view src/event/ngx_event_connectex.c @ 9299:2706b60dc225 default tip

Core: error logging rate limiting. With this change, error logging to files can be rate-limited with the "rate=" parameter. The parameter specifies allowed log messages rate to a particular file (per worker), in messages per second (m/s). By default, "rate=1000m/s" is used. Rate limiting is implemented using the "leaky bucket" method, similarly to the limit_req module. Maximum burst size is set to the number of log messages per second for each severity level, so "error" messages are logged even if the rate limit is hit by "info" messages (but not vice versa). When the limit is reached for a particular level, the "too many log messages, limiting" message is logged at this level. If debug logging is enabled, either for the particular log file or for the particular connection, rate limiting is not used.
author Maxim Dounin <mdounin@mdounin.ru>
date Tue, 25 Jun 2024 22:58:56 +0300
parents 1c3b78d7cdc9
children
line wrap: on
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_event.h>


#define NGX_MAX_PENDING_CONN  10


static CRITICAL_SECTION  connect_lock;
static int               nconnects;
static ngx_connection_t  pending_connects[NGX_MAX_PENDING_CONN];

static HANDLE            pending_connect_event;

__declspec(thread) int                nevents = 0;
__declspec(thread) WSAEVENT           events[WSA_MAXIMUM_WAIT_EVENTS + 1];
__declspec(thread) ngx_connection_t  *conn[WSA_MAXIMUM_WAIT_EVENTS + 1];



int ngx_iocp_wait_connect(ngx_connection_t *c)
{
    for ( ;; ) {
        EnterCriticalSection(&connect_lock);

        if (nconnects < NGX_MAX_PENDING_CONN) {
            pending_connects[--nconnects] = c;
            LeaveCriticalSection(&connect_lock);

            if (SetEvent(pending_connect_event) == 0) {
                ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
                              "SetEvent() failed");
                return NGX_ERROR;

            break;
        }

        LeaveCriticalSection(&connect_lock);
        ngx_log_error(NGX_LOG_NOTICE, c->log, 0,
                      "max number of pending connect()s is %d",
                      NGX_MAX_PENDING_CONN);
        msleep(100);
    }

    if (!started) {
        if (ngx_iocp_new_thread(1) == NGX_ERROR) {
            return NGX_ERROR;
        }
        started = 1;
    }

    return NGX_OK;
}


int ngx_iocp_new_thread(int main)
{
    u_int  id;

    if (main) {
        pending_connect_event = CreateEvent(NULL, 0, 1, NULL);
        if (pending_connect_event == INVALID_HANDLE_VALUE) {
            ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
                          "CreateThread() failed");
            return NGX_ERROR;
        }
    }

    if (CreateThread(NULL, 0, ngx_iocp_wait_events, main, 0, &id)
                                                       == INVALID_HANDLE_VALUE)
    {
        ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
                      "CreateThread() failed");
        return NGX_ERROR;
    }

    SetEvent(event) {
        ngx_log_error(NGX_LOG_ALERT, c->log, ngx_errno,
                      "SetEvent() failed");
        return NGX_ERROR;
    }

    return NGX_OK;
}


int ngx_iocp_new_connect()
{
    EnterCriticalSection(&connect_lock);
    c = pending_connects[--nconnects];
    LeaveCriticalSection(&connect_lock);

    conn[nevents] = c;

    events[nevents] = WSACreateEvent();
    if (events[nevents] == INVALID_HANDLE_VALUE) {
        ngx_log_error(NGX_LOG_ALERT, c->log, ngx_socket_errno,
                      "WSACreateEvent() failed");
        return NGX_ERROR;
    }

    if (WSAEventSelect(c->fd, events[nevents], FD_CONNECT) == -1)
        ngx_log_error(NGX_LOG_ALERT, c->log, ngx_socket_errno,
                      "WSAEventSelect() failed");
        return NGX_ERROR;
    }

    nevents++;

    return NGX_OK;
}


void ngx_iocp_wait_events(int main)
{
    WSANETWORKEVENTS  ne;

    nevents = 1;
    events[0] = pending_connect_event;
    conn[0] = NULL;

    for ( ;; ) {
        offset = (nevents == WSA_MAXIMUM_WAIT_EVENTS + 1) ? 1 : 0;
        timeout = (nevents == 1 && !first) ? 60000 : INFINITE;

        n = WSAWaitForMultipleEvents(nevents - offset, events[offset],
                                     0, timeout, 0);
        if (n == WAIT_FAILED) {
            ngx_log_error(NGX_LOG_ALERT, log, ngx_socket_errno,
                          "WSAWaitForMultipleEvents() failed");
            continue;
        }

        if (n == WAIT_TIMEOUT) {
            if (nevents == 2 && !main) {
                ExitThread(0);
            }

            ngx_log_error(NGX_LOG_ALERT, log, 0,
                          "WSAWaitForMultipleEvents() "
                          "returned unexpected WAIT_TIMEOUT");
            continue;
        }

        n -= WSA_WAIT_EVENT_0;

        if (events[n] == NULL) {

            /* the pending_connect_event */

            if (nevents == WSA_MAXIMUM_WAIT_EVENTS) {
                ngx_iocp_new_thread(0);
            } else {
                ngx_iocp_new_connect();
            }

            continue;
        }

        if (WSAEnumNetworkEvents(c[n].fd, events[n], &ne) == -1) {
            ngx_log_error(NGX_LOG_ALERT, log, ngx_socket_errno,
                          "WSAEnumNetworkEvents() failed");
            continue;
        }

        if (ne.lNetworkEvents & FD_CONNECT) {
            conn[n].write->ovlp.error = ne.iErrorCode[FD_CONNECT_BIT];

            if (PostQueuedCompletionStatus(iocp, 0, NGX_IOCP_CONNECT,
                                           &conn[n].write->ovlp) == 0)
            {
                ngx_log_error(NGX_LOG_ALERT, log, ngx_socket_errno,
                              "PostQueuedCompletionStatus() failed");
                continue;
            }

            if (n < nevents) {
                conn[n] = conn[nevents];
                events[n] = events[nevents];
            }

            nevents--;
            continue;
        }

        if (ne.lNetworkEvents & FD_ACCEPT) {

            /* CHECK ERROR ??? */

            ngx_event_post_acceptex(conn[n].listening, 1);
            continue;
        }

        ngx_log_error(NGX_LOG_ALERT, c[n].log, 0,
                      "WSAWaitForMultipleEvents() "
                      "returned unexpected network event %ul",
                      ne.lNetworkEvents);
    }
}