Move repetitive timeout code into helper functions.
This commit is contained in:
Martin Ling
parent
9a7945af84
commit
32dbe2d298
170
serialport.c
170
serialport.c
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@ -63,9 +63,18 @@ struct time {
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struct timeval tv;
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};
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struct timeout {
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unsigned int ms;
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struct time start, delta, now, end;
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struct timeval delta_tv;
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bool overflow;
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};
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#define TIME_ZERO {.tv = {0, 0}}
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#define TIME_MS(ms) {.tv = {ms / 1000, (ms % 1000) * 1000}}
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const struct time max_delta = TIME_MS(INT_MAX);
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static void time_get(struct time *time)
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{
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#ifdef HAVE_CLOCK_GETTIME
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@ -119,6 +128,53 @@ static unsigned int time_as_ms(const struct time *time)
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return time->tv.tv_sec * 1000 + time->tv.tv_usec / 1000;
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}
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static void timeout_start(struct timeout *timeout, unsigned int timeout_ms)
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{
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timeout->ms = timeout_ms;
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timeout->overflow = (timeout->ms > INT_MAX);
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/* Get time at start of operation. */
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time_get(&timeout->start);
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/* Define duration of timeout. */
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time_set_ms(&timeout->delta, timeout_ms);
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/* Calculate time at which we should give up. */
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time_add(&timeout->start, &timeout->delta, &timeout->end);
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}
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static bool timeout_check(struct timeout *timeout)
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{
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if (timeout->ms == 0)
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return false;
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time_get(&timeout->now);
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time_sub(&timeout->end, &timeout->now, &timeout->delta);
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if ((timeout->overflow = time_greater(&timeout->delta, &max_delta)))
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timeout->delta = max_delta;
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return time_greater(&timeout->now, &timeout->end);
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}
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static struct timeval *timeout_timeval(struct timeout *timeout)
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{
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if (timeout->ms == 0)
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return NULL;
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time_as_timeval(&timeout->delta, &timeout->delta_tv);
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return &timeout->delta_tv;
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}
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static unsigned int timeout_remaining_ms(struct timeout *timeout)
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{
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if (timeout->ms == 0)
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return -1;
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else if (timeout->overflow)
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return INT_MAX;
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else
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return time_as_ms(&timeout->delta);
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}
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#endif
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SP_API enum sp_return sp_get_port_by_name(const char *portname, struct sp_port **port_ptr)
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@ -887,19 +943,12 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
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#else
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size_t bytes_written = 0;
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unsigned char *ptr = (unsigned char *) buf;
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struct time start, delta, now, end = TIME_ZERO;
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struct timeout timeout;
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int started = 0;
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fd_set fds;
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int result;
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if (timeout_ms) {
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/* Get time at start of operation. */
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time_get(&start);
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/* Define duration of timeout. */
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time_set_ms(&delta, timeout_ms);
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/* Calculate time at which we should give up. */
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time_add(&start, &delta, &end);
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}
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timeout_start(&timeout, timeout_ms);
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FD_ZERO(&fds);
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FD_SET(port->fd, &fds);
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@ -911,16 +960,10 @@ SP_API enum sp_return sp_blocking_write(struct sp_port *port, const void *buf,
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* to avoid any issues if a short timeout is reached before
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* select() is even run.
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*/
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struct timeval tv;
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if (timeout_ms && started) {
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time_get(&now);
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if (time_greater(&now, &end))
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/* Timeout has expired. */
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break;
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time_sub(&end, &now, &delta);
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time_as_timeval(&delta, &tv);
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}
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result = select(port->fd + 1, NULL, &fds, NULL, timeout_ms ? &tv : NULL);
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if (started && timeout_check(&timeout))
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break;
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result = select(port->fd + 1, NULL, &fds, NULL, timeout_timeval(&timeout));
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started = 1;
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if (result < 0) {
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if (errno == EINTR) {
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@ -1108,19 +1151,12 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
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#else
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size_t bytes_read = 0;
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unsigned char *ptr = (unsigned char *) buf;
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struct time start, delta, now, end = TIME_ZERO;
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struct timeout timeout;
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int started = 0;
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fd_set fds;
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int result;
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if (timeout_ms) {
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/* Get time at start of operation. */
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time_get(&start);
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/* Define duration of timeout. */
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time_set_ms(&delta, timeout_ms);
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/* Calculate time at which we should give up. */
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time_add(&start, &delta, &end);
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}
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timeout_start(&timeout, timeout_ms);
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FD_ZERO(&fds);
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FD_SET(port->fd, &fds);
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@ -1132,16 +1168,11 @@ SP_API enum sp_return sp_blocking_read(struct sp_port *port, void *buf,
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* to avoid any issues if a short timeout is reached before
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* select() is even run.
