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/*
* uxsel.c
*
* This module is a sort of all-purpose interchange for file
* descriptors. At one end it talks to network.c and pty.c and
* anything else which might have one or more fds that need
* select() or poll()-type things doing to them during an extended
* program run; at the other end it talks to window.c or plink.c or
* anything else which might have its own means of actually doing
* those select()-type things.
*/
#include <assert.h>
#include "putty.h"
#include "tree234.h"
struct fd {
int fd;
int rwx; /* 4=except 2=write 1=read */
uxsel_callback_fn callback;
uxsel_id *id; /* for uxsel_input_remove */
};
static tree234 *fds;
static int uxsel_fd_cmp(void *av, void *bv)
{
struct fd *a = (struct fd *)av;
struct fd *b = (struct fd *)bv;
if (a->fd < b->fd)
return -1;
if (a->fd > b->fd)
return +1;
return 0;
}
static int uxsel_fd_findcmp(void *av, void *bv)
{
int *a = (int *)av;
struct fd *b = (struct fd *)bv;
if (*a < b->fd)
return -1;
if (*a > b->fd)
return +1;
return 0;
}
void uxsel_init(void)
{
fds = newtree234(uxsel_fd_cmp);
}
/*
* Here is the interface to fd-supplying modules. They supply an
* fd, a set of read/write/execute states, and a callback function
* for when the fd satisfies one of those states. Repeated calls to
* uxsel_set on the same fd are perfectly legal and serve to change
* the rwx state (typically you only want to select an fd for
* writing when you actually have pending data you want to write to
* it!).
*/
void uxsel_set(int fd, int rwx, uxsel_callback_fn callback)
{
struct fd *newfd;
assert(fd >= 0);
uxsel_del(fd);
if (rwx) {
newfd = snew(struct fd);
newfd->fd = fd;
newfd->rwx = rwx;
newfd->callback = callback;
newfd->id = uxsel_input_add(fd, rwx);
add234(fds, newfd);
}
}
void uxsel_del(int fd)
{
struct fd *oldfd = find234(fds, &fd, uxsel_fd_findcmp);
if (oldfd) {
if (oldfd->id)
uxsel_input_remove(oldfd->id);
del234(fds, oldfd);
sfree(oldfd);
}
}
/*
* And here is the interface to select-functionality-supplying
* modules.
*/
int next_fd(int *state, int *rwx)
{
struct fd *fd;
fd = index234(fds, (*state)++);
if (fd) {
*rwx = fd->rwx;
return fd->fd;
} else
return -1;
}
int first_fd(int *state, int *rwx)
{
*state = 0;
return next_fd(state, rwx);
}
void select_result(int fd, int event)
{
struct fd *fdstruct = find234(fds, &fd, uxsel_fd_findcmp);
noise_ultralight(NOISE_SOURCE_IOID, fd);
/*
* Apparently this can sometimes be NULL. Can't see how, but I
* assume it means I need to ignore the event since it's on an
* fd I've stopped being interested in. Sigh.
*/
if (fdstruct)
fdstruct->callback(fd, event);
}
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