nginx坑记录

int ngx_cdecl
main(int argc, char *const *argv)
{
    ngx_cycle_t      *cycle, init_cycle;
    ...
    ngx_memzero(&init_cycle, sizeof(ngx_cycle_t));
    init_cycle.log = log;
    ngx_cycle = &init_cycle;
    ...
    //配置解析前创建的pool，解析过程拿到的ngx_cycle->pool就是这个
    init_cycle.pool = ngx_create_pool(1024, log);
    if (init_cycle.pool == NULL) {
        return 1;
    }
    ...
    cycle = ngx_init_cycle(&init_cycle);
    if (cycle == NULL) {
        if (ngx_test_config) {
            ngx_log_stderr(0, "configuration file %s test failed",
                           init_cycle.conf_file.data);
        }

        return 1;
    }
    ...
    ngx_cycle = cycle;
}

ngx_cycle_t *
ngx_init_cycle(ngx_cycle_t *old_cycle)
{
    ngx_cycle_t         *cycle, **old;
    ...
    log = old_cycle->log;
    //这个pool放在cycle中带出去，配置解析之后赋值给ngx_cycle
    pool = ngx_create_pool(NGX_CYCLE_POOL_SIZE, log);
    if (pool == NULL) {
        return NULL;
    }
    pool->log = log;

    cycle = ngx_pcalloc(pool, sizeof(ngx_cycle_t));
    if (cycle == NULL) {
        ngx_destroy_pool(pool);
        return NULL;
    }

    cycle->pool = pool;
    cycle->log = log;
    cycle->old_cycle = old_cycle;
    .....
    配置解析
    ...
    return cycle;
}

void
ngx_array_destroy(ngx_array_t *a)
{
    ngx_pool_t  *p;

    p = a->pool;

    if ((u_char *) a->elts + a->size * a->nalloc == p->d.last) {
        p->d.last -= a->size * a->nalloc;
    }

    if ((u_char *) a + sizeof(ngx_array_t) == p->d.last) {
        p->d.last = (u_char *) a;
    }
}