Merge of r5004, r5019-r5025: ssl fixes. *) SSL: speedup loading of configs with many ssl servers. The patch saves one EC_KEY_generate_key() call per server{} block by informing OpenSSL about SSL_OP_SINGLE_ECDH_USE we are going to use before the SSL_CTX_set_tmp_ecdh() call. For a configuration file with 10k simple server{} blocks with SSL enabled this change reduces startup time from 18s to 5s on a slow test box here. *) SSL: removed conditions that always hold true. *) SSL: resetting of flush flag after the data was written. There is no need to flush next chunk of data if it does not contain a buffer with the flush or last_buf flags set. *) SSL: preservation of flush flag for buffered data. Previously, if SSL buffer was not sent we lost information that the data must be flushed. *) SSL: calculation of buffer size moved closer to its usage. No functional changes. *) SSL: avoid calling SSL_write() with zero data size. According to documentation, calling SSL_write() with num=0 bytes to be sent results in undefined behavior. We don't currently call ngx_ssl_send_chain() with empty chain and buffer. This check handles the case of a chain with total data size that is a multiple of NGX_SSL_BUFSIZE, and with the special buffer at the end. In practice such cases resulted in premature connection close and critical error "SSL_write() failed (SSL:)" in the error log. *) SSL: take into account data in the buffer while limiting output. In some rare cases this can result in a more smooth sending rate. *) SSL: fixed ngx_ssl_handshake() with level-triggered event methods. Missing calls to ngx_handle_write_event() and ngx_handle_read_event() resulted in a CPU hog during SSL handshake if an level-triggered event method (e.g. select) was used.

/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


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


ngx_int_t ngx_event_mutex_timedlock(ngx_event_mutex_t *m, ngx_msec_t timer,
                                    ngx_event_t *ev)
{
    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0,
                   "lock event mutex %p lock:%XD", m, m->lock);

    if (m->lock) {

        if (m->events == NULL) {
            m->events = ev;

        } else {
            m->last->next = ev;
        }

        m->last = ev;
        ev->next = NULL;

#if (NGX_THREADS0)
        ev->light = 1;
#endif

        ngx_add_timer(ev, timer);

        return NGX_AGAIN;
    }

    m->lock = 1;

    return NGX_OK;
}


ngx_int_t ngx_event_mutex_unlock(ngx_event_mutex_t *m, ngx_log_t *log)
{
    ngx_event_t  *ev;

    if (m->lock == 0) {
        ngx_log_error(NGX_LOG_ALERT, log, 0,
                      "tring to unlock the free event mutex %p", m);
        return NGX_ERROR;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_EVENT, log, 0,
                   "unlock event mutex %p, next event: %p", m, m->events);

    m->lock = 0;

    if (m->events) {
        ev = m->events;
        m->events = ev->next;

        ev->next = (ngx_event_t *) ngx_posted_events;
        ngx_posted_events = ev;
    }

    return NGX_OK;
}