source: trunk/kernel/libk/remote_queuelock.c @ 563

Last change on this file since 563 was 563, checked in by alain, 3 years ago

Complete restructuration of kernel spinlocks.

File size: 6.4 KB
RevLine 
[563]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
57///////////////////////////////////////////////
58void remote_queuelock_acquire( xptr_t lock_xp )
59{
60    thread_t * this = CURRENT_THREAD;
61
62    // check calling thread can yield
63    thread_assert_can_yield( this , __FUNCTION__ );
64
65    // get lock cluster and local pointer
66    cxy_t                lock_cxy = GET_CXY( lock_xp );
67    remote_queuelock_t * lock_ptr = GET_PTR( lock_xp );
68
69    // build extended pointer on busylock protecting queuelock
70    xptr_t busylock_xp = XPTR( lock_cxy , &lock_ptr->lock );
71
72    // get busylock
73    remote_busylock_acquire( busylock_xp );
74
75    // block and deschedule if lock already taken
76    while( hal_remote_l32( XPTR( lock_cxy, &lock_ptr->taken ) ) )
77    {
78
79#if DEBUG_QUEUELOCK
80if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
81{
82    uint32_t   type = hal_remote_l32( XPTR( lock_cxy , &locr_ptr->lock.type ) );
83    printk("\n[DBG] %s : thread %x in process %x BLOCK on q_lock %s [%x,%x]\n",
84    __FUNCTION__, this->trdid, this->process->pid,
85    lock_type_str[type], lock_cxy, lock_ptr );
86}
87#endif
88        // get pointer on calling thread
89        thread_t * this = CURRENT_THREAD;
90
91        // block calling thread
92        thread_block( XPTR( local_cxy , this ) , THREAD_BLOCKED_LOCK );
93
94        // register calling thread in waiting list
95        xlist_add_last( XPTR( lock_cxy  , &lock_ptr->xroot ),
96                        XPTR( local_cxy , &this->wait_xlist ) );
97
98        // release busylock
99        remote_busylock_release( busylock_xp );
100
101        // deschedule calling thread
102        sched_yield("wait remote_queuelock");
103
104        // get busylock
105        remote_busylock_acquire( busylock_xp );
106    }
107
108#if DEBUG_QUEUELOCK
109if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
110{
111    uint32_t   type = hal_remote_l32( XPTR( lock_cxy , &locr_ptr->lock.type ) );
112    printk("\n[DBG] %s : thread %x in process %x ACQUIRE q_lock %s [%x,%x]\n",
113    __FUNCTION__, this->trdid, this->process->pid,
114    lock_type_str[type], lock_cxy, lock_ptr );
115}
116#endif
117
118    // update remote_queuelock state
119    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->taken ) , 1 );
120
121    // release busylock
122    remote_busylock_release( busylock_xp );
123
124}  // end remote_queuelock_acquire()
125
126////////////////////////////////////////////////
127void remote_queuelock_release( xptr_t  lock_xp )
128{
129    // memory barrier before lock release
130    hal_fence();
131
132    // get lock cluster and local pointer
133    cxy_t                lock_cxy = GET_CXY( lock_xp );
134    remote_queuelock_t * lock_ptr = GET_PTR( lock_xp );
135
136    // build extended pointer on busylock protecting queuelock
137    xptr_t busylock_xp = XPTR( lock_cxy , &lock_ptr->lock );
138
139    // get busylock
140    remote_busylock_acquire( busylock_xp );
141
142#if DEBUG_QUEUELOCK
143if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
144{
145    thread_t * this = CURRENT_THREAD;
146    uint32_t   type = hal_remote_l32( XPTR( lock_cxy , &locr_ptr->lock.type ) );
147    printk("\n[DBG] %s : thread %x in process %x RELEASE q_lock %s (%x,%x)\n",
148    __FUNCTION__, this->trdid, this->process->pid,
149    lock_type_str[type], lock_cxy, lock_ptr );
150}
151#endif
152
153    // update remote_queuelock state
154    hal_remote_s32( XPTR( lock_cxy , &lock_ptr->taken ) , 0 );
155
156    // unblock first waiting thread if waiting list not empty
157    if( xlist_is_empty( XPTR( lock_cxy, &lock_ptr->xroot ) ) == false )
158    {
159        // get extended pointer on first waiting thread
160        xptr_t root_xp   = XPTR( lock_cxy , &lock_ptr->xroot );
161        xptr_t     thread_xp  = XLIST_FIRST( root_xp , thread_t , wait_xlist );
162        cxy_t      thread_cxy = GET_CXY( thread_xp );
163        thread_t * thread_ptr = GET_PTR( thread_xp );
164
165#if DEBUG_QUEUELOCK
166if( DEBUG_QUEUELOCK < (uint32_t)hal_get_cycles() )
167{
168    thread_t  * this    = CURRENT_THREAD;
169    uint32_t    type    = hal_remote_l32( XPTR( lock_cxy , &locr_ptr->lock.type ) );
170    trdid_t     trdid   = hal_remote_l32( XPTR( thread_cxy , &thread_ptr->trdid ) );
171    process_t * process = hal_remote_lpt( XPTR( thread_cxy , &thread_ptr->process ) );
172    pid_t       pid     = hal_remote_l32( XPTR( thread_cxy , &process->pid ) );
173    printk("\n[DBG] %s : thread %x in process %x UNBLOCK thread %x in process %d"
174    " / q_lock %s [%x,%x]\n",
175    __FUNCTION__, this->trdid, this->process->pid, trdid, pid, 
176    lock_type_str[type], lock_cxy, lock_ptr );
177}
178#endif
179
180        // remove this thread from waiting queue
181        xlist_unlink( XPTR( thread_cxy , &thread_ptr->wait_xlist ) );
182
183        // unblock this waiting thread
184        thread_unblock( thread_xp , THREAD_BLOCKED_LOCK );
185    }
186
187    // release busylock
188    remote_busylock_release( busylock_xp );
189
190}  // end remote_queuelock_release()
191
192
193
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