NAME

       unw_set_caching_policy -- set unwind caching policy

SYNOPSIS

       #include <libunwind.h>

       int unw_set_caching_policy(unw_addr_space_t as, unw_caching_policy_t policy);

DESCRIPTION

       The  unw_set_caching_policy()  routine  sets the caching policy of address space as to the
       policy specified by argument policy.  The policy argument can take one of  three  possible
       values:

       UNW_CACHE_NONE
               Turns  off  caching  completely.  This also implicitly flushes the contents of all
              caches as if unw_flush_cache() had been called.

       UNW_CACHE_GLOBAL
               Enables caching using a global cache that is shared  by  all  threads.  If  global
              caching  is  unavailable  or  unsupported,  libunwind  may  fall  back  on  using a
              per-thread cache, as if UNW_CACHE_PER_THREAD had been specified.

       UNW_CACHE_PER_THREAD
               Enables  caching  using  thread-local  caches.  If  a  thread-local  caching   are
              unavailable  or unsupported, libunwind may fall back on using a global cache, as if
              UNW_CACHE_GLOBAL had been specified.

       If caching is enabled, an application must  be  prepared  to  make  appropriate  calls  to
       unw_flush_cache()  whenever  the target changes in a way that could affect the validity of
       cached  information.   For  example,  after  unloading  (removing)   a   shared   library,
       unw_flush_cache()  would  have  to  be  called  (at  least) for the address-range that was
       covered by the shared library.

       For address spaces created via unw_create_addr_space(3), caching is turned off by default.
       For the local address space unw_local_addr_space, caching is turned on by default.

RETURN VALUE

       On  successful  completion,  unw_set_caching_policy()  returns  0.  Otherwise the negative
       value of one of the error-codes below is returned.

THREAD AND SIGNAL SAFETY

       unw_set_caching_policy() is thread-safe but not safe to use from a signal handler.

ERRORS

       UNW_ENOMEM
               The desired caching policy could not be established because the application is out
              of memory.

SEE ALSO

       libunwind(3), unw_create_addr_space(3), unw_flush_cache(3)

AUTHOR

       David Mosberger-Tang
       Email: dmosberger@gmail.com
       WWW: http://www.nongnu.org/libunwind/.