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UNW\_INIT\_LOCAL

UNW\_INIT\_LOCAL

Section: Programming Library (3) Updated: 16 August 2007
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NAME

unw_init_local -- initialize cursor for local unwinding

 

SYNOPSIS

#include <libunwind.h>

int unw_init_local(unw_cursor_t *c, unw_context_t *ctxt);

 

DESCRIPTION

The unw_init_local() routine initializes the unwind cursor pointed to by c with the machine-state in the context structure pointed to by ctxt. As such, the machine-state pointed to by ctxt identifies the initial stack frame at which unwinding starts. The machine-state must remain valid for the duration for which the cursor c is in use.

The unw_init_local() routine can be used only for unwinding in the address space of the current process (i.e., for local unwinding). For all other cases, unw_init_remote() must be used instead. From a behavioral point of view, the call:

    ret = unw_init_local(&cursor, &ucontext);


is equivalent to:

    ret = unw_init_remote(&cursor, unw_local_addr_space,
                          &ucontext);


However, unwind performance may be better when using unw_init_local(). Also, unw_init_local() is available even when UNW_LOCAL_ONLY has been defined before including <libunwind.h>, whereas unw_init_remote() is not.

 

RETURN VALUE

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

 

THREAD AND SIGNAL SAFETY

unw_init_local() is thread-safe as well as safe to use from a signal handler.

 

ERRORS

UNW_EINVAL

 unw_init_local() was called in a version of libunwind which supports remote unwinding only (this normally happens when calling unw_init_local() for a cross-platform version of libunwind).
UNW_EUNSPEC

 An unspecified error occurred. 
UNW_EBADREG

 A register needed by unw_init_local() wasn't accessible.

 

SEE ALSO

libunwind(3), unw_init_remote(3)

 

AUTHOR

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


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
THREAD AND SIGNAL SAFETY
ERRORS
SEE ALSO
AUTHOR

This document was created by man2html, using the manual pages.
Time: 21:57:57 GMT, April 16, 2011