X-Git-Url: http://sigrok.org/gitweb/?a=blobdiff_plain;ds=sidebyside;f=serialport.c;h=1b71cdbe59eb47ea84520157e0a9ec6998310979;hb=38b71192dd70336eba219994b0a4219a48e4cbe1;hp=f2d2edcd3b56349feb85e4116defe25f64201ceb;hpb=6aad5bdd474f7d41e06ba4dc094f7db50f0f94cd;p=libserialport.git diff --git a/serialport.c b/serialport.c index f2d2edc..1b71cdb 100644 --- a/serialport.c +++ b/serialport.c @@ -2,8 +2,8 @@ * This file is part of the libserialport project. * * Copyright (C) 2010-2012 Bert Vermeulen - * Copyright (C) 2010-2012 Uwe Hermann - * Copyright (C) 2013 Martin Ling + * Copyright (C) 2010-2015 Uwe Hermann + * Copyright (C) 2013-2015 Martin Ling * Copyright (C) 2013 Matthias Heidbrink * Copyright (C) 2014 Aurelien Jacobs * @@ -21,6 +21,7 @@ * along with this program. If not, see . */ +#include #include "libserialport.h" #include "libserialport_internal.h" @@ -74,6 +75,20 @@ 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"); @@ -334,6 +349,8 @@ SP_API enum sp_return sp_list_ports(struct sp_port ***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 @@ -386,12 +403,12 @@ SP_API void sp_free_port_list(struct sp_port **list) #ifdef _WIN32 #define CHECK_PORT_HANDLE() do { \ if (port->hdl == INVALID_HANDLE_VALUE) \ - RETURN_ERROR(SP_ERR_ARG, "Invalid port handle"); \ + 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, "Invalid port fd"); \ + RETURN_ERROR(SP_ERR_ARG, "Port not open"); \ } while (0) #endif #define CHECK_OPEN_PORT() do { \ @@ -714,6 +731,27 @@ 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) { @@ -736,41 +774,40 @@ 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. */ - port->timeouts.WriteTotalTimeoutConstant = timeout_ms; - if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) - RETURN_FAIL("SetCommTimeouts() failed"); + if (port->timeouts.WriteTotalTimeoutConstant != timeout_ms) { + port->timeouts.WriteTotalTimeoutConstant = timeout_ms; + if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) + RETURN_FAIL("SetCommTimeouts() failed"); + } /* Start write. */ - if (WriteFile(port->hdl, buf, count, NULL, &port->write_ovl) == 0) { - if (GetLastError() == ERROR_IO_PENDING) { - DEBUG("Waiting for write to complete"); - GetOverlappedResult(port->hdl, &port->write_ovl, &bytes_written, TRUE); - DEBUG_FMT("Write completed, %d/%d bytes written", bytes_written, count); - RETURN_INT(bytes_written); - } else { - RETURN_FAIL("WriteFile() failed"); - } - } else { + 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) { + 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 { + RETURN_FAIL("WriteFile() failed"); } #else size_t bytes_written = 0; unsigned char *ptr = (unsigned char *) buf; struct timeval start, delta, now, end = {0, 0}; + int started = 0; fd_set fds; int result; @@ -784,20 +821,25 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, timeradd(&start, &delta, &end); } + FD_ZERO(&fds); + FD_SET(port->fd, &fds); + /* Loop until we have written the requested number of bytes. */ while (bytes_written < count) { - /* Wait until space is available. */ - FD_ZERO(&fds); - FD_SET(port->fd, &fds); - if (timeout_ms) { + /* + * Check timeout only if we have run select() at least once, + * 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, >)) { - DEBUG("Write timed out"); - RETURN_INT(bytes_written); - } + if (timercmp(&now, &end, >)) + /* Timeout has expired. */ + break; timersub(&end, &now, &delta); } result = select(port->fd + 1, NULL, &fds, NULL, timeout_ms ? &delta : NULL); + started = 1; if (result < 0) { if (errno == EINTR) { DEBUG("select() call was interrupted, repeating"); @@ -806,8 +848,8 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, RETURN_FAIL("select() failed"); } } else if (result == 0) { - DEBUG("Write timed out"); - RETURN_INT(bytes_written); + /* Timeout has expired. */ + break; } /* Do write. */ @@ -826,6 +868,9 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf, ptr += result; } + if (bytes_written < count) + DEBUG("Write timed out"); + RETURN_INT(bytes_written); #endif } @@ -862,9 +907,11 @@ SP_API enum sp_return sp_nonblocking_write(struct sp_port *port, } /* Set timeout. */ - port->timeouts.WriteTotalTimeoutConstant = 0; - if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) - RETURN_FAIL("SetCommTimeouts() failed"); + if (port->timeouts.WriteTotalTimeoutConstant != 0) { + port->timeouts.WriteTotalTimeoutConstant = 0; + if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) + RETURN_FAIL("SetCommTimeouts() failed"); + } /* * Keep writing data until the OS has to actually start an async IO @@ -911,6 +958,26 @@ SP_API enum sp_return sp_nonblocking_write(struct sp_port *port, #endif } +#ifdef _WIN32 +/* Restart wait operation if