Initial commit

1 files changed, 1096 insertions, 0 deletions

diff --git a/depends/libxcb/src/xcb_in.c b/depends/libxcb/src/xcb_in.c
new file mode 100644
index 0000000..c9a264d
--- /dev/null
+++ b/depends/libxcb/src/xcb_in.c
@@ -0,0 +1,1096 @@
+/* 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.
+ */
+
+/* Stuff that reads stuff from the server. */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+
+#if USE_POLL
+#include <poll.h>
+#endif
+#ifndef _WIN32
+#include <unistd.h>
+#include <sys/select.h>
+#include <sys/socket.h>
+#endif
+
+#ifdef _WIN32
+#include "xcb_windefs.h"
+#endif /* _WIN32 */
+
+#include "xcb.h"
+#include "xcbext.h"
+#include "xcbint.h"
+
+#define XCB_ERROR 0
+#define XCB_REPLY 1
+#define XCB_XGE_EVENT 35
+
+struct event_list {
+    xcb_generic_event_t *event;
+    struct event_list *next;
+};
+
+struct xcb_special_event {
+
+    struct xcb_special_event *next;
+
+    /* Match XGE events for the specific extension and event ID (the
+     * first 32 bit word after evtype)
+     */
+    uint8_t     extension;
+    uint32_t    eid;
+    uint32_t    *stamp;
+
+    struct event_list   *events;
+    struct event_list   **events_tail;
+
+    pthread_cond_t special_event_cond;
+};
+
+struct reply_list {
+    void *reply;
+    struct reply_list *next;
+};
+
+typedef struct pending_reply {
+    uint64_t first_request;
+    uint64_t last_request;
+    enum workarounds workaround;
+    int flags;
+    struct pending_reply *next;
+} pending_reply;
+
+typedef struct reader_list {
+    uint64_t request;
+    pthread_cond_t *data;
+    struct reader_list *next;
+} reader_list;
+
+typedef struct special_list {
+    xcb_special_event_t *se;
+    struct special_list *next;
+} special_list;
+
+static void remove_finished_readers(reader_list **prev_reader, uint64_t completed)
+{
+    while(*prev_reader && XCB_SEQUENCE_COMPARE((*prev_reader)->request, <=, completed))
+    {
+        /* If you don't have what you're looking for now, you never
+         * will. Wake up and leave me alone. */
+        pthread_cond_signal((*prev_reader)->data);
+        *prev_reader = (*prev_reader)->next;
+    }
+}
+
+#if HAVE_SENDMSG
+static int read_fds(xcb_connection_t *c, int *fds, int nfd)
+{
+    int *ifds = &c->in.in_fd.fd[c->in.in_fd.ifd];
+    int infd = c->in.in_fd.nfd - c->in.in_fd.ifd;
+
+    if (nfd > infd)
+        return 0;
+    memcpy(fds, ifds, nfd * sizeof (int));
+    c->in.in_fd.ifd += nfd;
+    return 1;
+}
+#endif
+
+typedef struct xcb_ge_special_event_t {
+    uint8_t  response_type; /**<  */
+    uint8_t  extension; /**<  */
+    uint16_t sequence; /**<  */
+    uint32_t length; /**<  */
+    uint16_t evtype; /**<  */
+    uint8_t  pad0[2]; /**< */
+    uint32_t eid; /**< */
+    uint8_t  pad1[16]; /**<  */
+} xcb_ge_special_event_t;
+
+static int event_special(xcb_connection_t *c,
+                         struct event_list *event)
+{
+    struct xcb_special_event *special_event;
+    struct xcb_ge_special_event_t *ges = (void *) event->event;
+
+    /* Special events are always XGE events */
+    if ((ges->response_type & 0x7f) != XCB_XGE_EVENT)
+        return 0;
+
+    for (special_event = c->in.special_events;
+         special_event;
+         special_event = special_event->next)
+    {
+        if (ges->extension == special_event->extension &&
+            ges->eid == special_event->eid)
+        {
+            *special_event->events_tail = event;
+            special_event->events_tail = &event->next;
+            if (special_event->stamp)
+                ++(*special_event->stamp);
+            pthread_cond_signal(&special_event->special_event_cond);
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
+static int read_packet(xcb_connection_t *c)
+{
+    xcb_generic_reply_t genrep;
+    uint64_t length = 32;
+    uint64_t eventlength = 0; /* length after first 32 bytes for GenericEvents */
+    int nfd = 0;         /* Number of file descriptors attached to the reply */
+    uint64_t bufsize;
