From 03ff51230ea260b3aab05fe07c0c7f66c94b176c Mon Sep 17 00:00:00 2001 From: Jakub Hrozek Date: Thu, 28 Jan 2010 20:04:19 +0100 Subject: Initial import --- ares_library_init.3 | 97 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 ares_library_init.3 (limited to 'ares_library_init.3') diff --git a/ares_library_init.3 b/ares_library_init.3 new file mode 100644 index 0000000..94fb7ff --- /dev/null +++ b/ares_library_init.3 @@ -0,0 +1,97 @@ +.\" $Id: ares_library_init.3,v 1.6 2009-11-24 10:08:46 yangtse Exp $ +.\" +.\" 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_INIT 3 "19 May 2009" +.SH NAME +ares_library_init \- c-ares library initialization +.SH SYNOPSIS +.nf +.B #include +.PP +.B int ares_library_init(int \fIflags\fP) +.PP +.B cc file.c -lcares +.fi +.SH DESCRIPTION +.PP +The +.B ares_library_init +function performs initializations internally required by the c-ares +library that must take place before any other function provided by +c-ares can be used in a program. +.PP +This function must be called one time within the life of a program, +before the program actually executes any other c-ares library function. +Initializations done by this function remain effective until a +call to \fIares_library_cleanup(3)\fP is performed. +.PP +Successive calls to this function do nothing, only the first call done +when c-ares is in an uninitialized state is actually effective. +.PP +The +.I flags +parameter is a bit pattern that tells c-ares exactly which features +should be initialized, as described below. Set the desired bits by +ORing the values together. In normal operation you should specify +\fIARES_LIB_INIT_ALL\fP. Don't use any other value unless you are +familiar with it and trying to control some internal c-ares feature. +.PP +.B This function is not thread safe. +You have to call it once the program has started, but this call must be done +before the program starts any other thread. This is required to avoid +potential race conditions in library initialization, and also due to the fact +that \fIares_library_init(3)\fP 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 \fIares_library_init(3)\fP from the +DllMain function. Doing so will produce deadlocks and other problems. +.SH FLAGS +.TP 5 +.B ARES_LIB_INIT_ALL +Initialize everything possible. This sets all known bits. +.TP +.B ARES_LIB_INIT_WIN32 +Initialize Win32/64 specific libraries. +.TP +.B ARES_LIB_INIT_NONE +Initialize nothing extra. This sets no bit. +.SH RETURN VALUE +Upon successful completion, ares_library_init() will return 0. Otherwise, a +non-zero error number will be returned to indicate the error. Except for +\fIares_strerror(3)\fP, you shall not call any other c-ares function upon +\fIares_library_init(3)\fP failure. +.SH AVAILABILITY +This function was first introduced in c-ares version 1.7.0 along with the +definition of preprocessor symbol \fICARES_HAVE_ARES_LIBRARY_INIT\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 1.7.0 without calling +\fIares_library_init(3)\fP due to the fact that \fIcurrently\fP it is nearly +a do-nothing function on non-Win32/64 platforms at this point. +.SH SEE ALSO +.BR ares_library_cleanup(3), +.BR ares_strerror(3) +.SH AUTHOR +Yang Tse +.PP +Copyright 1998 by the Massachusetts Institute of Technology. +.br +Copyright (C) 2004-2009 by Daniel Stenberg. -- cgit