OpenSSL can safely be used in multi-threaded applications provided
that two callback functions are set.
-locking_function(int mode, int type, const char *file, int line) is
+locking_function(int mode, int n, const char *file, int line) is
needed to perform locking on shared data stuctures. Multi-threaded
applications will crash at random if it is not set.
locking_function() must be able to handle up to CRYPTO_num_locks()
-different mutex locks. It sets the B<n>th lock if B<mode> &
+different mutex locks. It sets the B<n>-th lock if B<mode> &
B<CRYPTO_LOCK>, and releases it otherwise.
B<file> and B<line> are the file number of the function setting the