diff options
Diffstat (limited to 'libcutils/fdevent.c')
| -rw-r--r-- | libcutils/fdevent.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/libcutils/fdevent.c b/libcutils/fdevent.c new file mode 100644 index 000000000..4cf46faf7 --- /dev/null +++ b/libcutils/fdevent.c @@ -0,0 +1,506 @@ +/* http://frotznet.googlecode.com/svn/trunk/utils/fdevent.c +** +** Copyright 2006, Brian Swetland <swetland@frotz.net> +** +** Licensed under the Apache License, Version 2.0 (the "License"); +** you may not use this file except in compliance with the License. +** You may obtain a copy of the License at +** +** http://www.apache.org/licenses/LICENSE-2.0 +** +** Unless required by applicable law or agreed to in writing, software +** distributed under the License is distributed on an "AS IS" BASIS, +** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +** See the License for the specific language governing permissions and +** limitations under the License. +*/ + +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> +#include <errno.h> + +#include <fcntl.h> + +#include <stdarg.h> +#include <stddef.h> + +#include <cutils/fdevent.h> + +#define TRACE(x...) fprintf(stderr,x) + +#define DEBUG 0 + +static void fatal(const char *fn, const char *fmt, ...) +{ + va_list ap; + va_start(ap, fmt); + fprintf(stderr, "%s:", fn); + vfprintf(stderr, fmt, ap); + va_end(ap); + abort(); +} + +#define FATAL(x...) fatal(__FUNCTION__, x) + +#if DEBUG +static void dump_fde(fdevent *fde, const char *info) +{ + fprintf(stderr,"FDE #%03d %c%c%c %s\n", fde->fd, + fde->state & FDE_READ ? 'R' : ' ', + fde->state & FDE_WRITE ? 'W' : ' ', + fde->state & FDE_ERROR ? 'E' : ' ', + info); +} +#else +#define dump_fde(fde, info) do { } while(0) +#endif + +#define FDE_EVENTMASK 0x00ff +#define FDE_STATEMASK 0xff00 + +#define FDE_ACTIVE 0x0100 +#define FDE_PENDING 0x0200 +#define FDE_CREATED 0x0400 + +static void fdevent_plist_enqueue(fdevent *node); +static void fdevent_plist_remove(fdevent *node); +static fdevent *fdevent_plist_dequeue(void); + +static fdevent list_pending = { + .next = &list_pending, + .prev = &list_pending, +}; + +static fdevent **fd_table = 0; +static int fd_table_max = 0; + +#ifdef CRAPTASTIC +//HAVE_EPOLL + +#include <sys/epoll.h> + +static int epoll_fd = -1; + +static void fdevent_init() +{ + /* XXX: what's a good size for the passed in hint? */ + epoll_fd = epoll_create(256); + + if(epoll_fd < 0) { + perror("epoll_create() failed"); + exit(1); + } + + /* mark for close-on-exec */ + fcntl(epoll_fd, F_SETFD, FD_CLOEXEC); +} + +static void fdevent_connect(fdevent *fde) +{ + struct epoll_event ev; + + memset(&ev, 0, sizeof(ev)); + ev.events = 0; + ev.data.ptr = fde; + +#if 0 + if(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fde->fd, &ev)) { + perror("epoll_ctl() failed\n"); + exit(1); + } +#endif +} + +static void fdevent_disconnect(fdevent *fde) +{ + struct epoll_event ev; + + memset(&ev, 0, sizeof(ev)); + ev.events = 0; + ev.data.ptr = fde; + + /* technically we only need to delete if we + ** were actively monitoring events, but let's + ** be aggressive and do it anyway, just in case + ** something's out of sync + */ + epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fde->fd, &ev); +} + +static void fdevent_update(fdevent *fde, unsigned events) +{ + struct epoll_event ev; + int active; + + active = (fde->state & FDE_EVENTMASK) != 0; + + memset(&ev, 0, sizeof(ev)); + ev.events = 0; + ev.data.ptr = fde; + + if(events & FDE_READ) ev.events |= EPOLLIN; + if(events & FDE_WRITE) ev.events |= EPOLLOUT; + if(events & FDE_ERROR) ev.events |= (EPOLLERR | EPOLLHUP); + + fde->state = (fde->state & FDE_STATEMASK) | events; + + if(active) { + /* we're already active. if we're changing to *no* + ** events being monitored, we need to delete, otherwise + ** we need to just modify + */ + if(ev.events) { + if(epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fde->fd, &ev)) { + perror("epoll_ctl() failed\n"); + exit(1); + } + } else { + if(epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fde->fd, &ev)) { + perror("epoll_ctl() failed\n"); + exit(1); + } + } + } else { + /* we're not active. if we're watching events, we need + ** to add, otherwise we can just do nothing + */ + if(ev.events) { + if(epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fde->fd, &ev)) { + perror("epoll_ctl() failed\n"); + exit(1); + } + } + } +} + +static void fdevent_process() +{ + struct epoll_event events[256]; + fdevent *fde; + int i, n; + + n = epoll_wait(epoll_fd, events, 256, -1); + + if(n < 0) { + if(errno == EINTR) return; + perror("epoll_wait"); + exit(1); + } + + for(i = 0; i < n; i++) { + struct epoll_event *ev = events + i; + fde = ev->data.ptr; + + if(ev->events & EPOLLIN) { + fde->events |= FDE_READ; + } + if(ev->events & EPOLLOUT) { + fde->events |= FDE_WRITE; + } + if(ev->events & (EPOLLERR | EPOLLHUP)) { + fde->events |= FDE_ERROR; + } + if(fde->events) { + if(fde->state & FDE_PENDING) continue; + fde->state |= FDE_PENDING; + fdevent_plist_enqueue(fde); + } + } +} + +#else /* USE_SELECT */ + +#ifdef HAVE_WINSOCK +#include <winsock2.h> +#else +#include <sys/select.h> +#endif + +static fd_set read_fds; +static fd_set write_fds; +static fd_set error_fds; + +static int select_n = 0; + +static void fdevent_init(void) +{ + FD_ZERO(&read_fds); + FD_ZERO(&write_fds); + FD_ZERO(&error_fds); +} + +static void fdevent_connect(fdevent *fde) +{ + if(fde->fd >= select_n) { + select_n = fde->fd + 1; + } +} + +static void fdevent_disconnect(fdevent *fde) +{ + int i, n; + + FD_CLR(fde->fd, &read_fds); + FD_CLR(fde->fd, &write_fds); + FD_CLR(fde->fd, &error_fds); + + for(n = 0, i = 0; i < select_n; i++) { + if(fd_table[i] != 0) n = i; + } + select_n = n + 1; +} + +static void fdevent_update(fdevent *fde, unsigned events) +{ + if(events & FDE_READ) { + FD_SET(fde->fd, &read_fds); + } else { + FD_CLR(fde->fd, &read_fds); + } + if(events & FDE_WRITE) { + FD_SET(fde->fd, &write_fds); + } else { + FD_CLR(fde->fd, &write_fds); + } + if(events & FDE_ERROR) { + FD_SET(fde->fd, &error_fds); + } else { + FD_CLR(fde->fd, &error_fds); + } + + fde->state = (fde->state & FDE_STATEMASK) | events; +} + +static void fdevent_process() +{ + int i, n; + fdevent *fde; + unsigned events; + fd_set rfd, wfd, efd; + + memcpy(&rfd, &read_fds, sizeof(fd_set)); + memcpy(&wfd, &write_fds, sizeof(fd_set)); + memcpy(&efd, &error_fds, sizeof(fd_set)); + + n = select(select_n, &rfd, &wfd, &efd, 0); + + if(n < 0) { + if(errno == EINTR) return; + perror("select"); + return; + } + + for(i = 0; (i < select_n) && (n > 0); i++) { + events = 0; + if(FD_ISSET(i, &rfd)) events |= FDE_READ; + if(FD_ISSET(i, &wfd)) events |= FDE_WRITE; + if(FD_ISSET(i, &efd)) events |= FDE_ERROR; + + if(events) { + n--; + + fde = fd_table[i]; + if(fde == 0) FATAL("missing fde for fd %d\n", i); + + fde->events |= events; + + if(fde->state & FDE_PENDING) continue; + fde->state |= FDE_PENDING; + fdevent_plist_enqueue(fde); + } + } +} + +#endif + +static void fdevent_register(fdevent *fde) +{ + if(fde->fd < 0) { + FATAL("bogus negative fd (%d)\n", fde->fd); + } + + if(fde->fd >= fd_table_max) { + int oldmax = fd_table_max; + if(fde->fd > 32000) { + FATAL("bogus huuuuge