windows: Always check and set ReadTotalTimeoutMultiplier.

[libserialport.git] / serialport.c

diff --git a/serialport.c b/serialport.c
index 35b6ac54fe20b067701be9d212f4d864de2e2df8..fb7adf65eb0aa7efb4f9b9260d96d81d74bd2722 100644 (file)
--- a/serialport.c
+++ b/serialport.c
@@ -774,6 +774,7 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
        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;
 
@@ -792,16 +793,20 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
 
        /* Loop until we have written the requested number of bytes. */
        while (bytes_written < count) {
-               /* Wait until space is available. */
-               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");
@@ -810,8 +815,8 @@ 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. */
@@ -830,6 +835,9 @@ 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
 }
@@ -962,8 +970,10 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
 
        /* Set timeout. */
        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");
@@ -990,6 +1000,7 @@ 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;
 
@@ -1008,15 +1019,20 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
 
        /* Loop until we have the requested number of bytes. */
        while (bytes_read < count) {
-               /* Wait until data is available. */
-               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");
@@ -1025,8 +1041,8 @@ 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. */
@@ -1034,7 +1050,10 @@ 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. */
@@ -1045,6 +1064,9 @@ 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
 }
@@ -1066,8 +1088,10 @@ SP_API enum sp_return sp_nonblocking_read(struct sp_port *port, void *buf,
 
        /* Set timeout. */
        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");
@@ -1262,6 +1286,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
        RETURN_OK();
 #else
        struct timeval start, delta, now, end = {0, 0};
+       int started = 0;
        int result, timeout_remaining_ms;
        struct pollfd *pollfds;
        unsigned int i;
@@ -1293,7 +1318,12 @@ 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 && started) {
                        gettimeofday(&now, NULL);
                        if (timercmp(&now, &end, >)) {
                                DEBUG("Wait timed out");
@@ -1304,6 +1334,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
                }
 
                result = poll(pollfds, event_set->count, timeout_ms ? timeout_remaining_ms : -1);
+               started = 1;
 
                if (result < 0) {
                        if (errno == EINTR) {