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*/
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struct timeval tv;
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if (timeout_ms && started) {
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time_get(&now);
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if (time_greater(&now, &end))
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/* Timeout has expired. */
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break;
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time_sub(&end, &now, &delta);
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time_as_timeval(&delta, &tv);
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}
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result = select(port->fd + 1, &fds, NULL, NULL, timeout_ms ? &tv : NULL);
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if (started && timeout_check(&timeout))
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/* Timeout has expired. */
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break;
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result = select(port->fd + 1, &fds, NULL, NULL, timeout_timeval(&timeout));
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started = 1;
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if (result < 0) {
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if (errno == EINTR) {
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@ -1246,19 +1277,12 @@ SP_API enum sp_return sp_blocking_read_next(struct sp_port *port, void *buf,
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#else
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size_t bytes_read = 0;
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struct time start, delta, now, end = TIME_ZERO;
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struct timeout timeout;
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int started = 0;
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fd_set fds;
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int result;
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if (timeout_ms) {
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/* Get time at start of operation. */
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time_get(&start);
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/* Define duration of timeout. */
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time_set_ms(&delta, timeout_ms);
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/* Calculate time at which we should give up. */
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time_add(&start, &delta, &end);
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}
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timeout_start(&timeout, timeout_ms);
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FD_ZERO(&fds);
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FD_SET(port->fd, &fds);
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@ -1270,16 +1294,11 @@ SP_API enum sp_return sp_blocking_read_next(struct sp_port *port, void *buf,
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* to avoid any issues if a short timeout is reached before
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* select() is even run.
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*/
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struct timeval tv;
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if (timeout_ms && started) {
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time_get(&now);
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if (time_greater(&now, &end))
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/* Timeout has expired. */
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break;
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time_sub(&end, &now, &delta);
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time_as_timeval(&delta, &tv);
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}
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result = select(port->fd + 1, &fds, NULL, NULL, timeout_ms ? &tv : NULL);
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if (started && timeout_check(&timeout))
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/* Timeout has expired. */
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break;
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result = select(port->fd + 1, &fds, NULL, NULL, timeout_timeval(&timeout));
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started = 1;
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if (result < 0) {
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if (errno == EINTR) {
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@ -1530,10 +1549,8 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
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RETURN_OK();
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#else
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struct time start, delta, now, end = TIME_ZERO;
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const struct time max_delta = TIME_MS(INT_MAX);
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int started = 0, timeout_overflow = 0;
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int result, timeout_remaining_ms;
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struct timeout timeout;
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int started = 0, result;
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struct pollfd *pollfds;
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unsigned int i;
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@ -1552,14 +1569,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
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pollfds[i].events |= POLLERR;
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}
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if (timeout_ms) {
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/* Get time at start of operation. */
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time_get(&start);
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/* Define duration of timeout. */
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time_set_ms(&delta, timeout_ms);
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/* Calculate time at which we should give up. */
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time_add(&start, &delta, &end);
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}
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timeout_start(&timeout, timeout_ms);
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/* Loop until an event occurs. */
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while (1) {
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@ -1568,24 +1578,12 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
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* to avoid any issues if a short timeout is reached before
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* poll() is even run.
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*/
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if (!timeout_ms) {
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timeout_remaining_ms = -1;
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} else if (!started) {
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timeout_overflow = (timeout_ms > INT_MAX);
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timeout_remaining_ms = timeout_overflow ? INT_MAX : timeout_ms;
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} else {
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time_get(&now);
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if (time_greater(&now, &end)) {
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DEBUG("Wait timed out");
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break;
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}
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time_sub(&end, &now, &delta);
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if ((timeout_overflow = time_greater(&delta, &max_delta)))
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delta = max_delta;
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timeout_remaining_ms = time_as_ms(&delta);
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if (started && timeout_check(&timeout)) {
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DEBUG("Wait timed out");
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break;
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}
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result = poll(pollfds, event_set->count, timeout_remaining_ms);
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result = poll(pollfds, event_set->count, timeout_remaining_ms(&timeout));
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started = 1;
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if (result < 0) {
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@ -1598,7 +1596,7 @@ SP_API enum sp_return sp_wait(struct sp_event_set *event_set,
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}
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} else if (result == 0) {
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DEBUG("poll() timed out");
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if (!timeout_overflow)
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if (!timeout.overflow)
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break;
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} else {
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DEBUG("poll() completed");
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