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unix/moduselect: register(): Allow to call with duplicate file descriptor.

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Per CPython docs, "Registering a file descriptor that’s already registered
is not an error, and has the same effect as registering the descriptor
exactly once."
https://docs.python.org/3/library/select.html#select.poll.register

That's somewhat ambiguous, what's implemented here is that if fd si not
yet registered, it is registered. Otherwise, the effect is equivalent to
modify() method.
This commit is contained in:
Paul Sokolovsky 2015-12-05 14:53:53 +02:00
parent f2d532c404
commit 082b12128d
1 changed files with 22 additions and 17 deletions
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39
unix/moduselect.c
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@ -47,6 +47,7 @@ typedef struct _mp_obj_poll_t {
/// \method register(obj[, eventmask])
STATIC mp_obj_t poll_register(uint n_args, const mp_obj_t *args) {
mp_obj_poll_t *self = MP_OBJ_TO_PTR(args[0]);
int fd = mp_obj_get_int(args[1]);
mp_uint_t flags;
if (n_args == 3) {
flags = mp_obj_get_int(args[2]);
@ -54,28 +55,32 @@ STATIC mp_obj_t poll_register(uint n_args, const mp_obj_t *args) {
flags = POLLIN | POLLOUT;
}
int i = 0;
if (self->len < self->alloc) {
i = self->len++;
} else {
struct pollfd *entries = self->entries;
for (i = 0; i < self->len; i++, entries++) {
if (entries->fd == -1) {
break;
}
struct pollfd *free_slot = NULL;
struct pollfd *entry = self->entries;
for (int i = 0; i < self->len; i++, entry++) {
int entry_fd = entry->fd;
if (entry_fd == fd) {
entry->events = flags;
return mp_const_false;
}
if (entries->fd != -1) {
i = self->len++;
self->entries = m_renew(struct pollfd, self->entries, self->alloc, self->alloc + 4);
self->alloc += 4;
if (entry_fd == -1) {
free_slot = entry;
}
}
self->entries[i].fd = mp_obj_get_int(args[1]);
self->entries[i].events = flags;
self->entries[i].revents = 0;
if (free_slot == NULL) {
if (self->len >= self->alloc) {
self->entries = m_renew(struct pollfd, self->entries, self->alloc, self->alloc + 4);
self->alloc += 4;
}
free_slot = &self->entries[self->len++];
}
return mp_const_none;
free_slot->fd = fd;
free_slot->events = flags;
free_slot->revents = 0;
return mp_const_true;
}
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(poll_register_obj, 2, 3, poll_register);