2003-04-01 09:19:34 +02:00
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\documentclass{article}
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\usepackage[fancyhdr,pdf]{latex2man}
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\input{common.tex}
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\begin{document}
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\begin{Name}{3}{unw\_getcontext}{David Mosberger-Tang}{Programming Library}{unw\_getcontext}unw\_getcontext -- get initial machine-state
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\end{Name}
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\section{Synopsis}
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\File{\#include $<$libunwind.h$>$}\\
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\Type{int} \Func{unw\_getcontext}(\Type{unw\_context\_t~*}\Var{ucp});\\
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\section{Description}
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The \Func{unw\_getcontext}() routine initializes the context structure
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pointed to by \Var{ucp} with the machine-state of the call-site. The
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exact set of registers stored by \Func{unw\_getcontext}() is
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platform-specific, but, in general, at least all preserved
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(``callee-saved'') and all frame-related registers, such as the
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stack-pointer, will be stored.
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2004-01-21 02:05:07 +01:00
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This routine is normally implemented as a macro and applications
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should not attempt to take its address.
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2004-03-31 02:52:17 +02:00
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\section{Platform-specific Notes}
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On IA-64, \Type{unw\_context\_t} has a layout that is compatible with
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that of \Type{ucontext\_t} and such structures can be initialized with
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\Func{getcontext}() instead of \Func{unw\_getcontext}(). However, the
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reverse is \emph{not} true and it is \emph{not} safe to use structures
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initialized by \Func{unw\_getcontext()} in places where a structure
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initialized by \Func{getcontext()} is expected. The reason for this
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asymmetry is that \Func{unw\_getcontext()} is optimized for maximum
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performance and does not, for example, save the signal mask.
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2003-04-01 09:19:34 +02:00
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\section{Return Value}
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On successful completion, \Func{unw\_getcontext}() returns 0.
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Otherwise, a value of -1 is returned.
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\section{Thread and Signal Safety}
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\Func{unw\_getcontext}() is thread-safe as well as safe to use
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from a signal handler.
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\section{See Also}
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\SeeAlso{libunwind(3)},
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\SeeAlso{unw\_init\_local(3)}
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\section{Author}
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\noindent
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David Mosberger-Tang\\
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Hewlett-Packard Labs\\
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Palo-Alto, CA 94304\\
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Email: \Email{davidm@hpl.hp.com}\\
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WWW: \URL{http://www.hpl.hp.com/research/linux/libunwind/}.
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\LatexManEnd
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\end{document}
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