SWrite.c

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#include "syshdrs.h"
 
#ifndef NO_SIGNALS
extern volatile Sjmp_buf gNetTimeoutJmp;
extern volatile Sjmp_buf gPipeJmp;
#endif
 
#ifndef NO_SIGNALS
 
int
SWrite(int sfd, const char *const buf0, size_t size, int tlen, int swopts)
{
    volatile int nleft;
    const char *volatile buf = buf0;
    int nwrote, tleft;
    vsio_sigproc_t sigalrm, sigpipe;
    time_t done, now;
 
    if (SSetjmp(gNetTimeoutJmp) != 0) {
        alarm(0);
        (void) SSignal(SIGALRM, (sio_sigproc_t) sigalrm);
        (void) SSignal(SIGPIPE, (sio_sigproc_t) sigpipe);
        nwrote = size - nleft;
        if (nwrote > 0)
            return (nwrote);
        errno = ETIMEDOUT;
        return (kTimeoutErr);
    }
 
    if (SSetjmp(gPipeJmp) != 0) {
        alarm(0);
        (void) SSignal(SIGALRM, (sio_sigproc_t) sigalrm);
        (void) SSignal(SIGPIPE, (sio_sigproc_t) sigpipe);
        nwrote = size - nleft;
        if (nwrote > 0)
            return (nwrote);
        errno = EPIPE;
        return (kBrokenPipeErr);
    }
 
    sigalrm = (vsio_sigproc_t) SSignal(SIGALRM, SIOHandler);
    sigpipe = (vsio_sigproc_t) SSignal(SIGPIPE, SIOHandler);
 
    nleft = (int) size;
    time(&now);
    done = now + tlen;
    forever {
        tleft = (int) (done - now);
        if (tleft < 1) {
            nwrote = size - nleft;
            if (nwrote == 0) {
                nwrote = kTimeoutErr;
                errno = ETIMEDOUT;
            }
            goto done;
        }
        (void) alarm((unsigned int) tleft);
        nwrote = write(sfd, buf, nleft);
        (void) alarm(0);
        if (nwrote < 0) {
            if (errno != EINTR) {
                nwrote = size - nleft;
                if (nwrote == 0)
                    nwrote = -1;
                goto done;
            } else {
                errno = 0;
                nwrote = 0;
                /* Try again. */
            }
        }
        nleft -= nwrote;
        if (nleft <= 0)
            break;
        buf += nwrote;
        time(&now);
    }
    nwrote = size - nleft;
 
done:
    (void) SSignal(SIGALRM, (sio_sigproc_t) sigalrm);
    (void) SSignal(SIGPIPE, (sio_sigproc_t) sigpipe);
 
    return (nwrote);
}   /* SWrite */
 
#else
 
int
SWrite(int sfd, const char *const buf0, size_t size, int tlen, int swopts)
{
    int nleft;
    const char *buf = buf0;
    int nwrote, tleft;
    time_t done, now;
    fd_set ss;
    struct timeval tv;
    int result, firstWrite;
 
    nleft = (int) size;
    time(&now);
    done = now + tlen;
    firstWrite = 1;
 
    forever {
        tleft = (int) (done - now);
        if (tleft < 1) {
            nwrote = size - nleft;
            if (nwrote == 0) {
                nwrote = kTimeoutErr;
                errno = ETIMEDOUT;
                SETWSATIMEOUTERR
            }
            goto done;
        }
 
 
        /* Unfortunately this doesn't help when the
         * send buffer fills during the time we're
         * writing to it, so you could still be
         * blocked after breaking this loop and starting
         * the write.
         */
        if (!firstWrite || ((swopts & kNoFirstSelect) == 0)) {
            forever {
                errno = 0;
                FD_ZERO(&ss);
                FD_SET(sfd, &ss);
                tv.tv_sec = tlen;
                tv.tv_usec = 0;
                result = select(sfd + 1, NULL, SELECT_TYPE_ARG234 &ss, NULL, SELECT_TYPE_ARG5 &tv);
                if (result == 1) {
                    /* ready */
                    break;
                } else if (result == 0) {
                    /* timeout */
                    nwrote = size - nleft;
                    if (nwrote > 0)
                        return (nwrote);
                    errno = ETIMEDOUT;
                    SETWSATIMEOUTERR
                        return (kTimeoutErr);
                } else if (errno != EINTR) {
                    return (-1);
                }
            }
            firstWrite = 0;
        }
 
#if defined(WIN32) || defined(_WINDOWS)
        nwrote = send(sfd, buf, size, 0);
#else
        nwrote = write(sfd, buf, size);
#endif
 
        if (nwrote < 0) {
            if (errno != EINTR) {
                nwrote = size - nleft;
                if (nwrote == 0)
                    nwrote = -1;
                goto done;
            } else {
                errno = 0;
                nwrote = 0;
                /* Try again. */
            }
        }
        nleft -= nwrote;
        if (nleft <= 0)
            break;
        buf += nwrote;
        time(&now);
    }
    nwrote = size - nleft;
 
done:
    return (nwrote);
}   /* SWrite */
 
#endif