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author | Alain Magloire <alainm@gnu.org> | 2003-02-24 05:14:08 +0000 |
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committer | Alain Magloire <alainm@gnu.org> | 2003-02-24 05:14:08 +0000 |
commit | aee5de3eb14ed3465cee88a349907f6084a5fee5 (patch) | |
tree | 4c72f9ab9e326006723dfb387f90c3cc93352f90 | |
parent | a73c55ce75ccd22d3eb606a1dc49461f97c8a842 (diff) | |
download | mailutils-aee5de3eb14ed3465cee88a349907f6084a5fee5.tar.gz mailutils-aee5de3eb14ed3465cee88a349907f6084a5fee5.tar.bz2 |
Simple thread-safe implementation of reference count.
-rw-r--r-- | mailbox/refcount.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/mailbox/refcount.c b/mailbox/refcount.c new file mode 100644 index 000000000..5ad95344d --- /dev/null +++ b/mailbox/refcount.c @@ -0,0 +1,93 @@ +/* GNU Mailutils -- a suite of utilities for electronic mail + Copyright (C) 1999, 2000, 2001, 2003 Free Software Foundation, Inc. + + 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; either + version 2 of the License, or (at your option) any later version. + + 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ + +#ifdef HAVE_CONFIG_H +# include <config.h> +#endif + +#include <stdlib.h> +#include <errno.h> + +#include <mailutils/monitor.h> +#include <mailutils/refcount.h> + +int +mu_refcount_create (mu_refcount_t *prefcount) +{ + int status = 0; + mu_refcount_t refcount; + if (prefcount == NULL) + return EINVAL; + refcount = calloc (1, sizeof *refcount); + if (refcount != NULL) + { + refcount->ref = 1; + status = monitor_create (&(refcount->lock)); + if (status == 0) + { + *prefcount = refcount; + } + else + { + free (refcount); + } + } + else + { + status = ENOMEM; + } + return status; +} + +void +mu_refcount_destroy (mu_refcount_t *prefcount) +{ + if (prefcount && *prefcount) + { + mu_refcount_t refcount = *prefcount; + monitor_destroy (&refcount->lock); + free (refcount); + *prefcount = NULL; + } +} + +int +mu_refcount_inc (mu_refcount_t refcount) +{ + int count = 0; + if (refcount) + { + monitor_lock (refcount->lock); + count = ++refcount->ref; + monitor_unlock (refcount->lock); + } + return count; +} + +int +mu_refcount_dec (mu_refcount_t refcount) +{ + int count = 0; + if (refcount) + { + monitor_lock (refcount->lock); + if (refcount->ref) + count = --refcount->ref; + monitor_unlock (refcount->lock); + } + return count; +} |