[Mesa-dev] [PATCH 06/14] vl/dri3: add back buffers support
Axel Davy
axel.davy at ens.fr
Wed May 11 18:42:48 UTC 2016
Another thing is that I think there is no guarantee the Xserver releases
all the pixmaps,
and that it could keep one infinitely (until window destruction).
Thus if the drawable is changed by the user, but the previous drawable
isn't destroyed by the user,
one buffer can stay busy forever. Change several times of drawable and
you get stuck...
I think the loader dri3 code suffers the same issues.
For gallium nine, we use the following code:
https://github.com/iXit/wine/blob/master/dlls/d3d9-nine/dri3.c#L739
the code is a bit complicated because of thread safety, but likely you
don't need the thread safety part for you.
Basically the idea is that when only one pixmap hasn't been released,
you send it again with the copy flag, which garantees it will get released.
Axel
On 11/05/2016 20:29, Axel Davy wrote:
> On 11/05/2016 17:06, Leo Liu wrote:
>> This implements DRI3 PixmapFromBuffer. Create buffer objects, and
>> associate it to a dma-buf fd, and then pass this fd with a pixmap
>> ID to X server for creating pixmap object; also add a function
>> for wait events.
>>
>> Signed-off-by: Leo Liu <leo.liu at amd.com>
>> ---
>> src/gallium/auxiliary/vl/vl_winsys_dri3.c | 187
>> +++++++++++++++++++++++++++++-
>> 1 file changed, 185 insertions(+), 2 deletions(-)
>>
>> diff --git a/src/gallium/auxiliary/vl/vl_winsys_dri3.c
>> b/src/gallium/auxiliary/vl/vl_winsys_dri3.c
>> index ef80730..e78ca07 100644
>> --- a/src/gallium/auxiliary/vl/vl_winsys_dri3.c
>> +++ b/src/gallium/auxiliary/vl/vl_winsys_dri3.c
>> @@ -28,17 +28,35 @@
>> #include <fcntl.h>
>> #include <X11/Xlib-xcb.h>
>> +#include <X11/xshmfence.h>
>> #include <xcb/dri3.h>
>> #include <xcb/present.h>
>> #include "loader.h"
>> #include "pipe/p_screen.h"
>> +#include "pipe/p_state.h"
>> #include "pipe-loader/pipe_loader.h"
>> #include "util/u_memory.h"
>> +#include "util/u_inlines.h"
>> +
>> #include "vl/vl_winsys.h"
>> +#define BACK_BUFFER_NUM 3
>> +
>> +struct vl_dri3_buffer
>> +{
>> + struct pipe_resource *texture;
>> +
>> + uint32_t pixmap;
>> + uint32_t sync_fence;
>> + struct xshmfence *shm_fence;
>> +
>> + bool busy;
>> + uint32_t width, height, pitch;
>> +};
>> +
>> struct vl_dri3_screen
>> {
>> struct vl_screen base;
>> @@ -48,9 +66,23 @@ struct vl_dri3_screen
>> uint32_t width, height, depth;
>> xcb_special_event_t *special_event;
>> +
>> + struct vl_dri3_buffer *back_buffers[BACK_BUFFER_NUM];
>> + int cur_back;
>> };
>> static void
>> +dri3_free_back_buffer(struct vl_dri3_screen *scrn,
>> + struct vl_dri3_buffer *buffer)
>> +{
>> + xcb_free_pixmap(scrn->conn, buffer->pixmap);
>> + xcb_sync_destroy_fence(scrn->conn, buffer->sync_fence);
>> + xshmfence_unmap_shm(buffer->shm_fence);
>> + pipe_resource_reference(&buffer->texture, NULL);
>> + FREE(buffer);
>> +}
>> +
>> +static void
>> dri3_handle_present_event(struct vl_dri3_screen *scrn,
>> xcb_present_generic_event_t *ge)
>> {
>> @@ -83,6 +115,145 @@ dri3_flush_present_events(struct vl_dri3_screen
>> *scrn)
>> }
>> static bool
>> +dri3_wait_present_events(struct vl_dri3_screen *scrn)
>> +{
>> + if (scrn->special_event) {
>> + xcb_generic_event_t *ev;
>> + ev = xcb_wait_for_special_event(scrn->conn, scrn->special_event);
>> + if (!ev)
>> + return false;
>> + dri3_handle_present_event(scrn, (xcb_present_generic_event_t
>> *)ev);
>> + return true;
>> + }
>> + return false;
>> +}
>> +
>> +static int
>> +dri3_find_back(struct vl_dri3_screen *scrn)
>> +{
>> + int b;
>> +
>> + for (;;) {
>> + for (b = 0; b < BACK_BUFFER_NUM; b++) {
>> + int id = (b + scrn->cur_back) % BACK_BUFFER_NUM;
>> + struct vl_dri3_buffer *buffer = scrn->back_buffers[id];
>> + if (!buffer || !buffer->busy)
>> + return id;
>> + }
>> + xcb_flush(scrn->conn);
>> + if (!dri3_wait_present_events(scrn))
>> + return -1;
>> + }
>> +}
>> +
>> +static struct vl_dri3_buffer *
>> +dri3_alloc_back_buffer(struct vl_dri3_screen *scrn)
>> +{
>> + struct vl_dri3_buffer *buffer;
>> + xcb_pixmap_t pixmap;
>> + xcb_sync_fence_t sync_fence;
>> + struct xshmfence *shm_fence;
>> + int buffer_fd, fence_fd;
>> + struct pipe_resource templ;
>> + struct winsys_handle whandle;
>> + unsigned usage;
>> +
>> + buffer = CALLOC_STRUCT(vl_dri3_buffer);
>> + if (!buffer)
>> + return NULL;
>> +
>> + fence_fd = xshmfence_alloc_shm();
>> + if (fence_fd < 0)
>> + goto free_buffer;
>> +
>> + shm_fence = xshmfence_map_shm(fence_fd);
>> + if (!shm_fence)
>> + goto close_fd;
>> +
>> + memset(&templ, 0, sizeof(templ));
>> + templ.bind = PIPE_BIND_RENDER_TARGET | PIPE_BIND_SAMPLER_VIEW |
>> + PIPE_BIND_SCANOUT | PIPE_BIND_SHARED;
>> + templ.format = PIPE_FORMAT_B8G8R8X8_UNORM;
>> + templ.target = PIPE_TEXTURE_2D;
>> + templ.last_level = 0;
>> + templ.width0 = scrn->width;
>> + templ.height0 = scrn->height;
>> + templ.depth0 = 1;
>> + templ.array_size = 1;
>> + buffer->texture =
>> scrn->base.pscreen->resource_create(scrn->base.pscreen,
>> + &templ);
>> + if (!buffer->texture)
>> + goto unmap_shm;
>> +
>> + memset(&whandle, 0, sizeof(whandle));
>> + whandle.type= DRM_API_HANDLE_TYPE_FD;
>> + usage = PIPE_HANDLE_USAGE_EXPLICIT_FLUSH | PIPE_HANDLE_USAGE_READ;
> Here using
>
> PIPE_HANDLE_USAGE_EXPLICIT_FLUSH
>
> is wrong. Both vaapi and vdpau don't call flush_resource.