buffer was emptied. */ +static enum sp_return restart_wait_if_needed(struct sp_port *port, unsigned int bytes_read) +{ + DWORD errors; + COMSTAT comstat; + + if (bytes_read == 0) + RETURN_OK(); + + if (ClearCommError(port->hdl, &errors, &comstat) == 0) + RETURN_FAIL("ClearCommError() failed"); + + if (comstat.cbInQue == 0) + TRY(restart_wait(port)); + + RETURN_OK(); +} +#endif + SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t count, unsigned int timeout_ms) { @@ -933,39 +1000,32 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf, #ifdef _WIN32 DWORD bytes_read = 0; - DWORD bytes_remaining; - int ret; /* Set timeout. */ - port->timeouts.ReadIntervalTimeout = 0; - port->timeouts.ReadTotalTimeoutConstant = timeout_ms; - if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) - RETURN_FAIL("SetCommTimeouts() failed"); + if (port->timeouts.ReadIntervalTimeout != 0 || + port->timeouts.ReadTotalTimeoutMultiplier != 0 || + port->timeouts.ReadTotalTimeoutConstant != timeout_ms) { + port->timeouts.ReadIntervalTimeout = 0; + port->timeouts.ReadTotalTimeoutMultiplier = 0; + port->timeouts.ReadTotalTimeoutConstant = timeout_ms; + if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) + RETURN_FAIL("SetCommTimeouts() failed"); + } /* Start read. */ - if (ReadFile(port->hdl, buf, count, NULL, &port->read_ovl) == 0) { - if (GetLastError() == ERROR_IO_PENDING) { - DEBUG("Waiting for read to complete"); - GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE); - DEBUG_FMT("Read completed, %d/%d bytes read", bytes_read, count); - } else { - RETURN_FAIL("ReadFile() failed"); - } - } else { + if (ReadFile(port->hdl, buf, count, NULL, &port->read_ovl)) { DEBUG("Read completed immediately"); bytes_read = count; + } else if (GetLastError() == ERROR_IO_PENDING) { + DEBUG("Waiting for read to complete"); + if (GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE) == 0) + RETURN_FAIL("GetOverlappedResult() failed"); + DEBUG_FMT("Read completed, %d/%d bytes read", bytes_read, count); + } else { + RETURN_FAIL("ReadFile() failed"); } - ret = sp_input_waiting(port); - - if (ret < 0) - RETURN_CODEVAL(ret); - - bytes_remaining = ret; - - /* Restart wait operation if buffer was emptied. */ - if (bytes_read > 0 && bytes_remaining == 0) - TRY(restart_wait(port)); + TRY(restart_wait_if_needed(port, bytes_read)); RETURN_INT(bytes_read); @@ -973,6 +1033,7 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf, size_t bytes_read = 0; unsigned char *ptr = (unsigned char *) buf; struct timeval start, delta, now, end = {0, 0}; + int started = 0; fd_set fds; int result; @@ -986,19 +1047,25 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf, timeradd(&start, &delta, &end); } + FD_ZERO(&fds); + FD_SET(port->fd, &fds); + /* Loop until we have the requested number of bytes. */ while (bytes_read < count) { - /* Wait until data is available. */ - FD_ZERO(&fds); - FD_SET(port->fd, &fds); - if (timeout_ms) { + /* + * Check timeout only if we have run select() at least once, + * 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. */ - RETURN_INT(bytes_read); + break; timersub(&end, &now, &delta); } result = select(port->fd + 1, &fds, NULL, NULL, timeout_ms ? &delta : NULL); + started = 1; if (result < 0) { if (errno == EINTR) { DEBUG("select() call was interrupted, repeating"); @@ -1007,8 +1074,8 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf, RETURN_FAIL("select() failed"); } } else if (result == 0) { - DEBUG("Read timed out"); - RETURN_INT(bytes_read); + /* Timeout has expired. */ + break; } /* Do read. */ @@ -1016,7 +1083,10 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf, if (result < 0) { if (errno == EAGAIN) - /* This shouldn't happen because we did a select() first, but handle anyway. */ + /* + * This shouldn't happen because we did a + * select() first, but handle anyway. + */ continue; else /* This is an actual failure. */ @@ -1027,6 +1097,142 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf, ptr += result; } + if (bytes_read < count) + DEBUG("Read timed out"); + + RETURN_INT(bytes_read); +#endif +} + +SP_API enum sp_return sp_blocking_read_next(struct sp_port *port, 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 (count == 0) + RETURN_ERROR(SP_ERR_ARG, "Zero count"); + + if (timeout_ms) + DEBUG_FMT("Reading next max %d bytes from port %s, timeout %d ms", + count, port->name, timeout_ms); + else + DEBUG_FMT("Reading next max %d bytes from port %s, no timeout", + count, port->name); + +#ifdef _WIN32 + DWORD bytes_read = 0; + + /* If timeout_ms == 0, set maximum timeout. */ + DWORD timeout_val = (timeout_ms == 0 ? MAXDWORD - 1 : timeout_ms); + + /* Set timeout. */ + if (port->timeouts.ReadIntervalTimeout != MAXDWORD || + port->timeouts.ReadTotalTimeoutMultiplier != MAXDWORD || + port->timeouts.ReadTotalTimeoutConstant != timeout_val) { + port->timeouts.ReadIntervalTimeout = MAXDWORD; + port->timeouts.ReadTotalTimeoutMultiplier = MAXDWORD; + port->timeouts.ReadTotalTimeoutConstant = timeout_val; + if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) + RETURN_FAIL("SetCommTimeouts() failed"); + } + + /* Loop until we have at least one byte, or timeout is reached. */ + while (bytes_read == 0) { + /* Start read. */ + if (ReadFile(port->hdl, buf, count, &bytes_read, &port->read_ovl)) { + DEBUG("Read completed immediately"); + } else if (GetLastError() == ERROR_IO_PENDING) { + DEBUG("Waiting for read to complete"); + if (GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE) == 0) + RETURN_FAIL("GetOverlappedResult() failed"); + if (bytes_read > 0) { + DEBUG("Read completed"); + } else if (timeout_ms > 0) { + DEBUG("Read timed out"); + break; + } else { + DEBUG("Restarting read"); + } + } else { + RETURN_FAIL("ReadFile() failed"); + } + } + + TRY(restart_wait_if_needed(port, bytes_read)); + + RETURN_INT(bytes_read); + +#else + size_t bytes_read = 0; + struct timeval start, delta, now, end = {0, 0}; + 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); + } + + FD_ZERO(&fds); + FD_SET(port->fd, &fds); + + /* Loop until we have at least one byte, or timeout is reached. */ + while (bytes_read == 0) { + /* + * Check timeout only if we have run select() at least once, + * 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); + started = 1; + 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 read. */ + result = read(port->fd, buf, count); + + 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("read() failed"); + } + + bytes_read = result; + } + + if (bytes_read == 0) + DEBUG("Read timed out"); + RETURN_INT(bytes_read); #endif } @@ -1045,33 +1251,28 @@ SP_API enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf, #ifdef _WIN32 DWORD bytes_read; - DWORD bytes_remaining; - int ret; /* Set timeout. */ - port->timeouts.ReadIntervalTimeout = MAXDWORD; - port->timeouts.ReadTotalTimeoutConstant = 0; - if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) - RETURN_FAIL("SetCommTimeouts() failed"); + if (port->timeouts.ReadIntervalTimeout != MAXDWORD || + port->timeouts.ReadTotalTimeoutMultiplier != 0 || + port->timeouts.ReadTotalTimeoutConstant != 0) { + port->timeouts.ReadIntervalTimeout = MAXDWORD; + port->timeouts.ReadTotalTimeoutMultiplier = 0; + port->timeouts.ReadTotalTimeoutConstant = 0; + if (SetCommTimeouts(port->hdl, &port->timeouts) == 0) + RETURN_FAIL("SetCommTimeouts() failed"); + } /* Do read. */ if (ReadFile(port->hdl, buf, count, NULL, &port->read_ovl) == 0) - RETURN_FAIL("ReadFile() failed"); + if (GetLastError() != ERROR_IO_PENDING) + RETURN_FAIL("ReadFile() failed"); /* Get number of bytes read. */ - if (GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, TRUE) == 0) + if (GetOverlappedResult(port->hdl, &port->read_ovl, &bytes_read, FALSE) == 0) RETURN_FAIL("GetOverlappedResult() failed"); - ret = sp_input_waiting(port); - - if (ret < 0) - RETURN_CODEVAL(ret); - - bytes_remaining = ret; - - /* Restart wait operation if buffer was emptied. */ - if (bytes_read > 0 && bytes_remaining == 0) - TRY(restart_wait(port)); + TRY(restart_wait_if_needed(port, bytes_read)); RETURN_INT(bytes_read); #else @@ -1252,6 +1453,9 @@ 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 pollfd *pollfds; unsigned int i; @@ -1283,17 +1487,30 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set, /* Loop until an event occurs. */ while (1) { - if (timeout_ms) { + /* + * Check timeout only if we have run poll() at least once, + * 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; } - result = poll(pollfds, event_set->count, timeout_ms ? timeout_remaining_ms : -1); + result = poll(pollfds, event_set->count, timeout_remaining_ms); + started = 1; if (result < 0) { if (errno == EINTR) { @@ -1305,7 +1522,8 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set, } } else if (result == 0) { DEBUG("poll() timed out"); - break; + if (!timeout_overflow) + break; } else { DEBUG("poll() completed"); break; @@ -2285,10 +2503,10 @@ SP_API char *sp_last_error_message(void) TRACE_VOID(); #ifdef _WIN32 - LPVOID message; + TCHAR *message; DWORD error = GetLastError(); - FormatMessage( + DWORD length = FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, @@ -2298,6 +2516,9 @@ SP_API char *sp_last_error_message(void) (LPTSTR) &message, 0, NULL ); + if (length >= 2 && message[length - 2] == '\r') + message[length - 2] = '\0'; + RETURN_STRING(message); #else RETURN_STRING(strerror(errno));