blob: 8c828214a09425d4a12019f12b0d6430658771fd [file] [log] [blame]
/*
* Pipe management
*
* Copyright 2000-2009 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 <unistd.h>
#include <fcntl.h>
#include <haproxy/api.h>
#include <haproxy/thread.h>
#include <common/memory.h>
#include <types/global.h>
#include <types/pipe.h>
DECLARE_STATIC_POOL(pool_head_pipe, "pipe", sizeof(struct pipe));
struct pipe *pipes_live = NULL; /* pipes which are still ready to use */
__decl_spinlock(pipes_lock); /* lock used to protect pipes list */
static THREAD_LOCAL int local_pipes_free = 0; /* #cache objects */
static THREAD_LOCAL struct pipe *local_pipes = NULL;
int pipes_used = 0; /* # of pipes in use (2 fds each) */
int pipes_free = 0; /* # of pipes unused */
/* return a pre-allocated empty pipe. Try to allocate one if there isn't any
* left. NULL is returned if a pipe could not be allocated.
*/
struct pipe *get_pipe()
{
struct pipe *ret = NULL;
int pipefd[2];
ret = local_pipes;
if (likely(ret)) {
local_pipes = ret->next;
local_pipes_free--;
HA_ATOMIC_SUB(&pipes_free, 1);
HA_ATOMIC_ADD(&pipes_used, 1);
goto out;
}
if (likely(pipes_live)) {
HA_SPIN_LOCK(PIPES_LOCK, &pipes_lock);
ret = pipes_live;
if (likely(ret))
pipes_live = ret->next;
HA_SPIN_UNLOCK(PIPES_LOCK, &pipes_lock);
if (ret) {
HA_ATOMIC_SUB(&pipes_free, 1);
HA_ATOMIC_ADD(&pipes_used, 1);
goto out;
}
}
HA_ATOMIC_ADD(&pipes_used, 1);
if (pipes_used + pipes_free >= global.maxpipes)
goto fail;
ret = pool_alloc(pool_head_pipe);
if (!ret)
goto fail;
if (pipe(pipefd) < 0)
goto fail;
#ifdef F_SETPIPE_SZ
if (global.tune.pipesize)
fcntl(pipefd[0], F_SETPIPE_SZ, global.tune.pipesize);
#endif
ret->data = 0;
ret->prod = pipefd[1];
ret->cons = pipefd[0];
ret->next = NULL;
out:
return ret;
fail:
pool_free(pool_head_pipe, ret);
HA_ATOMIC_SUB(&pipes_used, 1);
return NULL;
}
/* destroy a pipe, possibly because an error was encountered on it. Its FDs
* will be closed and it will not be reinjected into the live pool.
*/
void kill_pipe(struct pipe *p)
{
close(p->prod);
close(p->cons);
pool_free(pool_head_pipe, p);
HA_ATOMIC_SUB(&pipes_used, 1);
}
/* put back a unused pipe into the live pool. If it still has data in it, it is
* closed and not reinjected into the live pool. The caller is not allowed to
* use it once released.
*/
void put_pipe(struct pipe *p)
{
if (unlikely(p->data)) {
kill_pipe(p);
return;
}
if (likely(local_pipes_free * global.nbthread < global.maxpipes - pipes_used)) {
p->next = local_pipes;
local_pipes = p;
local_pipes_free++;
goto out;
}
HA_SPIN_LOCK(PIPES_LOCK, &pipes_lock);
p->next = pipes_live;
pipes_live = p;
HA_SPIN_UNLOCK(PIPES_LOCK, &pipes_lock);
out:
HA_ATOMIC_ADD(&pipes_free, 1);
HA_ATOMIC_SUB(&pipes_used, 1);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/