diff options
Diffstat (limited to 'src/fb.c')
| -rw-r--r-- | src/fb.c | 82 |
1 files changed, 43 insertions, 39 deletions
@@ -37,6 +37,17 @@ * longer be a flipper thread. * * Let me know if you're aware of a better way with existing mainline drm! + * + * + * XXX: fb_new() used to create a thread which did the equivalent of fb_flip() + * continuously in a loop. This posed a problem for the sdl_fb backend, due to + * the need for event pumping in the page flip hook. SDL internally uses TLS + * and requires that the same thread which initialized SDL call the event + * functions. To satisfy this requirement, the body of the flipper thread loop + * has been moved to the fb_flip() function. Rototiller's main thread is + * expected to call this repeatedly, turning it effectively into the flipper + * thread. This required rototiller to move what was previously the main + * thread's duties - page rendering dispatch, to a separate thread. */ @@ -55,8 +66,6 @@ typedef struct fb_t { const fb_ops_t *ops; void *ops_context; - pthread_t thread; - _fb_page_t *active_page; /* page currently displayed */ pthread_mutex_t ready_mutex; @@ -80,38 +89,39 @@ typedef struct fb_t { /* Consumes ready pages queued via fb_page_put(), submits them to drm to flip * on vsync. Produces inactive pages from those replaced, making them * available to fb_page_get(). */ -static void * fb_flipper_thread(void *_fb) +int fb_flip(fb_t *fb) { - fb_t *fb = _fb; - - for (;;) { - _fb_page_t *next_active_page; - /* wait for a flip req, submit the req page for flip on vsync, wait for it to flip before making the - * active page inactive/available, repeat. - */ - pthread_mutex_lock(&fb->ready_mutex); - while (!fb->ready_pages_head) - pthread_cond_wait(&fb->ready_cond, &fb->ready_mutex); - - next_active_page = fb->ready_pages_head; - fb->ready_pages_head = next_active_page->next; - if (!fb->ready_pages_head) - fb->ready_pages_tail = NULL; - pthread_mutex_unlock(&fb->ready_mutex); - - /* submit the next active page for page flip on vsync, and wait for it. */ - pexit_if(fb->ops->page_flip(fb->ops_context, next_active_page->ops_page) < 0, - "unable to flip page"); - - /* now that we're displaying a new page, make the previously active one inactive so rendering can reuse it */ - pthread_mutex_lock(&fb->inactive_mutex); - fb->active_page->next = fb->inactive_pages; - fb->inactive_pages = fb->active_page; - pthread_cond_signal(&fb->inactive_cond); - pthread_mutex_unlock(&fb->inactive_mutex); - - fb->active_page = next_active_page; - } + _fb_page_t *next_active_page; + int r; + + /* wait for a flip req, submit the req page for flip on vsync, wait for it to flip before making the + * active page inactive/available, repeat. + */ + pthread_mutex_lock(&fb->ready_mutex); + while (!fb->ready_pages_head) + pthread_cond_wait(&fb->ready_cond, &fb->ready_mutex); + + next_active_page = fb->ready_pages_head; + fb->ready_pages_head = next_active_page->next; + if (!fb->ready_pages_head) + fb->ready_pages_tail = NULL; + pthread_mutex_unlock(&fb->ready_mutex); + + /* submit the next active page for page flip on vsync, and wait for it. */ + r = fb->ops->page_flip(fb->ops_context, next_active_page->ops_page); + if (r < 0) /* TODO: vet this: what happens to this page? */ + return r; + + /* now that we're displaying a new page, make the previously active one inactive so rendering can reuse it */ + pthread_mutex_lock(&fb->inactive_mutex); + fb->active_page->next = fb->inactive_pages; + fb->inactive_pages = fb->active_page; + pthread_cond_signal(&fb->inactive_cond); + pthread_mutex_unlock(&fb->inactive_mutex); + + fb->active_page = next_active_page; + + return 0; } @@ -126,9 +136,6 @@ static int fb_acquire(fb_t *fb, _fb_page_t *page) fb->active_page = page; - /* start up the page flipper thread */ - pthread_create(&fb->thread, NULL, fb_flipper_thread, fb); - return 0; } @@ -136,9 +143,6 @@ static int fb_acquire(fb_t *fb, _fb_page_t *page) /* release the fb, making the visible page inactive */ static void fb_release(fb_t *fb) { - pthread_cancel(fb->thread); - pthread_join(fb->thread, NULL); - fb->ops->release(fb->ops_context); fb->active_page->next = fb->inactive_pages; fb->inactive_pages = fb->active_page; |