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serialport.c
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/*
* This file is part of the libserialport project.
*
* Copyright (C) 2010-2012 Bert Vermeulen <[email protected]>
* Copyright (C) 2010-2015 Uwe Hermann <[email protected]>
* Copyright (C) 2013-2015 Martin Ling <[email protected]>
* Copyright (C) 2013 Matthias Heidbrink <[email protected]>
* Copyright (C) 2014 Aurelien Jacobs <[email protected]>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "libserialport_internal.h"
static const struct std_baudrate std_baudrates[] = {
#ifdef _WIN32
/*
* The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
* have documented CBR_* macros.
*/
BAUD(110), BAUD(300), BAUD(600), BAUD(1200), BAUD(2400), BAUD(4800),
BAUD(9600), BAUD(14400), BAUD(19200), BAUD(38400), BAUD(57600),
BAUD(115200), BAUD(128000), BAUD(256000),
#else
BAUD(50), BAUD(75), BAUD(110), BAUD(134), BAUD(150), BAUD(200),
BAUD(300), BAUD(600), BAUD(1200), BAUD(1800), BAUD(2400), BAUD(4800),
BAUD(9600), BAUD(19200), BAUD(38400), BAUD(57600), BAUD(115200),
BAUD(230400),
#if !defined(__APPLE__) && !defined(__OpenBSD__)
BAUD(460800),
#endif
#endif
};
#define NUM_STD_BAUDRATES ARRAY_SIZE(std_baudrates)
void (*sp_debug_handler)(const char *format, ...) = sp_default_debug_handler;
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);
SP_API enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
{
struct sp_port *port;
#ifndef NO_PORT_METADATA
enum sp_return ret;
#endif
size_t len;
TRACE("%s, %p", portname, port_ptr);
if (!port_ptr)
RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
*port_ptr = NULL;
if (!portname)
RETURN_ERROR(SP_ERR_ARG, "Null port name");
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");
len = strlen(portname) + 1;
if (!(port->name = malloc(len))) {
free(port);
RETURN_ERROR(SP_ERR_MEM, "Port name malloc failed");
}
memcpy(port->name, portname, len);
#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
port->description = NULL;
port->transport = SP_TRANSPORT_NATIVE;
port->usb_bus = -1;
port->usb_address = -1;
port->usb_vid = -1;
port->usb_pid = -1;
port->usb_manufacturer = NULL;
port->usb_product = NULL;
port->usb_serial = NULL;
port->bluetooth_address = NULL;
#ifndef NO_PORT_METADATA
if ((ret = get_port_details(port)) != SP_OK) {
sp_free_port(port);
return ret;
}
#endif
*port_ptr = port;
RETURN_OK();
}
SP_API char *sp_get_port_name(const struct sp_port *port)
{
TRACE("%p", port);
if (!port)
return NULL;
RETURN_STRING(port->name);
}
SP_API char *sp_get_port_description(const struct sp_port *port)
{
TRACE("%p", port);
if (!port || !port->description)
return NULL;
RETURN_STRING(port->description);
}
SP_API enum sp_transport sp_get_port_transport(const struct sp_port *port)
{
TRACE("%p", port);
RETURN_INT(port ? port->transport : SP_TRANSPORT_NATIVE);
}
SP_API enum sp_return sp_get_port_usb_bus_address(const struct sp_port *port,
int *usb_bus,int *usb_address)
{
TRACE("%p", port);
if (!port)
RETURN_ERROR(SP_ERR_ARG, "Null port");
if (port->transport != SP_TRANSPORT_USB)
RETURN_ERROR(SP_ERR_ARG, "Port does not use USB transport");
if (port->usb_bus < 0 || port->usb_address < 0)
RETURN_ERROR(SP_ERR_SUPP, "Bus and address values are not available");
if (usb_bus)
*usb_bus = port->usb_bus;
if (usb_address)
*usb_address = port->usb_address;
RETURN_OK();
}
