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mpv/video/mp_image_pool.c
wm4 88aa3b8c98 mp_image_pool: add features needed for use with hwaccel
The plan is to get rid of the custom VAAPI and possibly VDPAU surface
allocators.

Add custom surface allocation, because hwaccel surfaces are allocated
completely differently from software surfaces.

Add optional LRU allocation, which is (probably) helpful for hwaccel,
but (probably) less optimal for software surfaces.

mp_image_pool_get_no_alloc() is specifically for VAAPI, which can't
allocate new decoder surfaces after decoder init.
2014-03-17 18:21:29 +01:00

206 lines
6.5 KiB
C

/*
* This file is part of mpv.
*
* mpv is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* mpv is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with mpv; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include <stddef.h>
#include <stdbool.h>
#include <pthread.h>
#include <assert.h>
#include "talloc.h"
#include "common/common.h"
#include "video/mp_image.h"
#include "mp_image_pool.h"
static pthread_mutex_t pool_mutex = PTHREAD_MUTEX_INITIALIZER;
#define pool_lock() pthread_mutex_lock(&pool_mutex)
#define pool_unlock() pthread_mutex_unlock(&pool_mutex)
// Thread-safety: the pool itself is not thread-safe, but pool-allocated images
// can be referenced and unreferenced from other threads. (As long as the image
// destructors are thread-safe.)
struct mp_image_pool {
int max_count;
struct mp_image **images;
int num_images;
mp_image_allocator allocator;
void *allocator_ctx;
bool use_lru;
unsigned int lru_counter;
};
// Used to gracefully handle the case when the pool is freed while image
// references allocated from the image pool are still held by someone.
struct image_flags {
// If both of these are false, the image must be freed.
bool referenced; // outside mp_image reference exists
bool pool_alive; // the mp_image_pool references this
unsigned int order; // for LRU allocation (basically a timestamp)
};
static void image_pool_destructor(void *ptr)
{
struct mp_image_pool *pool = ptr;
mp_image_pool_clear(pool);
}
struct mp_image_pool *mp_image_pool_new(int max_count)
{
struct mp_image_pool *pool = talloc_ptrtype(NULL, pool);
talloc_set_destructor(pool, image_pool_destructor);
*pool = (struct mp_image_pool) {
.max_count = max_count,
};
return pool;
}
void mp_image_pool_clear(struct mp_image_pool *pool)
{
for (int n = 0; n < pool->num_images; n++) {
struct mp_image *img = pool->images[n];
struct image_flags *it = img->priv;
bool referenced;
pool_lock();
assert(it->pool_alive);
it->pool_alive = false;
referenced = it->referenced;
pool_unlock();
if (!referenced)
talloc_free(img);
}
pool->num_images = 0;
}
// This is the only function that is allowed to run in a different thread.
// (Consider passing an image to another thread, which frees it.)
static void unref_image(void *ptr)
{
struct mp_image *img = ptr;
struct image_flags *it = img->priv;
bool alive;
pool_lock();
assert(it->referenced);
it->referenced = false;
alive = it->pool_alive;
pool_unlock();
if (!alive)
talloc_free(img);
}
// Return a new image of given format/size. Unlike mp_image_pool_get(), this
// returns NULL if there is no free image of this format/size.
struct mp_image *mp_image_pool_get_no_alloc(struct mp_image_pool *pool, int fmt,
int w, int h)
{
struct mp_image *new = NULL;
pool_lock();
for (int n = 0; n < pool->num_images; n++) {
struct mp_image *img = pool->images[n];
struct image_flags *img_it = img->priv;
assert(img_it->pool_alive);
if (!img_it->referenced) {
if (img->imgfmt == fmt && img->w == w && img->h == h) {
if (pool->use_lru) {
struct image_flags *new_it = new ? new->priv : NULL;
if (!new_it || new_it->order > img_it->order)
new = img;
} else {
new = img;
break;
}
}
}
}
pool_unlock();
if (!new)
return NULL;
struct image_flags *it = new->priv;
assert(!it->referenced && it->pool_alive);
it->referenced = true;
it->order = ++pool->lru_counter;
return mp_image_new_custom_ref(new, new, unref_image);
}
// Return a new image of given format/size. The only difference to
// mp_image_alloc() is that there is a transparent mechanism to recycle image
// data allocations through this pool.
// The image can be free'd with talloc_free().
struct mp_image *mp_image_pool_get(struct mp_image_pool *pool, int fmt,
int w, int h)
{
struct mp_image *new = mp_image_pool_get_no_alloc(pool, fmt, w, h);
if (!new) {
if (pool->num_images >= pool->max_count)
mp_image_pool_clear(pool);
if (pool->allocator) {
new = pool->allocator(pool->allocator_ctx, fmt, w, h);
} else {
new = mp_image_alloc(fmt, w, h);
}
if (!new)
return NULL;
struct image_flags *it = talloc_ptrtype(new, it);
*it = (struct image_flags) { .pool_alive = true };
new->priv = it;
MP_TARRAY_APPEND(pool, pool->images, pool->num_images, new);
new = mp_image_pool_get_no_alloc(pool, fmt, w, h);
}
return new;
}
// Like mp_image_new_copy(), but allocate the image out of the pool.
struct mp_image *mp_image_pool_new_copy(struct mp_image_pool *pool,
struct mp_image *img)
{
struct mp_image *new = mp_image_pool_get(pool, img->imgfmt, img->w, img->h);
mp_image_copy(new, img);
mp_image_copy_attributes(new, img);
return new;
}
// Like mp_image_make_writeable(), but if a copy has to be made, allocate it
// out of the pool.
void mp_image_pool_make_writeable(struct mp_image_pool *pool,
struct mp_image *img)
{
if (mp_image_is_writeable(img))
return;
mp_image_steal_data(img, mp_image_pool_new_copy(pool, img));
assert(mp_image_is_writeable(img));
}
void mp_image_pool_set_allocator(struct mp_image_pool *pool,
mp_image_allocator cb, void *cb_data)
{
pool->allocator = cb;
pool->allocator_ctx = cb_data;
}
// Put into LRU mode. (Likely better for hwaccel surfaces, but worse for memory.)
void mp_image_pool_set_lru(struct mp_image_pool *pool)
{
pool->use_lru = true;
}