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/.