+    void *buf;
+    pending_reply *pend = 0;
+    struct event_list *event;
+
+    /* Wait for there to be enough data for us to read a whole packet */
+    if(c->in.queue_len < length)
+        return 0;
+
+    /* Get the response type, length, and sequence number. */
+    memcpy(&genrep, c->in.queue, sizeof(genrep));
+
+    /* Compute 32-bit sequence number of this packet. */
+    if((genrep.response_type & 0x7f) != XCB_KEYMAP_NOTIFY)
+    {
+        uint64_t lastread = c->in.request_read;
+        c->in.request_read = (lastread & UINT64_C(0xffffffffffff0000)) | genrep.sequence;
+        if(XCB_SEQUENCE_COMPARE(c->in.request_read, <, lastread))
+            c->in.request_read += 0x10000;
+        if(XCB_SEQUENCE_COMPARE(c->in.request_read, >, c->in.request_expected))
+            c->in.request_expected = c->in.request_read;
+
+        if(c->in.request_read != lastread)
+        {
+            if(c->in.current_reply)
+            {
+                _xcb_map_put(c->in.replies, lastread, c->in.current_reply);
+                c->in.current_reply = 0;
+                c->in.current_reply_tail = &c->in.current_reply;
+            }
+            c->in.request_completed = c->in.request_read - 1;
+        }
+
+        while(c->in.pending_replies &&
+              c->in.pending_replies->workaround != WORKAROUND_EXTERNAL_SOCKET_OWNER &&
+              XCB_SEQUENCE_COMPARE (c->in.pending_replies->last_request, <=, c->in.request_completed))
+        {
+            pending_reply *oldpend = c->in.pending_replies;
+            c->in.pending_replies = oldpend->next;
+            if(!oldpend->next)
+                c->in.pending_replies_tail = &c->in.pending_replies;
+            free(oldpend);
+        }
+
+        if(genrep.response_type == XCB_ERROR)
+            c->in.request_completed = c->in.request_read;
+
+        remove_finished_readers(&c->in.readers, c->in.request_completed);
+    }
+
+    if(genrep.response_type == XCB_ERROR || genrep.response_type == XCB_REPLY)
+    {
+        pend = c->in.pending_replies;
+        if(pend &&
+           !(XCB_SEQUENCE_COMPARE(pend->first_request, <=, c->in.request_read) &&
+             (pend->workaround == WORKAROUND_EXTERNAL_SOCKET_OWNER ||
+              XCB_SEQUENCE_COMPARE(c->in.request_read, <=, pend->last_request))))
+            pend = 0;
+    }
+
+    /* For reply packets, check that the entire packet is available. */
+    if(genrep.response_type == XCB_REPLY)
+    {
+        if(pend && pend->workaround == WORKAROUND_GLX_GET_FB_CONFIGS_BUG)
+        {
+            uint32_t *p = (uint32_t *) c->in.queue;
+            uint64_t new_length = ((uint64_t)p[2]) * ((uint64_t)p[3]);
+            if(new_length >= (UINT32_MAX / UINT32_C(16)))
+            {
+                _xcb_conn_shutdown(c, XCB_CONN_CLOSED_MEM_INSUFFICIENT);
+                return 0;
+            }
+            genrep.length = (uint32_t)(new_length * UINT64_C(2));
+        }
+        length += genrep.length * UINT64_C(4);
+
+        /* XXX a bit of a hack -- we "know" that all FD replys place
+         * the number of fds in the pad0 byte */
+        if (pend && pend->flags & XCB_REQUEST_REPLY_FDS)
+            nfd = genrep.pad0;
+    }
+
+    /* XGE events may have sizes > 32 */
+    if ((genrep.response_type & 0x7f) == XCB_XGE_EVENT)
+        eventlength = genrep.length * UINT64_C(4);
+
+    bufsize = length + eventlength + nfd * sizeof(int)  +
+        (genrep.response_type == XCB_REPLY ? 0 : sizeof(uint32_t));
+    if (bufsize < INT32_MAX)
+        buf = malloc((size_t) bufsize);
+    else
+        buf = NULL;
+    if(!buf)
+    {
+        _xcb_conn_shutdown(c, XCB_CONN_CLOSED_MEM_INSUFFICIENT);
+        return 0;
+    }
+
+    if(_xcb_in_read_block(c, buf, length) <= 0)
+    {
+        free(buf);
+        return 0;
+    }
+
+    /* pull in XGE event data if available, append after event struct */
+    if (eventlength)
+    {
+        if(_xcb_in_read_block(c, &((xcb_generic_event_t*)buf)[1], eventlength) <= 0)
