 1;
-}
-
-/* precondition: there must be something for us to write. */
-static int write_vec(xcb_connection_t *c, struct iovec **vector, int *count)
-{
-    int n;
-    assert(!c->out.queue_len);
-
-#ifdef _WIN32
-    int i = 0;
-    int ret = 0,err = 0;
-    struct iovec *vec;
-    n = 0;
-
-    /* Could use the WSASend win32 function for scatter/gather i/o but setting up the WSABUF struct from
-       an iovec would require more work and I'm not sure of the benefit....works for now */
-    vec = *vector;
-    while(i < *count)
-    {         	 
-         ret = send(c->fd,vec->iov_base,vec->iov_len,0);	 
-         if(ret == SOCKET_ERROR)
-         {
-             err  = WSAGetLastError();
-             if(err == WSAEWOULDBLOCK)
-             {
-                 return 1;
-             }
-         }
-         n += ret;
-         *vec++;
-         i++;
-    }
-#else
-    n = writev(c->fd, *vector, *count);
-    if(n < 0 && errno == EAGAIN)
-        return 1;
-#endif /* _WIN32 */    
-
-    if(n <= 0)
-    {
-        _xcb_conn_shutdown(c);
-        return 0;
-    }
-
-    for(; *count; --*count, ++*vector)
-    {
-        int cur = (*vector)->iov_len;
-        if(cur > n)
-            cur = n;
-        (*vector)->iov_len -= cur;
-        (*vector)->iov_base = (char *) (*vector)->iov_base + cur;
-        n -= cur;
-        if((*vector)->iov_len)
-            break;
-    }
-    if(!*count)
-        *vector = 0;
-    assert(n == 0);
-    return 1;
-}
-
-/* Public interface */
-
-const xcb_setup_t *xcb_get_setup(xcb_connection_t *c)
-{
-    if(c->has_error)
-        return 0;
-    /* doesn't need locking because it's never written to. */
-    return c->setup;
-}
-
-int xcb_get_file_descriptor(xcb_connection_t *c)
-{
-    if(c->has_error)
-        return -1;
-    /* doesn't need locking because it's never written to. */
-    return c->fd;
-}
-
-int xcb_connection_has_error(xcb_connection_t *c)
-{
-    /* doesn't need locking because it's read and written atomically. */
-    return c->has_error;
-}
-
-xcb_connection_t *xcb_connect_to_fd(int fd, xcb_auth_info_t *auth_info)
-{
-    xcb_connection_t* c;
-
-#ifndef _WIN32
-#ifndef USE_POLL
-    if(fd >= FD_SETSIZE) /* would overflow in FD_SET */
-    {
-        close(fd);
-        return (xcb_connection_t *) &error_connection;
-    }
-#endif
-#endif /* !_WIN32*/
-
-    c = calloc(1, sizeof(xcb_connection_t));
-    if(!c) {
-        close(fd);
-        return (xcb_connection_t *) &error_connection;
-    }
-
-    c->fd = fd;
-
-    if(!(
-        set_fd_flags(fd) &&
-        pthread_mutex_init(&c->iolock, 0) == 0 &&
-        _xcb_in_init(&c->in) &&
-        _xcb_out_init(&c->out) &&
-        write_setup(c, auth_info) &&
-        read_setup(c) &&
-        _xcb_ext_init(c) &&
-        _xcb_xid_init(c)
-        ))
-    {
