Mercurial > hg > nginx
view src/http/ngx_http_busy_lock.c @ 5520:a336cbc3dd44
SPDY: send output queue after processing of read event.
During the processing of input some control frames can be added to the queue.
And if there were no writing streams at the moment, these control frames might
be left unsent for a long time (or even forever).
This long delay is especially critical for PING replies since a client can
consider connection as broken and then resend exactly the same request over
a new connection, which is not safe in case of non-idempotent HTTP methods.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Wed, 15 Jan 2014 17:16:38 +0400 |
parents | 14411ee4d89f |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> static int ngx_http_busy_lock_look_cacheable(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++; #if 0 ngx_add_timer(bc->event, 1000); bc->event->event_handler = bc->event_handler; #endif /* TODO: ngx_handle_level_read_event() */ return NGX_AGAIN; } return NGX_ERROR; } int ngx_http_busy_lock_cacheable(ngx_http_busy_lock_t *bl, ngx_http_busy_lock_ctx_t *bc, int lock) { int rc; rc = ngx_http_busy_lock_look_cacheable(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) { #if 0 bl->waiting++; ngx_add_timer(bc->event, 1000); bc->event->event_handler = bc->event_handler; #endif /* 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->cacheable--; } bl->busy--; } static int ngx_http_busy_lock_look_cacheable(ngx_http_busy_lock_t *bl, ngx_http_busy_lock_ctx_t *bc, int lock) { int i, b, cacheable, free; u_int mask; b = 0; cacheable = 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; } cacheable++; } else if (free == -1) { free = i; } #if 1 if (cacheable == bl->cacheable) { if (free == -1 && cacheable < 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->cacheable++; 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() */ bl = ngx_pcalloc(cf->pool, sizeof(ngx_http_busy_lock_t)); if (bl == NULL) { return NGX_CONF_ERROR; } *blp = bl; /* ngx_calloc_shared() */ bl->mutex = ngx_pcalloc(cf->pool, sizeof(ngx_event_mutex_t)); if (bl->mutex == NULL) { 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 == (time_t) 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; }