diff options
Diffstat (limited to 'src/pipe.c')
-rw-r--r-- | src/pipe.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/src/pipe.c b/src/pipe.c new file mode 100644 index 0000000..5599fe0 --- /dev/null +++ b/src/pipe.c @@ -0,0 +1,136 @@ +/* + * 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/global.h> +#include <haproxy/pipe-t.h> +#include <haproxy/pool.h> +#include <haproxy/thread.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_DEC(&pipes_free); + HA_ATOMIC_INC(&pipes_used); + 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_DEC(&pipes_free); + HA_ATOMIC_INC(&pipes_used); + goto out; + } + } + + HA_ATOMIC_INC(&pipes_used); + 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_DEC(&pipes_used); + 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_DEC(&pipes_used); +} + +/* 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_INC(&pipes_free); + HA_ATOMIC_DEC(&pipes_used); +} + +/* + * Local variables: + * c-indent-level: 8 + * c-basic-offset: 8 + * End: + */ |