diff options
Diffstat (limited to 'ares')
| -rw-r--r-- | ares/Makefile.inc | 2 | ||||
| -rw-r--r-- | ares/ares_library_cleanup.3 | 75 |
2 files changed, 76 insertions, 1 deletions
diff --git a/ares/Makefile.inc b/ares/Makefile.inc index 98c93f303..d5e18ac42 100644 --- a/ares/Makefile.inc +++ b/ares/Makefile.inc @@ -20,6 +20,6 @@ MANPAGES= ares_destroy.3 ares_expand_name.3 ares_expand_string.3 ares_fds.3 \ ares_parse_a_reply.3 ares_parse_ptr_reply.3 ares_process.3 \ ares_query.3 ares_search.3 ares_send.3 ares_strerror.3 ares_timeout.3 \ ares_version.3 ares_cancel.3 ares_parse_aaaa_reply.3 ares_getnameinfo.3 \ - ares_getsock.3 ares_parse_ns_reply.3 ares_dup.3 \ + ares_getsock.3 ares_parse_ns_reply.3 ares_dup.3 ares_library_cleanup.3 \ ares_destroy_options.3 ares_save_options.3 ares_gethostbyname_file.3 \ ares_set_socket_callback.3 ares_library_init.3 diff --git a/ares/ares_library_cleanup.3 b/ares/ares_library_cleanup.3 new file mode 100644 index 000000000..3cd9de90f --- /dev/null +++ b/ares/ares_library_cleanup.3 @@ -0,0 +1,75 @@ +.\" $Id$ +.\" +.\" Copyright 1998 by the Massachusetts Institute of Technology. +.\" Copyright (C) 2004-2009 by Daniel Stenberg +.\" +.\" Permission to use, copy, modify, and distribute this +.\" software and its documentation for any purpose and without +.\" fee is hereby granted, provided that the above copyright +.\" notice appear in all copies and that both that copyright +.\" notice and this permission notice appear in supporting +.\" documentation, and that the name of M.I.T. not be used in +.\" advertising or publicity pertaining to distribution of the +.\" software without specific, written prior permission. +.\" M.I.T. makes no representations about the suitability of +.\" this software for any purpose. It is provided "as is" +.\" without express or implied warranty. +.\" +.TH ARES_LIBRARY_CLEANUP 3 "19 May 2009" +.SH NAME +ares_library_cleanup \- c-ares library deinitialization +.SH SYNOPSIS +.nf +.B #include <ares.h> +.PP +.B void ares_library_cleanup(void) +.PP +.B cc file.c -lcares +.fi +.SH DESCRIPTION +.PP +The +.B ares_library_cleanup +function uninitializes the c-ares library, freeing all resources +previously aquired by \fIares_library_init(3)\fP when the library +was initialized. +.PP +This function must be called when the program using c-ares will +no longer need any c-ares function. Once the program has called +ares_library_cleanup() it shall not make any further call to any +c-ares function. +.PP +This function does not cancel any pending c-ares lookups or requests +previously done. Program must use \fIares_cancel(3)\fP for this purpose. +.PP +.B This function is not thread safe. +You have to call it once the program +is about to terminate, but this call must be done once the program has +terminated every single thread that it could have initiated. This is +required to avoid potential race conditions in library deinitialization, +and also due to the fact that ares_library_cleanup() might call functions +from other libraries that are thread unsafe, and could conflict with any +other thread that is already using these other libraries. +.PP +Win32/64 application DLLs shall not call ares_library_cleanup() from the +DllMain function. Doing so will produce deadlocks and other problems. +.SH NOTES +This function was first introduced in c-ares version 1.6.1 along with +the definition of preprocessor symbol \fICARES_HAVE_ARES_LIBRARY_CLEANUP\fP +as an indication of the availability of this function. +.PP +Since the introduction of this function, it is absolutely mandatory to +call it for any Win32/64 program using c-ares. +.PP +Non-Win32/64 systems can still use c-ares version 1.6.1 without calling +ares_library_cleanup() due to the fact that it is nearly a do-nothing +function on non-Win32/64 platforms. +.SH SEE ALSO +.BR ares_library_init(3), +.BR ares_cancel(3) +.SH AUTHOR +Yang Tse +.PP +Copyright 1998 by the Massachusetts Institute of Technology. +.br +Copyright (C) 2004-2009 by Daniel Stenberg. |