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Diffstat (limited to 'lib/libc/db/man/mpool.3')
| -rw-r--r-- | lib/libc/db/man/mpool.3 | 262 |
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diff --git a/lib/libc/db/man/mpool.3 b/lib/libc/db/man/mpool.3 deleted file mode 100644 index ed81fd95867..00000000000 --- a/lib/libc/db/man/mpool.3 +++ /dev/null @@ -1,262 +0,0 @@ -.\" $OpenBSD: mpool.3,v 1.16 2013/06/05 03:39:22 tedu Exp $ -.\" -.\" Copyright (c) 1990, 1993 -.\" The Regents of the University of California. All rights reserved. -.\" -.\" Redistribution and use in source and binary forms, with or without -.\" modification, are permitted provided that the following conditions -.\" are met: -.\" 1. Redistributions of source code must retain the above copyright -.\" notice, this list of conditions and the following disclaimer. -.\" 2. Redistributions in binary form must reproduce the above copyright -.\" notice, this list of conditions and the following disclaimer in the -.\" documentation and/or other materials provided with the distribution. -.\" 3. Neither the name of the University nor the names of its contributors -.\" may be used to endorse or promote products derived from this software -.\" without specific prior written permission. -.\" -.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND -.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE -.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL -.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS -.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) -.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY -.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF -.\" SUCH DAMAGE. -.\" -.\" @(#)mpool.3 8.1 (Berkeley) 6/4/93 -.\" -.Dd $Mdocdate: June 5 2013 $ -.Dt MPOOL 3 -.Os -.Sh NAME -.Nm mpool_open , -.Nm mpool_filter , -.Nm mpool_new , -.Nm mpool_delete , -.Nm mpool_get , -.Nm mpool_put , -.Nm mpool_sync , -.Nm mpool_close -.Nd shared memory buffer pool -.Sh SYNOPSIS -.In db.h -.In mpool.h -.Ft MPOOL * -.Fn mpool_open "void *key" "int fd" "pgno_t pagesize" "pgno_t maxcache" -.Ft void -.Fn mpool_filter "MPOOL *mp" "void (*pgin)(void *, pgno_t, void *)" \ - "void (*pgout)(void *, pgno_t, void *)" "void *pgcookie" -.Ft void * -.Fn mpool_new "MPOOL *mp" "pgno_t *pgnoaddr" "unsigned int flags" -.Ft int -.Fn mpool_delete "MPOOL *mp" "void *page" -.Ft void * -.Fn mpool_get "MPOOL *mp" "pgno_t pgno" "unsigned int flags" -.Ft int -.Fn mpool_put "MPOOL *mp" "void *pgaddr" "unsigned int flags" -.Ft int -.Fn mpool_sync "MPOOL *mp" -.Ft int -.Fn mpool_close "MPOOL *mp" -.Sh DESCRIPTION -.Nm mpool -is the library interface intended to provide page-oriented buffer management -of files. -The buffers may be shared between processes. -.Pp -The function -.Fn mpool_open -initializes a memory pool. -The -.Fa key -argument is the byte string used to negotiate between multiple -processes wishing to share buffers. -If the file buffers are mapped in shared memory, all processes using -the same key will share the buffers. -If -.Fa key -is -.Dv NULL , -the buffers are mapped into private memory. -The -.Fa fd -argument is a file descriptor for the underlying file, which must be seekable. -If -.Fa key -is non-NULL and matches a file already being mapped, the -.Fa fd -argument is ignored. -.Pp -The -.Fa pagesize -argument is the size, in bytes, of the pages into which the file is broken up. -The -.Fa maxcache -argument is the maximum number of pages from the underlying file to cache -at any one time. -This value is not relative to the number of processes which share a file's -buffers, but will be the largest value specified by any of the processes -sharing the file. -.Pp -The -.Fn mpool_filter -function is intended to make transparent input and output processing of the -pages possible. -If the -.Fa pgin -function is specified, it is called each time a buffer is read into the memory -pool from the backing file. -If the -.Fa pgout -function is specified, it is called each time a buffer is written into the -backing file. -Both functions are called with the -.Fa pgcookie -pointer, the page number, and a pointer to the page being read or written. -.Pp -The function -.Fn mpool_new -takes an -.Dv MPOOL -pointer, an address, and a set of flags as arguments. -If a new page can be allocated, a pointer to the page is returned and -the page number is stored into the -.Fa pgnoaddr -address. -Otherwise, -.Dv NULL -is returned and -.Va errno -is set. -The flags value is formed by -.Tn OR Ns 'ing -the following values: -.Bl -tag -width Ds -.It Dv MPOOL_PAGE_REQUEST -Allocate a new page with a specific page number. -.It Dv MPOOL_PAGE_NEXT -Allocate a new page with the next page number. -.El -.Pp -The function -.Fn mpool_delete -deletes the specified page from a pool and frees the page. -It takes an -.Dv MPOOL -pointer and a page as arguments. -The page must have been generated by -.Fn mpool_new . -.Pp -The function -.Fn mpool_get -takes an -.Dv MPOOL -pointer and a page number as arguments. -If the page exists, a pointer to the page is returned. -Otherwise, -.Dv NULL -is returned and -.Va errno -is set. -The flags parameter is not currently used. -.Pp -The function -.Fn mpool_put -unpins the page referenced by -.Fa pgaddr . -.Fa pgaddr -must be an address previously returned by -.Fn mpool_get -or -.Fn mpool_new . -The flags value is formed by -.Tn OR Ns 'ing -the following values: -.Bl -tag -width Ds -.It Dv MPOOL_DIRTY -The page has been modified and needs to be written to the backing file. -.El -.Pp -.Fn mpool_put -returns 0 on success and \-1 if an error occurs. -.Pp -The function -.Fn mpool_sync -writes all modified pages associated with the -.Dv MPOOL -pointer to the backing file. -.Fn mpool_sync -returns 0 on success and \-1 if an error occurs. -.Pp -The -.Fn mpool_close -function frees up any allocated memory associated with the memory pool -cookie. -Modified pages are -.Em not -written to the backing file. -.Fn mpool_close -returns 0 on success and \-1 if an error occurs. -.Sh ERRORS -The -.Fn mpool_open -function may fail and set -.Va errno -for any of the errors specified for the library routines -.Xr fstat 2 -and -.Xr malloc 3 , -or the following: -.Bl -tag -width Er -.It Bq Er ESPIPE -The given file descriptor is a pipe. -.El -.Pp -The -.Fn mpool_get -function may fail and set -.Va errno -for the following: -.Bl -tag -width Er -.It Bq Er EINVAL -The requested record doesn't exist. -.El -.Pp -The -.Fn mpool_new -and -.Fn mpool_get -functions may fail and set -.Va errno -for any of the errors specified for the library routines -.Xr pread 2 , -.Xr pwrite 2 , -and -.Xr malloc 3 . -.Pp -The -.Fn mpool_sync -function may fail and set -.Va errno -for any of the errors specified for the library routine -.Xr pwrite 2 . -.Pp -The -.Fn mpool_close -function may fail and set -.Va errno -for any of the errors specified for the library routine -.Xr free 3 . -.Pp -The -.Fn mpool_delete -always acts as if it succeeded. -.Sh SEE ALSO -.Xr btree 3 , -.Xr dbopen 3 , -.Xr hash 3 , -.Xr recno 3 |