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| author | rsc <devnull@localhost> | 2005-01-14 17:37:50 +0000 |
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| committer | rsc <devnull@localhost> | 2005-01-14 17:37:50 +0000 |
| commit | adc93f6097615f16d57e8a24a256302f2144ec4e (patch) | |
| tree | e190b0616aa060c646d62de835babf8396d36ccd /man/man3/notify.html | |
| parent | 1ac1981659ba7abcc1c76436e4b4dfc2bc616d2a (diff) | |
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cut out the html - they're going to cause diffing problems.
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| -rw-r--r-- | man/man3/notify.html | 183 |
1 files changed, 0 insertions, 183 deletions
diff --git a/man/man3/notify.html b/man/man3/notify.html deleted file mode 100644 index 9899e701..00000000 --- a/man/man3/notify.html +++ /dev/null @@ -1,183 +0,0 @@ -<head> -<title>notify(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>NOTIFY(3)</b><td align=right><b>NOTIFY(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> - - notify, noted, atnotify, noteenable, notedisable, notifyon, notifyoff - – handle asynchronous process notification<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><br> - #include <libc.h> - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - </font></tt> - <tt><font size=+1>int notify(void (*f)(void*, char*)) - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - </font></tt> - <tt><font size=+1>int noted(int v) - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - </font></tt> - <tt><font size=+1>int atnotify(int (*f)(void*, char*), int in) - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - </font></tt> - <tt><font size=+1>int noteenable(char *msg)<br> - int notedisable(char *msg) - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - </font></tt> - <tt><font size=+1>int notifyon(char *msg)<br> - int notifyoff(char *msg)<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> - - When a process raises an exceptional condition such as dividing - by zero or writing on a closed pipe, a <i>note</i> is posted to communicate - the exception. A note may also be posted by another process via - <a href="../man3/postnote.html"><i>postnote</i>(3)</a>. On Unix, notes are implemented as signals. - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - When a note is received, the action taken depends on the note. - See <a href="../man7/signal.html"><i>signal</i>(7)</a> for the full description of the defaults. - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - The default actions may be overridden. The <i>notify</i> function registers - a <i>notification handler</i> to be called within the process when a - note is received. The argument to <i>notify</i> replaces the previous - handler, if any. An argument of zero cancels a previous handler, - restoring the default action. A <a href="../man2/fork.html"><i>fork</i>(2)</a> system call leaves the - handler registered in both the parent and the child; <a href="../man3/exec.html"><i>exec</i>(3)</a> restores - the default behavior. Handlers may not perform floating point - operations. - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - After a note is posted, the handler is called with two arguments: - the first is unimplemented and should not be used (on Plan 9 it - is a <tt><font size=+1>Ureg</font></tt> structure giving the current values of registers); the - second is a pointer to the note itself, a null-terminated string. - - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - A notification handler must finish either by exiting the program - or by calling <i>noted</i>; if the handler returns the behavior is undefined - and probably erroneous. Until the program calls <i>noted</i>, any further - externally-generated notes (e.g., <tt><font size=+1>hangup</font></tt> or <tt><font size=+1>alarm</font></tt>) will be held - off, and any further notes generated by erroneous - behavior by the program (such as divide by zero) will kill the - program. The argument to <i>noted</i> defines the action to take: <tt><font size=+1>NDFLT</font></tt> - instructs the system to perform the default action as if the handler - had never been registered; <tt><font size=+1>NCONT</font></tt> instructs the system to resume - the process at the point it was notified. In neither case - does <i>noted</i> return to the handler. If the note interrupted an incomplete - system call, that call returns an error (with error string <tt><font size=+1>interrupted</font></tt>) - after the process resumes. A notification handler can also jump - out to an environment set up with <i>setjmp</i> using the <i>notejmp</i> function - (see <a href="../man3/setjmp.html"><i>setjmp</i>(3)</a>). - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - Unix provides a fixed set of notes (typically there are 32) called - <i>signals</i>. It also allows a process to block certain notes from - being delivered (see <a href="../man2/sigprocmask.html"><i>sigprocmask</i>(2)</a>) and to ignore certain notes - by setting the signal hander to the special value <tt><font size=+1>SIG_IGN</font></tt> (see - <a href="../man2/signal.html"><i>signal</i>(2)</a>). <i>Noteenable</i> and <i>notedisable</i> enable or disable receipt - of - a particular note by changing the current process’s blocked signal - mask. Receipt of a disabled note will be postponed until it is - reenabled. <i>Notifyon</i> and <i>notifyoff</i> enable or disable whether the - notification handler is called upon receipt of the note; if the - handler is not called, the note is discarded. - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - Regardless of the origin of the note or the presence of a handler, - if the process is being debugged (see <a href="../man2/ptrace.html"><i>ptrace</i>(2)</a>) the arrival of - a note puts the process in the <tt><font size=+1>Stopped</font></tt> state and awakens the debugger. - - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - Rather than using the system calls <i>notify</i> and <i>noted</i>, most programs - should use <i>atnotify</i> to register notification handlers. The parameter - <i>in</i> is non-zero to register the function <i>f</i>, and zero to cancel - registration. A handler must return a non-zero number if the note - was recognized (and resolved); otherwise it must return - zero. When the system posts a note to the process, each handler - registered with <i>atnotify</i> is called with arguments as described - above until one of the handlers returns non-zero. Then <i>noted</i> is - called with argument <tt><font size=+1>NCONT</font></tt>. If no registered function returns - non-zero, <i>atnotify</i> calls <i>noted</i> with argument <tt><font size=+1>NDFLT</font></tt>. - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - The set of notes a process may receive is system-dependent, but - there is a common set that includes: - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - - <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> - - <i>Note Meaning Unix signal<br> - </i><tt><font size=+1>interrupt </font></tt> user interrupt (DEL key) SIGINTR<br> - <tt><font size=+1>hangup </font></tt> I/O connection closed SIGHUP<br> - <tt><font size=+1>alarm </font></tt> alarm expired SIGLARM<br> - <tt><font size=+1>quit </font></tt> quit from keyboard SIGQUIT<br> - <tt><font size=+1>kill </font></tt> process requested to exit SIGTERM<br> - <tt><font size=+1>sys: kill </font></tt> process forced to exit SIGKILL<br> - <tt><font size=+1>sys: bus error </font></tt> bus error SIGBUS<br> - <tt><font size=+1>sys: segmentation violation </font></tt> segmentation violation SIGSEGV<br> - <tt><font size=+1>sys: write on closed pipe </font></tt> write on closed pipe SIGPIPE<br> - <tt><font size=+1>sys: child </font></tt> child wait status change SIGCHLD<br> - - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - - </table> - See <tt><font size=+1>/usr/local/plan9/src/lib9/await.c</font></tt> (sic) for the full list. - - <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> - - The notes prefixed <tt><font size=+1>sys:</font></tt> are usually generated by the operating - system.<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/notify.c<br> - /usr/local/plan9/src/lib9/atnotify.c<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/intro.html"><i>intro</i>(3)</a>, <i>notejmp</i> in <a href="../man3/setjmp.html"><i>setjmp</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> |