Don't use poll timeout for timing animation.

Receiving events breaks out of the poll and resets the time out.
Effectively, this blocks the animation when the client receives events.
As a quick fix, use timerfd for timing the animation.

diff --git a/Makefile b/Makefile
index 84b65aa..fa7ac49 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@ flower_objs = flower.o
 pointer_objs = pointer.o
 
 $(clients) : CFLAGS += $(shell pkg-config --cflags cairo)
-$(clients) : LDLIBS += $(shell pkg-config --libs cairo)
+$(clients) : LDLIBS += $(shell pkg-config --libs cairo) -lrt
 
 define client_template
 $(1): $$($(1)_objs) libwayland.so

diff --git a/flower.c b/flower.c
index 4654de0..46deb05 100644 (file)
--- a/flower.c
+++ b/flower.c
@@ -5,6 +5,8 @@
 #include <i915_drm.h>
 #include <sys/ioctl.h>
 #include <sys/poll.h>
+#include <sys/timerfd.h>
+#include <time.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <math.h>
@@ -151,9 +153,10 @@ int main(int argc, char *argv[])
        int fd, i, ret;
        uint32_t name, mask;
        cairo_surface_t *s;
-       struct pollfd p[1];
-
-       srandom(time(NULL));
+       struct pollfd p[2];
+       struct timespec ts;
+       struct itimerspec its;
+       uint64_t expires;
 
        fd = open(gem_device, O_RDWR);
        if (fd < 0) {
@@ -171,6 +174,24 @@ int main(int argc, char *argv[])
 
        surface = wl_display_create_surface(display);
 
+       p[1].fd = timerfd_create(CLOCK_MONOTONIC, 0);
+       if (p[1].fd < 0) {
+               fprintf(stderr, "could not create timerfd\n: %m");
+               return -1;
+       }
+
+       p[1].events = POLLIN;
+       clock_gettime(CLOCK_MONOTONIC, &ts);
+       its.it_value = ts;
+       its.it_interval.tv_sec = 0;
+       its.it_interval.tv_nsec = 20 * 1000000;
+       if (timerfd_settime(p[1].fd, TFD_TIMER_ABSTIME, &its, NULL) < 0) {
+               fprintf(stderr, "could not set timerfd\n: %m");
+               return -1;
+       }
+
+       srandom(ts.tv_nsec);
+
        s = draw_stuff(width, height);
        name = name_cairo_surface(fd, s);
 
@@ -178,8 +199,9 @@ int main(int argc, char *argv[])
                          cairo_image_surface_get_stride(s));
 
        i = 0;
-       while (ret = poll(p, 1, 20), ret >= 0) {
-               if (ret == 0) {
+       while (ret = poll(p, 2, -1), ret >= 0) {
+               if (p[1].revents & POLLIN) {
+                       read(p[1].fd, &expires, sizeof expires);
                        wl_surface_map(surface, 
                                       x + cos(i / 30.0) * 200,
                                       y + sin(i / 31.0) * 200,