+        {
+            free(buf);
+            return 0;
+        }
+    }
+
+#if HAVE_SENDMSG
+    if (nfd)
+    {
+        if (!read_fds(c, (int *) &((char *) buf)[length], nfd))
+        {
+            free(buf);
+            return 0;
+        }
+    }
+#endif
+
+    if(pend && (pend->flags & XCB_REQUEST_DISCARD_REPLY))
+    {
+        free(buf);
+        return 1;
+    }
+
+    if(genrep.response_type != XCB_REPLY)
+        ((xcb_generic_event_t *) buf)->full_sequence = c->in.request_read;
+
+    /* reply, or checked error */
+    if( genrep.response_type == XCB_REPLY ||
+       (genrep.response_type == XCB_ERROR && pend && (pend->flags & XCB_REQUEST_CHECKED)))
+    {
+        struct reply_list *cur = malloc(sizeof(struct reply_list));
+        if(!cur)
+        {
+            _xcb_conn_shutdown(c, XCB_CONN_CLOSED_MEM_INSUFFICIENT);
+            free(buf);
+            return 0;
+        }
+        cur->reply = buf;
+        cur->next = 0;
+        *c->in.current_reply_tail = cur;
+        c->in.current_reply_tail = &cur->next;
+        if(c->in.readers && c->in.readers->request == c->in.request_read)
+            pthread_cond_signal(c->in.readers->data);
+        return 1;
+    }
+
+    /* event, or unchecked error */
+    event = malloc(sizeof(struct event_list));
+    if(!event)
+    {
+        _xcb_conn_shutdown(c, XCB_CONN_CLOSED_MEM_INSUFFICIENT);
+        free(buf);
+        return 0;
+    }
+    event->event = buf;
+    event->next = 0;
+
+    if (!event_special(c, event)) {
+        *c->in.events_tail = event;
+        c->in.events_tail = &event->next;
+        pthread_cond_signal(&c->in.event_cond);
+    }
+    return 1; /* I have something for you... */
+}
+
+static xcb_generic_event_t *get_event(xcb_connection_t *c)
+{
+    struct event_list *cur = c->in.events;
+    xcb_generic_event_t *ret;
+    if(!c->in.events)
+        return 0;
+    ret = cur->event;
+    c->in.events = cur->next;
+    if(!cur->next)
+        c->in.events_tail = &c->in.events;
+    free(cur);
+    return ret;
+}
+
+static void free_reply_list(struct reply_list *head)
+{
+    while(head)
+    {
+        struct reply_list *cur = head;
+        head = cur->next;
+        free(cur->reply);
+        free(cur);
+    }
+}
+
+static int read_block(const int fd, void *buf, const intptr_t len)
+{
+    int done = 0;
+    while(done < len)
+    {
+        int ret = recv(fd, ((char *) buf) + done, len - done, 0);
+        if(ret > 0)
+            done += ret;
+#ifndef _WIN32
+        if(ret < 0 && errno == EAGAIN)
+#else
+        if(ret == SOCKET_ERROR && WSAGetLastError() == WSAEWOULDBLOCK)
+#endif /* !_Win32 */
+        {
+#if USE_POLL
+            struct pollfd pfd;
+            pfd.fd = fd;
+            pfd.events = POLLIN;
+            pfd.revents = 0;
+            do {
+                ret = poll(&pfd, 1, -1);
+            } while (ret == -1 && errno == EINTR);
+#else
+            fd_set fds;
+            FD_ZERO(&fds);
+            FD_SET(fd, &fds);
+
+            /* Initializing errno here makes sure that for Win32 this loop will execute only once */
+            errno = 0;
+            do {
+                ret = select(fd + 1, &fds, 0, 0, 0);
+            } while (ret == -1 && errno == EINTR);
+#endif /* USE_POLL */
+        }
+        if(ret <= 0)
+            return ret;
+    }
+    return len;
+}
+
+static int poll_for_reply(xcb_connection_t *c, uint64_t request, void **reply, xcb_generic_error_t **error)
+{
+    struct reply_list *head;
+
+    /* If an error occurred when issuing the request, fail immediately. */
+    if(!request)
+        head = 0;
+    /* We've read requests past the one we want, so if it has replies we have
+     * them all and they're in the replies map. */
+    else if(XCB_SEQUENCE_COMPARE(request, <, c->in.request_read))
+    {
+        head = _xcb_map_remove(c->in.replies, request);
+        if(head && head->next)
+            _xcb_map_put(c->in.replies, request, head->next);
+    }
