blob: fa3eb814b3f6500ac8d4f947d929e390c2b74b4c [file] [log] [blame]
 \documentclass{article} \usepackage[fancyhdr,pdf]{latex2man} \input{common.tex} \begin{document} \begin{Name}{3}{unw\_getcontext}{David Mosberger-Tang}{Programming Library}{unw\_getcontext}unw\_getcontext -- get initial machine-state \end{Name} \section{Synopsis} \File{\#include $<$libunwind.h$>$}\\ \Type{int} \Func{unw\_getcontext}(\Type{unw\_context\_t~*}\Var{ucp});\\ \section{Description} The \Func{unw\_getcontext}() routine initializes the context structure pointed to by \Var{ucp} with the machine-state of the call-site. The exact set of registers stored by \Func{unw\_getcontext}() is platform-specific, but, in general, at least all preserved (callee-saved'') and all frame-related registers, such as the stack-pointer, will be stored. This routine is normally implemented as a macro and applications should not attempt to take its address. \section{Platform-specific Notes} On IA-64, \Type{unw\_context\_t} has a layout that is compatible with that of \Type{ucontext\_t} and such structures can be initialized with \Func{getcontext}() instead of \Func{unw\_getcontext}(). However, the reverse is \emph{not} true and it is \emph{not} safe to use structures initialized by \Func{unw\_getcontext()} in places where a structure initialized by \Func{getcontext()} is expected. The reason for this asymmetry is that \Func{unw\_getcontext()} is optimized for maximum performance and does not, for example, save the signal mask. \section{Return Value} On successful completion, \Func{unw\_getcontext}() returns 0. Otherwise, a value of -1 is returned. \section{Thread and Signal Safety} \Func{unw\_getcontext}() is thread-safe as well as safe to use from a signal handler. \section{See Also} \SeeAlso{libunwind(3)}, \SeeAlso{unw\_init\_local(3)} \section{Author} \noindent David Mosberger-Tang\\ Email: \Email{dmosberger@gmail.com}\\ WWW: \URL{http://www.nongnu.org/libunwind/}. \LatexManEnd \end{document}