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| <title>9p-fid(3) - Plan 9 from User Space</title> |
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| <tr><td width=20><td><b>9P-FID(3)</b><td align=right><b>9P-FID(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> |
| |
| Fid, Fidpool, allocfidpool, freefidpool, allocfid, closefid, lookupfid, |
| removefid, Req, Reqpool, allocreqpool, freereqpool, allocreq, |
| closereq, lookupreq, removereq – 9P fid, request tracking<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><br> |
| #include <fcall.h><br> |
| #include <thread.h><br> |
| #include <9p.h><br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| typedef struct Fid<br> |
| {<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| ulong fid;<br> |
| char omode; /* −1 if not open */<br> |
| char *uid;<br> |
| Qid qid;<br> |
| File *file;<br> |
| void *aux;<br> |
| |
| </table> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <i>...<br> |
| </i> |
| </table> |
| <tt><font size=+1>} Fid;<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| typedef struct Req<br> |
| {<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| ulong tag;<br> |
| Fcall ifcall;<br> |
| Fcall ofcall;<br> |
| Req *oldreq;<br> |
| void *aux;<br> |
| |
| </table> |
| </font></tt> |
| <table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td> |
| |
| <i>...<br> |
| </i> |
| </table> |
| <tt><font size=+1>} Req;<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| Fidpool* allocfidpool(void (*destroy)(Fid*))<br> |
| void freefidpool(Fidpool *p)<br> |
| Fid* allocfid(Fidpool *p, ulong fid)<br> |
| Fid* lookupfid(Fidpool *p, ulong fid)<br> |
| void closefid(Fid *f)<br> |
| void removefid(Fid *f)<br> |
| |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| Reqpool* allocreqpool(void (*destroy)(Req*))<br> |
| void freereqpool(Reqpool *p)<br> |
| Req* allocreq(Reqpool *p, ulong tag)<br> |
| Req* lookupreq(Reqpool *p, ulong tag)<br> |
| void closereq(Req *f)<br> |
| void removereq(Req *r)<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> |
| |
| These routines provide management of <tt><font size=+1>Fid</font></tt> and <tt><font size=+1>Req</font></tt> structures from |
| <tt><font size=+1>Fidpool</font></tt>s and <tt><font size=+1>Reqpool</font></tt>s. They are primarily used by the 9P server |
| loop described in <a href="../man3/9p.html"><i>9p</i>(3)</a>. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <tt><font size=+1>Fid</font></tt> structures are intended to represent active fids in a 9P connection, |
| as <tt><font size=+1>Chan</font></tt> structures do in the Plan 9 kernel. The <tt><font size=+1>fid</font></tt> element is |
| the integer fid used in the 9P connection. <tt><font size=+1>Omode</font></tt> is the mode under |
| which the fid was opened, or <tt><font size=+1>−1</font></tt> if this fid has not been opened |
| yet. Note that in addition to the values <tt><font size=+1>OREAD</font></tt>, |
| <tt><font size=+1>OWRITE</font></tt>, and <tt><font size=+1>ORDWR</font></tt>, <tt><font size=+1>omode</font></tt> can contain the various flags permissible |
| in an open call. To ignore the flags, use <tt><font size=+1>omode&OMASK</font></tt>. <tt><font size=+1>Omode</font></tt> should |
| not be changed by the client. The fid derives from a successful |
| authentication by <tt><font size=+1>uid</font></tt>. <tt><font size=+1>Qid</font></tt> contains the qid returned in the last |
| successful <tt><font size=+1>walk</font></tt> or <tt><font size=+1>create</font></tt> transaction |
| involving the fid. In a file tree-based server, the <tt><font size=+1>Fid</font></tt>’s <tt><font size=+1>file</font></tt> |
| element points at a <tt><font size=+1>File</font></tt> structure (see <a href="../man3/9p-file.html"><i>9p-file</i>(3)</a>) corresponding |
| to the fid. The <tt><font size=+1>aux</font></tt> member is intended for use by the client to |
| hold information specific to a particular <tt><font size=+1>Fid</font></tt>. With the exception |
| of <tt><font size=+1>aux</font></tt>, these elements should be treated as read-only by |
| the client. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Allocfidpool</i> creates a new <tt><font size=+1>Fidpool</font></tt>. <i>Freefidpool</i> destroys such |
| a pool. <i>Allocfid</i> returns a new <tt><font size=+1>Fid</font></tt> whose fid number is <i>fid</i>. There |
| must not already be an extant <tt><font size=+1>Fid</font></tt> with that number in the pool. |
| Once a <tt><font size=+1>Fid</font></tt> has been allocated, it can be looked up by fid number |
| using <i>lookupfid</i>. <tt><font size=+1>Fid</font></tt>s are reference counted: both |
| <i>allocfid</i> and <i>lookupfid</i> increment the reference count on the <tt><font size=+1>Fid</font></tt> |
| structure before returning. When a reference to a <tt><font size=+1>Fid</font></tt> is no longer |
| needed, <i>closefid</i> should be called to note the destruction of the |
| reference. When the last reference to a <tt><font size=+1>Fid</font></tt> is removed, if <i>destroy</i> |
| (supplied when creating the fid pool) is not zero, it is |
| called with the <tt><font size=+1>Fid</font></tt> as a parameter. It should perform whatever |
| cleanup is necessary regarding the <tt><font size=+1>aux</font></tt> element. <i>Removefid</i> is equivalent |
| to <i>closefid</i> but also removes the <tt><font size=+1>Fid</font></tt> from the pool. Note that |
| due to lingering references, the return of <i>removefid</i> may not mean |
| that <i>destroy</i> has been called. |
| <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> |
| |
| <i>Allocreqpool</i>, <i>freereqpool</i>, <i>allocreq</i>, <i>lookupreq</i>, <i>closereq</i>, and |
| <i>removereq</i> are analogous but operate on <tt><font size=+1>Reqpool</font></tt>s and <tt><font size=+1>Req</font></tt> structures.<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/lib9p<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="../man3/9p.html"><i>9p</i>(3)</a>, <a href="../man3/9p-file.html"><i>9p-file</i>(3)</a><br> |
| |
| </table> |
| |
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