static void monitor_requests(struct sched_ent *alarm)
{
if (config.debug.dnahelper) {
DEBUGF("sched_requests.poll.fd=%d .revents=%s",
sched_requests.poll.fd,
strbuf_str(strbuf_append_poll_events(strbuf_alloca(40), sched_requests.poll.revents))
);
}
assert(alarm == &sched_requests);
// On Linux, poll(2) returns ERR when the remote reader dies. On Mac OS X, poll(2) returns NVAL,
// which is documented to mean the file descriptor is not open, but testing revealed that in this
// case it is still open. See issue #5.
if (sched_requests.poll.revents & (POLLHUP | POLLERR | POLLNVAL)) {
if (config.debug.dnahelper)
DEBUGF("DNAHELPER closing stdin fd=%d", dna_helper_stdin);
close(dna_helper_stdin);
dna_helper_stdin = -1;
unwatch(&sched_requests);
sched_requests.poll.fd = -1;
dna_helper_kill();
}
else if (sched_requests.poll.revents & POLLOUT) {
if (request_bufptr) {
if (request_bufptr < request_bufend) {
size_t remaining = request_bufend - request_bufptr;
sigPipeFlag = 0;
ssize_t written = write_nonblock(dna_helper_stdin, request_bufptr, remaining);
if (sigPipeFlag) {
/* Broken pipe is probably due to a dead helper, but make sure the helper is dead, just to be
sure. It will be harvested at the next harvester() timeout, and restarted on the first
request that arrives after a suitable pause has elapsed. Losing the current request is not
a big problem, because DNA preemptively retries.
*/
INFO("DNAHELPER got SIGPIPE on write -- stopping process");
dna_helper_kill();
} else if (written > 0) {
if (config.debug.dnahelper)
DEBUGF("DNAHELPER wrote request %s", alloca_toprint(-1, request_bufptr, written));
request_bufptr += written;
}
}
if (request_bufptr >= request_bufend) {
// Request sent successfully. Start watching for reply.
request_bufptr = request_bufend = NULL;
awaiting_reply = 1;
sched_timeout.alarm = gettime_ms() + 1500;
sched_timeout.deadline = sched_timeout.alarm + 3000;
schedule(&sched_timeout);
}
}
// If no request to send, stop monitoring the helper's stdin pipe.
if (!request_bufptr) {
unwatch(&sched_requests);
sched_requests.poll.fd = -1;
}
}
}
static void monitor_replies(struct sched_ent *alarm)
{
if (config.debug.dnahelper) {
DEBUGF("sched_replies.poll.fd=%d .revents=%s",
sched_replies.poll.fd,
strbuf_str(strbuf_append_poll_events(strbuf_alloca(40), sched_replies.poll.revents))
);
}
assert(alarm == &sched_replies);
if (sched_replies.poll.revents & POLLIN) {
size_t remaining = reply_buffer + sizeof reply_buffer - reply_bufend;
ssize_t nread = read_nonblock(sched_replies.poll.fd, reply_bufend, remaining);
if (nread > 0) {
char *bufp = reply_buffer;
char *readp = reply_bufend;
reply_bufend += nread;
char *nl;
while (nread > 0 && (nl = srv_strnstr(readp, nread, "\n"))) {
size_t len = nl - bufp + 1;
if (discarding_until_nl) {
if (config.debug.dnahelper)
DEBUGF("Discarding %s", alloca_toprint(-1, bufp, len));
discarding_until_nl = 0;
} else {
handle_reply_line(bufp, len);
}
readp = bufp = nl + 1;
nread = reply_bufend - readp;
}
if (bufp != reply_buffer) {
size_t len = reply_bufend - bufp;
memmove(reply_buffer, bufp, len);
reply_bufend = reply_buffer + len;
} else if (reply_bufend >= reply_buffer + sizeof reply_buffer) {
WHY("DNAHELPER reply buffer overrun");
if (config.debug.dnahelper)
DEBUGF("Discarding %s", alloca_toprint(-1, reply_buffer, sizeof reply_buffer));
reply_bufend = reply_buffer;
discarding_until_nl = 1;
}
}
}
if (sched_replies.poll.revents & (POLLHUP | POLLERR | POLLNVAL)) {
if (config.debug.dnahelper)
DEBUGF("DNAHELPER closing stdout fd=%d", dna_helper_stdout);
close(dna_helper_stdout);
dna_helper_stdout = -1;
unwatch(&sched_replies);
sched_replies.poll.fd = -1;
dna_helper_kill();
}
}
static void monitor_errors(struct sched_ent *alarm)
{
if (debug & DEBUG_DNAHELPER) {
DEBUGF("sched_errors.poll.fd=%d .revents=%s",
sched_errors.poll.fd,
strbuf_str(strbuf_append_poll_events(strbuf_alloca(40), sched_errors.poll.revents))
);
}
if (sched_errors.poll.revents & POLLIN) {
char buffer[1024];
ssize_t nread = read_nonblock(sched_errors.poll.fd, buffer, sizeof buffer);
if (nread > 0)
WHYF("DNAHELPER stderr %s", alloca_toprint(-1, buffer, nread));
}
if (sched_errors.poll.revents & (POLLHUP | POLLERR | POLLNVAL)) {
if (debug & DEBUG_DNAHELPER)
DEBUGF("DNAHELPER closing stderr fd=%d", dna_helper_stderr);
close(dna_helper_stderr);
dna_helper_stderr = -1;
unwatch(&sched_errors);
sched_errors.poll.fd = -1;
}
}
