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Diffstat (limited to 'include/haproxy/dynbuf.h')
| -rw-r--r-- | include/haproxy/dynbuf.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/include/haproxy/dynbuf.h b/include/haproxy/dynbuf.h new file mode 100644 index 0000000..a89800c --- /dev/null +++ b/include/haproxy/dynbuf.h @@ -0,0 +1,131 @@ +/* + * include/haproxy/dynbuf.h + * Buffer management functions. + * + * Copyright (C) 2000-2020 Willy Tarreau - w@1wt.eu + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation, version 2.1 + * exclusively. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef _HAPROXY_DYNBUF_H +#define _HAPROXY_DYNBUF_H + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include <import/ist.h> +#include <haproxy/activity.h> +#include <haproxy/api.h> +#include <haproxy/buf.h> +#include <haproxy/chunk.h> +#include <haproxy/dynbuf-t.h> +#include <haproxy/pool.h> + +extern struct pool_head *pool_head_buffer; + +int init_buffer(void); +void buffer_dump(FILE *o, struct buffer *b, int from, int to); + +/*****************************************************************/ +/* These functions are used to compute various buffer area sizes */ +/*****************************************************************/ + +/* Return 1 if the buffer has less than 1/4 of its capacity free, otherwise 0 */ +static inline int buffer_almost_full(const struct buffer *buf) +{ + if (b_is_null(buf)) + return 0; + + return b_almost_full(buf); +} + +/**************************************************/ +/* Functions below are used for buffer allocation */ +/**************************************************/ + +/* Ensures that <buf> is allocated, or allocates it. If no memory is available, + * ((char *)1) is assigned instead with a zero size. The allocated buffer is + * returned, or NULL in case no memory is available. Since buffers only contain + * user data, poisonning is always disabled as it brings no benefit and impacts + * performance. Due to the difficult buffer_wait management, they are not + * subject to forced allocation failures either. + */ +#define b_alloc(_buf) \ +({ \ + char *_area; \ + struct buffer *_retbuf = _buf; \ + \ + if (!_retbuf->size) { \ + *_retbuf = BUF_WANTED; \ + _area = pool_alloc_flag(pool_head_buffer, POOL_F_NO_POISON | POOL_F_NO_FAIL); \ + if (unlikely(!_area)) { \ + activity[tid].buf_wait++; \ + _retbuf = NULL; \ + } \ + else { \ + _retbuf->area = _area; \ + _retbuf->size = pool_head_buffer->size; \ + } \ + } \ + _retbuf; \ + }) + +/* Releases buffer <buf> (no check of emptiness). The buffer's head is marked + * empty. + */ +#define __b_free(_buf) \ + do { \ + char *area = (_buf)->area; \ + \ + /* let's first clear the area to save an occasional "show sess all" \ + * glancing over our shoulder from getting a dangling pointer. \ + */ \ + *(_buf) = BUF_NULL; \ + __ha_barrier_store(); \ + pool_free(pool_head_buffer, area); \ + } while (0) \ + +/* Releases buffer <buf> if allocated, and marks it empty. */ +#define b_free(_buf) \ + do { \ + if ((_buf)->size) \ + __b_free((_buf)); \ + } while (0) + +/* Offer one or multiple buffer currently belonging to target <from> to whoever + * needs one. Any pointer is valid for <from>, including NULL. Its purpose is + * to avoid passing a buffer to oneself in case of failed allocations (e.g. + * need two buffers, get one, fail, release it and wake up self again). In case + * of normal buffer release where it is expected that the caller is not waiting + * for a buffer, NULL is fine. It will wake waiters on the current thread only. + */ +void __offer_buffers(void *from, unsigned int count); + +static inline void offer_buffers(void *from, unsigned int count) +{ + if (!LIST_ISEMPTY(&th_ctx->buffer_wq)) + __offer_buffers(from, count); +} + + +#endif /* _HAPROXY_DYNBUF_H */ + +/* + * Local variables: + * c-indent-level: 8 + * c-basic-offset: 8 + * End: + */ |