NAME

       unw_is_signal_frame -- check if current frame is a signal frame

SYNOPSIS

       #include <libunwind.h>

       int unw_is_signal_frame(unw_cursor_t *cp);

DESCRIPTION

       The  unw_is_signal_frame()  routine  returns  a positive value if the current frame identified by cp is a
       signal frame, and a value of 0 otherwise. For the purpose of this discussion, a signal frame is  a  frame
       that  was  created  in  response  to  a  potentially  asynchronous  interruption.  For UNIX and UNIX-like
       platforms,  such  frames  are  normally  created  by  the  kernel  when  delivering  a  signal.    In   a
       kernel-environment,  a  signal  frame  might, for example, correspond to a frame created in response to a
       device interrupt.

       Signal frames are somewhat unusual because the asynchronous nature of the events that create them require
       storing the contents of registers that are normally treated as scratch (``caller-saved'') registers.

RETURN VALUE

       On successful completion, unw_is_signal_frame() returns a positive value if the current frame is a signal
       frame, or 0 if it is not. Otherwise, a negative value of one of the error-codes below is returned.

THREAD AND SIGNAL SAFETY

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

ERRORS

       UNW_ENOINFO
               Libunwind is unable to determine whether or not the current frame is a signal frame.

SEE ALSO

       libunwind(3), unw_get_reg(3), unw_set_reg(3), unw_get_fpreg(3), unw_set_fpreg(3)

AUTHOR

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

Programming Library                              16 August 2007                           UNW_IS_SIGNAL_FRAME(3)