X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;f=serialport.c;h=07a0aaa54b915fac58053e83c7541c55de925c89;hb=573feabc63340ef853108762682dce8aa4644cb5;hp=fb603b3edc97c0a5e317b80df7ca870633113792;hpb=888fb45d66aada134f36fa9129499ec180161c0a;p=libserialport.git

diff --git a/serialport.c b/serialport.c
index fb603b3..07a0aaa 100644
--- a/serialport.c
+++ b/serialport.c
@@ -49,12 +49,19 @@ static const struct std_baudrate std_baudrates[] = {
 
 void (*sp_debug_handler)(const char *format, ...) = sp_default_debug_handler;
 
+static void get_time(struct timeval *time);
+
 static enum sp_return get_config(struct sp_port *port, struct port_data *data,
 	struct sp_port_config *config);
 
 static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 	const struct sp_port_config *config);
 
+static void get_time(struct timeval *time)
+{
+	gettimeofday(time, NULL);
+}
+
 SP_API enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
 {
 	struct sp_port *port;
@@ -75,6 +82,20 @@ SP_API enum sp_return sp_get_port_by_name(const char *portname, struct sp_port *
 
 	DEBUG_FMT("Building structure for port %s", portname);
 
+#if !defined(_WIN32) && defined(HAVE_REALPATH)
+	/*
+	 * get_port_details() below tries to be too smart and figure out
+	 * some transport properties from the port name which breaks with
+	 * symlinks. Therefore we canonicalize the portname first.
+	 */
+	char pathbuf[PATH_MAX + 1];
+	char *res = realpath(portname, pathbuf);
+	if (!res)
+		RETURN_ERROR(SP_ERR_ARG, "Could not retrieve realpath behind port name");
+
+	portname = pathbuf;
+#endif
+
 	if (!(port = malloc(sizeof(struct sp_port))))
 		RETURN_ERROR(SP_ERR_MEM, "Port structure malloc failed");
 
@@ -90,6 +111,8 @@ SP_API enum sp_return sp_get_port_by_name(const char *portname, struct sp_port *
 #ifdef _WIN32
 	port->usb_path = NULL;
 	port->hdl = INVALID_HANDLE_VALUE;
+	port->write_buf = NULL;
+	port->write_buf_size = 0;
 #else
 	port->fd = -1;
 #endif
@@ -296,6 +319,8 @@ SP_API void sp_free_port(struct sp_port *port)
 #ifdef _WIN32
 	if (port->usb_path)
 		free(port->usb_path);
+	if (port->write_buf)
+		free(port->write_buf);
 #endif
 
 	free(port);
@@ -309,7 +334,8 @@ SP_PRIV struct sp_port **list_append(struct sp_port **list,
 	void *tmp;
 	unsigned int count;
 
-	for (count = 0; list[count]; count++);
+	for (count = 0; list[count]; count++)
+		;
 	if (!(tmp = realloc(list, sizeof(struct sp_port *) * (count + 2))))
 		goto fail;
 	list = tmp;
@@ -628,6 +654,10 @@ SP_API enum sp_return sp_close(struct sp_port *port)
 	CLOSE_OVERLAPPED(write_ovl);
 	CLOSE_OVERLAPPED(wait_ovl);
 
+	if (port->write_buf) {
+		free(port->write_buf);
+		port->write_buf = NULL;
+	}
 #else
 	/* Returns 0 upon success, -1 upon failure. */
 	if (close(port->fd) == -1)
@@ -717,6 +747,27 @@ SP_API enum sp_return sp_drain(struct sp_port *port)
 #endif
 }
 
+#ifdef _WIN32
+static enum sp_return await_write_completion(struct sp_port *port)
+{
+	TRACE("%p", port);
+	DWORD bytes_written;
+	BOOL result;
+
+	/* Wait for previous non-blocking write to complete, if any. */
+	if (port->writing) {
+		DEBUG("Waiting for previous write to complete");
+		result = GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE);
+		port->writing = 0;
+		if (!result)
+			RETURN_FAIL("Previous write failed to complete");
+		DEBUG("Previous write completed");
+	}
+
+	RETURN_OK();
+}
+#endif
+
 SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
                                         size_t count, unsigned int timeout_ms)
 {
@@ -739,17 +790,8 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
 
 #ifdef _WIN32
 	DWORD bytes_written = 0;
-	BOOL result;
 
-	/* Wait for previous non-blocking write to complete, if any. */
-	if (port->writing) {
-		DEBUG("Waiting for previous write to complete");
-		result = GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE);
-		port->writing = 0;
-		if (!result)
-			RETURN_FAIL("Previous write failed to complete");
-		DEBUG("Previous write completed");
-	}
+	TRY(await_write_completion(port));
 
