C++ PROBE函数代码示例

static int
virNetClientCallDispatch(virNetClientPtr client)
{
    PROBE(RPC_CLIENT_MSG_RX,
          "client=%p len=%zu prog=%u vers=%u proc=%u type=%u status=%u serial=%u",
          client, client->msg.bufferLength,
          client->msg.header.prog, client->msg.header.vers, client->msg.header.proc,
          client->msg.header.type, client->msg.header.status, client->msg.header.serial);

    switch (client->msg.header.type) {
    case VIR_NET_REPLY: /* Normal RPC replies */
    case VIR_NET_REPLY_WITH_FDS: /* Normal RPC replies with FDs */
        return virNetClientCallDispatchReply(client);

    case VIR_NET_MESSAGE: /* Async notifications */
        return virNetClientCallDispatchMessage(client);

    case VIR_NET_STREAM: /* Stream protocol */
        return virNetClientCallDispatchStream(client);

    default:
        virNetError(VIR_ERR_RPC,
                    _("got unexpected RPC call prog %d vers %d proc %d type %d"),
                    client->msg.header.prog, client->msg.header.vers,
                    client->msg.header.proc, client->msg.header.type);
        return -1;
    }
}

virKeepAlivePtr
virKeepAliveNew(int interval,
                unsigned int count,
                void *client,
                virKeepAliveSendFunc sendCB,
                virKeepAliveDeadFunc deadCB,
                virKeepAliveFreeFunc freeCB)
{
    virKeepAlivePtr ka;

    VIR_DEBUG("client=%p, interval=%d, count=%u", client, interval, count);

    if (virKeepAliveInitialize() < 0)
        return NULL;

    if (!(ka = virObjectLockableNew(virKeepAliveClass)))
        return NULL;

    ka->interval = interval;
    ka->count = count;
    ka->countToDeath = count;
    ka->timer = -1;
    ka->client = client;
    ka->sendCB = sendCB;
    ka->deadCB = deadCB;
    ka->freeCB = freeCB;

    PROBE(RPC_KEEPALIVE_NEW,
          "ka=%p client=%p",
          ka, ka->client);

    return ka;
}

void virNetServerClientDispose(void *obj)
{
    virNetServerClientPtr client = obj;

    PROBE(RPC_SERVER_CLIENT_DISPOSE,
          "client=%p", client);

    virObjectUnref(client->identity);

    if (client->privateData &&
        client->privateDataFreeFunc)
        client->privateDataFreeFunc(client->privateData);

#if WITH_SASL
    virObjectUnref(client->sasl);
#endif
    if (client->sockTimer > 0)
        virEventRemoveTimeout(client->sockTimer);
#if WITH_GNUTLS
    virObjectUnref(client->tls);
    virObjectUnref(client->tlsCtxt);
#endif
    virObjectUnref(client->sock);
    virObjectUnlock(client);
}

void virEventPollUpdateTimeout(int timer, int frequency)
{
    unsigned long long now;
    int i;
    PROBE(EVENT_POLL_UPDATE_TIMEOUT,
          "timer=%d frequency=%d",
          timer, frequency);

    if (timer <= 0) {
        VIR_WARN("Ignoring invalid update timer %d", timer);
        return;
    }

    if (virTimeMillisNow(&now) < 0) {
        return;
    }

    virMutexLock(&eventLoop.lock);
    for (i = 0 ; i < eventLoop.timeoutsCount ; i++) {
        if (eventLoop.timeouts[i].timer == timer) {
            eventLoop.timeouts[i].frequency = frequency;
            eventLoop.timeouts[i].expiresAt =
                frequency >= 0 ? frequency + now : 0;
            virEventPollInterruptLocked();
            break;
        }
    }
    virMutexUnlock(&eventLoop.lock);
}

void virEventPollUpdateHandle(int watch, int events) {
    int i;
    bool found = false;
    PROBE(EVENT_POLL_UPDATE_HANDLE,
          "watch=%d events=%d",
          watch, events);

    if (watch <= 0) {
        VIR_WARN("Ignoring invalid update watch %d", watch);
        return;
    }

    virMutexLock(&eventLoop.lock);
    for (i = 0; i < eventLoop.handlesCount; i++) {
        if (eventLoop.handles[i].watch == watch) {
            eventLoop.handles[i].events =
                    virEventPollToNativeEvents(events);
            virEventPollInterruptLocked();
            found = true;
            break;
        }
    }
    virMutexUnlock(&eventLoop.lock);

    if (!found)
        VIR_WARN("Got update for non-existent handle watch %d", watch);
}

/*
 * Unregister a callback from a file handle
 * NB, it *must* be safe to call this from within a callback
 * For this reason we only ever set a flag in the existing list.
 * Actual deletion will be done out-of-band
 */
int virEventPollRemoveHandle(int watch) {
    int i;
    PROBE(EVENT_POLL_REMOVE_HANDLE,
          "watch=%d",
          watch);

    if (watch <= 0) {
        VIR_WARN("Ignoring invalid remove watch %d", watch);
        return -1;
    }

    virMutexLock(&eventLoop.lock);
    for (i = 0; i < eventLoop.handlesCount; i++) {
        if (eventLoop.handles[i].deleted)
            continue;

        if (eventLoop.handles[i].watch == watch) {
            EVENT_DEBUG("mark delete %d %d", i, eventLoop.handles[i].fd);
            eventLoop.handles[i].deleted = 1;
            virEventPollInterruptLocked();
            virMutexUnlock(&eventLoop.lock);
            return 0;
        }
    }
    virMutexUnlock(&eventLoop.lock);
    return -1;
}

