test/output-present-fault.c

1/* SPDX-License-Identifier: BSD-3-Clause

2 * A test-owned barrier withholds presentation, without changing product code. */

3#define _GNU_SOURCE

4#include <dlfcn.h>

5#include <stdatomic.h>

6#include <stdlib.h>

7#include <unistd.h>

8#include <wlr/interfaces/wlr_output.h>

9static atomic_uint withheld;

10unsigned wm_test_withheld_presents(void) { return atomic_load(&withheld); }

11void wlr_output_send_present(struct wlr_output *output,

12 struct wlr_output_event_present *event) {

13 const char *barrier=getenv("SIGIL_WM_PRESENT_BARRIER");

14 if(barrier && access(barrier,F_OK)==0) {

15 atomic_fetch_add(&withheld,1);

16 return;

17 }

18 typedef void (*present_fn)(struct wlr_output *,struct wlr_output_event_present *);

19 present_fn present=(present_fn)dlsym(RTLD_NEXT,"wlr_output_send_present");

20 if(!present) abort();

21 present(output,event);

22}