fd (%d)\n", fde->fd); + } + if(fd_table_max == 0) { + fdevent_init(); + fd_table_max = 256; + } + while(fd_table_max <= fde->fd) { + fd_table_max *= 2; + } + fd_table = realloc(fd_table, sizeof(fdevent*) * fd_table_max); + if(fd_table == 0) { + FATAL("could not expand fd_table to %d entries\n", fd_table_max); + } + memset(fd_table + oldmax, 0, sizeof(int) * (fd_table_max - oldmax)); + } + + fd_table[fde->fd] = fde; +} + +static void fdevent_unregister(fdevent *fde) +{ + if((fde->fd < 0) || (fde->fd >= fd_table_max)) { + FATAL("fd out of range (%d)\n", fde->fd); + } + + if(fd_table[fde->fd] != fde) { + FATAL("fd_table out of sync"); + } + + fd_table[fde->fd] = 0; + + if(!(fde->state & FDE_DONT_CLOSE)) { + dump_fde(fde, "close"); + close(fde->fd); + } +} + +static void fdevent_plist_enqueue(fdevent *node) +{ + fdevent *list = &list_pending; + + node->next = list; + node->prev = list->prev; + node->prev->next = node; + list->prev = node; +} + +static void fdevent_plist_remove(fdevent *node) +{ + node->prev->next = node->next; + node->next->prev = node->prev; + node->next = 0; + node->prev = 0; +} + +static fdevent *fdevent_plist_dequeue(void) +{ + fdevent *list = &list_pending; + fdevent *node = list->next; + + if(node == list) return 0; + + list->next = node->next; + list->next->prev = list; + node->next = 0; + node->prev = 0; + + return node; +} + +fdevent *fdevent_create(int fd, fd_func func, void *arg) +{ + fdevent *fde = (fdevent*) malloc(sizeof(fdevent)); + if(fde == 0) return 0; + fdevent_install(fde, fd, func, arg); + fde->state |= FDE_CREATED; + return fde; +} + +void fdevent_destroy(fdevent *fde) +{ + if(fde == 0) return; + if(!(fde->state & FDE_CREATED)) { + FATAL("fde %p not created by fdevent_create()\n", fde); + } + fdevent_remove(fde); +} + +void fdevent_install(fdevent *fde, int fd, fd_func func, void *arg) +{ + memset(fde, 0, sizeof(fdevent)); + fde->state = FDE_ACTIVE; + fde->fd = fd; + fde->func = func; + fde->arg = arg; + +#ifndef HAVE_WINSOCK + fcntl(fd, F_SETFL, O_NONBLOCK); +#endif + fdevent_register(fde); + dump_fde(fde, "connect"); + fdevent_connect(fde); + fde->state |= FDE_ACTIVE; +} + +void fdevent_remove(fdevent *fde) +{ + if(fde->state & FDE_PENDING) { + fdevent_plist_remove(fde); + } + + if(fde->state & FDE_ACTIVE) { + fdevent_disconnect(fde); + dump_fde(fde, "disconnect"); + fdevent_unregister(fde); + } + + fde->state = 0; + fde->events = 0; +} + + +void fdevent_set(fdevent *fde, unsigned events) +{ + events &= FDE_EVENTMASK; + + if((fde->state & FDE_EVENTMASK) == events) return; + + if(fde->state & FDE_ACTIVE) { + fdevent_update(fde, events); + dump_fde(fde, "update"); + } + + fde->state = (fde->state & FDE_STATEMASK) | events; + + if(fde->state & FDE_PENDING) { + /* if we're pending, make sure + ** we don't signal an event that + ** is no longer wanted. + */ + fde->events &= (~events); + if(fde->events == 0) { + fdevent_plist_remove(fde); + fde->state &= (~FDE_PENDING); + } + } +} + +void fdevent_add(fdevent *fde, unsigned events) +{ + fdevent_set( + fde, (fde->state & FDE_EVENTMASK) | (events & FDE_EVENTMASK)); +} + +void fdevent_del(fdevent *fde, unsigned events) +{ + fdevent_set( + fde, (fde->state & FDE_EVENTMASK) & (~(events & FDE_EVENTMASK))); +} + +void fdevent_loop() +{ + fdevent *fde; + + for(;;) { +#if DEBUG + fprintf(stderr,"--- ---- waiting for events\n"); +#endif + fdevent_process(); + + while((fde = fdevent_plist_dequeue())) { + unsigned events = fde->events; + fde->events = 0; + fde->state &= (~FDE_PENDING); + dump_fde(fde, "callback"); + fde->func(fde->fd, events, fde->arg); + } + } +} + |