SP_API enum sp_return sp_get_port_usb_vid_pid(const struct sp_port *port,
int *usb_vid, int *usb_pid)
{
TRACE("%p", port);
if (!port)
RETURN_ERROR(SP_ERR_ARG, "Null port");
if (port->transport != SP_TRANSPORT_USB)
RETURN_ERROR(SP_ERR_ARG, "Port does not use USB transport");
if (port->usb_vid < 0 || port->usb_pid < 0)
RETURN_ERROR(SP_ERR_SUPP, "VID:PID values are not available");
if (usb_vid)
*usb_vid = port->usb_vid;
if (usb_pid)
*usb_pid = port->usb_pid;
RETURN_OK();
}
SP_API char *sp_get_port_usb_manufacturer(const struct sp_port *port)
{
TRACE("%p", port);
if (!port || port->transport != SP_TRANSPORT_USB || !port->usb_manufacturer)
return NULL;
RETURN_STRING(port->usb_manufacturer);
}
SP_API char *sp_get_port_usb_product(const struct sp_port *port)
{
TRACE("%p", port);
if (!port || port->transport != SP_TRANSPORT_USB || !port->usb_product)
return NULL;
RETURN_STRING(port->usb_product);
}
SP_API char *sp_get_port_usb_serial(const struct sp_port *port)
{
TRACE("%p", port);
if (!port || port->transport != SP_TRANSPORT_USB || !port->usb_serial)
return NULL;
RETURN_STRING(port->usb_serial);
}
SP_API char *sp_get_port_bluetooth_address(const struct sp_port *port)
{
TRACE("%p", port);
if (!port || port->transport != SP_TRANSPORT_BLUETOOTH
|| !port->bluetooth_address)
return NULL;
RETURN_STRING(port->bluetooth_address);
}
SP_API enum sp_return sp_get_port_handle(const struct sp_port *port,
void *result_ptr)
{
TRACE("%p, %p", port, result_ptr);
if (!port)
RETURN_ERROR(SP_ERR_ARG, "Null port");
if (!result_ptr)
RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
#ifdef _WIN32
HANDLE *handle_ptr = result_ptr;
*handle_ptr = port->hdl;
#else
int *fd_ptr = result_ptr;
*fd_ptr = port->fd;
#endif
RETURN_OK();
}
SP_API enum sp_return sp_copy_port(const struct sp_port *port,
struct sp_port **copy_ptr)
{
TRACE("%p, %p", port, copy_ptr);
if (!copy_ptr)
RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
*copy_ptr = NULL;
if (!port)
RETURN_ERROR(SP_ERR_ARG, "Null port");
if (!port->name)
RETURN_ERROR(SP_ERR_ARG, "Null port name");
DEBUG("Copying port structure");
RETURN_INT(sp_get_port_by_name(port->name, copy_ptr));
}
SP_API void sp_free_port(struct sp_port *port)
{
TRACE("%p", port);
if (!port) {
DEBUG("Null port");
RETURN();
}
DEBUG("Freeing port structure");
if (port->name)
free(port->name);
if (port->description)
free(port->description);
if (port->usb_manufacturer)
free(port->usb_manufacturer);
if (port->usb_product)
free(port->usb_product);
if (port->usb_serial)
free(port->usb_serial);
if (port->bluetooth_address)
free(port->bluetooth_address);
#ifdef _WIN32
if (port->usb_path)
free(port->usb_path);
if (port->write_buf)
free(port->write_buf);
#endif
free(port);
RETURN();
}
SP_PRIV struct sp_port **list_append(struct sp_port **list,
const char *portname)
{
void *tmp;
size_t count;
for (count = 0; list[count]; count++)
;
if (!(tmp = realloc(list, sizeof(struct sp_port *) * (count + 2))))
goto fail;
list = tmp;
if (sp_get_port_by_name(portname, &list[count]) != SP_OK)
goto fail;
list[count + 1] = NULL;
return list;
fail:
sp_free_port_list(list);
return NULL;
}
SP_API enum sp_return sp_list_ports(struct sp_port ***list_ptr)
{
#ifndef NO_ENUMERATION
struct sp_port **list;
int ret;
#endif
TRACE("%p", list_ptr);
if (!list_ptr)
RETURN_ERROR(SP_ERR_ARG, "Null result pointer");
*list_ptr = NULL;
#ifdef NO_ENUMERATION
RETURN_ERROR(SP_ERR_SUPP, "Enumeration not supported on this platform");
