On Fri, Jul 05, 2002 at 08:47:32PM -0400, [EMAIL PROTECTED] wrote:
> This also creates a support library for APR, this is basically just a
> series of functions that APR can use internally to get the job
> done. Since wait_for_io_or_timeout was identical between files and
> sockets, I have moved that function to the support lib, it also now uses
> apr_poll().
What's the rationale behind a 'support library' for APR? All of the
content in newpoll.tar.gz seems like it should just stay in APR. You
have me thoroughly confused here. Perhaps in a new directory, but
definitely not a separate library.
I'm also not clear what the additional num parameter to apr_poll is
buying us. Why not just use the *nsds value on input as your num
parameter? The number of descriptors read is what *nsds is on the
output. No signature change required.
Aha, it seems that httpd uses a broken apr_poll() semantic. If you
read the documentation for apr_poll, it says:
* @param nsds The number of sockets we are polling.
...
* The number of sockets signalled is returned in the second argument (nsds)
But, httpd-2.0 doesn't pass in the number of sockets we are polling.
flood does because I read the docs not the code. I think we should
switch the code to match the docs.
I know I took it to mean that nsds on input is the number of fds we
are polling and on completion, it is the number of signaled fds. I
believe that the docs have the right API.
So, why not do something like this (very rough):
(Some OS does the low magic number off the stack, but I can't
remember which for the life of me.)
apr_status_t apr_poll(apr_pollfd_t *aprset, apr_int32_t *nsds,
apr_interval_time_t timeout)
{
int i, rv;
struct pollfd *pollset;
struct pollfd stack_pollset[SOME_LOW_MAGIC_NUMBER_LIKE_SAY_6];
if (*nsds < SOME_LOW_MAGIC_NUMBER_LIKE_SAY_6) {
pollset = &stack_pollset;
}
else {
pollset = apr_palloc(aprset->p,
sizeof(struct pollfd) * *nsds);
}
for (i = 0; i < *nsds; i++) {
if (aprset[i].desc_type == APR_POLL_SOCKET) {
pollset[i].fd = aprset[i].desc.s->socketdes;
}
else if (aprset[i].desc_type == APR_POLL_FILE) {
pollset[i].fd = aprset[i].desc.f->filedes;
}
pollset[i].events = get_event(aprset[i].events);
}
if (timeout > 0) {
/* FIXME: need apr conversion macro from apr_interval_time_t
* to milliseconds.
*/
timeout /= 1000; /* convert microseconds to milliseconds */
}
rv = poll(pollset, *nsds, timeout);
if (rv < 0) {
return errno;
}
for (i = 0; i < *nsds; i++) {
aprset[i].revents = get_revent(pollset[i].revents);
}
*nsds = rv;
return APR_SUCCESS;
}
It seems that you might have originally meant to go down this route
because you have:
struct pollfd *pollset = apr_palloc(aprset->p,
sizeof(struct pollfd) * *nsds);
Which means that the pollset is allocated to contain *nsds
pollfds. And, I think that means you need to have *nsds to be
equivalent to num, or you will segfault. (Perhaps it hasn't in
your tests by sheer luck.) -- justin
