QXcbShmImage::QXcbShmImage(QXcbScreen *screen, const QSize &size, uint depth, QImage::Format format)
: QXcbObject(screen->connection())
, m_gc(0)
, m_gc_window(0)
{
Q_XCB_NOOP(connection());
m_xcb_image = xcb_image_create_native(xcb_connection(),
size.width(),
size.height(),
XCB_IMAGE_FORMAT_Z_PIXMAP,
depth,
0,
~0,
0);
m_shm_info.shmid = shmget (IPC_PRIVATE,
m_xcb_image->stride * m_xcb_image->height, IPC_CREAT|0777);
m_shm_info.shmaddr = m_xcb_image->data = (quint8 *)shmat (m_shm_info.shmid, 0, 0);
m_shm_info.shmseg = xcb_generate_id(xcb_connection());
xcb_generic_error_t *error = xcb_request_check(xcb_connection(), xcb_shm_attach_checked(xcb_connection(), m_shm_info.shmseg, m_shm_info.shmid, false));
if (error) {
qWarning() << "QXcbWindowSurface: Unable to attach to shared memory segment";
free(error);
}
if (shmctl(m_shm_info.shmid, IPC_RMID, 0) == -1)
qWarning() << "QXcbWindowSurface: Error while marking the shared memory segment to be destroyed";
m_qimage = QImage( (uchar*) m_xcb_image->data, m_xcb_image->width, m_xcb_image->height, m_xcb_image->stride, format);
}
ExcCode screen_shm_init() {
xcb_query_extension_cookie_t extension_cookie =
xcb_query_extension(display,
strlen(MIT_SHM_EXTENSION_NAME), MIT_SHM_EXTENSION_NAME);
xcb_query_extension_reply_t *extension_reply =
xcb_query_extension_reply(display, extension_cookie, NULL);
if (extension_reply == NULL)
PANIC(ERR_X_EXTENSION, MIT_SHM_EXTENSION_NAME);
free(extension_reply);
xcb_shm_query_version_cookie_t version_cookie =
xcb_shm_query_version(display);
xcb_shm_query_version_reply_t *version_reply =
xcb_shm_query_version_reply(display, version_cookie, NULL);
if (version_reply == NULL)
PANIC(ERR_X_EXTENSION, MIT_SHM_EXTENSION_NAME);
free(version_reply);
size_t max_size = screen->width_in_pixels * screen->height_in_pixels *
sizeof (unsigned);
shmid = shmget(IPC_PRIVATE, max_size, IPC_CREAT | 0777);
if (shmid < 0)
PANIC(ERR_SHM_ALLOC);
shmaddr = shmat(shmid, 0, 0);
if (shmaddr == (uint8_t *) -1)
PANIC(ERR_SHM_ATTACH);
shmseg = xcb_generate_id(display);
xcb_void_cookie_t attach_cookie = xcb_shm_attach_checked(display,
shmseg, shmid, 0);
if (xcb_request_check(display, attach_cookie) != NULL)
PANIC(ERR_SHM_ATTACH);
return 0;
}
QXcbShmImage::QXcbShmImage(QXcbScreen *screen, const QSize &size, uint depth, QImage::Format format)
: QXcbObject(screen->connection())
, m_gc(0)
, m_gc_window(0)
{
Q_XCB_NOOP(connection());
m_xcb_image = xcb_image_create_native(xcb_connection(),
size.width(),
size.height(),
XCB_IMAGE_FORMAT_Z_PIXMAP,
depth,
0,
~0,
0);
const int segmentSize = m_xcb_image->stride * m_xcb_image->height;
if (!segmentSize)
return;
int id = shmget(IPC_PRIVATE, segmentSize, IPC_CREAT | 0600);
if (id == -1)
qWarning("QXcbShmImage: shmget() failed (%d) for size %d (%dx%d)",
errno, segmentSize, size.width(), size.height());
else
m_shm_info.shmid = id;
m_shm_info.shmaddr = m_xcb_image->data = (quint8 *)shmat (m_shm_info.shmid, 0, 0);
m_shm_info.shmseg = xcb_generate_id(xcb_connection());
const xcb_query_extension_reply_t *shm_reply = xcb_get_extension_data(xcb_connection(), &xcb_shm_id);
bool shm_present = shm_reply != NULL && shm_reply->present;
xcb_generic_error_t *error = NULL;
if (shm_present)
error = xcb_request_check(xcb_connection(), xcb_shm_attach_checked(xcb_connection(), m_shm_info.shmseg, m_shm_info.shmid, false));
if (!shm_present || error) {
free(error);
shmdt(m_shm_info.shmaddr);
shmctl(m_shm_info.shmid, IPC_RMID, 0);
m_shm_info.shmaddr = 0;
m_xcb_image->data = (uint8_t *)malloc(segmentSize);
} else {
if (shmctl(m_shm_info.shmid, IPC_RMID, 0) == -1)
qWarning() << "QXcbBackingStore: Error while marking the shared memory segment to be destroyed";
}
m_qimage = QImage( (uchar*) m_xcb_image->data, m_xcb_image->width, m_xcb_image->height, m_xcb_image->stride, format);
}
/**
* Initialize a picture buffer as shared memory, according to the video output
* format. If a attach is true, the segment is attached to
* the X server (MIT-SHM extension).
*/
int PictureResourceAlloc (vout_display_t *vd, picture_resource_t *res, size_t size,
xcb_connection_t *conn, bool attach)
{
res->p_sys = malloc (sizeof(*res->p_sys));
if (!res->p_sys)
return VLC_EGENERIC;
#ifdef HAVE_SYS_SHM_H
/* Allocate shared memory segment */
int id = shmget (IPC_PRIVATE, size, IPC_CREAT | S_IRWXU);
if (id == -1)
{
msg_Err (vd, "shared memory allocation error: %m");
free (res->p_sys);
return VLC_EGENERIC;
}
/* Attach the segment to VLC */
void *shm = shmat (id, NULL, 0 /* read/write */);
if (-1 == (intptr_t)shm)
{
msg_Err (vd, "shared memory attachment error: %m");
shmctl (id, IPC_RMID, 0);
free (res->p_sys);
return VLC_EGENERIC;
}
xcb_shm_seg_t segment;
if (attach)
{
/* Attach the segment to X */
xcb_void_cookie_t ck;
segment = xcb_generate_id (conn);
ck = xcb_shm_attach_checked (conn, segment, id, 1);
switch (CheckError (vd, conn, "shared memory server-side error", ck))
{
case 0:
break;
case XCB_ACCESS:
{
struct shmid_ds buf;
/* Retry with promiscuous permissions */
shmctl (id, IPC_STAT, &buf);
buf.shm_perm.mode |= S_IRGRP|S_IROTH;
shmctl (id, IPC_SET, &buf);
ck = xcb_shm_attach_checked (conn, segment, id, 1);
if (CheckError (vd, conn, "same error on retry", ck) == 0)
break;
/* fall through */
}
default:
msg_Info (vd, "using buggy X11 server - SSH proxying?");
segment = 0;
}
}
else
segment = 0;
shmctl (id, IPC_RMID, NULL);
res->p_sys->segment = segment;
res->p->p_pixels = shm;
#else
assert (!attach);
res->p_sys->segment = 0;
/* XXX: align on 32 bytes for VLC chroma filters */
res->p->p_pixels = malloc (size);
if (unlikely(res->p->p_pixels == NULL))
{
free (res->p_sys);
return VLC_EGENERIC;
}
#endif
return VLC_SUCCESS;
}
