mpmt_os2_child.c

Apache 2.0.63 is the current stable version of the 2.0 series, and is recommended over any previous

        }

        if (rv != APR_SUCCESS) {
            if (!APR_STATUS_IS_EINTR(rv)) {
                ap_log_error(APLOG_MARK, APLOG_ERR, rv, ap_server_conf,
                             "apr_accept");
                clean_child_exit(APEXIT_CHILDFATAL);
            }
        } else {
            DosWriteQueue(workq, WORKTYPE_CONN, sizeof(worker_args_t), worker_args, 0);
            requests_this_child++;
        }

        if (ap_max_requests_per_child != 0 && requests_this_child >= ap_max_requests_per_child)
            break;
    } while (!shutdown_pending && ap_my_generation == ap_scoreboard_image->global->running_generation);

    ap_scoreboard_image->parent[child_slot].quiescing = 1;
    DosPostEventSem(shutdown_event);
    DosWaitThread(&server_maint_tid, DCWW_WAIT);

    if (is_graceful) {
        char someleft;

        /* tell our worker threads to exit */
        for (c=0; c<HARD_THREAD_LIMIT; c++) {
            if (ap_scoreboard_image->servers[child_slot][c].status != SERVER_DEAD) {
                DosWriteQueue(workq, WORKTYPE_EXIT, 0, NULL, 0);
            }
        }

        do {
            someleft = 0;

            for (c=0; c<HARD_THREAD_LIMIT; c++) {
                if (ap_scoreboard_image->servers[child_slot][c].status != SERVER_DEAD) {
                    someleft = 1;
                    DosSleep(1000);
                    break;
                }
            }
        } while (someleft);
    } else {
        DosPurgeQueue(workq);

        for (c=0; c<HARD_THREAD_LIMIT; c++) {
            if (ap_scoreboard_image->servers[child_slot][c].status != SERVER_DEAD) {
                DosKillThread(ap_scoreboard_image->servers[child_slot][c].tid);
            }
        }
    }

    apr_pool_destroy(pchild);
}



void add_worker()
{
    int thread_slot;

    /* Find a free thread slot */
    for (thread_slot=0; thread_slot < HARD_THREAD_LIMIT; thread_slot++) {
        if (ap_scoreboard_image->servers[child_slot][thread_slot].status == SERVER_DEAD) {
            ap_scoreboard_image->servers[child_slot][thread_slot].status = SERVER_STARTING;
            ap_scoreboard_image->servers[child_slot][thread_slot].tid =
                _beginthread(worker_main, NULL, 128*1024, (void *)thread_slot);
            break;
        }
    }
}



ULONG APIENTRY thread_exception_handler(EXCEPTIONREPORTRECORD *pReportRec,
                                        EXCEPTIONREGISTRATIONRECORD *pRegRec,
                                        CONTEXTRECORD *pContext,
                                        PVOID p)
{
    int c;

    if (pReportRec->fHandlerFlags & EH_NESTED_CALL) {
        return XCPT_CONTINUE_SEARCH;
    }

    if (pReportRec->ExceptionNum == XCPT_ACCESS_VIOLATION ||
        pReportRec->ExceptionNum == XCPT_INTEGER_DIVIDE_BY_ZERO) {
        ap_log_error(APLOG_MARK, APLOG_ERR, 0, ap_server_conf,
                     "caught exception in worker thread, initiating child shutdown pid=%d", getpid());
        for (c=0; c<HARD_THREAD_LIMIT; c++) {
            if (ap_scoreboard_image->servers[child_slot][c].tid == _gettid()) {
                ap_scoreboard_image->servers[child_slot][c].status = SERVER_DEAD;
                break;
            }
        }

        /* Shut down process ASAP, it could be quite unhealthy & leaking resources */
        shutdown_pending = 1;
        ap_scoreboard_image->parent[child_slot].quiescing = 1;
        kill(getpid(), SIGHUP);
        DosUnwindException(UNWIND_ALL, 0, 0);
    }
  
    return XCPT_CONTINUE_SEARCH;
}



static void worker_main(void *vpArg)
{
    long conn_id;
    conn_rec *current_conn;
    apr_pool_t *pconn;
    apr_allocator_t *allocator;
    apr_bucket_alloc_t *bucket_alloc;
    worker_args_t *worker_args;
    HQUEUE workq;
    PID owner;
    int rc;
    REQUESTDATA rd;
    ULONG len;
    BYTE priority;
    int thread_slot = (int)vpArg;
    EXCEPTIONREGISTRATIONRECORD reg_rec = { NULL, thread_exception_handler };
    ap_sb_handle_t *sbh;
  
