Mercurial > hg > nginx
view src/http/ngx_http_busy_lock.c @ 5510:3ff29c30effb
SPDY: elimination of r->blocked counter usage for queuing frames.
It was used to prevent destroying of request object when there are unsent
frames in queue for the stream. Since it was incremented for each frame
and is only 8 bits long, so it was not very hard to overflow the counter.
Now the stream->queued counter is checked instead.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Tue, 14 Jan 2014 16:24:45 +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; }