#else
DEBUG("Enumerating ports");
if (!(list = malloc(sizeof(struct sp_port *))))
RETURN_ERROR(SP_ERR_MEM, "Port list malloc failed");
list[0] = NULL;
ret = list_ports(&list);
if (ret == SP_OK) {
*list_ptr = list;
} else {
sp_free_port_list(list);
*list_ptr = NULL;
}
RETURN_CODEVAL(ret);
#endif
}
SP_API void sp_free_port_list(struct sp_port **list)
{
unsigned int i;
TRACE("%p", list);
if (!list) {
DEBUG("Null list");
RETURN();
}
DEBUG("Freeing port list");
for (i = 0; list[i]; i++)
sp_free_port(list[i]);
free(list);
RETURN();
}
#define CHECK_PORT() do { \
if (!port) \
RETURN_ERROR(SP_ERR_ARG, "Null port"); \
if (!port->name) \
RETURN_ERROR(SP_ERR_ARG, "Null port name"); \
} while (0)
#ifdef _WIN32
#define CHECK_PORT_HANDLE() do { \
if (port->hdl == INVALID_HANDLE_VALUE) \
RETURN_ERROR(SP_ERR_ARG, "Port not open"); \
} while (0)
#else
#define CHECK_PORT_HANDLE() do { \
if (port->fd < 0) \
RETURN_ERROR(SP_ERR_ARG, "Port not open"); \
} while (0)
#endif
#define CHECK_OPEN_PORT() do { \
CHECK_PORT(); \
CHECK_PORT_HANDLE(); \
} while (0)
#ifdef WIN32
/** To be called after port receive buffer is emptied. */
static enum sp_return restart_wait(struct sp_port *port)
{
DWORD wait_result;
if (port->wait_running) {
/* Check status of running wait operation. */
if (GetOverlappedResult(port->hdl, &port->wait_ovl,
&wait_result, FALSE)) {
DEBUG("Previous wait completed");
port->wait_running = FALSE;
} else if (GetLastError() == ERROR_IO_INCOMPLETE) {
DEBUG("Previous wait still running");
RETURN_OK();
} else {
RETURN_FAIL("GetOverlappedResult() failed");
}
}
if (!port->wait_running) {
/* Start new wait operation. */
if (WaitCommEvent(port->hdl, &port->events,
&port->wait_ovl)) {
DEBUG("New wait returned, events already pending");
} else if (GetLastError() == ERROR_IO_PENDING) {
DEBUG("New wait running in background");
port->wait_running = TRUE;
} else {
RETURN_FAIL("WaitCommEvent() failed");
}
}
RETURN_OK();
}
#endif
SP_API enum sp_return sp_open(struct sp_port *port, enum sp_mode flags)
{
struct port_data data;
struct sp_port_config config;
enum sp_return ret;
TRACE("%p, 0x%x", port, flags);
CHECK_PORT();
if (flags > SP_MODE_READ_WRITE)
RETURN_ERROR(SP_ERR_ARG, "Invalid flags");
DEBUG_FMT("Opening port %s", port->name);
#ifdef _WIN32
DWORD desired_access = 0, flags_and_attributes = 0, errors;
char *escaped_port_name;
COMSTAT status;
/* Prefix port name with '\\.\' to work with ports above COM9. */
if (!(escaped_port_name = malloc(strlen(port->name) + 5)))
RETURN_ERROR(SP_ERR_MEM, "Escaped port name malloc failed");
sprintf(escaped_port_name, "\\\\.\\%s", port->name);
/* Map 'flags' to the OS-specific settings. */
flags_and_attributes = FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED;
if (flags & SP_MODE_READ)
desired_access |= GENERIC_READ;
if (flags & SP_MODE_WRITE)
desired_access |= GENERIC_WRITE;
port->hdl = CreateFileA(escaped_port_name, desired_access, 0, 0,
OPEN_EXISTING, flags_and_attributes, 0);
free(escaped_port_name);
if (port->hdl == INVALID_HANDLE_VALUE)
RETURN_FAIL("Port CreateFile() failed");
/* All timeouts initially disabled. */
port->timeouts.ReadIntervalTimeout = 0;
port->timeouts.ReadTotalTimeoutMultiplier = 0;
port->timeouts.ReadTotalTimeoutConstant = 0;
port->timeouts.WriteTotalTimeoutMultiplier = 0;
port->timeouts.WriteTotalTimeoutConstant = 0;
if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) {