+    /* We're currently processing the responses to the request we want, and we
+     * have a reply ready to return. So just return it without blocking. */
+    else if(request == c->in.request_read && c->in.current_reply)
+    {
+        head = c->in.current_reply;
+        c->in.current_reply = head->next;
+        if(!head->next)
+            c->in.current_reply_tail = &c->in.current_reply;
+    }
+    /* We know this request can't have any more replies, and we've already
+     * established it doesn't have a reply now. Don't bother blocking. */
+    else if(request == c->in.request_completed)
+        head = 0;
+    /* We may have more replies on the way for this request: block until we're
+     * sure. */
+    else
+        return 0;
+
+    if(error)
+        *error = 0;
+    *reply = 0;
+
+    if(head)
+    {
+        if(((xcb_generic_reply_t *) head->reply)->response_type == XCB_ERROR)
+        {
+            if(error)
+                *error = head->reply;
+            else
+                free(head->reply);
+        }
+        else
+            *reply = head->reply;
+
+        free(head);
+    }
+
+    return 1;
+}
+
+static void insert_reader(reader_list **prev_reader, reader_list *reader, uint64_t request, pthread_cond_t *cond)
+{
+    while(*prev_reader && XCB_SEQUENCE_COMPARE((*prev_reader)->request, <=, request))
+        prev_reader = &(*prev_reader)->next;
+    reader->request = request;
+    reader->data = cond;
+    reader->next = *prev_reader;
+    *prev_reader = reader;
+}
+
+static void remove_reader(reader_list **prev_reader, reader_list *reader)
+{
+    while(*prev_reader && XCB_SEQUENCE_COMPARE((*prev_reader)->request, <=, reader->request))
+        if(*prev_reader == reader)
+        {
+            *prev_reader = (*prev_reader)->next;
+            break;
+        }
+}
+
+static void insert_special(special_list **prev_special, special_list *special, xcb_special_event_t *se)
+{
+    special->se = se;
+    special->next = *prev_special;
+    *prev_special = special;
+}
+
+static void remove_special(special_list **prev_special, special_list *special)
+{
+    while(*prev_special)
+    {
+        if(*prev_special == special)
+        {
+            *prev_special = (*prev_special)->next;
+            break;
+        }
+        prev_special = &(*prev_special)->next;
+    }
+}
+
+static void *wait_for_reply(xcb_connection_t *c, uint64_t request, xcb_generic_error_t **e)
+{
+    void *ret = 0;
+
+    /* If this request has not been written yet, write it. */
+    if(c->out.return_socket || _xcb_out_flush_to(c, request))
+    {
+        pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
+        reader_list reader;
+
+        insert_reader(&c->in.readers, &reader, request, &cond);
+
+        while(!poll_for_reply(c, request, &ret, e))
+            if(!_xcb_conn_wait(c, &cond, 0, 0))
+                break;
+
+        remove_reader(&c->in.readers, &reader);
+        pthread_cond_destroy(&cond);
+    }
+
+    _xcb_in_wake_up_next_reader(c);
+    return ret;
+}
+
+static uint64_t widen(xcb_connection_t *c, unsigned int request)
+{
+    uint64_t widened_request = (c->out.request & UINT64_C(0xffffffff00000000)) | request;
+    if(widened_request > c->out.request)
+        widened_request -= UINT64_C(1) << 32;
+    return widened_request;
+}
+
+/* Public interface */
+
+void *xcb_wait_for_reply(xcb_connection_t *c, unsigned int request, xcb_generic_error_t **e)
+{
+    void *ret;
+    if(e)
+        *e = 0;
+    if(c->has_error)
+        return 0;
+
+    pthread_mutex_lock(&c->iolock);
+    ret = wait_for_reply(c, widen(c, request), e);
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
+void *xcb_wait_for_reply64(xcb_connection_t *c, uint64_t request, xcb_generic_error_t **e)
+{
+    void *ret;
+    if(e)
+        *e = 0;
+    if(c->has_error)
+        return 0;
+
+    pthread_mutex_lock(&c->iolock);
+    ret = wait_for_reply(c, request, e);
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
