[PATCH] modetest: Use threads for cursors instead of SIGALRM

[Jasper St. Pierre]

This fixes an issue when trying to use -v and -C together. When trying
to read the page flip event, we are interrupted by the SIGALRM that
comes in, and so we think we timed out when we simply got EINTR. While
we could just loop checking for EINTR, SIGALRM is just bad idea to
begin with, so just rewrite it to use a thread.
---
 tests/modetest/Makefile.am |  3 ++-
 tests/modetest/cursor.c    | 57 +++++++++++++++++++++++-----------------------
 2 files changed, 31 insertions(+), 29 deletions(-)

diff --git a/tests/modetest/Makefile.am b/tests/modetest/Makefile.am
index 0a6af01..8fc924a 100644
--- a/tests/modetest/Makefile.am
+++ b/tests/modetest/Makefile.am
@@ -19,7 +19,8 @@ modetest_SOURCES = $(MODETEST_FILES)
 
 modetest_LDADD = \
 	$(top_builddir)/libdrm.la \
-	$(top_builddir)/libkms/libkms.la
+	$(top_builddir)/libkms/libkms.la \
+	-lpthread
 
 if HAVE_CAIRO
 AM_CFLAGS += $(CAIRO_CFLAGS)
diff --git a/tests/modetest/cursor.c b/tests/modetest/cursor.c
index 60f240a..62a50ef 100644
--- a/tests/modetest/cursor.c
+++ b/tests/modetest/cursor.c
@@ -34,6 +34,8 @@
 #include <string.h>
 #include <signal.h>
 #include <sys/time.h>
+#include <pthread.h>
+#include <unistd.h>
 
 #include "xf86drm.h"
 #include "xf86drmMode.h"
@@ -59,6 +61,9 @@ struct cursor {
 static struct cursor cursors[MAX_CURSORS];
 static int ncursors;
 
+static pthread_t cursor_thread;
+static int cursor_running;
+
 /*
  * Timer driven program loops through these steps to move/enable/disable
  * the cursor
@@ -137,33 +142,29 @@ static struct cursor_step steps[] = {
 		{  set_cursor, 10,   0,  0 },  /* disable */
 };
 
-/*
- * Cursor API:
- */
-
-static void run_step(int sig)
+static void *cursor_thread_func(void *data)
 {
-	struct cursor_step *step = &steps[indx % ARRAY_SIZE(steps)];
-	struct itimerval itimer = {
-			.it_value.tv_usec = 1000 * step->msec,
-	};
-	int i;
-
-	for (i = 0; i < ncursors; i++) {
-		struct cursor *cursor = &cursors[i];
-		step->run(cursor, step);
-	}
-
-	/* iterate to next count/step: */
-	if (count < step->repeat) {
-		count++;
-	} else {
-		count = 0;
-		indx++;
+	while (cursor_running) {
+		struct cursor_step *step = &steps[indx % ARRAY_SIZE(steps)];
+		int i;
+
+		for (i = 0; i < ncursors; i++) {
+			struct cursor *cursor = &cursors[i];
+			step->run(cursor, step);
+		}
+
+		/* iterate to next count/step: */
+		if (count < step->repeat) {
+			count++;
+		} else {
+			count = 0;
+			indx++;
+		}
+
+		usleep(1000 * step->msec);
 	}
 
-	/* and lastly, setup timer for next step */
-	setitimer(ITIMER_REAL, &itimer, NULL);
+	return NULL;
 }
 
 int cursor_init(int fd, uint32_t bo_handle, uint32_t crtc_id,
@@ -194,16 +195,16 @@ int cursor_init(int fd, uint32_t bo_handle, uint32_t crtc_id,
 
 int cursor_start(void)
 {
-	/* setup signal handler to update cursor: */
-	signal(SIGALRM, run_step);
+	cursor_running = 1;
+	pthread_create(&cursor_thread, NULL, cursor_thread_func, NULL);
 	printf("starting cursor\n");
-	run_step(SIGALRM);
 	return 0;
 }
 
 int cursor_stop(void)
 {
-	signal(SIGALRM, NULL);
+	cursor_running = 0;
+	pthread_join(cursor_thread, NULL);
 	printf("cursor stopped\n");
 	return 0;
 }
-- 
2.1.0