| /* |
| Copyright (c) 2012 Martin Sustrik All rights reserved. |
| |
| Permission is hereby granted, free of charge, to any person obtaining a copy |
| of this software and associated documentation files (the "Software"), |
| to deal in the Software without restriction, including without limitation |
| the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| and/or sell copies of the Software, and to permit persons to whom |
| the Software is furnished to do so, subject to the following conditions: |
| |
| The above copyright notice and this permission notice shall be included |
| in all copies or substantial portions of the Software. |
| |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| IN THE SOFTWARE. |
| */ |
| |
| #include "../utils/alloc.h" |
| #include "../utils/err.h" |
| |
| #define NN_POLLER_GRANULARITY 16 |
| |
| int nn_poller_init (struct nn_poller *self) |
| { |
| self->size = 0; |
| self->index = 0; |
| self->capacity = NN_POLLER_GRANULARITY; |
| self->pollset = |
| nn_alloc (sizeof (struct pollfd) * NN_POLLER_GRANULARITY, |
| "pollset"); |
| alloc_assert (self->pollset); |
| self->hndls = |
| nn_alloc (sizeof (struct nn_hndls_item) * NN_POLLER_GRANULARITY, |
| "hndlset"); |
| alloc_assert (self->hndls); |
| self->removed = -1; |
| |
| return 0; |
| } |
| |
| void nn_poller_term (struct nn_poller *self) |
| { |
| nn_free (self->pollset); |
| nn_free (self->hndls); |
| } |
| |
| void nn_poller_add (struct nn_poller *self, int fd, |
| struct nn_poller_hndl *hndl) |
| { |
| int rc; |
| |
| /* If the capacity is too low to accommodate the next item, resize it. */ |
| if (nn_slow (self->size >= self->capacity)) { |
| self->capacity *= 2; |
| self->pollset = nn_realloc (self->pollset, |
| sizeof (struct pollfd) * self->capacity); |
| alloc_assert (self->pollset); |
| self->hndls = nn_realloc (self->hndls, |
| sizeof (struct nn_hndls_item) * self->capacity); |
| alloc_assert (self->hndls); |
| } |
| |
| /* Add the fd to the pollset. */ |
| self->pollset [self->size].fd = fd; |
| self->pollset [self->size].events = 0; |
| self->pollset [self->size].revents = 0; |
| hndl->index = self->size; |
| self->hndls [self->size].hndl = hndl; |
| ++self->size; |
| } |
| |
| void nn_poller_rm (struct nn_poller *self, struct nn_poller_hndl *hndl) |
| { |
| /* No more events will be reported on this fd. */ |
| self->pollset [hndl->index].revents = 0; |
| |
| /* Add the fd into the list of removed fds. */ |
| if (self->removed != -1) |
| self->hndls [self->removed].prev = hndl->index; |
| self->hndls [hndl->index].hndl = NULL; |
| self->hndls [hndl->index].prev = -1; |
| self->hndls [hndl->index].next = self->removed; |
| self->removed = hndl->index; |
| } |
| |
| void nn_poller_set_in (struct nn_poller *self, struct nn_poller_hndl *hndl) |
| { |
| self->pollset [hndl->index].events |= POLLIN; |
| } |
| |
| void nn_poller_reset_in (struct nn_poller *self, struct nn_poller_hndl *hndl) |
| { |
| self->pollset [hndl->index].events &= ~POLLIN; |
| self->pollset [hndl->index].revents &= ~POLLIN; |
| } |
| |
| void nn_poller_set_out (struct nn_poller *self, struct nn_poller_hndl *hndl) |
| { |
| self->pollset [hndl->index].events |= POLLOUT; |
| } |
| |
| void nn_poller_reset_out (struct nn_poller *self, struct nn_poller_hndl *hndl) |
| { |
| self->pollset [hndl->index].events &= ~POLLOUT; |
| self->pollset [hndl->index].revents &= ~POLLOUT; |
| } |
| |
| int nn_poller_wait (struct nn_poller *self, int timeout) |
| { |
| int rc; |
| int i; |
| |
| /* First, get rid of removed fds. */ |
| while (self->removed != -1) { |
| |
| /* Remove the fd from the list of removed fds. */ |
| i = self->removed; |
| self->removed = self->hndls [i].next; |
| |
| /* Replace the removed fd by the one at the end of the pollset. */ |
| --self->size; |
| if (i != self->size) { |
| self->pollset [i] = self->pollset [self->size]; |
| if (self->hndls [i].next != -1) |
| self->hndls [self->hndls [i].next].prev = -1; |
| self->hndls [i] = self->hndls [self->size]; |
| if (self->hndls [i].hndl) |
| self->hndls [i].hndl->index = i; |
| } |
| |
| /* The fd from the end of the pollset may have been on removed fds |
| list itself. If so, adjust the removed list. */ |
| if (nn_slow (!self->hndls [i].hndl)) { |
| if (self->hndls [i].prev != -1) |
| self->hndls [self->hndls [i].prev].next = i; |
| if (self->hndls [i].next != -1) |
| self->hndls [self->hndls [i].next].prev = i; |
| if (self->removed == self->size) |
| self->removed = i; |
| } |
| } |
| |
| self->index = 0; |
| |
| /* Wait for new events. */ |
| #if defined NN_IGNORE_EINTR |
| again: |
| #endif |
| rc = poll (self->pollset, self->size, timeout); |
| if (nn_slow (rc < 0 && errno == EINTR)) |
| #if defined NN_IGNORE_EINTR |
| goto again; |
| #else |
| return -EINTR; |
| #endif |
| errno_assert (rc >= 0); |
| return 0; |
| } |
| |
| int nn_poller_event (struct nn_poller *self, int *event, |
| struct nn_poller_hndl **hndl) |
| { |
| int rc; |
| |
| /* Skip over empty events. This will also skip over removed fds as they |
| have their revents nullified. */ |
| while (self->index < self->size) { |
| if (self->pollset [self->index].revents != 0) |
| break; |
| ++self->index; |
| } |
| |
| /* If there is no available event, let the caller know. */ |
| if (nn_slow (self->index >= self->size)) |
| return -EAGAIN; |
| |
| /* Return next event to the caller. Remove the event from revents. */ |
| *hndl = self->hndls [self->index].hndl; |
| if (nn_fast (self->pollset [self->index].revents & POLLIN)) { |
| *event = NN_POLLER_IN; |
| self->pollset [self->index].revents &= ~POLLIN; |
| return 0; |
| } |
| else if (nn_fast (self->pollset [self->index].revents & POLLOUT)) { |
| *event = NN_POLLER_OUT; |
| self->pollset [self->index].revents &= ~POLLOUT; |
| return 0; |
| } |
| else { |
| *event = NN_POLLER_ERR; |
| ++self->index; |
| return 0; |
| } |
| } |
| |