blob: c4d61405135f690484b497a8b25b14b8d6d7bf8a [file] [log] [blame]
/*
* Buffer management functions.
*
* Copyright 2000-2012 Willy Tarreau <w@1wt.eu>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <common/config.h>
#include <common/buffer.h>
#include <common/memory.h>
#include <types/global.h>
struct pool_head *pool_head_buffer;
/* list of objects waiting for at least one buffer */
struct list buffer_wq = LIST_HEAD_INIT(buffer_wq);
__decl_aligned_spinlock(buffer_wq_lock);
/* perform minimal intializations, report 0 in case of error, 1 if OK. */
int init_buffer()
{
void *buffer;
pool_head_buffer = create_pool("buffer", global.tune.bufsize, MEM_F_SHARED|MEM_F_EXACT);
if (!pool_head_buffer)
return 0;
/* The reserved buffer is what we leave behind us. Thus we always need
* at least one extra buffer in minavail otherwise we'll end up waking
* up tasks with no memory available, causing a lot of useless wakeups.
* That means that we always want to have at least 3 buffers available
* (2 for current session, one for next session that might be needed to
* release a server connection).
*/
pool_head_buffer->minavail = MAX(global.tune.reserved_bufs, 3);
if (global.tune.buf_limit)
pool_head_buffer->limit = global.tune.buf_limit;
buffer = pool_refill_alloc(pool_head_buffer, pool_head_buffer->minavail - 1);
if (!buffer)
return 0;
pool_free(pool_head_buffer, buffer);
return 1;
}
/*
* Dumps part or all of a buffer.
*/
void buffer_dump(FILE *o, struct buffer *b, int from, int to)
{
fprintf(o, "Dumping buffer %p\n", b);
fprintf(o, " orig=%p size=%u head=%u tail=%u data=%u\n",
b_orig(b), (unsigned int)b_size(b), (unsigned int)b_head_ofs(b), (unsigned int)b_tail_ofs(b), (unsigned int)b_data(b));
fprintf(o, "Dumping contents from byte %d to byte %d\n", from, to);
fprintf(o, " 0 1 2 3 4 5 6 7 8 9 a b c d e f\n");
/* dump hexa */
while (from < to) {
int i;
fprintf(o, " %04x: ", from);
for (i = 0; ((from + i) < to) && (i < 16) ; i++) {
fprintf(o, "%02x ", (unsigned char)b_orig(b)[from + i]);
if (((from + i) & 15) == 7)
fprintf(o, "- ");
}
if (to - from < 16) {
int j = 0;
for (j = 0; j < from + 16 - to; j++)
fprintf(o, " ");
if (j > 8)
fprintf(o, " ");
}
fprintf(o, " ");
for (i = 0; (from + i < to) && (i < 16) ; i++) {
fprintf(o, "%c", isprint((int)b_orig(b)[from + i]) ? b_orig(b)[from + i] : '.') ;
if ((((from + i) & 15) == 15) && ((from + i) != to-1))
fprintf(o, "\n");
}
from += i;
}
fprintf(o, "\n--\n");
fflush(o);
}
/* see offer_buffer() for details */
void __offer_buffer(void *from, unsigned int threshold)
{
struct buffer_wait *wait, *bak;
int avail;
/* For now, we consider that all objects need 1 buffer, so we can stop
* waking up them once we have enough of them to eat all the available
* buffers. Note that we don't really know if they are streams or just
* other tasks, but that's a rough estimate. Similarly, for each cached
* event we'll need 1 buffer. If no buffer is currently used, always
* wake up the number of tasks we can offer a buffer based on what is
* allocated, and in any case at least one task per two reserved
* buffers.
*/
avail = pool_head_buffer->allocated - pool_head_buffer->used - global.tune.reserved_bufs / 2;
list_for_each_entry_safe(wait, bak, &buffer_wq, list) {
if (avail <= threshold)
break;
if (wait->target == from || !wait->wakeup_cb(wait->target))
continue;
LIST_DEL(&wait->list);
LIST_INIT(&wait->list);
avail--;
}
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/