From adc93f6097615f16d57e8a24a256302f2144ec4e Mon Sep 17 00:00:00 2001 From: rsc Date: Fri, 14 Jan 2005 17:37:50 +0000 Subject: cut out the html - they're going to cause diffing problems. --- man/man3/needstack.html | 98 ------------------------------------------------- 1 file changed, 98 deletions(-) delete mode 100644 man/man3/needstack.html (limited to 'man/man3/needstack.html') diff --git a/man/man3/needstack.html b/man/man3/needstack.html deleted file mode 100644 index bba5fbe8..00000000 --- a/man/man3/needstack.html +++ /dev/null @@ -1,98 +0,0 @@ - -needstack(3) - Plan 9 from User Space - - - - -
-
-
NEEDSTACK(3)NEEDSTACK(3) -
-
-

NAME
- -
- - needstack – check for execution stack overflow
- -
-

SYNOPSIS
- -
- - #include <u.h> -
- - #include <libc.h> -
- - int    needstack(int n)
- -
-

DESCRIPTION
- -
- - Stack overflow in the thread library leads to bugs that are difficult - to diagnose. The Plan 9 libraries are careful about not allocating - large structures on the stack, so typically four or eight kilobytes - is plenty of stack for a thread. Other libraries are not always - as careful. Calling needstack indicates to the thread library - that an external routine is about to be called that will require - n bytes of stack space. If there is not enough space left on the - stack, the thread library prints an error and terminates the program. - The call needstack(0) can be used to check whether the stack is - currently overflowed. -
- - Needstack is defined in libc.h so that library functions used - in threaded and non-threaded contexts can call it. The implementation - of needstack in lib9 is a no-op. -
- - Needstack should be thought of as a comment checked at run time, - like assert(3).
- -
-

EXAMPLE
- -
- - The X Window library implementation of XLookupString allocates - some very large buffers on the stack, so /usr/local/plan9/src/libdraw/x11−itrans.c - calls needstack(20*1024) before making calls to XLookupString. - If a thread (in this case, the keyboard-reading thread used inside - the draw(3) - library) does not allocate a large enough stack, the problem is - diagnosed immediately rather than left to corrupt memory.
- -
-

SOURCE
- -
- - /usr/local/plan9/src/lib9/needstack.c
- /usr/local/plan9/src/libthread
- -
-

SEE ALSO
- -
- - thread(3)
- -
- -

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- - -
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-Space Glenda -
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