 	/* Set timeout. */
 	if (port->timeouts.WriteTotalTimeoutConstant != timeout_ms) {
@@ -758,14 +800,24 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
 			RETURN_FAIL("SetCommTimeouts() failed");
 	}
 
+	/* Reduce count if it exceeds the WriteFile limit. */
+	if (count > WRITEFILE_MAX_SIZE)
+		count = WRITEFILE_MAX_SIZE;
+
 	/* Start write. */
 	if (WriteFile(port->hdl, buf, count, NULL, &port->write_ovl)) {
 		DEBUG("Write completed immediately");
 		RETURN_INT(count);
 	} else if (GetLastError() == ERROR_IO_PENDING) {
 		DEBUG("Waiting for write to complete");
-		if (GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE) == 0)
-			RETURN_FAIL("GetOverlappedResult() failed");
+		if (GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE) == 0) {
+			if (GetLastError() == ERROR_SEM_TIMEOUT) {
+				DEBUG("Write timed out");
+				RETURN_INT(0);
+			} else {
+				RETURN_FAIL("GetOverlappedResult() failed");
+			}
+		}
 		DEBUG_FMT("Write completed, %d/%d bytes written", bytes_written, count);
 		RETURN_INT(bytes_written);
 	} else {
@@ -781,7 +833,7 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
 
 	if (timeout_ms) {
 		/* Get time at start of operation. */
-		gettimeofday(&start, NULL);
+		get_time(&start);
 		/* Define duration of timeout. */
 		delta.tv_sec = timeout_ms / 1000;
 		delta.tv_usec = (timeout_ms % 1000) * 1000;
@@ -800,7 +852,7 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
 		 * select() is even run.
 		 */
 		if (timeout_ms && started) {
-			gettimeofday(&now, NULL);
+			get_time(&now);
 			if (timercmp(&now, &end, >))
 				/* Timeout has expired. */
 				break;
@@ -859,8 +911,7 @@ SP_API enum sp_return sp_nonblocking_write(struct sp_port *port,
 		RETURN_INT(0);
 
 #ifdef _WIN32
-	DWORD written = 0;
-	BYTE *ptr = (BYTE *) buf;
+	DWORD buf_bytes;
 
 	/* Check whether previous write is complete. */
 	if (port->writing) {
@@ -881,48 +932,43 @@ SP_API enum sp_return sp_nonblocking_write(struct sp_port *port,
 			RETURN_FAIL("SetCommTimeouts() failed");
 	}
 
-	/*
-	 * Keep writing data until the OS has to actually start an async IO
-	 * for it. At that point we know the buffer is full.
-	 */
-	while (written < count) {
-		/* Copy first byte of user buffer. */
-		port->pending_byte = *ptr++;
-
-		/* Start asynchronous write. */
-		if (WriteFile(port->hdl, &port->pending_byte, 1, NULL, &port->write_ovl) == 0) {
-			if (GetLastError() == ERROR_IO_PENDING) {
-				if (HasOverlappedIoCompleted(&port->write_ovl)) {
-					DEBUG("Asynchronous write completed immediately");
-					port->writing = 0;
-					written++;
-					continue;
-				} else {
-					DEBUG("Asynchronous write running");
-					port->writing = 1;
-					RETURN_INT(++written);
-				}
-			} else {
-				/* Actual failure of some kind. */
-				RETURN_FAIL("WriteFile() failed");
-			}
+	/* Reduce count if it exceeds the WriteFile limit. */
+	if (count > WRITEFILE_MAX_SIZE)
+		count = WRITEFILE_MAX_SIZE;
+
+	/* Copy data to our write buffer. */
+	buf_bytes = min(port->write_buf_size, count);
+	memcpy(port->write_buf, buf, buf_bytes);
+
+	/* Start asynchronous write. */
+	if (WriteFile(port->hdl, port->write_buf, buf_bytes, NULL, &port->write_ovl) == 0) {
+		if (GetLastError() == ERROR_IO_PENDING) {
+			if ((port->writing = !HasOverlappedIoCompleted(&port->write_ovl)))
+				DEBUG("Asynchronous write completed immediately");
+			else
+				DEBUG("Asynchronous write running");
 		} else {
-			DEBUG("Single byte written immediately");
-			written++;
+			/* Actual failure of some kind. */
+			RETURN_FAIL("WriteFile() failed");
 		}
 	}
 
 	DEBUG("All bytes written immediately");
 
-	RETURN_INT(written);
+	RETURN_INT(buf_bytes);
 #else
 	/* Returns the number of bytes written, or -1 upon failure. */
 	ssize_t written = write(port->fd, buf, count);
 
