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/*
* 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 <common/config.h>
#include <common/hathreads.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 */
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];
HA_SPIN_LOCK(PIPES_LOCK, &pipes_lock);
if (likely(pipes_live)) {
ret = pipes_live;
pipes_live = pipes_live->next;
pipes_free--;
pipes_used++;
goto out;
}
if (pipes_used >= global.maxpipes)
goto out;
ret = pool_alloc(pool_head_pipe);
if (!ret)
goto out;
if (pipe(pipefd) < 0) {
pool_free(pool_head_pipe, ret);
ret = NULL;
goto out;
}
#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;
pipes_used++;
out:
HA_SPIN_UNLOCK(PIPES_LOCK, &pipes_lock);
return ret;
}
static inline void __kill_pipe(struct pipe *p)
{
close(p->prod);
close(p->cons);
pool_free(pool_head_pipe, p);
pipes_used--;
return;
}
/* 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)
{
HA_SPIN_LOCK(PIPES_LOCK, &pipes_lock);
__kill_pipe(p);
HA_SPIN_UNLOCK(PIPES_LOCK, &pipes_lock);
return;
}
/* 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)
{
HA_SPIN_LOCK(PIPES_LOCK, &pipes_lock);
if (p->data) {
__kill_pipe(p);
goto out;
}
p->next = pipes_live;
pipes_live = p;
pipes_free++;
pipes_used--;
out:
HA_SPIN_UNLOCK(PIPES_LOCK, &pipes_lock);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/