This commit updates the documentation of ares_library_init() and
ares_library_cleanup() with regard to the newly introduced reference
counting of initializations and deinitializations.
Previously, a single call to ares_library_cleanup() would deinitialise
the c-ares library, regardless of how many times ares_library_init() was
called. This behaviour may cause problems in programs linking two or
more libraries which, in turn, use c-ares. The present commit fixes this
problem, deinitializing the library only after a number of calls to
ares_library_cleanup() matching the number of calls to
ares_library_init().
This commit clarifies the behaviour of ares_cancel() with respect to
callbacks and adds missing documentation of ARES_ECANCELLED to the man
pages of the affected functions.
An invocation of ares_cancel() walks through the request list, calling
the callbacks of all pending requests on a channel. Previously, if such
a callback added a new request to the channel, the request list might
not end up empty, causing an abort by assertion failure. The present
commit ensures that precisely all requests present upon entry of
ares_cancel() are cancelled, and that adding new requests through
callbacks is safe.
GCC specific adjustments:
- check __ILP32__ before 32 and 64bit processor architectures in
order to detect ILP32 programming model on 64 bit processors
which, of course, also support LP64 programming model, when using
gcc 4.7 or newer.
- keep 32bit processor architecture checks in order to support gcc
versions older than 4.7 which don't define __ILP32__
- check __LP64__ for gcc 3.3 and newer, while keeping 64bit processor
architecture checks for older versions which don't define __LP64__
Make sure that the symbols are always exported and present in c-ares.
Make the headers prefixed with 'ares'.
Removed the inet_ntop.h version as it no longer features any content.
