Use select() instead of O_NONBLOCKopenmoocow-0.2

1 files changed, 34 insertions, 5 deletions

diff --git a/src/accelerometers.c b/src/accelerometers.c
index 61118fc..3d8c968 100644
--- a/src/accelerometers.c
+++ b/src/accelerometers.c
@@ -32,6 +32,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/select.h>
 #include <fcntl.h>
 
 #include "types.h"
@@ -66,7 +67,7 @@ AccelHandle *accelerometer_open() {
 	accel->type = ACCEL_UNKNOWN;
 	
 	/* Determine accelerometer type */
-	accel->fd = open("/dev/input/event3", O_RDONLY, O_NONBLOCK);
+	accel->fd = open("/dev/input/event3", O_RDONLY, 0);
 	if ( accel->fd != -1 ) {
 		accel->type = ACCEL_FREERUNNER;
 		printf("Neo Freerunner detected\n");
@@ -80,15 +81,43 @@ AccelHandle *accelerometer_open() {
 
 }
 
+double utils_highresms() {
+
+	struct timeval tv;
+	suseconds_t us;
+	time_t sec;
+	
+	gettimeofday(&tv, NULL);
+	us = tv.tv_usec;
+	sec = tv.tv_sec;
+	
+	return ((double)us+1000000.0*sec)/1000.0;
+
+}
+
 void accelerometer_update_freerunner(AccelHandle *accel) {
 
 	struct input_event ev;
 	size_t rval;
+	fd_set fds;
+	struct timeval t;
 	
-	rval = read(accel->fd, &ev, sizeof(ev));
-	if ( rval != sizeof(ev) ) {
-		fprintf(stderr, "Couldn't read accelerometer data");
-		return;
+	FD_ZERO(&fds);
+	FD_SET(accel->fd, &fds);
+	t.tv_sec = 0;
+	t.tv_usec = 0;
+	select(1+accel->fd, &fds, NULL, NULL, &t);
+	
+	if ( FD_ISSET(accel->fd, &fds) ) {
+	
+		rval = read(accel->fd, &ev, sizeof(ev));
+		if ( rval != sizeof(ev) ) {
+			fprintf(stderr, "Couldn't read accelerometer data");
+			return;
+		}
+		
+	} else {
+		return;	/* No data */
 	}
 	
 	if ( ev.type == EV_REL ) {