php-fpm epoll封装

参考 http://www.jianshu.com/p/dac223d7d9ad

 

事件对象结构

//fpm_event.h
struct fpm_event_s {
    int fd;                   /* IO 文件句柄*/
    struct timeval timeout;   
    struct timeval frequency;
    void (*callback)(struct fpm_event_s *, short, void *); /* 回调函数 */
    void *arg; /* 回调函数的参数 */
    int flags;
    int index;         
    short which;       
};
//队列,多个事件对象的容器
typedef struct fpm_event_queue_s {
    struct fpm_event_queue_s *prev;
    struct fpm_event_queue_s *next;
    struct fpm_event_s *ev;
} fpm_event_queue;

 

事件模块封装结构

struct fpm_event_module_s {
    const char *name;
    int support_edge_trigger;
    int (*init)(int max_fd);
    int (*clean)(void);
    //等待多个事件
    int (*wait)(struct fpm_event_queue_s *queue, unsigned long int timeout);
    int (*add)(struct fpm_event_s *ev);
    int (*remove)(struct fpm_event_s *ev);
};

//events/epoll.c
//环境变量,在编译时确定是否纳入.
#if HAVE_EPOLL

#include <sys/epoll.h>
#include <errno.h>

static int fpm_event_epoll_init(int max);
static int fpm_event_epoll_clean();
static int fpm_event_epoll_wait(struct fpm_event_queue_s *queue, unsigned long int timeout);
static int fpm_event_epoll_add(struct fpm_event_s *ev);
static int fpm_event_epoll_remove(struct fpm_event_s *ev);

static struct fpm_event_module_s epoll_module = {
    .name = "epoll",
    .support_edge_trigger = 1,
    .init = fpm_event_epoll_init,
    .clean = fpm_event_epoll_clean,
    .wait = fpm_event_epoll_wait,
    .add = fpm_event_epoll_add,
    .remove = fpm_event_epoll_remove, 
};

//全局变量
static struct epoll_event *epollfds = NULL;
static int nepollfds = 0;
static int epollfd = -1;

#endif /* HAVE_EPOLL */

//这是使用时,获取模块对象的函数
//系统不支持返回NULL,这个函数总是编入二进制文件里.
struct fpm_event_module_s *fpm_event_epoll_module() /* {{{ */
{
#if HAVE_EPOLL
    return &epoll_module;
#else
    return NULL;
#endif /* HAVE_EPOLL */
}
/* }}} */

#if HAVE_EPOLL

/*
 * Init the module
 */
static int fpm_event_epoll_init(int max) /* {{{ */
{
    if (max < 1) {
        return 0;
    }

    /* init epoll */
    epollfd = epoll_create(max + 1);
    if (epollfd < 0) {
        zlog(ZLOG_ERROR, "epoll: unable to initialize");
        return -1;
    }

    /* allocate fds */
    epollfds = malloc(sizeof(struct epoll_event) * max);
    if (!epollfds) {
        zlog(ZLOG_ERROR, "epoll: unable to allocate %d events", max);
        return -1;
    }
    memset(epollfds, 0, sizeof(struct epoll_event) * max);

    /* save max */
    nepollfds = max;

    return 0;
}
/* }}} */

/*
 * Clean the module
 */
static int fpm_event_epoll_clean() /* {{{ */
{
    /* free epollfds */
    if (epollfds) {
        free(epollfds);
        epollfds = NULL;
    }
    if (epollfd != -1) {
        close(epollfd);
        epollfd = -1;
    }

    nepollfds = 0;

    return 0;
}
/* }}} */

/*
 * wait for events or timeout
 */
static int fpm_event_epoll_wait(struct fpm_event_queue_s *queue, unsigned long int timeout) /* {{{ */
{
    int ret, i;

    /* ensure we have a clean epoolfds before calling epoll_wait() */
    memset(epollfds, 0, sizeof(struct epoll_event) * nepollfds);

    /* wait for inconming event or timeout */
    ret = epoll_wait(epollfd, epollfds, nepollfds, timeout);
    if (ret == -1) {

        /* trigger error unless signal interrupt */
        if (errno != EINTR) {
            zlog(ZLOG_WARNING, "epoll_wait() returns %d", errno);
            return -1;
        }
    }

    /* events have been triggered, let's fire them */
    for (i = 0; i < ret; i++) {

        /* do we have a valid ev ptr ? */
        if (!epollfds[i].data.ptr) {
            continue;
        }

        /* fire the event */
        fpm_event_fire((struct fpm_event_s *)epollfds[i].data.ptr);

        /* sanity check */
        if (fpm_globals.parent_pid != getpid()) {
            return -2;
        }
    }

    return ret;
}
/* }}} */

/*
 * Add a FD to the fd set
 */
static int fpm_event_epoll_add(struct fpm_event_s *ev) /* {{{ */
{
    struct epoll_event e;