+int *xcb_get_reply_fds(xcb_connection_t *c, void *reply, size_t reply_size)
+{
+    return (int *) (&((char *) reply)[reply_size]);
+}
+
+static void insert_pending_discard(xcb_connection_t *c, pending_reply **prev_next, uint64_t seq)
+{
+    pending_reply *pend;
+    pend = malloc(sizeof(*pend));
+    if(!pend)
+    {
+        _xcb_conn_shutdown(c, XCB_CONN_CLOSED_MEM_INSUFFICIENT);
+        return;
+    }
+
+    pend->first_request = seq;
+    pend->last_request = seq;
+    pend->workaround = 0;
+    pend->flags = XCB_REQUEST_DISCARD_REPLY;
+    pend->next = *prev_next;
+    *prev_next = pend;
+
+    if(!pend->next)
+        c->in.pending_replies_tail = &pend->next;
+}
+
+static void discard_reply(xcb_connection_t *c, uint64_t request)
+{
+    void *reply;
+    pending_reply **prev_pend;
+
+    /* Free any replies or errors that we've already read. Stop if
+     * xcb_wait_for_reply would block or we've run out of replies. */
+    while(poll_for_reply(c, request, &reply, 0) && reply)
+        free(reply);
+
+    /* If we've proven there are no more responses coming, we're done. */
+    if(XCB_SEQUENCE_COMPARE(request, <=, c->in.request_completed))
+        return;
+
+    /* Walk the list of pending requests. Mark the first match for deletion. */
+    for(prev_pend = &c->in.pending_replies; *prev_pend; prev_pend = &(*prev_pend)->next)
+    {
+        if(XCB_SEQUENCE_COMPARE((*prev_pend)->first_request, >, request))
+            break;
+
+        if((*prev_pend)->first_request == request)
+        {
+            /* Pending reply found. Mark for discard: */
+            (*prev_pend)->flags |= XCB_REQUEST_DISCARD_REPLY;
+            return;
+        }
+    }
+
+    /* Pending reply not found (likely due to _unchecked request). Create one: */
+    insert_pending_discard(c, prev_pend, request);
+}
+
+void xcb_discard_reply(xcb_connection_t *c, unsigned int sequence)
+{
+    if(c->has_error)
+        return;
+
+    /* If an error occurred when issuing the request, fail immediately. */
+    if(!sequence)
+        return;
+
+    pthread_mutex_lock(&c->iolock);
+    discard_reply(c, widen(c, sequence));
+    pthread_mutex_unlock(&c->iolock);
+}
+
+void xcb_discard_reply64(xcb_connection_t *c, uint64_t sequence)
+{
+    if(c->has_error)
+        return;
+
+    /* If an error occurred when issuing the request, fail immediately. */
+    if(!sequence)
+        return;
+
+    pthread_mutex_lock(&c->iolock);
+    discard_reply(c, sequence);
+    pthread_mutex_unlock(&c->iolock);
+}
+
+int xcb_poll_for_reply(xcb_connection_t *c, unsigned int request, void **reply, xcb_generic_error_t **error)
+{
+    int ret;
+    if(c->has_error)
+    {
+        *reply = 0;
+        if(error)
+            *error = 0;
+        return 1; /* would not block */
+    }
+    assert(reply != 0);
+    pthread_mutex_lock(&c->iolock);
+    ret = poll_for_reply(c, widen(c, request), reply, error);
+    if(!ret && c->in.reading == 0 && _xcb_in_read(c)) /* _xcb_in_read shuts down the connection on error */
+        ret = poll_for_reply(c, widen(c, request), reply, error);
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
+int xcb_poll_for_reply64(xcb_connection_t *c, uint64_t request, void **reply, xcb_generic_error_t **error)
+{
+    int ret;
+    if(c->has_error)
+    {
+        *reply = 0;
+        if(error)
+            *error = 0;
+        return 1; /* would not block */
+    }
+    assert(reply != 0);
+    pthread_mutex_lock(&c->iolock);
+    ret = poll_for_reply(c, request, reply, error);
+    if(!ret && c->in.reading == 0 && _xcb_in_read(c)) /* _xcb_in_read shuts down the connection on error */
+        ret = poll_for_reply(c, request, reply, error);
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
+xcb_generic_event_t *xcb_wait_for_event(xcb_connection_t *c)
+{
+    xcb_generic_event_t *ret;
+    if(c->has_error)
+        return 0;
+    pthread_mutex_lock(&c->iolock);
+    /* get_event returns 0 on empty list. */
+    while(!(ret = get_event(c)))
