UNW_SET_CACHING_POLICY(3) Programming Library UNW_SET_CACHING_POLICY(3)
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/.
Programming Library 16 August 2007 UNW_SET_CACHING_POLICY(3)