X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=serialport.c;h=1a9b4415438422afebc989a6b20cc6f6767a32a7;hb=32dbe2d2984c330642e2f7cad30fc7501a923e4c;hp=74d46eede7953d7ac0c761c18001cd0a3a102ffe;hpb=b457865b8f42b68953bf2910dcc02d3fe27fc2a8;p=libserialport.git

diff --git a/serialport.c b/serialport.c
index 74d46ee..1a9b441 100644
--- a/serialport.c
+++ b/serialport.c
@@ -55,6 +55,128 @@ static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 	const struct sp_port_config *config);
 
+#ifndef _WIN32
+
+/* Timing abstraction */
+
+struct time {
+	struct timeval tv;
+};
+
+struct timeout {
+	unsigned int ms;
+	struct time start, delta, now, end;
+	struct timeval delta_tv;
+	bool overflow;
+};
+
+#define TIME_ZERO {.tv = {0, 0}}
+#define TIME_MS(ms) {.tv = {ms / 1000, (ms % 1000) * 1000}}
+
+const struct time max_delta = TIME_MS(INT_MAX);
+
+static void time_get(struct time *time)
+{
+#ifdef HAVE_CLOCK_GETTIME
+	struct timespec ts;
+	if (clock_gettime(CLOCK_MONOTONIC, &ts) == -1)
+		clock_gettime(CLOCK_REALTIME, &ts);
+	time->tv.tv_sec = ts.tv_sec;
+	time->tv.tv_usec = ts.tv_nsec / 1000;
+#elif defined(__APPLE__)
+	mach_timebase_info_data_t info;
+	mach_timebase_info(&info);
+	uint64_t ticks = mach_absolute_time();
+	uint64_t ns = (ticks * info.numer) / info.denom;
+	time->tv.tv_sec = ns / 1000000000;
+	time->tv.tv_usec = (ns % 1000000000) / 1000;
+#else
+	gettimeofday(&time->tv, NULL);
+#endif
+}
+
+static void time_set_ms(struct time *time, unsigned int ms)
+{
+	time->tv.tv_sec = ms / 1000;
+	time->tv.tv_usec = (ms % 1000) * 1000;
+}
+
+static void time_add(const struct time *a,
+		const struct time *b, struct time *result)
+{
+	timeradd(&a->tv, &b->tv, &result->tv);
+}
+
+static void time_sub(const struct time *a,
+		const struct time *b, struct time *result)
+{
+	timersub(&a->tv, &b->tv, &result->tv);
+}
+
+static bool time_greater(const struct time *a, const struct time *b)
+{
+	return timercmp(&a->tv, &b->tv, >);
+}
+
+static void time_as_timeval(const struct time *time, struct timeval *tv)
+{
+	*tv = time->tv;
+}
+
+static unsigned int time_as_ms(const struct time *time)
+{
+	return time->tv.tv_sec * 1000 + time->tv.tv_usec / 1000;
+}
+
+static void timeout_start(struct timeout *timeout, unsigned int timeout_ms)
+{
+	timeout->ms = timeout_ms;
+
+	timeout->overflow = (timeout->ms > INT_MAX);
+
+	/* Get time at start of operation. */
+	time_get(&timeout->start);
+	/* Define duration of timeout. */
+	time_set_ms(&timeout->delta, timeout_ms);
+	/* Calculate time at which we should give up. */
+	time_add(&timeout->start, &timeout->delta, &timeout->end);
+}
+
+static bool timeout_check(struct timeout *timeout)
+{
+	if (timeout->ms == 0)
+		return false;
+
+	time_get(&timeout->now);
+	time_sub(&timeout->end, &timeout->now, &timeout->delta);
+	if ((timeout->overflow = time_greater(&timeout->delta, &max_delta)))
+		timeout->delta = max_delta;
+
+	return time_greater(&timeout->now, &timeout->end);
+}
+
+static struct timeval *timeout_timeval(struct timeout *timeout)
+{
+	if (timeout->ms == 0)
+		return NULL;
+
+	time_as_timeval(&timeout->delta, &timeout->delta_tv);
+
+	return &timeout->delta_tv;
+}
+
+static unsigned int timeout_remaining_ms(struct timeout *timeout)
+{
+	if (timeout->ms == 0)
+		return -1;
+	else if (timeout->overflow)
+		return INT_MAX;
+	else
+		return time_as_ms(&timeout->delta);
+}
+
+#endif
+
 SP_API enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
 {
 	struct sp_port *port;
@@ -541,7 +663,7 @@ SP_API enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
 		RETURN_CODEVAL(ret);
 	}
 #else
-	int flags_local = O_NONBLOCK | O_NOCTTY;
+	int flags_local = O_NONBLOCK | O_NOCTTY | O_CLOEXEC;
 
