diff options
Diffstat (limited to 'src/ae_kqueue.c')
-rw-r--r-- | src/ae_kqueue.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/src/ae_kqueue.c b/src/ae_kqueue.c new file mode 100644 index 0000000..e845424 --- /dev/null +++ b/src/ae_kqueue.c @@ -0,0 +1,190 @@ +/* Kqueue(2)-based ae.c module + * + * Copyright (C) 2009 Harish Mallipeddi - harish.mallipeddi@gmail.com + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * * Neither the name of Redis nor the names of its contributors may be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + + +#include <sys/types.h> +#include <sys/event.h> +#include <sys/time.h> + +typedef struct aeApiState { + int kqfd; + struct kevent *events; + + /* Events mask for merge read and write event. + * To reduce memory consumption, we use 2 bits to store the mask + * of an event, so that 1 byte will store the mask of 4 events. */ + char *eventsMask; +} aeApiState; + +#define EVENT_MASK_MALLOC_SIZE(sz) (((sz) + 3) / 4) +#define EVENT_MASK_OFFSET(fd) ((fd) % 4 * 2) +#define EVENT_MASK_ENCODE(fd, mask) (((mask) & 0x3) << EVENT_MASK_OFFSET(fd)) + +static inline int getEventMask(const char *eventsMask, int fd) { + return (eventsMask[fd/4] >> EVENT_MASK_OFFSET(fd)) & 0x3; +} + +static inline void addEventMask(char *eventsMask, int fd, int mask) { + eventsMask[fd/4] |= EVENT_MASK_ENCODE(fd, mask); +} + +static inline void resetEventMask(char *eventsMask, int fd) { + eventsMask[fd/4] &= ~EVENT_MASK_ENCODE(fd, 0x3); +} + +static int aeApiCreate(aeEventLoop *eventLoop) { + aeApiState *state = zmalloc(sizeof(aeApiState)); + + if (!state) return -1; + state->events = zmalloc(sizeof(struct kevent)*eventLoop->setsize); + if (!state->events) { + zfree(state); + return -1; + } + state->kqfd = kqueue(); + if (state->kqfd == -1) { + zfree(state->events); + zfree(state); + return -1; + } + anetCloexec(state->kqfd); + state->eventsMask = zmalloc(EVENT_MASK_MALLOC_SIZE(eventLoop->setsize)); + memset(state->eventsMask, 0, EVENT_MASK_MALLOC_SIZE(eventLoop->setsize)); + eventLoop->apidata = state; + return 0; +} + +static int aeApiResize(aeEventLoop *eventLoop, int setsize) { + aeApiState *state = eventLoop->apidata; + + state->events = zrealloc(state->events, sizeof(struct kevent)*setsize); + state->eventsMask = zrealloc(state->eventsMask, EVENT_MASK_MALLOC_SIZE(setsize)); + memset(state->eventsMask, 0, EVENT_MASK_MALLOC_SIZE(setsize)); + return 0; +} + +static void aeApiFree(aeEventLoop *eventLoop) { + aeApiState *state = eventLoop->apidata; + + close(state->kqfd); + zfree(state->events); + zfree(state->eventsMask); + zfree(state); +} + +static int aeApiAddEvent(aeEventLoop *eventLoop, int fd, int mask) { + aeApiState *state = eventLoop->apidata; + struct kevent ke; + + if (mask & AE_READABLE) { + EV_SET(&ke, fd, EVFILT_READ, EV_ADD, 0, 0, NULL); + if (kevent(state->kqfd, &ke, 1, NULL, 0, NULL) == -1) return -1; + } + if (mask & AE_WRITABLE) { + EV_SET(&ke, fd, EVFILT_WRITE, EV_ADD, 0, 0, NULL); + if (kevent(state->kqfd, &ke, 1, NULL, 0, NULL) == -1) return -1; + } + return 0; +} + +static void aeApiDelEvent(aeEventLoop *eventLoop, int fd, int mask) { + aeApiState *state = eventLoop->apidata; + struct kevent ke; + + if (mask & AE_READABLE) { + EV_SET(&ke, fd, EVFILT_READ, EV_DELETE, 0, 0, NULL); + kevent(state->kqfd, &ke, 1, NULL, 0, NULL); + } + if (mask & AE_WRITABLE) { + EV_SET(&ke, fd, EVFILT_WRITE, EV_DELETE, 0, 0, NULL); + kevent(state->kqfd, &ke, 1, NULL, 0, NULL); + } +} + +static int aeApiPoll(aeEventLoop *eventLoop, struct timeval *tvp) { + aeApiState *state = eventLoop->apidata; + int retval, numevents = 0; + + if (tvp != NULL) { + struct timespec timeout; + timeout.tv_sec = tvp->tv_sec; + timeout.tv_nsec = tvp->tv_usec * 1000; + retval = kevent(state->kqfd, NULL, 0, state->events, eventLoop->setsize, + &timeout); + } else { + retval = kevent(state->kqfd, NULL, 0, state->events, eventLoop->setsize, + NULL); + } + + if (retval > 0) { + int j; + + /* Normally we execute the read event first and then the write event. + * When the barrier is set, we will do it reverse. + * + * However, under kqueue, read and write events would be separate + * events, which would make it impossible to control the order of + * reads and writes. So we store the event's mask we've got and merge + * the same fd events later. */ + for (j = 0; j < retval; j++) { + struct kevent *e = state->events+j; + int fd = e->ident; + int mask = 0; + + if (e->filter == EVFILT_READ) mask = AE_READABLE; + else if (e->filter == EVFILT_WRITE) mask = AE_WRITABLE; + addEventMask(state->eventsMask, fd, mask); + } + + /* Re-traversal to merge read and write events, and set the fd's mask to + * 0 so that events are not added again when the fd is encountered again. */ + numevents = 0; + for (j = 0; j < retval; j++) { + struct kevent *e = state->events+j; + int fd = e->ident; + int mask = getEventMask(state->eventsMask, fd); + + if (mask) { + eventLoop->fired[numevents].fd = fd; + eventLoop->fired[numevents].mask = mask; + resetEventMask(state->eventsMask, fd); + numevents++; + } + } + } else if (retval == -1 && errno != EINTR) { + panic("aeApiPoll: kevent, %s", strerror(errno)); + } + + return numevents; +} + +static char *aeApiName(void) { + return "kqueue"; +} |