diff options
Diffstat (limited to 'src/common/fdset_epoll.c')
| -rw-r--r-- | src/common/fdset_epoll.c | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/src/common/fdset_epoll.c b/src/common/fdset_epoll.c new file mode 100644 index 0000000..cb2e3e1 --- /dev/null +++ b/src/common/fdset_epoll.c @@ -0,0 +1,216 @@ +/* Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <config.h> + +#ifdef HAVE_EPOLL_WAIT + +#include <sys/epoll.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> + +#include "fdset_epoll.h" + +#define OS_FDS_CHUNKSIZE 8 /*!< Number of pollfd structs in a chunk. */ +#define OS_FDS_KEEPCHUNKS 32 /*!< Will attempt to free memory when reached. */ + +struct fdset_t { + int epfd; + struct epoll_event *events; + size_t nfds; + size_t reserved; + size_t polled; +}; + +fdset_t *fdset_epoll_new() +{ + fdset_t *set = malloc(sizeof(fdset_t)); + if (!set) { + return 0; + } + + /* Blank memory. */ + memset(set, 0, sizeof(fdset_t)); + + /* Create epoll fd. */ + set->epfd = epoll_create(OS_FDS_CHUNKSIZE); + + return set; +} + +int fdset_epoll_destroy(fdset_t * fdset) +{ + if(!fdset) { + return -1; + } + + /* Teardown epoll. */ + close(fdset->epfd); + + /* OK if NULL. */ + free(fdset->events); + free(fdset); + return 0; +} + +int fdset_epoll_add(fdset_t *fdset, int fd, int events) +{ + if (!fdset || fd < 0 || events <= 0) { + return -1; + } + + /* Realloc needed. */ + if (fdset->nfds == fdset->reserved) { + const size_t chunk = OS_FDS_CHUNKSIZE; + const size_t nsize = (fdset->reserved + chunk) * + sizeof(struct epoll_event); + struct epoll_event *events_n = malloc(nsize); + if (!events_n) { + return -1; + } + + /* Clear and copy old fdset data. */ + memset(events_n, 0, nsize); + memcpy(events_n, fdset->events, + fdset->nfds * sizeof(struct epoll_event)); + free(fdset->events); + fdset->events = events_n; + fdset->reserved += chunk; + } + + /* Add to epoll set. */ + struct epoll_event ev; + memset(&ev, 0, sizeof(struct epoll_event)); + ev.events = EPOLLIN; /*! \todo MAP events. */ + ev.data.fd = fd; + if (epoll_ctl(fdset->epfd, EPOLL_CTL_ADD, fd, &ev) < 0) { + return -1; + } + + ++fdset->nfds; + return 0; +} + +int fdset_epoll_remove(fdset_t *fdset, int fd) +{ + if (!fdset || fd < 0) { + return -1; + } + + /* Attempt to remove from set. */ + struct epoll_event ev; + memset(&ev, 0, sizeof(struct epoll_event)); + if (epoll_ctl(fdset->epfd, EPOLL_CTL_DEL, fd, &ev) < 0) { + return -1; + } + + /* Overwrite current item. */ + --fdset->nfds; + + /*! \todo Return memory if overallocated (nfds is far lower than reserved). */ + return 0; +} + +int fdset_epoll_wait(fdset_t *fdset) +{ + if (!fdset || fdset->nfds < 1 || !fdset->events) { + return -1; + } + + /* Poll new events. */ + fdset->polled = 0; + int nfds = epoll_wait(fdset->epfd, fdset->events, fdset->nfds, -1); + + /* Check. */ + if (nfds < 0) { + return -1; + } + + /* Events array is ordered from 0 to nfds. */ + fdset->polled = nfds; + return nfds; +} + +int fdset_epoll_begin(fdset_t *fdset, fdset_it_t *it) +{ + if (!fdset || !it) { + return -1; + } + + /* Find first. */ + it->pos = 0; + return fdset_next(fdset, it); +} + +int fdset_epoll_end(fdset_t *fdset, fdset_it_t *it) +{ + if (!fdset || !it || fdset->nfds < 1) { + return -1; + } + + /* Check for polled events. */ + if (fdset->polled < 1) { + it->fd = -1; + it->pos = 0; + return -1; + } + + /* No end found, ends on the beginning. */ + size_t nid = fdset->polled - 1; + it->fd = fdset->events[nid].data.fd; + it->pos = nid; + it->events = 0; /*! \todo Map events. */ + return -1; +} + +int fdset_epoll_next(fdset_t *fdset, fdset_it_t *it) +{ + if (!fdset || !it || fdset->nfds < 1) { + return -1; + } + + /* Check boundaries. */ + if (it->pos >= fdset->polled) { + return -1; + } + + /* Select next. */ + size_t nid = it->pos++; + it->fd = fdset->events[nid].data.fd; + it->events = 0; /*! \todo Map events. */ + return 0; +} + +const char* fdset_epoll_method() +{ + return "epoll"; +} + +/* Package APIs. */ +struct fdset_backend_t FDSET_EPOLL = { + .fdset_new = fdset_epoll_new, + .fdset_destroy = fdset_epoll_destroy, + .fdset_add = fdset_epoll_add, + .fdset_remove = fdset_epoll_remove, + .fdset_wait = fdset_epoll_wait, + .fdset_begin = fdset_epoll_begin, + .fdset_end = fdset_epoll_end, + .fdset_next = fdset_epoll_next, + .fdset_method = fdset_epoll_method +}; + +#endif |