+        if(!_xcb_conn_wait(c, &c->in.event_cond, 0, 0))
+            break;
+
+    _xcb_in_wake_up_next_reader(c);
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
+static xcb_generic_event_t *poll_for_next_event(xcb_connection_t *c, int queued)
+{
+    xcb_generic_event_t *ret = 0;
+    if(!c->has_error)
+    {
+        pthread_mutex_lock(&c->iolock);
+        /* FIXME: follow X meets Z architecture changes. */
+        ret = get_event(c);
+        if(!ret && !queued && c->in.reading == 0 && _xcb_in_read(c)) /* _xcb_in_read shuts down the connection on error */
+            ret = get_event(c);
+        pthread_mutex_unlock(&c->iolock);
+    }
+    return ret;
+}
+
+xcb_generic_event_t *xcb_poll_for_event(xcb_connection_t *c)
+{
+    return poll_for_next_event(c, 0);
+}
+
+xcb_generic_event_t *xcb_poll_for_queued_event(xcb_connection_t *c)
+{
+    return poll_for_next_event(c, 1);
+}
+
+xcb_generic_error_t *xcb_request_check(xcb_connection_t *c, xcb_void_cookie_t cookie)
+{
+    uint64_t request;
+    xcb_generic_error_t *ret = 0;
+    void *reply;
+    if(c->has_error)
+        return 0;
+    pthread_mutex_lock(&c->iolock);
+    request = widen(c, cookie.sequence);
+    if (XCB_SEQUENCE_COMPARE(request, >, c->in.request_completed))
+    {
+        if(XCB_SEQUENCE_COMPARE(request, >=, c->in.request_expected))
+        {
+            _xcb_out_send_sync(c);
+        }
+        if (XCB_SEQUENCE_COMPARE(request, >=, c->out.request_expected_written))
+        {
+            _xcb_out_flush_to(c, c->out.request);
+        }
+    }
+    reply = wait_for_reply(c, request, &ret);
+    assert(!reply);
+    pthread_mutex_unlock(&c->iolock);
+    return ret;
+}
+
+static xcb_generic_event_t *get_special_event(xcb_connection_t *c,
+                                              xcb_special_event_t *se)
+{
+    xcb_generic_event_t *event = NULL;
+    struct event_list *events;
+
+    if ((events = se->events) != NULL) {
+        event = events->event;
+        if (!(se->events = events->next))
+            se->events_tail = &se->events;
+        free (events);
+    }
+    return event;
+}
+
+xcb_generic_event_t *xcb_poll_for_special_event(xcb_connection_t *c,
+                                                xcb_special_event_t *se)
+{
+    xcb_generic_event_t *event;
+
+    if(c->has_error)
+        return 0;
+    pthread_mutex_lock(&c->iolock);
+    event = get_special_event(c, se);
+    if(!event && c->in.reading == 0 && _xcb_in_read(c)) /* _xcb_in_read shuts down the connection on error */
+        event = get_special_event(c, se);
+    pthread_mutex_unlock(&c->iolock);
+    return event;
+}
+
+xcb_generic_event_t *xcb_wait_for_special_event(xcb_connection_t *c,
+                                                xcb_special_event_t *se)
+{
+    special_list special;
+    xcb_generic_event_t *event;
+
+    if(c->has_error)
+        return 0;
+    pthread_mutex_lock(&c->iolock);
+
+    insert_special(&c->in.special_waiters, &special, se);
+
+    /* get_special_event returns 0 on empty list. */
+    while(!(event = get_special_event(c, se)))
+        if(!_xcb_conn_wait(c, &se->special_event_cond, 0, 0))
+            break;
+
+    remove_special(&c->in.special_waiters, &special);
+
+    _xcb_in_wake_up_next_reader(c);
+    pthread_mutex_unlock(&c->iolock);
+    return event;
+}
+
+xcb_special_event_t *
+xcb_register_for_special_xge(xcb_connection_t *c,
+                             xcb_extension_t *ext,
+                             uint32_t eid,
+                             uint32_t *stamp)
+{
+    xcb_special_event_t *se;
+    const xcb_query_extension_reply_t   *ext_reply;
+
+    if(c->has_error)
+        return NULL;
+    ext_reply = xcb_get_extension_data(c, ext);
+    if (!ext_reply)
+        return NULL;
+    pthread_mutex_lock(&c->iolock);
+    for (se = c->in.special_events; se; se = se->next) {
+        if (se->extension == ext_reply->major_opcode &&
+            se->eid == eid) {
+            pthread_mutex_unlock(&c->iolock);