sp_close(port);
RETURN_FAIL("SetCommTimeouts() failed");
}
/* Prepare OVERLAPPED structures. */
#define INIT_OVERLAPPED(ovl) do { \
memset(&port->ovl, 0, sizeof(port->ovl)); \
port->ovl.hEvent = INVALID_HANDLE_VALUE; \
if ((port->ovl.hEvent = CreateEvent(NULL, TRUE, TRUE, NULL)) \
== INVALID_HANDLE_VALUE) { \
sp_close(port); \
RETURN_FAIL(#ovl "CreateEvent() failed"); \
} \
} while (0)
INIT_OVERLAPPED(read_ovl);
INIT_OVERLAPPED(write_ovl);
INIT_OVERLAPPED(wait_ovl);
/* Set event mask for RX and error events. */
if (SetCommMask(port->hdl, EV_RXCHAR | EV_ERR) == 0) {
sp_close(port);
RETURN_FAIL("SetCommMask() failed");
}
port->writing = FALSE;
port->wait_running = FALSE;
ret = restart_wait(port);
if (ret < 0) {
sp_close(port);
RETURN_CODEVAL(ret);
}
#else
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)
flags_local |= O_RDWR;
else if (flags & SP_MODE_READ)
flags_local |= O_RDONLY;
else if (flags & SP_MODE_WRITE)
flags_local |= O_WRONLY;
if ((port->fd = open(port->name, flags_local)) < 0)
RETURN_FAIL("open() failed");
/*
* On POSIX in the default case the file descriptor of a serial port
* is not opened exclusively. Therefore the settings of a port are
* overwritten if the serial port is opened a second time. Windows
* opens all serial ports exclusively.
* So the idea is to open the serial ports alike in the exclusive mode.
*
* ioctl(*, TIOCEXCL) defines the file descriptor as exclusive. So all
* further open calls on the serial port will fail.
*
* There is a race condition if two processes open the same serial
* port. None of the processes will notice the exclusive ownership of
* the other process because ioctl() doesn't return an error code if
* the file descriptor is already marked as exclusive.
* This can be solved with flock(). It returns an error if the file
* descriptor is already locked by another process.
*/
#ifdef HAVE_FLOCK
if (flock(port->fd, LOCK_EX | LOCK_NB) < 0)
RETURN_FAIL("flock() failed");
#endif
#ifdef TIOCEXCL
/*
* Before Linux 3.8 ioctl(*, TIOCEXCL) was not implemented and could
* lead to EINVAL or ENOTTY.
* These errors aren't fatal and can be ignored.
*/
if (ioctl(port->fd, TIOCEXCL) < 0 && errno != EINVAL && errno != ENOTTY)
RETURN_FAIL("ioctl() failed");
#endif
#endif
ret = get_config(port, &data, &config);
if (ret < 0) {
sp_close(port);
RETURN_CODEVAL(ret);
}
/* Set sane port settings. */
#ifdef _WIN32
data.dcb.fBinary = TRUE;
data.dcb.fDsrSensitivity = FALSE;
data.dcb.fErrorChar = FALSE;
data.dcb.fNull = FALSE;
data.dcb.fAbortOnError = FALSE;
#else
/* Turn off all fancy termios tricks, give us a raw channel. */
data.term.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IMAXBEL);
#ifdef IUCLC
data.term.c_iflag &= ~IUCLC;
#endif
data.term.c_oflag &= ~(OPOST | ONLCR | OCRNL | ONOCR | ONLRET);
#ifdef OLCUC
data.term.c_oflag &= ~OLCUC;
#endif
#ifdef NLDLY
data.term.c_oflag &= ~NLDLY;
#endif
#ifdef CRDLY
data.term.c_oflag &= ~CRDLY;
#endif
#ifdef TABDLY
data.term.c_oflag &= ~TABDLY;
#endif
#ifdef BSDLY
data.term.c_oflag &= ~BSDLY;
#endif
#ifdef VTDLY
data.term.c_oflag &= ~VTDLY;
#endif
#ifdef FFDLY
data.term.c_oflag &= ~FFDLY;
#endif
#ifdef OFILL
data.term.c_oflag &= ~OFILL;
#endif
data.term.c_lflag &= ~(ISIG | ICANON | ECHO | IEXTEN);
data.term.c_cc[VMIN] = 0;
data.term.c_cc[VTIME] = 0;
/* Ignore modem status lines; enable receiver; leave control lines alone on close. */
