FreeRDP/server/X11/xf_event.c
Asbjørn Heid 151182cbc8 xfreerdp-server: Fixed deadlock issue in event queue.
Writing to the pipe may block if the pipe is full. Holding the mutex while writing prevents listeners from
aquiring the mutex and unblocking the write. This leads to a deadlock situation.
2012-02-15 08:22:12 +01:00

212 lines
4.3 KiB
C

/**
* FreeRDP: A Remote Desktop Protocol Client
* X11 Server Event Handling
*
* Copyright 2011 Marc-Andre Moreau <marcandre.moreau@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <X11/Xlib.h>
#include <freerdp/utils/memory.h>
#include "xf_event.h"
int xf_is_event_set(xfEventQueue* event_queue)
{
fd_set rfds;
int num_set;
struct timeval time;
FD_ZERO(&rfds);
FD_SET(event_queue->pipe_fd[0], &rfds);
memset(&time, 0, sizeof(time));
num_set = select(event_queue->pipe_fd[0] + 1, &rfds, 0, 0, &time);
return (num_set == 1);
}
void xf_signal_event(xfEventQueue* event_queue)
{
int length;
length = write(event_queue->pipe_fd[1], "sig", 4);
if (length != 4)
printf("xf_signal_event: error\n");
}
void xf_set_event(xfEventQueue* event_queue)
{
int length;
length = write(event_queue->pipe_fd[1], "sig", 4);
if (length != 4)
printf("xf_set_event: error\n");
}
void xf_clear_events(xfEventQueue* event_queue)
{
int length;
while (xf_is_event_set(event_queue))
{
length = read(event_queue->pipe_fd[0], &length, 4);
if (length != 4)
printf("xf_clear_event: error\n");
}
}
void xf_clear_event(xfEventQueue* event_queue)
{
int length;
length = read(event_queue->pipe_fd[0], &length, 4);
if (length != 4)
printf("xf_clear_event: error\n");
}
void xf_event_push(xfEventQueue* event_queue, xfEvent* event)
{
pthread_mutex_lock(&(event_queue->mutex));
if (event_queue->count >= event_queue->size)
{
event_queue->size *= 2;
event_queue->events = (xfEvent**) xrealloc((void*) event_queue->events, sizeof(xfEvent*) * event_queue->size);
}
event_queue->events[(event_queue->count)++] = event;
pthread_mutex_unlock(&(event_queue->mutex));
xf_set_event(event_queue);
}
xfEvent* xf_event_peek(xfEventQueue* event_queue)
{
xfEvent* event;
pthread_mutex_lock(&(event_queue->mutex));
if (event_queue->count < 1)
event = NULL;
else
event = event_queue->events[0];
pthread_mutex_unlock(&(event_queue->mutex));
return event;
}
xfEvent* xf_event_pop(xfEventQueue* event_queue)
{
xfEvent* event;
pthread_mutex_lock(&(event_queue->mutex));
if (event_queue->count < 1)
return NULL;
/* remove event signal */
xf_clear_event(event_queue);
event = event_queue->events[0];
(event_queue->count)--;
memmove(&event_queue->events[0], &event_queue->events[1], event_queue->count * sizeof(void*));
pthread_mutex_unlock(&(event_queue->mutex));
return event;
}
xfEventRegion* xf_event_region_new(int x, int y, int width, int height)
{
xfEventRegion* event_region = xnew(xfEventRegion);
if (event_region != NULL)
{
event_region->x = x;
event_region->y = y;
event_region->width = width;
event_region->height = height;
}
return event_region;
}
void xf_event_region_free(xfEventRegion* event_region)
{
xfree(event_region);
}
xfEvent* xf_event_new(int type)
{
xfEvent* event = xnew(xfEvent);
event->type = type;
return event;
}
void xf_event_free(xfEvent* event)
{
xfree(event);
}
xfEventQueue* xf_event_queue_new()
{
xfEventQueue* event_queue = xnew(xfEventQueue);
if (event_queue != NULL)
{
event_queue->pipe_fd[0] = -1;
event_queue->pipe_fd[1] = -1;
event_queue->size = 16;
event_queue->count = 0;
event_queue->events = (xfEvent**) xzalloc(sizeof(xfEvent*) * event_queue->size);
if (pipe(event_queue->pipe_fd) < 0)
printf("xf_event_queue_new: pipe failed\n");
pthread_mutex_init(&(event_queue->mutex), NULL);
}
return event_queue;
}
void xf_event_queue_free(xfEventQueue* event_queue)
{
if (event_queue->pipe_fd[0] != -1)
{
close(event_queue->pipe_fd[0]);
event_queue->pipe_fd[0] = -1;
}
if (event_queue->pipe_fd[1] != -1)
{
close(event_queue->pipe_fd[1]);
event_queue->pipe_fd[1] = -1;
}
pthread_mutex_destroy(&(event_queue->mutex));
}