+            return NULL;
+        }
+    }
+    se = calloc(1, sizeof(xcb_special_event_t));
+    if (!se) {
+        pthread_mutex_unlock(&c->iolock);
+        return NULL;
+    }
+
+    se->extension = ext_reply->major_opcode;
+    se->eid = eid;
+
+    se->events = NULL;
+    se->events_tail = &se->events;
+    se->stamp = stamp;
+
+    pthread_cond_init(&se->special_event_cond, 0);
+
+    se->next = c->in.special_events;
+    c->in.special_events = se;
+    pthread_mutex_unlock(&c->iolock);
+    return se;
+}
+
+void
+xcb_unregister_for_special_event(xcb_connection_t *c,
+                                 xcb_special_event_t *se)
+{
+    xcb_special_event_t *s, **prev;
+    struct event_list   *events, *next;
+
+    if (!se)
+        return;
+
+    if (c->has_error)
+        return;
+
+    pthread_mutex_lock(&c->iolock);
+
+    for (prev = &c->in.special_events; (s = *prev) != NULL; prev = &(s->next)) {
+        if (s == se) {
+            *prev = se->next;
+            for (events = se->events; events; events = next) {
+                next = events->next;
+                free (events->event);
+                free (events);
+            }
+            pthread_cond_destroy(&se->special_event_cond);
+            free (se);
+            break;
+        }
+    }
+    pthread_mutex_unlock(&c->iolock);
+}
+
+/* Private interface */
+
+int _xcb_in_init(_xcb_in *in)
+{
+    if(pthread_cond_init(&in->event_cond, 0))
+        return 0;
+    in->reading = 0;
+
+    in->queue_len = 0;
+
+    in->request_read = 0;
+    in->request_completed = 0;
+
+    in->replies = _xcb_map_new();
+    if(!in->replies)
+        return 0;
+
+    in->current_reply_tail = &in->current_reply;
+    in->events_tail = &in->events;
+    in->pending_replies_tail = &in->pending_replies;
+
+    return 1;
+}
+
+void _xcb_in_destroy(_xcb_in *in)
+{
+    pthread_cond_destroy(&in->event_cond);
+    free_reply_list(in->current_reply);
+    _xcb_map_delete(in->replies, (void (*)(void *)) free_reply_list);
+    while(in->events)
+    {
+        struct event_list *e = in->events;
+        in->events = e->next;
+        free(e->event);
+        free(e);
+    }
+    while(in->pending_replies)
+    {
+        pending_reply *pend = in->pending_replies;
+        in->pending_replies = pend->next;
+        free(pend);
+    }
+}
+
+void _xcb_in_wake_up_next_reader(xcb_connection_t *c)
+{
+    int pthreadret;
+    if(c->in.readers)
+        pthreadret = pthread_cond_signal(c->in.readers->data);
+    else if(c->in.special_waiters)
+        pthreadret = pthread_cond_signal(&c->in.special_waiters->se->special_event_cond);
+    else
+        pthreadret = pthread_cond_signal(&c->in.event_cond);
+    assert(pthreadret == 0);
+}
+
+int _xcb_in_expect_reply(xcb_connection_t *c, uint64_t request, enum workarounds workaround, int flags)
+{
+    pending_reply *pend = malloc(sizeof(pending_reply));
+    assert(workaround != WORKAROUND_NONE || flags != 0);
+    if(!pend)
+    {
+        _xcb_conn_shutdown(c, XCB_CONN_CLOSED_MEM_INSUFFICIENT);
+        return 0;
+    }
+    pend->first_request = pend->last_request = request;
+    pend->workaround = workaround;
+    pend->flags = flags;
+    pend->next = 0;
+    *c->in.pending_replies_tail = pend;
+    c->in.pending_replies_tail = &pend->next;
+    return 1;
+}
+
+void _xcb_in_replies_done(xcb_connection_t *c)
+{
+    struct pending_reply *pend;
+    if (c->in.pending_replies_tail != &c->in.pending_replies)
+    {
+        pend = container_of(c->in.pending_replies_tail, struct pending_reply, next);
+        if(pend->workaround == WORKAROUND_EXTERNAL_SOCKET_OWNER)
+        {
+            if (XCB_SEQUENCE_COMPARE(pend->first_request, <=, c->out.request)) {
+                pend->last_request = c->out.request;
+                pend->workaround = WORKAROUND_NONE;
+            } else {
+                /* The socket was taken, but no requests were actually sent
+                 * so just discard the pending_reply that was created.
