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diff --git a/man/man3/9p-intmap.html b/man/man3/9p-intmap.html new file mode 100644 index 00000000..f6d1822f --- /dev/null +++ b/man/man3/9p-intmap.html @@ -0,0 +1,110 @@ +<head> +<title>9p-intmap(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>9P-INTMAP(3)</b><td align=right><b>9P-INTMAP(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> + + Intmap, allocmap, freemap, insertkey, caninsertkey, lookupkey, + deletekey – integer to data structure maps<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> + + Intmap* allocmap(void (*inc)(void*))<br> + void freemap(Intmap *map, void (*dec)(void*))<br> + void* lookupkey(Intmap *map, ulong key)<br> + void* insertkey(Intmap *map, ulong key, void *val)<br> + int caninsertkey(Intmap *map, ulong key, void *val)<br> + void* lookupkey(Intmap *map, ulong key)<br> + void* deletekey(Intmap *map, ulong key)<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> + + An <tt><font size=+1>Intmap</font></tt> is an arbitrary mapping from integers to pointers. <i>Allocmap</i> + creates a new map, and <i>freemap</i> destroys it. The <i>inc</i> function is + called each time a new pointer is added to the map; similarly, + <i>dec</i> is called on each pointer left in the map when it is being + freed. Typically these functions maintain reference counts. + New entries are added to the map by calling <i>insertkey</i>, which will + return the previous value associated with the given <i>key</i>, or zero + if there was no previous value. <i>Caninsertkey</i> is like <i>insertkey</i> + but only inserts <i>val</i> if there is no current mapping. It returns + 1 if <i>val</i> was inserted, 0 otherwise. <i>Lookupkey</i> returns the pointer + associated with <i>key</i>, or zero if there is no such pointer. <i>Deletekey</i> + removes the entry for <i>id</i> from the map, returning the associated + pointer, if any. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + Concurrent access to <tt><font size=+1>Intmap</font></tt>s is safe, moderated via a <tt><font size=+1>QLock</font></tt> stored + in the <tt><font size=+1>Intmap</font></tt> structure. + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + In anticipation of the storage of reference-counted structures, + an increment function <i>inc</i> may be specified at map creation time. + <i>Lookupkey</i> calls <i>inc</i> (if non-zero) on pointers before returning + them. If the reference count adjustments were left to the caller + (and thus not protected by the lock), it would be possible to + accidentally reclaim a structure if, for example, it was deleted + from the map and its reference count decremented between the return + of <i>insertkey</i> and the external increment. <i>Insertkey</i> and <i>caninsertkey</i> + do <i>not</i> call <i>inc</i> when inserting <i>val</i> into the map, nor do <i>insertkey</i> + or <i>deletekey</i> call <i>inc</i> when returning old map entries. + The rationale is that calling an insertion function transfers + responsibility for the reference to the map, and responsibility + is given back via the return value of <i>deletekey</i> or the next <i>insertkey</i>. + + <table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table> + + <tt><font size=+1>Intmap</font></tt>s are used by the 9P library to implement <tt><font size=+1>Fidpool</font></tt>s and <tt><font size=+1>Reqpool</font></tt>s.<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/intmap.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="../man3/9p.html"><i>9p</i>(3)</a>, <a href="../man3/9p-fid.html"><i>9p-fid</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> |