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diff --git a/man/man9/flush.html b/man/man9/flush.html new file mode 100644 index 00000000..20544557 --- /dev/null +++ b/man/man9/flush.html @@ -0,0 +1,98 @@ +<head> +<title>flush(9P) - 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>FLUSH(9P)</b><td align=right><b>FLUSH(9P)</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> + + flush – abort a message<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> + + <i>size</i>[4] <tt><font size=+1>Tflush</font></tt> <i>tag</i>[2] <i>oldtag</i>[2]<br> + <i>size</i>[4] <tt><font size=+1>Rflush</font></tt> <i>tag</i>[2]<br> + +</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 the response to a request is no longer needed, such as when + a user interrupts a process doing a <i>read</i>(9p), a <tt><font size=+1>Tflush</font></tt> request + is sent to the server to purge the pending response. The message + being flushed is identified by <i>oldtag</i>. The semantics of <tt><font size=+1>flush</font></tt> + depends on messages arriving in order. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + The server should answer the <tt><font size=+1>flush</font></tt> message immediately. If it + recognizes <i>oldtag</i> as the tag of a pending transaction, it should + abort any pending response and discard that tag. In either case, + it should respond with an <tt><font size=+1>Rflush</font></tt> echoing the <i>tag</i> (not <i>oldtag</i>) + of the <tt><font size=+1>Tflush</font></tt> message. A <tt><font size=+1>Tflush</font></tt> can never be + responded to by an <tt><font size=+1>Rerror</font></tt> message. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + The server may respond to the pending request before responding + to the <tt><font size=+1>Tflush</font></tt>. It is possible for a client to send multiple <tt><font size=+1>Tflush</font></tt> + messages for a particular pending request. Each subsequent <tt><font size=+1>Tflush</font></tt> + must contain as <i>oldtag</i> the tag of the pending request (not a previous + <tt><font size=+1>Tflush</font></tt>). Should multiple <tt><font size=+1>Tflush</font></tt>es be + received for a pending request, they must be answered in order. + A <tt><font size=+1>Rflush</font></tt> for any of the multiple <tt><font size=+1>Tflush</font></tt>es implies an answer for + all previous ones. Therefore, should a server receive a request + and then multiple flushes for that request, it need respond only + to the last flush. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + When the client sends a <tt><font size=+1>Tflush</font></tt>, it must wait to receive the corresponding + <tt><font size=+1>Rflush</font></tt> before reusing <i>oldtag</i> for subsequent messages. If a response + to the flushed request is received before the <tt><font size=+1>Rflush</font></tt>, the client + must honor the response as if it had not been flushed, since the + completed request may signify a state + change in the server. For instance, <tt><font size=+1>Tcreate</font></tt> may have created a + file and <tt><font size=+1>Twalk</font></tt> may have allocated a fid. If no response is received + before the <tt><font size=+1>Rflush</font></tt>, the flushed transaction is considered to have + been canceled, and should be treated as though it had never been + sent. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Several exceptional conditions are handled correctly by the above + specification: sending multiple flushes for a single tag, flushing + after a transaction is completed, flushing a <tt><font size=+1>Tflush</font></tt>, and flushing + an invalid tag.<br> + +</table> +<p><font size=+1><b>ENTRY POINTS </b></font><br> + +<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> + + The <a href="../man3/9pclient.html"><i>9pclient</i>(3)</a> library does not generate <tt><font size=+1>flush</font></tt> transactions.. + <a href="../man4/9pserve.html"><i>9pserve</i>(4)</a> generates <tt><font size=+1>flush</font></tt> transactions to cancel transactions + pending when a client hangs up.<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> |