Subversion Repositories HelenOS

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Ignore whitespace Rev 2679 → Rev 2680

/trunk/uspace/lib/libc/include/rwlock.h
0,0 → 1,56
/*
* Copyright (c) 2008 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
 
/** @addtogroup libc
* @{
*/
/**
* @file
* @brief This file contains rwlock API and provides its fake
* implementation based on futexes.
*/
 
#ifndef LIBC_RWLOCK_H_
#define LIBC_RWLOCK_H_
 
#include <atomic.h>
#include <sys/types.h>
#include <futex.h>
 
typedef atomic_t rwlock_t;
 
#define rwlock_initialize(rwlock) futex_initialize((rwlock), 1)
#define rwlock_reader_lock(rwlock) futex_down((rwlock))
#define rwlock_writer_lock(rwlock) futex_down((rwlock))
#define rwlock_reader_unlock(rwlock) futex_up((rwlock))
#define rwlock_writer_unlock(rwlock) futex_up((rwlock))
 
#endif
 
/** @}
*/
/trunk/uspace/srv/vfs/vfs.h
36,6 → 36,7
#include <ipc/ipc.h>
#include <libadt/list.h>
#include <atomic.h>
#include <rwlock.h>
#include <sys/types.h>
#include <bool.h>
 
135,8 → 136,8
unsigned refcnt; /**< Usage counter. */
link_t nh_link; /**< Node hash-table link. */
 
/** Holding this futex prevents modifications of the node's contents. */
atomic_t contents_futex;
/** Holding this rwlock prevents modifications of the node's contents. */
atomic_t contents_rwlock;
} vfs_node_t;
 
/**
/trunk/uspace/srv/vfs/vfs_node.c
40,6 → 40,7
#include <string.h>
#include <atomic.h>
#include <futex.h>
#include <rwlock.h>
#include <libadt/hash_table.h>
 
/** Futex protecting the VFS node hash table. */
146,7 → 147,7
node->dev_handle = triplet->fs_handle;
node->index = triplet->index;
link_initialize(&node->nh_link);
futex_initialize(&node->contents_futex, 1);
rwlock_initialize(&node->contents_rwlock);
hash_table_insert(&nodes, key, &node->nh_link);
} else {
node = hash_table_get_instance(tmp, vfs_node_t, nh_link);
/trunk/uspace/srv/vfs/vfs_rdwr.c
39,7 → 39,7
#include <ipc/ipc.h>
#include <async.h>
#include <errno.h>
#include <futex.h>
#include <rwlock.h>
 
static void vfs_rdwr(ipc_callid_t rid, ipc_call_t *request, bool read)
{
85,7 → 85,10
* Lock the file's node so that no other client can read/write to it at
* the same time.
*/
futex_down(&file->node->contents_futex);
if (read)
rwlock_reader_lock(&file->node->contents_rwlock);
else
rwlock_writer_lock(&file->node->contents_rwlock);
 
int fs_phone = vfs_grab_phone(file->node->fs_handle);
117,7 → 120,10
/*
* Unlock the VFS node.
*/
futex_up(&file->node->contents_futex);
if (read)
rwlock_reader_unlock(&file->node->contents_rwlock);
else
rwlock_writer_unlock(&file->node->contents_rwlock);
 
/*
* Update the position pointer.