+                 */
+                struct pending_reply **prev_next = &c->in.pending_replies;
+                while (*prev_next != pend)
+                    prev_next = &(*prev_next)->next;
+                *prev_next = NULL;
+                c->in.pending_replies_tail = prev_next;
+                free(pend);
+            }
+        }
+    }
+}
+
+int _xcb_in_read(xcb_connection_t *c)
+{
+    int n;
+
+#if HAVE_SENDMSG
+    struct iovec    iov = {
+        .iov_base = c->in.queue + c->in.queue_len,
+        .iov_len = sizeof(c->in.queue) - c->in.queue_len,
+    };
+    union {
+        struct cmsghdr cmsghdr;
+        char buf[CMSG_SPACE(XCB_MAX_PASS_FD * sizeof(int))];
+    } cmsgbuf;
+    struct msghdr msg = {
+        .msg_name = NULL,
+        .msg_namelen = 0,
+        .msg_iov = &iov,
+        .msg_iovlen = 1,
+        .msg_control = cmsgbuf.buf,
+        .msg_controllen = CMSG_SPACE(sizeof(int) * (XCB_MAX_PASS_FD - c->in.in_fd.nfd)),
+    };
+    n = recvmsg(c->fd, &msg, 0);
+
+    /* Check for truncation errors. Only MSG_CTRUNC is
+     * probably possible here, which would indicate that
+     * the sender tried to transmit more than XCB_MAX_PASS_FD
+     * file descriptors.
+     */
+    if (msg.msg_flags & (MSG_TRUNC|MSG_CTRUNC)) {
+        _xcb_conn_shutdown(c, XCB_CONN_CLOSED_FDPASSING_FAILED);
+        return 0;
+    }
+#else
+    n = recv(c->fd, c->in.queue + c->in.queue_len, sizeof(c->in.queue) - c->in.queue_len, 0);
+#endif
+    if(n > 0) {
+#if HAVE_SENDMSG
+        struct cmsghdr *hdr;
+
+        if (msg.msg_controllen >= sizeof (struct cmsghdr)) {
+            for (hdr = CMSG_FIRSTHDR(&msg); hdr; hdr = CMSG_NXTHDR(&msg, hdr)) {
+                if (hdr->cmsg_level == SOL_SOCKET && hdr->cmsg_type == SCM_RIGHTS) {
+                    int nfd = (hdr->cmsg_len - CMSG_LEN(0)) / sizeof (int);
+                    memcpy(&c->in.in_fd.fd[c->in.in_fd.nfd], CMSG_DATA(hdr), nfd * sizeof (int));
+                    c->in.in_fd.nfd += nfd;
+                }
+            }
+        }
+#endif
+        c->in.total_read += n;
+        c->in.queue_len += n;
+    }
+    while(read_packet(c))
+        /* empty */;
+#if HAVE_SENDMSG
+    if (c->in.in_fd.nfd) {
+        c->in.in_fd.nfd -= c->in.in_fd.ifd;
+        memmove(&c->in.in_fd.fd[0],
+                &c->in.in_fd.fd[c->in.in_fd.ifd],
+                c->in.in_fd.nfd * sizeof (int));
+        c->in.in_fd.ifd = 0;
+
+        /* If we have any left-over file descriptors after emptying
+         * the input buffer, then the server sent some that we weren't
+         * expecting.  Close them and mark the connection as broken;
+         */
+        if (c->in.queue_len == 0 && c->in.in_fd.nfd != 0) {
+            int i;
+            for (i = 0; i < c->in.in_fd.nfd; i++)
+                close(c->in.in_fd.fd[i]);
+            _xcb_conn_shutdown(c, XCB_CONN_CLOSED_FDPASSING_FAILED);
+            return 0;
+        }
+    }
+#endif
+#ifndef _WIN32
+    if((n > 0) || (n < 0 && (errno == EAGAIN || errno == EINTR)))
+#else
+    if((n > 0) || (n < 0 && WSAGetLastError() == WSAEWOULDBLOCK))
+#endif /* !_WIN32 */
+        return 1;
+    _xcb_conn_shutdown(c, XCB_CONN_ERROR);
+    return 0;
+}
+
+int _xcb_in_read_block(xcb_connection_t *c, void *buf, int len)
+{
+    int done = c->in.queue_len;
+    if(len < done)
+        done = len;
+
+    memcpy(buf, c->in.queue, done);
+    c->in.queue_len -= done;
+    memmove(c->in.queue, c->in.queue + done, c->in.queue_len);
+
+    if(len > done)
+    {
+        int ret = read_block(c->fd, (char *) buf + done, len - done);
+        if(ret <= 0)
+        {
+            _xcb_conn_shutdown(c, XCB_CONN_ERROR);
+            return ret;
+        }
+    }
+
+    return len;
+}