sys/sys/mpipe.h

   1 /*
   2  * Copyright (c) 2003,2004 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/sys/sys/mpipe.h,v 1.4 2004/07/16 05:51:57 dillon Exp $
  35  */
  36
  37 #ifndef _SYS_MPIPE_H_
  38 #define _SYS_MPIPE_H_
  39
  40 #ifndef _SYS_MALLOC_H_
  41 #include <sys/malloc.h>
  42 #endif
  43
  44 /*
  45  * Pipeline memory allocations with persistent store capabilities.  This
  46  * implements a pipeline for allocations of a particular size.  It is used
  47  * in order to allow memory allocations to block while at the same time
  48  * guarenteeing that no deadlocks will occur.
  49  *
  50  * By default new allocations are zero'd out.
  51  *
  52  * MPF_NOZERO           If specified the underlying buffers are not zero'd.
  53  *                      Note this also means you have no way of knowing which
  54  *                      buffers are coming from the cache and which are new
  55  *                      allocations.
  56  *
  57  * MPF_CACHEDATA        If specified the deconstructor will be called when
  58  *                      the underlying buffer is free()'d, but the buffer may
  59  *                      be reused many times before/if that happens.  The
  60  *                      buffer is NOT zero'd on reuse regardless of the
  61  *                      MPF_NOZERO flag.
  62  *
  63  *                      If not specified and MPF_NOZERO is also not specified,
  64  *                      then buffers reused from the cache will be zero'd as
  65  *                      well as new allocations.
  66  *
  67  *                      Note that the deconstructor function may still be NULL
  68  *                      if this flag is specified, meaning that you don't need
  69  *                      notification when the cached contents is physically
  70  *                      free()'d.
  71  *
  72  * MPF_INT              Use the interrupt reserve if necessary.
  73  */
  74 struct mpipe_buf;
  75
  76 struct malloc_pipe {
  77     malloc_type_t type;         /* malloc bucket */
  78     int         bytes;          /* allocation size */
  79     int         mpflags;        /* MPF_ flags */
  80     int         mflags;         /* M_ flags (used internally) */
  81     int         pending;        /* there is a request pending */
  82     int         free_count;     /* entries in array[] */
  83     int         total_count;    /* total outstanding allocations incl free */
  84     int         ary_count;      /* guarenteed allocation count */
  85     int         max_count;      /* maximum count (M_NOWAIT used beyond nom) */
  86     void        **array;        /* array[ary_count] */
  87     void        (*deconstruct)(struct malloc_pipe *, void *buf);
  88 };
  89
  90 #define MPF_CACHEDATA           0x0001  /* cache old buffers (do not zero) */
  91 #define MPF_NOZERO              0x0002  /* do not zero-out new allocations */
  92 #define MPF_INT                 0x0004  /* use the interrupt memory reserve */
  93
  94 typedef struct malloc_pipe *malloc_pipe_t;
  95
  96 #ifdef _KERNEL
  97
  98 void mpipe_init(malloc_pipe_t mpipe, malloc_type_t type,
  99                 int bytes, int nnom, int nmax,
 100                 int mpflags, void (*deconstruct)(struct malloc_pipe *, void *));
 101 void mpipe_done(malloc_pipe_t mpipe);
 102 void *mpipe_alloc_waitok(malloc_pipe_t mpipe);
 103 void *mpipe_alloc_nowait(malloc_pipe_t mpipe);
 104 void mpipe_free(malloc_pipe_t mpipe, void *vbuf);
 105
 106 #endif
 107
 108 #endif
 109