data.term.c_cflag |= (CLOCAL | CREAD);
data.term.c_cflag &= ~(HUPCL);
#endif
#ifdef _WIN32
if (ClearCommError(port->hdl, &errors, &status) == 0)
RETURN_FAIL("ClearCommError() failed");
#endif
ret = set_config(port, &data, &config);
if (ret < 0) {
sp_close(port);
RETURN_CODEVAL(ret);
}
RETURN_OK();
}
SP_API enum sp_return sp_close(struct sp_port *port)
{
TRACE("%p", port);
CHECK_OPEN_PORT();
DEBUG_FMT("Closing port %s", port->name);
#ifdef _WIN32
/* Returns non-zero upon success, 0 upon failure. */
if (CloseHandle(port->hdl) == 0)
RETURN_FAIL("Port CloseHandle() failed");
port->hdl = INVALID_HANDLE_VALUE;
/* Close event handles for overlapped structures. */
#define CLOSE_OVERLAPPED(ovl) do { \
if (port->ovl.hEvent != INVALID_HANDLE_VALUE && \
CloseHandle(port->ovl.hEvent) == 0) \
RETURN_FAIL(# ovl "event CloseHandle() failed"); \
} while (0)
CLOSE_OVERLAPPED(read_ovl);
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)
RETURN_FAIL("close() failed");
port->fd = -1;
#endif
RETURN_OK();
}
SP_API enum sp_return sp_flush(struct sp_port *port, enum sp_buffer buffers)
{
TRACE("%p, 0x%x", port, buffers);
CHECK_OPEN_PORT();
if (buffers > SP_BUF_BOTH)
RETURN_ERROR(SP_ERR_ARG, "Invalid buffer selection");
const char *buffer_names[] = {"no", "input", "output", "both"};
DEBUG_FMT("Flushing %s buffers on port %s",
buffer_names[buffers], port->name);
#ifdef _WIN32
DWORD flags = 0;
if (buffers & SP_BUF_INPUT)
flags |= PURGE_RXCLEAR;
if (buffers & SP_BUF_OUTPUT)
flags |= PURGE_TXCLEAR;
/* Returns non-zero upon success, 0 upon failure. */
if (PurgeComm(port->hdl, flags) == 0)
RETURN_FAIL("PurgeComm() failed");
if (buffers & SP_BUF_INPUT)
TRY(restart_wait(port));
#else
int flags = 0;
if (buffers == SP_BUF_BOTH)
flags = TCIOFLUSH;
else if (buffers == SP_BUF_INPUT)
flags = TCIFLUSH;
else if (buffers == SP_BUF_OUTPUT)
flags = TCOFLUSH;
/* Returns 0 upon success, -1 upon failure. */
if (tcflush(port->fd, flags) < 0)
RETURN_FAIL("tcflush() failed");
#endif
RETURN_OK();
}
SP_API enum sp_return sp_drain(struct sp_port *port)
{
TRACE("%p", port);
CHECK_OPEN_PORT();
DEBUG_FMT("Draining port %s", port->name);
#ifdef _WIN32
/* Returns non-zero upon success, 0 upon failure. */
if (FlushFileBuffers(port->hdl) == 0)
RETURN_FAIL("FlushFileBuffers() failed");
RETURN_OK();
#else
int result;
while (1) {
#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
result = tcdrain(port->fd);
#endif
if (result < 0) {
if (errno == EINTR) {
DEBUG("tcdrain() was interrupted");
continue;
} else {
RETURN_FAIL("tcdrain() failed");
}
} else {
RETURN_OK();
}
}
#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)
{
TRACE("%p, %p, %d, %d", port, buf, count, timeout_ms);
CHECK_OPEN_PORT();
if (!buf)
RETURN_ERROR(SP_ERR_ARG, "Null buffer");
if (timeout_ms)
DEBUG_FMT("Writing %d bytes to port %s, timeout %d ms",
count, port->name, timeout_ms);
else
DEBUG_FMT("Writing %d bytes to port %s, no timeout",
count, port->name);
if (count == 0)
RETURN_INT(0);
#ifdef _WIN32
DWORD remaining_ms, write_size, bytes_written;
size_t remaining_bytes, total_bytes_written = 0;
const uint8_t *write_ptr = (uint8_t *) buf;
bool result;
struct timeout timeout;
timeout_start(&timeout, timeout_ms);
TRY(await_write_completion(port));
while (total_bytes_written < count) {
if (timeout_check(&timeout))
break;
remaining_ms = timeout_remaining_ms(&timeout);
if (port->timeouts.WriteTotalTimeoutConstant != remaining_ms) {