-	if (written < 0)
-		RETURN_FAIL("write() failed");
-	else
+	if (written < 0) {
+		if (errno == EAGAIN)
+			// Buffer is full, no bytes written.
+			RETURN_INT(0);
+		else
+			RETURN_FAIL("write() failed");
+	} else {
 		RETURN_INT(written);
+	}
 #endif
 }
 
@@ -999,7 +1045,7 @@ 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;
+	unsigned char *ptr = (unsigned char *)buf;
 	struct timeval start, delta, now, end = {0, 0};
 	int started = 0;
 	fd_set fds;
@@ -1007,7 +1053,7 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
 
 	if (timeout_ms) {
 		/* Get time at start of operation. */
-		gettimeofday(&start, NULL);
+		get_time(&start);
 		/* Define duration of timeout. */
 		delta.tv_sec = timeout_ms / 1000;
 		delta.tv_usec = (timeout_ms % 1000) * 1000;
@@ -1026,7 +1072,7 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
 		 * select() is even run.
 		 */
 		if (timeout_ms && started) {
-			gettimeofday(&now, NULL);
+			get_time(&now);
 			if (timercmp(&now, &end, >))
 				/* Timeout has expired. */
 				break;
@@ -1144,7 +1190,7 @@ SP_API enum sp_return sp_blocking_read_next(struct sp_port *port, void *buf,
 
 	if (timeout_ms) {
 		/* Get time at start of operation. */
-		gettimeofday(&start, NULL);
+		get_time(&start);
 		/* Define duration of timeout. */
 		delta.tv_sec = timeout_ms / 1000;
 		delta.tv_usec = (timeout_ms % 1000) * 1000;
@@ -1163,7 +1209,7 @@ SP_API enum sp_return sp_blocking_read_next(struct sp_port *port, void *buf,
 		 * select() is even run.
 		 */
 		if (timeout_ms && started) {
-			gettimeofday(&now, NULL);
+			get_time(&now);
 			if (timercmp(&now, &end, >))
 				/* Timeout has expired. */
 				break;
@@ -1422,7 +1468,8 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
 #else
 	struct timeval start, delta, now, end = {0, 0};
 	const struct timeval max_delta = {
-		(INT_MAX / 1000), (INT_MAX % 1000) * 1000};
+		(INT_MAX / 1000), (INT_MAX % 1000) * 1000
+	};
 	int started = 0, timeout_overflow = 0;
 	int result, timeout_remaining_ms;
 	struct pollfd *pollfds;
@@ -1432,7 +1479,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
 		RETURN_ERROR(SP_ERR_MEM, "pollfds malloc() failed");
 
 	for (i = 0; i < event_set->count; i++) {
-		pollfds[i].fd = ((int *) event_set->handles)[i];
+		pollfds[i].fd = ((int *)event_set->handles)[i];
 		pollfds[i].events = 0;
 		pollfds[i].revents = 0;
 		if (event_set->masks[i] & SP_EVENT_RX_READY)
@@ -1445,7 +1492,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
 
 	if (timeout_ms) {
 		/* Get time at start of operation. */
-		gettimeofday(&start, NULL);
+		get_time(&start);
 		/* Define duration of timeout. */
 		delta.tv_sec = timeout_ms / 1000;
 		delta.tv_usec = (timeout_ms % 1000) * 1000;
@@ -1466,7 +1513,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
 			timeout_overflow = (timeout_ms > INT_MAX);
 			timeout_remaining_ms = timeout_overflow ? INT_MAX : timeout_ms;
 		} else {
-			gettimeofday(&now, NULL);
+			get_time(&now);
 			if (timercmp(&now, &end, >)) {
 				DEBUG("Wait timed out");
 				break;
@@ -1842,6 +1889,9 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 	DEBUG_FMT("Setting configuration for port %s", port->name);
 
 #ifdef _WIN32
+
+	TRY(await_write_completion(port));
+
 	if (config->baudrate >= 0) {
 		for (i = 0; i < NUM_STD_BAUDRATES; i++) {
 			if (config->baudrate == std_baudrates[i].value) {
@@ -1852,6 +1902,14 @@ static enum sp_return set_config(struct sp_port *port, struct port_data *data,
 
 		if (i == NUM_STD_BAUDRATES)
 			data->dcb.BaudRate = config->baudrate;
+
+		/* Allocate write buffer for 50ms of data at baud rate. */
+		port->write_buf_size = max(config->baudrate / (8 * 20), 1);
+		port->write_buf = realloc(port->write_buf,
+					  port->write_buf_size);
+
+		if (!port->write_buf)
+			RETURN_ERROR(SP_ERR_MEM, "Allocating write buffer failed");
 	}
 
 	if (config->bits >= 0)