 	/* Map 'flags' to the OS-specific settings. */
 	if ((flags & SP_MODE_READ_WRITE) == SP_MODE_READ_WRITE)
@@ -720,7 +842,9 @@ SP_API enum sp_return sp_drain(struct sp_port *port)
 #else
 	int result;
 	while (1) {
-#ifdef __ANDROID__
+#if defined(__ANDROID__) && (__ANDROID_API__ < 21)
+		/* Android only has tcdrain from platform 21 onwards.
+		 * On previous API versions, use the ioctl directly. */
 		int arg = 1;
 		result = ioctl(port->fd, TCSBRK, &arg);
 #else
@@ -819,20 +943,12 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
 #else
 	size_t bytes_written = 0;
 	unsigned char *ptr = (unsigned char *) buf;
-	struct timeval start, delta, now, end = {0, 0};
+	struct timeout timeout;
 	int started = 0;
 	fd_set fds;
 	int result;
 
-	if (timeout_ms) {
-		/* Get time at start of operation. */
-		gettimeofday(&start, NULL);
-		/* Define duration of timeout. */
-		delta.tv_sec = timeout_ms / 1000;
-		delta.tv_usec = (timeout_ms % 1000) * 1000;
-		/* Calculate time at which we should give up. */
-		timeradd(&start, &delta, &end);
-	}
+	timeout_start(&timeout, timeout_ms);
 
 	FD_ZERO(&fds);
 	FD_SET(port->fd, &fds);
@@ -844,14 +960,10 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
 		 * to avoid any issues if a short timeout is reached before
 		 * select() is even run.
 		 */
-		if (timeout_ms && started) {
-			gettimeofday(&now, NULL);
-			if (timercmp(&now, &end, >))
-				/* Timeout has expired. */
-				break;
-			timersub(&end, &now, &delta);
-		}
-		result = select(port->fd + 1, NULL, &fds, NULL, timeout_ms ? &delta : NULL);
+		if (started && timeout_check(&timeout))
+			break;
+
+		result = select(port->fd + 1, NULL, &fds, NULL, timeout_timeval(&timeout));
 		started = 1;
 		if (result < 0) {
 			if (errno == EINTR) {
@@ -1038,21 +1150,13 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
 
 #else
 	size_t bytes_read = 0;
-	unsigned char *ptr = (unsigned char *)buf;
-	struct timeval start, delta, now, end = {0, 0};
+	unsigned char *ptr = (unsigned char *) buf;
+	struct timeout timeout;
 	int started = 0;
 	fd_set fds;
 	int result;
 
-	if (timeout_ms) {
-		/* Get time at start of operation. */
-		gettimeofday(&start, NULL);
-		/* Define duration of timeout. */
-		delta.tv_sec = timeout_ms / 1000;
-		delta.tv_usec = (timeout_ms % 1000) * 1000;
-		/* Calculate time at which we should give up. */
-		timeradd(&start, &delta, &end);
-	}
+	timeout_start(&timeout, timeout_ms);
 
 	FD_ZERO(&fds);
 	FD_SET(port->fd, &fds);
@@ -1064,14 +1168,11 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
 		 * to avoid any issues if a short timeout is reached before
 		 * select() is even run.
 		 */
-		if (timeout_ms && started) {
-			gettimeofday(&now, NULL);
-			if (timercmp(&now, &end, >))
-				/* Timeout has expired. */
-				break;
-			timersub(&end, &now, &delta);
-		}
-		result = select(port->fd + 1, &fds, NULL, NULL, timeout_ms ? &delta : NULL);
+		if (started && timeout_check(&timeout))
+			/* Timeout has expired. */
+			break;
+
+		result = select(port->fd + 1, &fds, NULL, NULL, timeout_timeval(&timeout));
 		started = 1;
 		if (result < 0) {
 			if (errno == EINTR) {
@@ -1176,20 +1277,12 @@ SP_API enum sp_return sp_blocking_read_next(struct sp_port *port, void *buf,
 