port->timeouts.WriteTotalTimeoutConstant = remaining_ms;
if (SetCommTimeouts(port->hdl, &port->timeouts) == 0)
RETURN_FAIL("SetCommTimeouts() failed");
}
/* Reduce write size if it exceeds the WriteFile limit. */
remaining_bytes = count - total_bytes_written;
if (remaining_bytes > WRITEFILE_MAX_SIZE)
write_size = WRITEFILE_MAX_SIZE;
else
write_size = (DWORD) remaining_bytes;
/* Start write. */
result = WriteFile(port->hdl, write_ptr, write_size, NULL, &port->write_ovl);
timeout_update(&timeout);
if (result) {
DEBUG("Write completed immediately");
bytes_written = write_size;
} else if (GetLastError() == ERROR_IO_PENDING) {
DEBUG("Waiting for write to complete");
if (GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE) == 0) {
if (GetLastError() == ERROR_SEM_TIMEOUT) {
DEBUG("Write timed out");
break;
} else {
RETURN_FAIL("GetOverlappedResult() failed");
}
}
DEBUG_FMT("Write completed, %d/%d bytes written", bytes_written, write_size);
} else {
RETURN_FAIL("WriteFile() failed");
}
write_ptr += bytes_written;
total_bytes_written += bytes_written;
}
RETURN_INT((int) total_bytes_written);
#else
size_t bytes_written = 0;
unsigned char *ptr = (unsigned char *) buf;
struct timeout timeout;
fd_set fds;
int result;
timeout_start(&timeout, timeout_ms);
FD_ZERO(&fds);
FD_SET(port->fd, &fds);
/* Loop until we have written the requested number of bytes. */
while (bytes_written < count) {
if (timeout_check(&timeout))
break;
result = select(port->fd + 1, NULL, &fds, NULL, timeout_timeval(&timeout));
timeout_update(&timeout);
if (result < 0) {
if (errno == EINTR) {
DEBUG("select() call was interrupted, repeating");
continue;
} else {
RETURN_FAIL("select() failed");
}
} else if (result == 0) {
/* Timeout has expired. */
break;
}
/* Do write. */
result = write(port->fd, ptr, count - bytes_written);
if (result < 0) {
if (errno == EAGAIN)
/* This shouldn't happen because we did a select() first, but handle anyway. */
continue;
else
/* This is an actual failure. */
RETURN_FAIL("write() failed");
}
bytes_written += result;
ptr += result;
}
if (bytes_written < count)
DEBUG("Write timed out");
RETURN_INT(bytes_written);
#endif
}
SP_API enum sp_return sp_nonblocking_write(struct sp_port *port,
const void *buf, size_t count)
{
TRACE("%p, %p, %d", port, buf, count);
CHECK_OPEN_PORT();
if (!buf)
RETURN_ERROR(SP_ERR_ARG, "Null buffer");
DEBUG_FMT("Writing up to %d bytes to port %s", count, port->name);
if (count == 0)
RETURN_INT(0);
#ifdef _WIN32
size_t buf_bytes;
/* Check whether previous write is complete. */
if (port->writing) {
if (HasOverlappedIoCompleted(&port->write_ovl)) {
DEBUG("Previous write completed");
port->writing = 0;
} else {
DEBUG("Previous write not complete");
/* Can't take a new write until the previous one finishes. */
RETURN_INT(0);
}
}
/* Set timeout. */
if (port->timeouts.WriteTotalTimeoutConstant != 0) {
port->timeouts.WriteTotalTimeoutConstant = 0;
if (SetCommTimeouts(port->hdl, &port->timeouts) == 0)
RETURN_FAIL("SetCommTimeouts() 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, (DWORD) 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 {
/* Actual failure of some kind. */
RETURN_FAIL("WriteFile() failed");
}
}
DEBUG("All bytes written immediately");
RETURN_INT((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) {
if (errno == EAGAIN)
// Buffer is full, no bytes written.
RETURN_INT(0);