routine initializes the unwind cursor
pointed to by c
for unwinding in the address space identified by
argument can either be set to
(local address space) or to an arbitrary
address space created with unw_create_addr_space().
void-pointer tells the address space exactly what entity
should be unwound. For example, if unw_local_addr_space
passed in as,
needs to be a pointer to a context
structure containing the machine-state of the initial stack frame.
However, other address-spaces may instead expect a process-id, a
thread-id, or a pointer to an arbitrary structure which identifies the
stack-frame chain to be unwound. In other words, the interpretation
is entirely dependent on the address-space in use;
never interprets the argument in any way on its own.
Note that unw_init_remote()
can be used to initiate unwinding
process, including the local process in which the
unwinder itself is running. However, for local unwinding, it is
generally preferable to use unw_init_local()
it is easier to use and because it may perform better.