diff options
Diffstat (limited to 'man/man3/needstack.html')
| -rw-r--r-- | man/man3/needstack.html | 98 |
1 files changed, 0 insertions, 98 deletions
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 @@ -<head> -<title>needstack(3) - Plan 9 from User Space</title> -<meta content="text/html; charset=utf-8" http-equiv=Content-Type> -</head> -<body bgcolor=#ffffff> -<table border=0 cellpadding=0 cellspacing=0 width=100%> -<tr height=10><td> -<tr><td width=20><td> -<tr><td width=20><td><b>NEEDSTACK(3)</b><td align=right><b>NEEDSTACK(3)</b> -<tr><td width=20><td colspan=2> - <br> -<p><font size=+1><b>NAME </b></font><br> - -<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> - - needstack – check for execution stack overflow<br> - -</table> -<p><font size=+1><b>SYNOPSIS </b></font><br> - -<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> - - <tt><font size=+1>#include <u.h> - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - </font></tt> - <tt><font size=+1>#include <libc.h> - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - </font></tt> - <tt><font size=+1>int needstack(int n)<br> - </font></tt> -</table> -<p><font size=+1><b>DESCRIPTION </b></font><br> - -<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> - - 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 <i>needstack</i> indicates to the thread library - that an external routine is about to be called that will require - <i>n</i> 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 <tt><font size=+1>needstack(0)</font></tt> can be used to check whether the stack is - currently overflowed. - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - <i>Needstack</i> is defined in <tt><font size=+1>libc.h</font></tt> so that library functions used - in threaded and non-threaded contexts can call it. The implementation - of <i>needstack</i> in <tt><font size=+1>lib9</font></tt> is a no-op. - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - <i>Needstack</i> should be thought of as a comment checked at run time, - like <a href="../man3/assert.html"><i>assert</i>(3)</a>.<br> - -</table> -<p><font size=+1><b>EXAMPLE </b></font><br> - -<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> - - The X Window library implementation of <i>XLookupString</i> allocates - some very large buffers on the stack, so <tt><font size=+1>/usr/local/plan9/src/libdraw/x11−itrans.c</font></tt> - calls <tt><font size=+1>needstack(20*1024)</font></tt> before making calls to <i>XLookupString</i>. - If a thread (in this case, the keyboard-reading thread used inside - the <a href="../man3/draw.html"><i>draw</i>(3)</a> - library) does not allocate a large enough stack, the problem is - diagnosed immediately rather than left to corrupt memory.<br> - -</table> -<p><font size=+1><b>SOURCE </b></font><br> - -<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> - - <tt><font size=+1>/usr/local/plan9/src/lib9/needstack.c<br> - /usr/local/plan9/src/libthread<br> - </font></tt> -</table> -<p><font size=+1><b>SEE ALSO </b></font><br> - -<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> - - <a href="../man3/thread.html"><i>thread</i>(3)</a><br> - -</table> - -<td width=20> -<tr height=20><td> -</table> -<!-- TRAILER --> -<table border=0 cellpadding=0 cellspacing=0 width=100%> -<tr height=15><td width=10><td><td width=10> -<tr><td><td> -<center> -<a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a> -</center> -</table> -<!-- TRAILER --> -</body></html> |