diff options
Diffstat (limited to 'ares_library_cleanup.3')
-rw-r--r-- | ares_library_cleanup.3 | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/ares_library_cleanup.3 b/ares_library_cleanup.3 index 9fcf896..d60c378 100644 --- a/ares_library_cleanup.3 +++ b/ares_library_cleanup.3 @@ -31,11 +31,19 @@ The .B ares_library_cleanup function uninitializes the c-ares library, freeing all resources previously acquired by \fIares_library_init(3)\fP when the library -was initialized. +was initialized, provided there was only one single previous call to +\fIares_library_init(3)\fP. If there was more than one previous call to +\fIares_library_init(3)\fP, this function uninitializes the c-ares +library only if it is the call matching the call to +\fIares_library_init(3)\fP which initialized the library +(usually the very first call to \fIares_library_init(3)\fP). +Other calls to \fIares_library_cleanup(3)\fP have no effect other than +decrementing an internal counter. .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 -\fIares_library_cleanup(3)\fP it shall not make any further call to any +\fIares_library_cleanup(3)\fP sufficiently often such that the +library is uninitialised, 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 @@ -54,7 +62,12 @@ the DllMain function. Doing so will produce deadlocks and other problems. .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_CLEANUP\fP as an -indication of the availability of this function. +indication of the availability of this function. Reference counting in +\fIares_library_init()\fP and \fIares_library_cleanup()\fP, which requires +calls to the former function to match calls to the latter, is present since +c-ares version 1.10.0. +Earlier versions would deinitialize the library on the first call +to \fIares_library_cleanup()\fP. .PP Since the introduction of this function, it is absolutely mandatory to call it for any Win32/64 program using c-ares. |