漫话Redis源码之八十五

学习C语言，一定要了解宏，开头这部分就是好了兼容不同平台，其余的代码主要还是状态位的设置：

/* Include the best multiplexing layer supported by this system.
 * The following should be ordered by performances, descending. */
#ifdef HAVE_EVPORT
#include "ae_evport.c"
#else
    #ifdef HAVE_EPOLL
    #include "ae_epoll.c"
    #else
        #ifdef HAVE_KQUEUE
        #include "ae_kqueue.c"
        #else
        #include "ae_select.c"
        #endif
    #endif
#endif


aeEventLoop *aeCreateEventLoop(int setsize) {
    aeEventLoop *eventLoop;
    int i;

    monotonicInit();    /* just in case the calling app didn't initialize */

    if ((eventLoop = zmalloc(sizeof(*eventLoop))) == NULL) goto err;
    eventLoop->events = zmalloc(sizeof(aeFileEvent)*setsize);
    eventLoop->fired = zmalloc(sizeof(aeFiredEvent)*setsize);
    if (eventLoop->events == NULL || eventLoop->fired == NULL) goto err;
    eventLoop->setsize = setsize;
    eventLoop->timeEventHead = NULL;
    eventLoop->timeEventNextId = 0;
    eventLoop->stop = 0;
    eventLoop->maxfd = -1;
    eventLoop->beforesleep = NULL;
    eventLoop->aftersleep = NULL;
    eventLoop->flags = 0;
    if (aeApiCreate(eventLoop) == -1) goto err;
    /* Events with mask == AE_NONE are not set. So let's initialize the
     * vector with it. */
    for (i = 0; i < setsize; i++)
        eventLoop->events[i].mask = AE_NONE;
    return eventLoop;

err:
    if (eventLoop) {
        zfree(eventLoop->events);
        zfree(eventLoop->fired);
        zfree(eventLoop);
    }
    return NULL;
}

/* Return the current set size. */
int aeGetSetSize(aeEventLoop *eventLoop) {
    return eventLoop->setsize;
}

/* Tells the next iteration/s of the event processing to set timeout of 0. */
void aeSetDontWait(aeEventLoop *eventLoop, int noWait) {
    if (noWait)
        eventLoop->flags |= AE_DONT_WAIT;
    else
        eventLoop->flags &= ~AE_DONT_WAIT;
}

/* Resize the maximum set size of the event loop.
 * If the requested set size is smaller than the current set size, but
 * there is already a file descriptor in use that is >= the requested
 * set size minus one, AE_ERR is returned and the operation is not
 * performed at all.
 *
 * Otherwise AE_OK is returned and the operation is successful. */
int aeResizeSetSize(aeEventLoop *eventLoop, int setsize) {
    int i;

    if (setsize == eventLoop->setsize) return AE_OK;
    if (eventLoop->maxfd >= setsize) return AE_ERR;
    if (aeApiResize(eventLoop,setsize) == -1) return AE_ERR;

    eventLoop->events = zrealloc(eventLoop->events,sizeof(aeFileEvent)*setsize);
    eventLoop->fired = zrealloc(eventLoop->fired,sizeof(aeFiredEvent)*setsize);
    eventLoop->setsize = setsize;

    /* Make sure that if we created new slots, they are initialized with
     * an AE_NONE mask. */
    for (i = eventLoop->maxfd+1; i < setsize; i++)
        eventLoop->events[i].mask = AE_NONE;
    return AE_OK;
}

void aeDeleteEventLoop(aeEventLoop *eventLoop) {
    aeApiFree(eventLoop);
    zfree(eventLoop->events);
    zfree(eventLoop->fired);

    /* Free the time events list. */
    aeTimeEvent *next_te, *te = eventLoop->timeEventHead;
    while (te) {
        next_te = te->next;
        zfree(te);
        te = next_te;
    }
    zfree(eventLoop);
}

void aeStop(aeEventLoop *eventLoop) {
    eventLoop->stop = 1;
}

int aeCreateFileEvent(aeEventLoop *eventLoop, int fd, int mask,
        aeFileProc *proc, void *clientData)
{
    if (fd >= eventLoop->setsize) {
        errno = ERANGE;
        return AE_ERR;
    }
    aeFileEvent *fe = &eventLoop->events[fd];

    if (aeApiAddEvent(eventLoop, fd, mask) == -1)
        return AE_ERR;
    fe->mask |= mask;
    if (mask & AE_READABLE) fe->rfileProc = proc;
    if (mask & AE_WRITABLE) fe->wfileProc = proc;
    fe->clientData = clientData;
    if (fd > eventLoop->maxfd)
        eventLoop->maxfd = fd;
    return AE_OK;
}

void aeDeleteFileEvent(aeEventLoop *eventLoop, int fd, int mask)
{
    if (fd >= eventLoop->setsize) return;
    aeFileEvent *fe = &eventLoop->events[fd];
    if (fe->mask == AE_NONE) return;

    /* We want to always remove AE_BARRIER if set when AE_WRITABLE
     * is removed. */
    if (mask & AE_WRITABLE) mask |= AE_BARRIER;

    aeApiDelEvent(eventLoop, fd, mask);
    fe->mask = fe->mask & (~mask);
    if (fd == eventLoop->maxfd && fe->mask == AE_NONE) {
        /* Update the max fd */
        int j;

        for (j = eventLoop->maxfd-1; j >= 0; j--)
            if (eventLoop->events[j].mask != AE_NONE) break;
        eventLoop->maxfd = j;
    }
}

int aeGetFileEvents(aeEventLoop *eventLoop, int fd) {
    if (fd >= eventLoop->setsize) return 0;
    aeFileEvent *fe = &eventLoop->events[fd];

    return fe->mask;
}

long long aeCreateTimeEvent(aeEventLoop *eventLoop, long long milliseconds,
        aeTimeProc *proc, void *clientData,
        aeEventFinalizerProc *finalizerProc)
{
    long long id = eventLoop->timeEventNextId++;
    aeTimeEvent *te;

    te = zmalloc(sizeof(*te));
    if (te == NULL) return AE_ERR;
    te->id = id;
    te->when = getMonotonicUs() + milliseconds * 1000;
    te->timeProc = proc;
    te->finalizerProc = finalizerProc;
    te->clientData = clientData;
    te->prev = NULL;
    te->next = eventLoop->timeEventHead;
    te->refcount = 0;
    if (te->next)
        te->next->prev = te;
    eventLoop->timeEventHead = te;
    return id;
}

int aeDeleteTimeEvent(aeEventLoop *eventLoop, long long id)
{
    aeTimeEvent *te = eventLoop->timeEventHead;
    while(te) {
        if (te->id == id) {
            te->id = AE_DELETED_EVENT_ID;
            return AE_OK;
        }
        te = te->next;
    }
    return AE_ERR; /* NO event with the specified ID found */
}