    /* fill epoll struct */
    e.events = EPOLLIN;
    e.data.fd = ev->fd;

    //data.ptr 设为自定义对象, 事件触发时,以此获取自定义对象
    e.data.ptr = (void *)ev;

    if (ev->flags & FPM_EV_EDGE) {
        e.events = e.events | EPOLLET;
    }

    /* add the event to epoll internal queue */
    if (epoll_ctl(epollfd, EPOLL_CTL_ADD, ev->fd, &e) == -1) {
        zlog(ZLOG_ERROR, "epoll: unable to add fd %d", ev->fd);
        return -1;
    }

    /* mark the event as registered */
    ev->index = ev->fd;
    return 0;
}
/* }}} */

/*
 * Remove a FD from the fd set
 */
static int fpm_event_epoll_remove(struct fpm_event_s *ev) /* {{{ */
{
    struct epoll_event e;

    /* fill epoll struct the same way we did in fpm_event_epoll_add() */
    e.events = EPOLLIN;
    e.data.fd = ev->fd;
    e.data.ptr = (void *)ev;

    if (ev->flags & FPM_EV_EDGE) {
        e.events = e.events | EPOLLET;
    }

    /* remove the event from epoll internal queue */
    if (epoll_ctl(epollfd, EPOLL_CTL_DEL, ev->fd, &e) == -1) {
        zlog(ZLOG_ERROR, "epoll: unable to remove fd %d", ev->fd);
        return -1;
    }

    /* mark the event as not registered */
    ev->index = -1;
    return 0;
}
/* }}} */

#endif /* HAVE_EPOLL */

fpm_event_set(&signal_fd_event, fpm_signals_get_fd(), FPM_EV_READ, &fpm_got_signal, NULL);

初始化变量 ev

int fpm_event_set(struct fpm_event_s *ev, int fd, int flags, void (*callback)(struct fpm_event_s *, short, void *), void *arg) /* {{{ */
{
    if (!ev || !callback || fd < -1) {
        return -1;
    }
    memset(ev, 0, sizeof(struct fpm_event_s));
    ev->fd = fd;
    ev->callback = callback;
    ev->arg = arg;
    ev->flags = flags;
    return 0;
}

fpm_event_add(&signal_fd_event, 0);

如果是io事件 则放到epoll_ctl，如果是定时器，则放到定时器队列里 

int fpm_event_add(struct fpm_event_s *ev, unsigned long int frequency) /* {{{ */
{
    struct timeval now;
    struct timeval tmp;

    if (!ev) {
        return -1;
    }

    ev->index = -1;

    /* it's a triggered event on incoming data */
    if (ev->flags & FPM_EV_READ) {
        ev->which = FPM_EV_READ;
        if (fpm_event_queue_add(&fpm_event_queue_fd, ev) != 0) {
            return -1;
        }
        return 0;
    }

    /* it's a timer event */
    ev->which = FPM_EV_TIMEOUT;

    fpm_clock_get(&now);
    if (frequency >= 1000) {
        tmp.tv_sec = frequency / 1000;
        tmp.tv_usec = (frequency % 1000) * 1000;
    } else {
        tmp.tv_sec = 0;
        tmp.tv_usec = frequency * 1000;
    }
    ev->frequency = tmp;
    fpm_event_set_timeout(ev, now);

    if (fpm_event_queue_add(&fpm_event_queue_timer, ev) != 0) {
        return -1;
    }

    return 0;
}

如果是io事件，则放到epoll_ctl里

static int fpm_event_queue_add(struct fpm_event_queue_s **queue, struct fpm_event_s *ev) /* {{{ */
{
    struct fpm_event_queue_s *elt;

    if (!queue || !ev) {
        return -1;
    }

    if (fpm_event_queue_isset(*queue, ev)) {
        return 0;
    }

    if (!(elt = malloc(sizeof(struct fpm_event_queue_s)))) {
        zlog(ZLOG_SYSERROR, "Unable to add the event to queue: malloc() failed");
        return -1;
    }
    elt->prev = NULL;
    elt->next = NULL;
    elt->ev = ev;

    if (*queue) {
        (*queue)->prev = elt;
        elt->next = *queue;
    }
    *queue = elt;

    /* ask the event module to add the fd from its own queue */
    if (*queue == fpm_event_queue_fd && module->add) {
        module->add(ev);
    }

    return 0;    
}

执行事件

void fpm_event_fire(struct fpm_event_s *ev) /* {{{ */
{
    if (!ev || !ev->callback) {
        return;
    }

    (*ev->callback)( (struct fpm_event_s *) ev, ev->which, ev->arg);    
}