/*
 * Unregister a callback for a timer
 * NB, it *must* be safe to call this from within a callback
 * For this reason we only ever set a flag in the existing list.
 * Actual deletion will be done out-of-band
 */
int virEventPollRemoveTimeout(int timer)
{
    size_t i;
    PROBE(EVENT_POLL_REMOVE_TIMEOUT,
          "timer=%d",
          timer);

    if (timer <= 0) {
        VIR_WARN("Ignoring invalid remove timer %d", timer);
        return -1;
    }

    virMutexLock(&eventLoop.lock);
    for (i = 0; i < eventLoop.timeoutsCount; i++) {
        if (eventLoop.timeouts[i].deleted)
            continue;

        if (eventLoop.timeouts[i].timer == timer) {
            eventLoop.timeouts[i].deleted = 1;
            virEventPollInterruptLocked();
            virMutexUnlock(&eventLoop.lock);
            return 0;
        }
    }
    virMutexUnlock(&eventLoop.lock);
    return -1;
}

int
virKeepAliveStart(virKeepAlivePtr ka,
                  int interval,
                  unsigned int count)
{
    int ret = -1;
    time_t delay;
    int timeout;
    time_t now;

    virKeepAliveLock(ka);

    if (ka->timer >= 0) {
        VIR_DEBUG("Keepalive messages already enabled");
        ret = 0;
        goto cleanup;
    }

    if (interval > 0) {
        if (ka->interval > 0) {
            virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                           _("keepalive interval already set"));
            goto cleanup;
        }
        ka->interval = interval;
        ka->count = count;
        ka->countToDeath = count;
    }

    if (ka->interval <= 0) {
        VIR_DEBUG("Keepalive messages disabled by configuration");
        ret = 0;
        goto cleanup;
    }

    PROBE(RPC_KEEPALIVE_START,
          "ka=%p client=%p interval=%d count=%u",
          ka, ka->client, interval, count);

    now = time(NULL);
    delay = now - ka->lastPacketReceived;
    if (delay > ka->interval)
        timeout = 0;
    else
        timeout = ka->interval - delay;
    ka->intervalStart = now - (ka->interval - timeout);
    ka->timer = virEventAddTimeout(timeout * 1000, virKeepAliveTimer,
                                   ka, virKeepAliveTimerFree);
    if (ka->timer < 0)
        goto cleanup;

    /* the timer now has another reference to this object */
    ka->refs++;
    ret = 0;

cleanup:
    virKeepAliveUnlock(ka);
    return ret;
}

void virNetClientRef(virNetClientPtr client)
{
    virNetClientLock(client);
    client->refs++;
    PROBE(RPC_CLIENT_REF,
          "client=%p refs=%d",
          client, client->refs);
    virNetClientUnlock(client);
}

/*
 * Run a single iteration of the event loop, blocking until
 * at least one file handle has an event, or a timer expires
 */
int virEventPollRunOnce(void)
{
    struct pollfd *fds = NULL;
    int ret, timeout, nfds;

    virMutexLock(&eventLoop.lock);
    eventLoop.running = 1;
    virThreadSelf(&eventLoop.leader);

    virEventPollCleanupTimeouts();
    virEventPollCleanupHandles();

    if (!(fds = virEventPollMakePollFDs(&nfds)) ||
        virEventPollCalculateTimeout(&timeout) < 0)
        goto error;

    virMutexUnlock(&eventLoop.lock);

 retry:
    PROBE(EVENT_POLL_RUN,
          "nhandles=%d timeout=%d",
          nfds, timeout);
    ret = poll(fds, nfds, timeout);
    if (ret < 0) {
        EVENT_DEBUG("Poll got error event %d", errno);
        if (errno == EINTR || errno == EAGAIN) {
            goto retry;
        }
        virReportSystemError(errno, "%s",
                             _("Unable to poll on file handles"));
        goto error_unlocked;
    }
    EVENT_DEBUG("Poll got %d event(s)", ret);

    virMutexLock(&eventLoop.lock);
    if (virEventPollDispatchTimeouts() < 0)
        goto error;

    if (ret > 0 &&
        virEventPollDispatchHandles(nfds, fds) < 0)
        goto error;

    virEventPollCleanupTimeouts();
    virEventPollCleanupHandles();

    eventLoop.running = 0;
    virMutexUnlock(&eventLoop.lock);
    VIR_FREE(fds);
    return 0;

 error:
    virMutexUnlock(&eventLoop.lock);
 error_unlocked:
    VIR_FREE(fds);
    return -1;
}

void
virKeepAliveRef(virKeepAlivePtr ka)
{
    virKeepAliveLock(ka);
    ka->refs++;
    PROBE(RPC_KEEPALIVE_REF,
          "ka=%p client=%p refs=%d",
          ka, ka->client, ka->refs);
    virKeepAliveUnlock(ka);
}

void
virKeepAliveDispose(void *obj)
{
    virKeepAlivePtr ka = obj;