-        xcb_disconnect(c);
-        return (xcb_connection_t *) &error_connection;
-    }
-
-    return c;
-}
-
-void xcb_disconnect(xcb_connection_t *c)
-{
-    if(c == (xcb_connection_t *) &error_connection)
-        return;
-
-    free(c->setup);
-
-    /* disallow further sends and receives */
-    shutdown(c->fd, SHUT_RDWR);
-    close(c->fd);
-
-    pthread_mutex_destroy(&c->iolock);
-    _xcb_in_destroy(&c->in);
-    _xcb_out_destroy(&c->out);
-
-    _xcb_ext_destroy(c);
-    _xcb_xid_destroy(c);
-
-    free(c);
-}
-
-/* Private interface */
-
-void _xcb_conn_shutdown(xcb_connection_t *c)
-{
-    c->has_error = 1;
-}
-
-int _xcb_conn_wait(xcb_connection_t *c, pthread_cond_t *cond, struct iovec **vector, int *count)
-{
-    int ret;
-#if USE_POLL
-    struct pollfd fd;
-#else
-    fd_set rfds, wfds;
-#endif
-
-    /* If the thing I should be doing is already being done, wait for it. */
-    if(count ? c->out.writing : c->in.reading)
-    {
-        pthread_cond_wait(cond, &c->iolock);
-        return 1;
-    }
-
-#if USE_POLL
-    memset(&fd, 0, sizeof(fd));
-    fd.fd = c->fd;
-    fd.events = POLLIN;
-#else
-    FD_ZERO(&rfds);
-    FD_SET(c->fd, &rfds);
-#endif
-    ++c->in.reading;
-
-#if USE_POLL
-    if(count)
-    {
-        fd.events |= POLLOUT;
-        ++c->out.writing;
-    }
-#else
-    FD_ZERO(&wfds);
-    if(count)
-    {
-        FD_SET(c->fd, &wfds);
-        ++c->out.writing;
-    }
-#endif
-
-    pthread_mutex_unlock(&c->iolock);
-    do {
-#if USE_POLL
-        ret = poll(&fd, 1, -1);
-        /* If poll() returns an event we didn't expect, such as POLLNVAL, treat
-         * it as if it failed. */
-        if(ret >= 0 && (fd.revents & ~fd.events))
-        {
-            ret = -1;
-            break;
-        }
-#else
-        ret = select(c->fd + 1, &rfds, &wfds, 0, 0);
-#endif
-    } while (ret == -1 && errno == EINTR);
-    if(ret < 0)
-    {
-        _xcb_conn_shutdown(c);
-        ret = 0;
-    }
-    pthread_mutex_lock(&c->iolock);
-
-    if(ret)
-    {
-#if USE_POLL
-        if((fd.revents & POLLIN) == POLLIN)
-#else
-        if(FD_ISSET(c->fd, &rfds))
-#endif
-            ret = ret && _xcb_in_read(c);
-
-#if USE_POLL
-        if((fd.revents & POLLOUT) == POLLOUT)
-#else
-        if(FD_ISSET(c->fd, &wfds))
-#endif
-            ret = ret && write_vec(c, vector, count);
-    }
-
-    if(count)
-        --c->out.writing;
-    --c->in.reading;
-
-    return ret;
-}
+/* Copyright (C) 2001-2004 Bart Massey and Jamey Sharp.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * 
+ * Except as contained in this notice, the names of the authors or their
+ * institutions shall not be used in advertising or otherwise to promote the
+ * sale, use or other dealings in this Software without prior written
+ * authorization from the authors.