 #else
 	size_t bytes_read = 0;
-	struct timeval start, delta, now, end = {0, 0};
+	struct timeout timeout;
 	int started = 0;
 	fd_set fds;
 	int result;
 
-	if (timeout_ms) {
-		/* Get time at start of operation. */
-		gettimeofday(&start, NULL);
-		/* Define duration of timeout. */
-		delta.tv_sec = timeout_ms / 1000;
-		delta.tv_usec = (timeout_ms % 1000) * 1000;
-		/* Calculate time at which we should give up. */
-		timeradd(&start, &delta, &end);
-	}
+	timeout_start(&timeout, timeout_ms);
 
 	FD_ZERO(&fds);
 	FD_SET(port->fd, &fds);
@@ -1201,14 +1294,11 @@ SP_API enum sp_return sp_blocking_read_next(struct sp_port *port, void *buf,
 		 * to avoid any issues if a short timeout is reached before
 		 * select() is even run.
 		 */
-		if (timeout_ms && started) {
-			gettimeofday(&now, NULL);
-			if (timercmp(&now, &end, >))
-				/* Timeout has expired. */
-				break;
-			timersub(&end, &now, &delta);
-		}
-		result = select(port->fd + 1, &fds, NULL, NULL, timeout_ms ? &delta : NULL);
+		if (started && timeout_check(&timeout))
+			/* Timeout has expired. */
+			break;
+
+		result = select(port->fd + 1, &fds, NULL, NULL, timeout_timeval(&timeout));
 		started = 1;
 		if (result < 0) {
 			if (errno == EINTR) {
@@ -1459,12 +1549,8 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
 
 	RETURN_OK();
 #else
-	struct timeval start, delta, now, end = {0, 0};
-	const struct timeval max_delta = {
-		(INT_MAX / 1000), (INT_MAX % 1000) * 1000
-	};
-	int started = 0, timeout_overflow = 0;
-	int result, timeout_remaining_ms;
+	struct timeout timeout;
+	int started = 0, result;
 	struct pollfd *pollfds;
 	unsigned int i;
 
@@ -1483,15 +1569,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
 			pollfds[i].events |= POLLERR;
 	}
 
-	if (timeout_ms) {
-		/* Get time at start of operation. */
-		gettimeofday(&start, NULL);
-		/* Define duration of timeout. */
-		delta.tv_sec = timeout_ms / 1000;
-		delta.tv_usec = (timeout_ms % 1000) * 1000;
-		/* Calculate time at which we should give up. */
-		timeradd(&start, &delta, &end);
-	}
+	timeout_start(&timeout, timeout_ms);
 
 	/* Loop until an event occurs. */
 	while (1) {
@@ -1500,24 +1578,12 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
 		 * to avoid any issues if a short timeout is reached before
 		 * poll() is even run.
 		 */
-		if (!timeout_ms) {
-			timeout_remaining_ms = -1;
-		} else if (!started) {
-			timeout_overflow = (timeout_ms > INT_MAX);
-			timeout_remaining_ms = timeout_overflow ? INT_MAX : timeout_ms;
-		} else {
-			gettimeofday(&now, NULL);
-			if (timercmp(&now, &end, >)) {
-				DEBUG("Wait timed out");
-				break;
-			}
-			timersub(&end, &now, &delta);
-			if ((timeout_overflow = timercmp(&delta, &max_delta, >)))
-				delta = max_delta;
-			timeout_remaining_ms = delta.tv_sec * 1000 + delta.tv_usec / 1000;
+		if (started && timeout_check(&timeout)) {
+			DEBUG("Wait timed out");
+			break;
 		}
 
-		result = poll(pollfds, event_set->count, timeout_remaining_ms);
+		result = poll(pollfds, event_set->count, timeout_remaining_ms(&timeout));
 		started = 1;
 
 		if (result < 0) {
@@ -1530,7 +1596,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
 			}
 		} else if (result == 0) {
 			DEBUG("poll() timed out");
-			if (!timeout_overflow)
+			if (!timeout.overflow)
 				break;
 		} else {
 			DEBUG("poll() completed");