    PROBE(RPC_KEEPALIVE_DISPOSE,
          "ka=%p", ka);

    ka->freeCB(ka->client);
}

static virNetClientPtr virNetClientNew(virNetSocketPtr sock,
                                       const char *hostname)
{
    virNetClientPtr client = NULL;
    int wakeupFD[2] = { -1, -1 };

    if (pipe2(wakeupFD, O_CLOEXEC) < 0) {
        virReportSystemError(errno, "%s",
                             _("unable to make pipe"));
        goto error;
    }

    if (VIR_ALLOC(client) < 0)
        goto no_memory;

    client->refs = 1;

    if (virMutexInit(&client->lock) < 0)
        goto error;

    client->sock = sock;
    client->wakeupReadFD = wakeupFD[0];
    client->wakeupSendFD = wakeupFD[1];
    wakeupFD[0] = wakeupFD[1] = -1;

    if (hostname &&
        !(client->hostname = strdup(hostname)))
        goto no_memory;

    /* Set up a callback to listen on the socket data */
    client->refs++;
    if (virNetSocketAddIOCallback(client->sock,
                                  VIR_EVENT_HANDLE_READABLE,
                                  virNetClientIncomingEvent,
                                  client,
                                  virNetClientEventFree) < 0) {
        client->refs--;
        VIR_DEBUG("Failed to add event watch, disabling events");
    }

    PROBE(RPC_CLIENT_NEW,
          "client=%p refs=%d sock=%p",
          client, client->refs, client->sock);

    return client;

no_memory:
    virReportOOMError();
error:
    VIR_FORCE_CLOSE(wakeupFD[0]);
    VIR_FORCE_CLOSE(wakeupFD[1]);
    virNetClientFree(client);
    return NULL;
}

static virNetServerClientPtr
virNetServerClientNewInternal(unsigned long long id,
                              virNetSocketPtr sock,
                              int auth,
#ifdef WITH_GNUTLS
                              virNetTLSContextPtr tls,
#endif
                              bool readonly,
                              size_t nrequests_max,
                              long long timestamp)
{
    virNetServerClientPtr client;

    if (virNetServerClientInitialize() < 0)
        return NULL;

    if (!(client = virObjectLockableNew(virNetServerClientClass)))
        return NULL;

    client->id = id;
    client->sock = virObjectRef(sock);
    client->auth = auth;
    client->readonly = readonly;
#ifdef WITH_GNUTLS
    client->tlsCtxt = virObjectRef(tls);
#endif
    client->nrequests_max = nrequests_max;
    client->conn_time = timestamp;

    client->sockTimer = virEventAddTimeout(-1, virNetServerClientSockTimerFunc,
                                           client, NULL);
    if (client->sockTimer < 0)
        goto error;

    /* Prepare one for packet receive */
    if (!(client->rx = virNetMessageNew(true)))
        goto error;
    client->rx->bufferLength = VIR_NET_MESSAGE_LEN_MAX;
    if (VIR_ALLOC_N(client->rx->buffer, client->rx->bufferLength) < 0)
        goto error;
    client->nrequests = 1;

    PROBE(RPC_SERVER_CLIENT_NEW,
          "client=%p sock=%p",
          client, client->sock);

    return client;

 error:
    virObjectUnref(client);
    return NULL;
}

static virNetServerClientPtr
virNetServerClientNewInternal(virNetSocketPtr sock,
                              int auth,
                              bool readonly,
                              size_t nrequests_max,
                              virNetTLSContextPtr tls)
{
    virNetServerClientPtr client;

    if (virNetServerClientInitialize() < 0)
        return NULL;

    if (!(client = virObjectNew(virNetServerClientClass)))
        return NULL;

    if (virMutexInit(&client->lock) < 0) {
        VIR_FREE(client);
        return NULL;
    }

    client->sock = virObjectRef(sock);
    client->auth = auth;
    client->readonly = readonly;
    client->tlsCtxt = virObjectRef(tls);
    client->nrequests_max = nrequests_max;

    client->sockTimer = virEventAddTimeout(-1, virNetServerClientSockTimerFunc,
                                           client, NULL);
    if (client->sockTimer < 0)
        goto error;

    /* Prepare one for packet receive */
    if (!(client->rx = virNetMessageNew(true)))
        goto error;
    client->rx->bufferLength = VIR_NET_MESSAGE_LEN_MAX;
    if (VIR_ALLOC_N(client->rx->buffer, client->rx->bufferLength) < 0) {
        virReportOOMError();
        goto error;
    }
    client->nrequests = 1;

    PROBE(RPC_SERVER_CLIENT_NEW,
          "client=%p sock=%p",
          client, client->sock);

    return client;

error:
    virObjectUnref(client);
    return NULL;
}