+ */
+
+/* Connection management: the core of XCB. */
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <errno.h>
+
+#include "xcb.h"
+#include "xcbint.h"
+#if USE_POLL
+#include <poll.h>
+#elif !defined _WIN32
+#include <sys/select.h>
+#endif
+
+#ifdef _WIN32
+#include "xcb_windefs.h"
+#else
+#include <sys/socket.h>
+#include <netinet/in.h>
+#endif /* _WIN32 */
+
+/* SHUT_RDWR is fairly recent and is not available on all platforms */
+#if !defined(SHUT_RDWR)
+#define SHUT_RDWR 2
+#endif
+
+typedef struct {
+    uint8_t  status;
+    uint8_t  pad0[5];
+    uint16_t length;
+} xcb_setup_generic_t;
+
+static const int xcb_con_error = XCB_CONN_ERROR;
+static const int xcb_con_closed_mem_er = XCB_CONN_CLOSED_MEM_INSUFFICIENT;
+static const int xcb_con_closed_parse_er = XCB_CONN_CLOSED_PARSE_ERR;
+
+static int set_fd_flags(const int fd)
+{
+/* Win32 doesn't have file descriptors and the fcntl function. This block sets the socket in non-blocking mode */
+
+#ifdef _WIN32
+   u_long iMode = 1; /* non-zero puts it in non-blocking mode, 0 in blocking mode */   
+   int ret = 0;
+
+   ret = ioctlsocket(fd, FIONBIO, &iMode);
+   if(ret != 0) 
+       return 0;
+   return 1;
+#else
+    int flags = fcntl(fd, F_GETFL, 0);
+    if(flags == -1)
+        return 0;
+    flags |= O_NONBLOCK;
+    if(fcntl(fd, F_SETFL, flags) == -1)
+        return 0;
+    if(fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
+        return 0;
+    return 1;
+#endif /* _WIN32 */
+}
+
+static int write_setup(xcb_connection_t *c, xcb_auth_info_t *auth_info)
+{
+    static const char pad[3];
+    xcb_setup_request_t out;
+    struct iovec parts[6];
+    int count = 0;
+    static const uint32_t endian = 0x01020304;
+    int ret;
+
+    memset(&out, 0, sizeof(out));
+
+    /* B = 0x42 = MSB first, l = 0x6c = LSB first */
+    if(htonl(endian) == endian)
+        out.byte_order = 0x42;
+    else
+        out.byte_order = 0x6c;
+    out.protocol_major_version = X_PROTOCOL;
+    out.protocol_minor_version = X_PROTOCOL_REVISION;
+    out.authorization_protocol_name_len = 0;
+    out.authorization_protocol_data_len = 0;
+    parts[count].iov_len = sizeof(xcb_setup_request_t);
+    parts[count++].iov_base = &out;
+    parts[count].iov_len = XCB_PAD(sizeof(xcb_setup_request_t));
+    parts[count++].iov_base = (char *) pad;
+
+    if(auth_info)
+    {
+        parts[count].iov_len = out.authorization_protocol_name_len = auth_info->namelen;
+        parts[count++].iov_base = auth_info->name;
+        parts[count].iov_len = XCB_PAD(out.authorization_protocol_name_len);
+        parts[count++].iov_base = (char *) pad;
+        parts[count].iov_len = out.authorization_protocol_data_len = auth_info->datalen;
+        parts[count++].iov_base = auth_info->data;
+        parts[count].iov_len = XCB_PAD(out.authorization_protocol_data_len);
+        parts[count++].iov_base = (char *) pad;
+    }
+    assert(count <= (int) (sizeof(parts) / sizeof(*parts)));
+
+    pthread_mutex_lock(&c->iolock);
+    ret = _xcb_out_send(c, parts, count);
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
+static int read_setup(xcb_connection_t *c)
+{
+    /* Read the server response */
+    c->setup = malloc(sizeof(xcb_setup_generic_t));
+    if(!c->setup)
+        return 0;
+
+    if(_xcb_in_read_block(c, c->setup, sizeof(xcb_setup_generic_t)) != sizeof(xcb_setup_generic_t))
+        return 0;
+
+    {
+        void *tmp = realloc(c->setup, c->setup->length * 4 + sizeof(xcb_setup_generic_t));
+        if(!tmp)
+            return 0;
+        c->setup = tmp;
+    }
+
+    if(_xcb_in_read_block(c, (char *) c->setup + sizeof(xcb_setup_generic_t), c->setup->length * 4) <= 0)
+        return 0;
+
+    /* 0 = failed, 2 = authenticate, 1 = success */
+    switch(c->setup->status)
+    {
+    case 0: /* failed */
+        {
+            xcb_setup_failed_t *setup = (xcb_setup_failed_t *) c->setup;
