Mercurial > hg > nginx-vendor-1-0
diff src/http/ngx_http_busy_lock.c @ 0:f0b350454894 NGINX_0_1_0
nginx 0.1.0
*) The first public version.
author | Igor Sysoev <http://sysoev.ru> |
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date | Mon, 04 Oct 2004 00:00:00 +0400 |
parents | |
children | 72eb30262aac |
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new file mode 100644 --- /dev/null +++ b/src/http/ngx_http_busy_lock.c @@ -0,0 +1,300 @@ + +/* + * Copyright (C) Igor Sysoev + */ + + +#include <ngx_config.h> +#include <ngx_core.h> +#include <ngx_http.h> + + + +static int ngx_http_busy_lock_look_cachable(ngx_http_busy_lock_t *bl, + ngx_http_busy_lock_ctx_t *bc, + int lock); + + +int ngx_http_busy_lock(ngx_http_busy_lock_t *bl, ngx_http_busy_lock_ctx_t *bc) +{ + if (bl->busy < bl->max_busy) { + bl->busy++; + + if (bc->time) { + bc->time = 0; + bl->waiting--; + } + + return NGX_OK; + } + + if (bc->time) { + if (bc->time < bl->timeout) { + ngx_add_timer(bc->event, 1000); + return NGX_AGAIN; + } + + bl->waiting--; + return NGX_DONE; + + } + + if (bl->timeout == 0) { + return NGX_DONE; + } + + if (bl->waiting < bl->max_waiting) { + bl->waiting++; + + ngx_add_timer(bc->event, 1000); + bc->event->event_handler = bc->event_handler; + + /* TODO: ngx_handle_level_read_event() */ + + return NGX_AGAIN; + } + + return NGX_ERROR; +} + + +int ngx_http_busy_lock_cachable(ngx_http_busy_lock_t *bl, + ngx_http_busy_lock_ctx_t *bc, int lock) +{ + int rc; + + rc = ngx_http_busy_lock_look_cachable(bl, bc, lock); + + ngx_log_debug3(NGX_LOG_DEBUG_HTTP, bc->event->log, 0, + "http busylock: %d w:%d mw::%d", + rc, bl->waiting, bl->max_waiting); + + if (rc == NGX_OK) { /* no the same request, there's free slot */ + return NGX_OK; + } + + if (rc == NGX_ERROR && !lock) { /* no the same request, no free slot */ + return NGX_OK; + } + + /* rc == NGX_AGAIN: the same request */ + + if (bc->time) { + if (bc->time < bl->timeout) { + ngx_add_timer(bc->event, 1000); + return NGX_AGAIN; + } + + bl->waiting--; + return NGX_DONE; + + } + + if (bl->timeout == 0) { + return NGX_DONE; + } + + if (bl->waiting < bl->max_waiting) { + bl->waiting++; + ngx_add_timer(bc->event, 1000); + bc->event->event_handler = bc->event_handler; + + /* TODO: ngx_handle_level_read_event() */ + + return NGX_AGAIN; + } + + return NGX_ERROR; +} + + +void ngx_http_busy_unlock(ngx_http_busy_lock_t *bl, + ngx_http_busy_lock_ctx_t *bc) +{ + if (bl == NULL) { + return; + } + + if (bl->md5) { + bl->md5_mask[bc->slot / 8] &= ~(1 << (bc->slot & 7)); + bl->cachable--; + } + + bl->busy--; +} + + +static int ngx_http_busy_lock_look_cachable(ngx_http_busy_lock_t *bl, + ngx_http_busy_lock_ctx_t *bc, + int lock) +{ + int i, b, cachable, free; + u_int mask; + + b = 0; + cachable = 0; + free = -1; + +#if (NGX_SUPPRESS_WARN) + mask = 0; +#endif + + for (i = 0; i < bl->max_busy; i++) { + + if ((b & 7) == 0) { + mask = bl->md5_mask[i / 8]; + } + + if (mask & 1) { + if (ngx_memcmp(&bl->md5[i * 16], bc->md5, 16) == 0) { + return NGX_AGAIN; + } + cachable++; + + } else if (free == -1) { + free = i; + } + +#if 1 + if (cachable == bl->cachable) { + if (free == -1 && cachable < bl->max_busy) { + free = i + 1; + } + + break; + } +#endif + + mask >>= 1; + b++; + } + + if (free == -1) { + return NGX_ERROR; + } + + if (lock) { + if (bl->busy == bl->max_busy) { + return NGX_ERROR; + } + + ngx_memcpy(&bl->md5[free * 16], bc->md5, 16); + bl->md5_mask[free / 8] |= 1 << (free & 7); + bc->slot = free; + + bl->cachable++; + bl->busy++; + } + + return NGX_OK; +} + + +char *ngx_http_set_busy_lock_slot(ngx_conf_t *cf, ngx_command_t *cmd, + void *conf) +{ + char *p = conf; + + ngx_uint_t i, dup, invalid; + ngx_str_t *value, line; + ngx_http_busy_lock_t *bl, **blp; + + blp = (ngx_http_busy_lock_t **) (p + cmd->offset); + if (*blp) { + return "is duplicate"; + } + + /* ngx_calloc_shared() */ + if (!(bl = ngx_pcalloc(cf->pool, sizeof(ngx_http_busy_lock_t)))) { + return NGX_CONF_ERROR; + } + *blp = bl; + + /* ngx_calloc_shared() */ + if (!(bl->mutex = ngx_pcalloc(cf->pool, sizeof(ngx_event_mutex_t)))) { + return NGX_CONF_ERROR; + } + + dup = 0; + invalid = 0; + value = cf->args->elts; + + for (i = 1; i < cf->args->nelts; i++) { + + if (value[i].data[1] != '=') { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "invalid value \"%s\"", value[i].data); + return NGX_CONF_ERROR; + } + + switch (value[i].data[0]) { + + case 'b': + if (bl->max_busy) { + dup = 1; + break; + } + + bl->max_busy = ngx_atoi(value[i].data + 2, value[i].len - 2); + if (bl->max_busy == NGX_ERROR) { + invalid = 1; + break; + } + + continue; + + case 'w': + if (bl->max_waiting) { + dup = 1; + break; + } + + bl->max_waiting = ngx_atoi(value[i].data + 2, value[i].len - 2); + if (bl->max_waiting == NGX_ERROR) { + invalid = 1; + break; + } + + continue; + + case 't': + if (bl->timeout) { + dup = 1; + break; + } + + line.len = value[i].len - 2; + line.data = value[i].data + 2; + + bl->timeout = ngx_parse_time(&line, 1); + if (bl->timeout == NGX_ERROR) { + invalid = 1; + break; + } + + continue; + + default: + invalid = 1; + } + + if (dup) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "duplicate value \"%s\"", value[i].data); + return NGX_CONF_ERROR; + } + + if (invalid) { + ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, + "invalid value \"%s\"", value[i].data); + return NGX_CONF_ERROR; + } + } + + if (bl->timeout == 0 && bl->max_waiting) { + ngx_conf_log_error(NGX_LOG_WARN, cf, 0, + "busy lock waiting is useless with zero timeout, ignoring"); + } + + return NGX_CONF_OK; +}