Loading ares/ares_library_init.3 +36 −19 Original line number Original line Diff line number Diff line Loading @@ -23,38 +23,41 @@ ares_library_init \- c-ares library initialization .B #include <ares.h> .B #include <ares.h> .PP .PP .B int ares_library_init(int \fIflags\fP) .B int ares_library_init(int \fIflags\fP) .PP .B cc file.c -lcares .fi .fi .SH DESCRIPTION .SH DESCRIPTION .PP .PP The The .B ares_library_init .B ares_library_init function performs initializations internally required by the c-ares function performs initializations internally required by the c-ares library that must take place before any other c-ares function can be library that must take place before any other function provided by used. c-ares can be used in a program. .PP .PP This function must be called one time within the life of a program This function must be called one time within the life of a program, before the program actually executes any other c-ares library function before the program actually executes any other c-ares library function. call. Initializations done by this function remain effective until a Initializations done by this function remain effective until a call to \fIares_library_cleanup(3)\fP is performed. call to \fIares_library_cleanup(3)\fP is performed. .PP .PP Successive calls to this function are ignored, only the first one with Successive calls to this function do nothing, only the first call done c-ares in an uninitialized state is effective. when c-ares is in an uninitialized state is actually effective. .PP .PP The The .I flags .I flags parameter is a bit pattern that tells c-ares exactly which features parameter is a bit pattern that tells c-ares exactly which features should be initialized, as described below. Set the desired bits by should be initialized, as described below. Set the desired bits by ORing the values together. In normal operation, you must specify ORing the values together. In normal operation you should specify .I ARES_LIB_INIT_ALL. \fIARES_LIB_INIT_ALL\fP. Don't use any other value unless you are Don't use any other value unless you are familiar with it and trying familiar with it and trying to control some internal c-ares feature. to control some internal c-ares features. .PP .PP .B This function is not thread safe. .B This function is not thread safe. You have to call it once the program You have to call it once the program has started but must be called before the program starts any other thread. has started, but this call must be done before the program starts any Due to the fact that ares_library_init() might call functions from other other thread. This is required to avoid potential race conditions in libraries that are thread unsafe, it could conflict with any other thread library initialization, and also due to the fact that ares_library_init() that uses these other libraries. might call functions from other libraries that are thread unsafe, and could conflict with any other thread that is already using these other libraries. .SH FLAGS .SH FLAGS .TP 5 .TP 5 .B ARES_LIB_INIT_ALL .B ARES_LIB_INIT_ALL Loading @@ -66,13 +69,27 @@ Initialize Win32 specific libraries. .B ARES_LIB_INIT_NONE .B ARES_LIB_INIT_NONE Initialize nothing extra. This sets no bit. Initialize nothing extra. This sets no bit. .SH RETURN VALUE .SH RETURN VALUE If this function returns non-zero, something went wrong and you cannot Upon successful completion, ares_library_init() will return 0. use the other c-ares functions. 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 ares_library_init() failure. .SH NOTES .SH NOTES This function was first introduced in c-ares version 1.6.1 along with This function was first introduced in c-ares version 1.6.1 along with the definition of preprocessor symbol CARES_HAVE_ARES_LIBRARY_INIT the definition of preprocessor symbol \fICARES_HAVE_ARES_LIBRARY_INIT\fP as an indication of the availability of this function. 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 program using c-ares. .PP Non-Win32 systems can still use c-ares version 1.6.1 without calling ares_library_init() due to the fact that it is nearly a do-nothing function on non-Win32 platforms. .SH SEE ALSO .SH SEE ALSO .BR ares_library_cleanup (3) .BR ares_library_cleanup(3), .BR ares_strerror(3) .SH AUTHOR .SH AUTHOR Yang Tse Yang Tse .PP Copyright 1998 by the Massachusetts Institute of Technology. .br Copyright (C) 2004-2009 by Daniel Stenberg. Loading