+            write(STDERR_FILENO, xcb_setup_failed_reason(setup), xcb_setup_failed_reason_length(setup));
+            return 0;
+        }
+
+    case 2: /* authenticate */
+        {
+            xcb_setup_authenticate_t *setup = (xcb_setup_authenticate_t *) c->setup;
+            write(STDERR_FILENO, xcb_setup_authenticate_reason(setup), xcb_setup_authenticate_reason_length(setup));
+            return 0;
+        }
+    }
+
+    return 1;
+}
+
+/* precondition: there must be something for us to write. */
+static int write_vec(xcb_connection_t *c, struct iovec **vector, int *count)
+{
+    int n;
+    assert(!c->out.queue_len);
+
+#ifdef _WIN32
+    int i = 0;
+    int ret = 0,err = 0;
+    struct iovec *vec;
+    n = 0;
+
+    /* Could use the WSASend win32 function for scatter/gather i/o but setting up the WSABUF struct from
+       an iovec would require more work and I'm not sure of the benefit....works for now */
+    vec = *vector;
+    while(i < *count)
+    {         	 
+         ret = send(c->fd,vec->iov_base,vec->iov_len,0);	 
+         if(ret == SOCKET_ERROR)
+         {
+             err  = WSAGetLastError();
+             if(err == WSAEWOULDBLOCK)
+             {
+                 return 1;
+             }
+         }
+         n += ret;
+         *vec++;
+         i++;
+    }
+#else
+    n = writev(c->fd, *vector, *count);
+    if(n < 0 && errno == EAGAIN)
+        return 1;
+#endif /* _WIN32 */    
+
+    if(n <= 0)
+    {
+        _xcb_conn_shutdown(c, XCB_CONN_ERROR);
+        return 0;
+    }
+
+    for(; *count; --*count, ++*vector)
+    {
+        int cur = (*vector)->iov_len;
+        if(cur > n)
+            cur = n;
+        (*vector)->iov_len -= cur;
+        (*vector)->iov_base = (char *) (*vector)->iov_base + cur;
+        n -= cur;
+        if((*vector)->iov_len)
+            break;
+    }
+    if(!*count)
+        *vector = 0;
+    assert(n == 0);
+    return 1;
+}
+
+/* Public interface */
+
+const xcb_setup_t *xcb_get_setup(xcb_connection_t *c)
+{
+    if(c->has_error)
+        return 0;
+    /* doesn't need locking because it's never written to. */
+    return c->setup;
+}
+
+int xcb_get_file_descriptor(xcb_connection_t *c)
+{
+    if(c->has_error)
+        return -1;
+    /* doesn't need locking because it's never written to. */
+    return c->fd;
+}
+
+int xcb_connection_has_error(xcb_connection_t *c)
+{
+    /* doesn't need locking because it's read and written atomically. */
+    return c->has_error;
+}
+
+xcb_connection_t *xcb_connect_to_fd(int fd, xcb_auth_info_t *auth_info)
+{
+    xcb_connection_t* c;
+
+#ifndef _WIN32
+#ifndef USE_POLL
+    if(fd >= FD_SETSIZE) /* would overflow in FD_SET */
+    {
+        close(fd);
+        return _xcb_conn_ret_error(XCB_CONN_ERROR);
+    }
+#endif
+#endif /* !_WIN32*/
+
+    c = calloc(1, sizeof(xcb_connection_t));
+    if(!c) {
+        close(fd);
+        return _xcb_conn_ret_error(XCB_CONN_CLOSED_MEM_INSUFFICIENT) ;
+    }
+
+    c->fd = fd;
+
+    if(!(
+        set_fd_flags(fd) &&
+        pthread_mutex_init(&c->iolock, 0) == 0 &&
+        _xcb_in_init(&c->in) &&
+        _xcb_out_init(&c->out) &&
+        write_setup(c, auth_info) &&
+        read_setup(c) &&
+        _xcb_ext_init(c) &&
+        _xcb_xid_init(c)
+        ))
+    {
+        xcb_disconnect(c);
+        return _xcb_conn_ret_error(XCB_CONN_ERROR);
+    }
+
+    return c;
+}
+
+void xcb_disconnect(xcb_connection_t *c)
+{
+    if(c->has_error)
+        return;
+
+    free(c->setup);
+
+    /* disallow further sends and receives */
+    shutdown(c->fd, SHUT_RDWR);
+    close(c->fd);
+
+    pthread_mutex_destroy(&c->iolock);
+    _xcb_in_destroy(&c->in);
+    _xcb_out_destroy(&c->out);
+
+    _xcb_ext_destroy(c);
+    _xcb_xid_destroy(c);
+
+    free(c);
+
+#ifdef _WIN32
+    WSACleanup();
+#endif
+}
+
+/* Private interface */
+
+void _xcb_conn_shutdown(xcb_connection_t *c, int err)
+{
+    c->has_error = err;
+}
+
+/* Return connection error state.
