source: trunk/kernel/libk/remote_queuelock.c @ 603

Last change on this file since 603 was 603, checked in by alain, 3 years ago

Improve the FAT32 file system to support cat, rm, cp commands.

File size: 6.4 KB
Line 
1/*
2 * remote_queuelock.c - remote kernel lock with waiting queue implementation.
3 *
4 * Authors   Alain Greiner     (2016,2017,2018)
5 *
6 * Copyright (c) UPMC Sorbonne Universites
7 *
8 * This file is part of ALMOS-MKH.
9 *
10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; version 2.0 of the License.
13 *
14 * ALMOS-MKH is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24#include <kernel_config.h>
25#include <hal_kernel_types.h>
26#include <hal_atomic.h>
27#include <thread.h>
28#include <scheduler.h>
29#include <busylock.h>
30#include <remote_queuelock.h>
31
32//////////////////////////////////////////////////////////////////////////////
33//                Extern global variables
34//////////////////////////////////////////////////////////////////////////////
35
36extern char * lock_type_str[];          // allocated in kernel_init.c
37
38
39/////////////////////////////////////////////
40void remote_queuelock_init( xptr_t   lock_xp,
41                            uint32_t type )
42{
43    // get remote lock cluster and local pointer
44    cxy_t                lock_cxy = GET_CXY( lock_xp );
45    remote_queuelock_t * lock_ptr = GET_PTR( lock_xp );
46
47    // initialise taken field
48    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->taken ), 0 );
49
50    // initialise xroot field
51    xlist_root_init( XPTR( lock_cxy , &lock_ptr->xroot ) );
52
53    // initialise busylock field
54    remote_busylock_init( XPTR( lock_cxy , &lock_ptr->lock ) , type );
55
56#if DEBUG_QUEUELOCK
57thread_t * this = CURRENT_THREAD;
58if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
59printk("\n[%s] thread[%x,%x] initialise lock %s [%x,%x]\n",
60__FUNCTION__, this->process->pid, this->trdid,
61lock_type_str[type], lock_cxy, lock_ptr );
62#endif
63
64}  // end remote_queuelock_init()
65
66///////////////////////////////////////////////
67void remote_queuelock_acquire( xptr_t lock_xp )
68{
69    thread_t * this = CURRENT_THREAD;
70
71    // check calling thread can yield
72    thread_assert_can_yield( this , __FUNCTION__ );
73
74    // get lock cluster and local pointer
75    cxy_t                lock_cxy = GET_CXY( lock_xp );
76    remote_queuelock_t * lock_ptr = GET_PTR( lock_xp );
77
78#if DEBUG_QUEUELOCK
79uint32_t lock_type = hal_remote_l32( XPTR( lock_cxy , &lock_ptr->lock.type ) );
80#endif
81
82    // build extended pointer on busylock protecting queuelock
83    xptr_t busylock_xp = XPTR( lock_cxy , &lock_ptr->lock );
84
85    // get busylock
86    remote_busylock_acquire( busylock_xp );
87
88    // block and deschedule if lock already taken
89    while( hal_remote_l32( XPTR( lock_cxy, &lock_ptr->taken ) ) )
90    {
91
92#if DEBUG_QUEUELOCK
93if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
94printk("\n[%s] thread[%x,%x] BLOCK on q_lock %s [%x,%x]\n",
95__FUNCTION__, this->process->pid, this->trdid, 
96lock_type_str[lock_type], lock_cxy, lock_ptr );
97#endif
98        // get pointer on calling thread
99        thread_t * this = CURRENT_THREAD;
100
101        // block calling thread
102        thread_block( XPTR( local_cxy , this ) , THREAD_BLOCKED_LOCK );
103
104        // register calling thread in waiting list
105        xlist_add_last( XPTR( lock_cxy  , &lock_ptr->xroot ),
106                        XPTR( local_cxy , &this->wait_xlist ) );
107
108        // release busylock
109        remote_busylock_release( busylock_xp );
110
111        // deschedule calling thread
112        sched_yield("wait remote_queuelock");
113
114        // get busylock
115        remote_busylock_acquire( busylock_xp );
116    }
117
118#if DEBUG_QUEUELOCK
119if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
120printk("\n[%s] thread[%x,%x] ACQUIRE q_lock %s [%x,%x]\n",
121__FUNCTION__, this->process->pid, this->trdid, 
122lock_type_str[lock_type], lock_cxy, lock_ptr );
123#endif
124
125    // update remote_queuelock state
126    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->taken ) , 1 );
127
128    // release busylock
129    remote_busylock_release( busylock_xp );
130
131}  // end remote_queuelock_acquire()
132
133////////////////////////////////////////////////
134void remote_queuelock_release( xptr_t  lock_xp )
135{
136    // memory barrier before lock release
137    hal_fence();
138
139    // get lock cluster and local pointer
140    cxy_t                lock_cxy = GET_CXY( lock_xp );
141    remote_queuelock_t * lock_ptr = GET_PTR( lock_xp );
142
143    // build extended pointer on busylock protecting queuelock
144    xptr_t busylock_xp = XPTR( lock_cxy , &lock_ptr->lock );
145
146    // get busylock
147    remote_busylock_acquire( busylock_xp );
148
149#if DEBUG_QUEUELOCK
150thread_t * this      = CURRENT_THREAD;
151uint32_t   lock_type = hal_remote_l32( XPTR( lock_cxy , &lock_ptr->lock.type ) );
152if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
153printk("\n[%s] thread[%x,%x] RELEASE q_lock %s (%x,%x)\n",
154__FUNCTION__, this->process->pid, this->trdid,
155lock_type_str[lock_type], lock_cxy, lock_ptr );
156#endif
157
158    // update remote_queuelock state
159    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->taken ) , 0 );
160
161    // unblock first waiting thread if waiting list not empty
162    if( xlist_is_empty( XPTR( lock_cxy, &lock_ptr->xroot ) ) == false )
163    {
164        // get extended pointer on first waiting thread
165        xptr_t root_xp   = XPTR( lock_cxy , &lock_ptr->xroot );
166        xptr_t     thread_xp  = XLIST_FIRST( root_xp , thread_t , wait_xlist );
167        cxy_t      thread_cxy = GET_CXY( thread_xp );
168        thread_t * thread_ptr = GET_PTR( thread_xp );
169
170#if DEBUG_QUEUELOCK
171if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
172{
173    trdid_t     trdid   = hal_remote_l32( XPTR( thread_cxy , &thread_ptr->trdid ) );
174    process_t * process = hal_remote_lpt( XPTR( thread_cxy , &thread_ptr->process ) );
175    pid_t       pid     = hal_remote_l32( XPTR( thread_cxy , &process->pid ) );
176    printk("\n[%s] thread[%x,%x] UNBLOCK thread[%x,%x] / q_lock %s [%x,%x]\n",
177    __FUNCTION__, this->process->pid, this->trdid, trdid, pid, 
178    lock_type_str[lock_type], lock_cxy, lock_ptr );
179}
180#endif
181
182        // remove this thread from waiting queue
183        xlist_unlink( XPTR( thread_cxy , &thread_ptr->wait_xlist ) );
184
185        // unblock this waiting thread
186        thread_unblock( thread_xp , THREAD_BLOCKED_LOCK );
187    }
188
189    // release busylock
190    remote_busylock_release( busylock_xp );
191
192}  // end remote_queuelock_release()
193
194
195
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