ares/ares_library_init.3 +36 −19 Original line number Original line Diff line number Diff line Loading @@ -23,38 +23,41 @@ ares_library_init \- c-ares library initialization .B #include <ares.h> .B #include <ares.h> .PP .PP .B int ares_library_init(int \fIflags\fP) .B int ares_library_init(int \fIflags\fP) .PP .B cc file.c -lcares .fi .fi .SH DESCRIPTION .SH DESCRIPTION .PP .PP The The .B ares_library_init .B ares_library_init function performs initializations internally required by the c-ares function performs initializations internally required by the c-ares library that must take place before any other c-ares function can be library that must take place before any other function provided by used. c-ares can be used in a program. .PP .PP This function must be called one time within the life of a program This function must be called one time within the life of a program, before the program actually executes any other c-ares library function before the program actually executes any other c-ares library function. call. Initializations done by this function remain effective until a Initializations done by this function remain effective until a call to \fIares_library_cleanup(3)\fP is performed. call to \fIares_library_cleanup(3)\fP is performed. .PP .PP Successive calls to this function are ignored, only the first one with Successive calls to this function do nothing, only the first call done c-ares in an uninitialized state is effective. when c-ares is in an uninitialized state is actually effective. .PP .PP The The .I flags .I flags parameter is a bit pattern that tells c-ares exactly which features parameter is a bit pattern that tells c-ares exactly which features should be initialized, as described below. Set the desired bits by should be initialized, as described below. Set the desired bits by ORing the values together. In normal operation, you must specify ORing the values together. In normal operation you should specify .I ARES_LIB_INIT_ALL. \fIARES_LIB_INIT_ALL\fP. Don't use any other value unless you are Don't use any other value unless you are familiar with it and trying familiar with it and trying to control some internal c-ares feature. to control some internal c-ares features. .PP .PP .B This function is not thread safe. .B This function is not thread safe. You have to call it once the program You have to call it once the program has started but must be called before the program starts any other thread. has started, but this call must be done before the program starts any Due to the fact that ares_library_init() might call functions from other other thread. This is required to avoid potential race conditions in libraries that are thread unsafe, it could conflict with any other thread library initialization, and also due to the fact that ares_library_init() that uses these other libraries. might call functions from other libraries that are thread unsafe, and could conflict with any other thread that is already using these other libraries. .SH FLAGS .SH FLAGS .TP 5 .TP 5 .B ARES_LIB_INIT_ALL .B ARES_LIB_INIT_ALL Loading @@ -66,13 +69,27 @@ Initialize Win32 specific libraries. .B ARES_LIB_INIT_NONE .B ARES_LIB_INIT_NONE Initialize nothing extra. This sets no bit. Initialize nothing extra. This sets no bit. .SH RETURN VALUE .SH RETURN VALUE If this function returns non-zero, something went wrong and you cannot Upon successful completion, ares_library_init() will return 0. use the other c-ares functions. 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 ares_library_init() failure. .SH NOTES .SH NOTES This function was first introduced in c-ares version 1.6.1 along with This function was first introduced in c-ares version 1.6.1 along with the definition of preprocessor symbol CARES_HAVE_ARES_LIBRARY_INIT the definition of preprocessor symbol \fICARES_HAVE_ARES_LIBRARY_INIT\fP as an indication of the availability of this function. 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 program using c-ares. .PP Non-Win32 systems can still use c-ares version 1.6.1 without calling ares_library_init() due to the fact that it is nearly a do-nothing function on non-Win32 platforms. .SH SEE ALSO .SH SEE ALSO .BR ares_library_cleanup (3) .BR ares_library_cleanup(3), .BR ares_strerror(3) .SH AUTHOR .SH AUTHOR Yang Tse Yang Tse .PP Copyright 1998 by the Massachusetts Institute of Technology. .br Copyright (C) 2004-2009 by Daniel Stenberg.
