exec/schedwrk.c

   1 /*
   2  * Copyright (c) 2009-2010 Red Hat, Inc.
   3  *
   4  * All rights reserved.
   5  *
   6  * Author: Steven Dake (sdake@redhat.com)
   7  *
   8  * This software licensed under BSD license, the text of which follows:
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions are met:
  12  *
  13  * - Redistributions of source code must retain the above copyright notice,
  14  *   this list of conditions and the following disclaimer.
  15  * - Redistributions in binary form must reproduce the above copyright notice,
  16  *   this list of conditions and the following disclaimer in the documentation
  17  *   and/or other materials provided with the distribution.
  18  * - Neither the name of the MontaVista Software, Inc. nor the names of its
  19  *   contributors may be used to endorse or promote products derived from this
  20  *   software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTIBUTORS "AS IS"
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  32  * THE POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include <config.h>
  36 #include <corosync/totem/totempg.h>
  37 #include <corosync/hdb.h>
  38 #include "schedwrk.h"
  39
  40 static void (*serialize_lock) (void);
  41 static void (*serialize_unlock) (void);
  42
  43 DECLARE_HDB_DATABASE (schedwrk_instance_database,NULL);
  44
  45 struct schedwrk_instance {
  46         int (*schedwrk_fn) (const void *);
  47         const void *context;
  48         void *callback_handle;
  49         int lock;
  50 };
  51
  52 static int schedwrk_do (enum totem_callback_token_type type, const void *context)
  53 {
  54         hdb_handle_t handle = *((hdb_handle_t *)context);
  55         struct schedwrk_instance *instance;
  56         int res;
  57
  58         res = hdb_handle_get (&schedwrk_instance_database,
  59                 handle,
  60                 (void *)&instance);
  61         if (res != 0) {
  62                 goto error_exit;
  63         }
  64
  65         if (instance->lock)
  66                 serialize_lock ();
  67
  68         res = instance->schedwrk_fn (instance->context);
  69
  70         if (instance->lock)
  71                 serialize_unlock ();
  72
  73         if (res == 0) {
  74                 hdb_handle_destroy (&schedwrk_instance_database, handle);
  75         }
  76         hdb_handle_put (&schedwrk_instance_database, handle);
  77         return (res);
  78
  79 error_exit:
  80         return (-1);
  81 }
  82
  83 void schedwrk_init (
  84         void (*serialize_lock_fn) (void),
  85         void (*serialize_unlock_fn) (void))
  86 {
  87         serialize_lock = serialize_lock_fn;
  88         serialize_unlock = serialize_unlock_fn;
  89 }
  90
  91 static int schedwrk_internal_create (
  92         hdb_handle_t *handle,
  93         int (schedwrk_fn) (const void *),
  94         const void *context,
  95         int lock)
  96 {
  97         struct schedwrk_instance *instance;
  98         int res;
  99
 100         res = hdb_handle_create (&schedwrk_instance_database,
 101                 sizeof (struct schedwrk_instance), handle);
 102         if (res != 0) {
 103                 goto error_exit;
 104         }
 105         res = hdb_handle_get (&schedwrk_instance_database, *handle,
 106                 (void *)&instance);
 107         if (res != 0) {
 108                 goto error_destroy;
 109         }
 110
 111         totempg_callback_token_create (
 112                 &instance->callback_handle,
 113                 TOTEM_CALLBACK_TOKEN_SENT,
 114                 1,
 115                 schedwrk_do,
 116                 handle);
 117
 118         instance->schedwrk_fn = schedwrk_fn;
 119         instance->context = context;
 120         instance->lock = lock;
 121
 122         hdb_handle_put (&schedwrk_instance_database, *handle);
 123
 124         return (0);
 125
 126 error_destroy:
 127         hdb_handle_destroy (&schedwrk_instance_database, *handle);
 128
 129 error_exit:
 130         return (-1);
 131 }
 132
 133 /*
 134  * handle pointer is internally used by totempg_callback_token_create. To make schedwrk work,
 135  * handle must be pointer to ether heap or .text or static memory (not stack) which is not
 136  * changed by caller.
 137  */
 138 int schedwrk_create (
 139         hdb_handle_t *handle,
 140         int (schedwrk_fn) (const void *),
 141         const void *context)
 142 {
 143         return schedwrk_internal_create (handle, schedwrk_fn, context, 1);
 144 }
 145
 146 int schedwrk_create_nolock (
 147         hdb_handle_t *handle,
 148         int (schedwrk_fn) (const void *),
 149         const void *context)
 150 {
 151         return schedwrk_internal_create (handle, schedwrk_fn, context, 0);
 152 }
 153
 154 void schedwrk_destroy (hdb_handle_t handle)
 155 {
 156         hdb_handle_destroy (&schedwrk_instance_database, handle);
 157 }