+ * To make thread-safe, I need a seperate static
+ * variable for every possible error.
+ */
+xcb_connection_t *_xcb_conn_ret_error(int err)
+{
+
+    switch(err)
+    {
+        case XCB_CONN_CLOSED_MEM_INSUFFICIENT:
+        {
+            return (xcb_connection_t *) &xcb_con_closed_mem_er;
+        }
+        case XCB_CONN_CLOSED_PARSE_ERR:
+        {
+            return (xcb_connection_t *) &xcb_con_closed_parse_er;
+        }
+        case XCB_CONN_ERROR:
+        default:
+        {
+            return (xcb_connection_t *) &xcb_con_error;
+        }
+    }
+}
+
+int _xcb_conn_wait(xcb_connection_t *c, pthread_cond_t *cond, struct iovec **vector, int *count)
+{
+    int ret;
+#if USE_POLL
+    struct pollfd fd;
+#else
+    fd_set rfds, wfds;
+#endif
+
+    /* If the thing I should be doing is already being done, wait for it. */
+    if(count ? c->out.writing : c->in.reading)
+    {
+        pthread_cond_wait(cond, &c->iolock);
+        return 1;
+    }
+
+#if USE_POLL
+    memset(&fd, 0, sizeof(fd));
+    fd.fd = c->fd;
+    fd.events = POLLIN;
+#else
+    FD_ZERO(&rfds);
+    FD_SET(c->fd, &rfds);
+#endif
+    ++c->in.reading;
+
+#if USE_POLL
+    if(count)
+    {
+        fd.events |= POLLOUT;
+        ++c->out.writing;
+    }
+#else
+    FD_ZERO(&wfds);
+    if(count)
+    {
+        FD_SET(c->fd, &wfds);
+        ++c->out.writing;
+    }
+#endif
+
+    pthread_mutex_unlock(&c->iolock);
+    do {
+#if USE_POLL
+        ret = poll(&fd, 1, -1);
+        /* If poll() returns an event we didn't expect, such as POLLNVAL, treat
+         * it as if it failed. */
+        if(ret >= 0 && (fd.revents & ~fd.events))
+        {
+            ret = -1;
+            break;
+        }
+#else
+        ret = select(c->fd + 1, &rfds, &wfds, 0, 0);
+#endif
+    } while (ret == -1 && errno == EINTR);
+    if(ret < 0)
+    {
+        _xcb_conn_shutdown(c, XCB_CONN_ERROR);
+        ret = 0;
+    }
+    pthread_mutex_lock(&c->iolock);
+
+    if(ret)
+    {
+#if USE_POLL
+        if((fd.revents & POLLIN) == POLLIN)
+#else
+        if(FD_ISSET(c->fd, &rfds))
+#endif
+            ret = ret && _xcb_in_read(c);
+
+#if USE_POLL
+        if((fd.revents & POLLOUT) == POLLOUT)
+#else
+        if(FD_ISSET(c->fd, &wfds))
+#endif
+            ret = ret && write_vec(c, vector, count);
+    }
+
+    if(count)
+        --c->out.writing;
+    --c->in.reading;
+
+    return ret;
+}