    /* Trap exceptions in this thread so we don't take down the whole process */
    DosSetExceptionHandler( &reg_rec );

    rc = DosOpenQueue(&owner, &workq,
                      apr_psprintf(pchild, "/queues/httpd/work.%d", getpid()));

    if (rc) {
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
                     "unable to open work queue, exiting");
        ap_scoreboard_image->servers[child_slot][thread_slot].tid = 0;
    }

    conn_id = ID_FROM_CHILD_THREAD(child_slot, thread_slot);
    ap_update_child_status_from_indexes(child_slot, thread_slot, SERVER_READY, 
                                        NULL);

    apr_allocator_create(&allocator);
    apr_allocator_max_free_set(allocator, ap_max_mem_free);
    bucket_alloc = apr_bucket_alloc_create_ex(allocator);

    while (rc = DosReadQueue(workq, &rd, &len, (PPVOID)&worker_args, 0, DCWW_WAIT, &priority, NULLHANDLE),
           rc == 0 && rd.ulData != WORKTYPE_EXIT) {
        pconn = worker_args->pconn;
        ap_create_sb_handle(&sbh, pconn, child_slot, thread_slot);
        current_conn = ap_run_create_connection(pconn, ap_server_conf,
                                                worker_args->conn_sd, conn_id,
                                                sbh, bucket_alloc);

        if (current_conn) {
            ap_process_connection(current_conn, worker_args->conn_sd);
            ap_lingering_close(current_conn);
        }

        apr_pool_destroy(pconn);
        ap_update_child_status_from_indexes(child_slot, thread_slot, 
                                            SERVER_READY, NULL);
    }

    ap_update_child_status_from_indexes(child_slot, thread_slot, SERVER_DEAD, 
                                        NULL);

    apr_bucket_alloc_destroy(bucket_alloc);
    apr_allocator_destroy(allocator);
}



static void server_maintenance(void *vpArg)
{
    int num_idle, num_needed;
    ULONG num_pending = 0;
    int threadnum;
    HQUEUE workq;
    ULONG rc;
    PID owner;

    rc = DosOpenQueue(&owner, &workq,
                      apr_psprintf(pchild, "/queues/httpd/work.%d", getpid()));

    if (rc) {
        ap_log_error(APLOG_MARK, APLOG_ERR, APR_FROM_OS_ERROR(rc), ap_server_conf,
                     "unable to open work queue in maintenance thread");
        return;
    }

    do {
        for (num_idle=0, threadnum=0; threadnum < HARD_THREAD_LIMIT; threadnum++) {
            num_idle += ap_scoreboard_image->servers[child_slot][threadnum].status == SERVER_READY;
        }

        DosQueryQueue(workq, &num_pending);
        num_needed = ap_min_spare_threads - num_idle + num_pending;

        if (num_needed > 0) {
            for (threadnum=0; threadnum < num_needed; threadnum++) {
                add_worker();
            }
        }

        if (num_idle - num_pending > ap_max_spare_threads) {
            DosWriteQueue(workq, WORKTYPE_EXIT, 0, NULL, 0);
        }
    } while (DosWaitEventSem(shutdown_event, 500) == ERROR_TIMEOUT);
}



/* Signal handling routines */

static void sig_term(int sig)
{
    shutdown_pending = 1;
    is_graceful = 0;
    signal(SIGTERM, SIG_DFL);
}



static void sig_hup(int sig)
{
    shutdown_pending = 1;
    is_graceful = 1;
}



static void set_signals()
{
    struct sigaction sa;

    sigemptyset(&sa.sa_mask);
    sa.sa_flags = 0;
    sa.sa_handler = sig_term;

    if (sigaction(SIGTERM, &sa, NULL) < 0)
	ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGTERM)");

    sa.sa_handler = sig_hup;

    if (sigaction(SIGHUP, &sa, NULL) < 0)
	ap_log_error(APLOG_MARK, APLOG_WARNING, errno, ap_server_conf, "sigaction(SIGHUP)");
}