>
> Perhaps vaapi and vdpau can get fixed to call it, I don't know which
> is best
> for the target usage of the resources.
>> + scrn->base.pscreen->resource_get_handle(scrn->base.pscreen,
>> + buffer->texture, &whandle,
>> + usage);
>> + buffer_fd = whandle.handle;
>> + buffer->pitch = whandle.stride;
>> + xcb_dri3_pixmap_from_buffer(scrn->conn,
>> + (pixmap = xcb_generate_id(scrn->conn)),
>> + scrn->drawable,
>> + 0,
>> + scrn->width, scrn->height,
>> buffer->pitch,
>> + scrn->depth, 32,
>> + buffer_fd);
>> + xcb_dri3_fence_from_fd(scrn->conn,
>> + pixmap,
>> + (sync_fence = xcb_generate_id(scrn->conn)),
>> + false,
>> + fence_fd);
>> +
>> + buffer->pixmap = pixmap;
>> + buffer->sync_fence = sync_fence;
>> + buffer->shm_fence = shm_fence;
>> + buffer->width = scrn->width;
>> + buffer->height = scrn->height;
>> +
>> + xshmfence_trigger(buffer->shm_fence);
>> +
>> + return buffer;
>> +
>> +unmap_shm:
>> + xshmfence_unmap_shm(shm_fence);
>> +close_fd:
>> + close(fence_fd);
>> +free_buffer:
>> + FREE(buffer);
>> + return NULL;
>> +}
>> +
>> +static struct vl_dri3_buffer *
>> +dri3_get_back_buffer(struct vl_dri3_screen *scrn)
>> +{
>> + struct vl_dri3_buffer *buffer;
>> + struct pipe_resource *texture = NULL;
>> +
>> + assert(scrn);
>> +
>> + scrn->cur_back = dri3_find_back(scrn);
>> + if (scrn->cur_back < 0)
>> + return NULL;
>> + buffer = scrn->back_buffers[scrn->cur_back];
>> +
>> + if (!buffer) {
>> + buffer = dri3_alloc_back_buffer(scrn);
>> + if (!buffer)
>> + return NULL;
>> +
>> + scrn->back_buffers[scrn->cur_back] = buffer;
>> + }
>> +
>> + pipe_resource_reference(&texture, buffer->texture);
>> + xcb_flush(scrn->conn);
>> + xshmfence_await(buffer->shm_fence);
>> +
>> + return buffer;
>> +}
>> +
>> +static bool
>> dri3_set_drawable(struct vl_dri3_screen *scrn, Drawable drawable)
>> {
>> xcb_get_geometry_cookie_t geom_cookie;
>> @@ -147,14 +318,18 @@ static struct pipe_resource *
>> vl_dri3_screen_texture_from_drawable(struct vl_screen *vscreen,
>> void *drawable)
>> {
>> struct vl_dri3_screen *scrn = (struct vl_dri3_screen *)vscreen;
>> + struct vl_dri3_buffer *buffer;
>> assert(scrn);
>> if (!dri3_set_drawable(scrn, (Drawable)drawable))
>> return NULL;
>> - /* TODO */
>> - return NULL;
>> + buffer = dri3_get_back_buffer(scrn);
>> + if (!buffer)
>> + return NULL;
>> +
>> + return buffer->texture;
>> }
>> static struct u_rect *
>> @@ -188,11 +363,19 @@ static void
>> vl_dri3_screen_destroy(struct vl_screen *vscreen)
>> {
>> struct vl_dri3_screen *scrn = (struct vl_dri3_screen *)vscreen;
>> + int i;
>> assert(vscreen);
>> dri3_flush_present_events(scrn);
>> + for (i = 0; i < BACK_BUFFER_NUM; ++i) {
>> + if (scrn->back_buffers[i]) {
>> + dri3_free_back_buffer(scrn, scrn->back_buffers[i]);
>> + scrn->back_buffers[i] = NULL;
>> + }
>> + }
>> +
>> if (scrn->special_event)
>> xcb_unregister_for_special_event(scrn->conn,
>> scrn->special_event);
>> scrn->base.pscreen->destroy(scrn->base.pscreen);
>
>
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