source: trunk/kernel/syscalls/sys_sem.c @ 469

Last change on this file since 469 was 469, checked in by alain, 3 years ago

1) Introduce the libsemaphore library.
2) Introduce a small libmath library, required by the "fft" application..
3) Introduce the multithreaded "fft" application.
4) Fix a bad synchronisation bug in the Copy-On-Write mechanism.

File size: 7.8 KB
Line 
1/*
2 * sys_sem.c - Acces a POSIX unamed semaphore.
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 <hal_kernel_types.h>
25#include <hal_uspace.h>
26#include <shared_semaphore.h>
27#include <errno.h>
28#include <thread.h>
29#include <printk.h>
30#include <vmm.h>
31#include <remote_sem.h>
32#include <syscalls.h>
33
34#if DEBUG_SYS_SEM
35//////////////////////////////////////////////////
36static char * sys_sem_op_str( uint32_t operation )
37{
38        if     ( operation == SEM_INIT     ) return "INIT";
39        else if( operation == SEM_WAIT     ) return "WAIT";
40        else if( operation == SEM_POST     ) return "POST";
41        else if( operation == SEM_GETVALUE ) return "GETVALUE";
42        else if( operation == SEM_DESTROY  ) return "DESTROY";
43        else                                 return "undefined";
44}
45#endif
46
47//////////////////////////////////
48int sys_sem( void         * vaddr,            // semaphore virtual  address
49             uint32_t       operation,        // requested operation type
50             uint32_t       init_value,       // initial value
51             uint32_t     * current_value )   // pointer on current value buffer
52{
53        vseg_t         * vseg;
54    error_t          error;
55    uint32_t         current;     // semaphore current value
56    xptr_t           sem_xp;      // extended pointer on semaphore
57
58    thread_t       * this    = CURRENT_THREAD;
59    process_t      * process = this->process;
60
61#if DEBUG_SYS_SEM
62uint64_t    tm_start;
63uint64_t    tm_end;
64tm_start = hal_get_cycles();
65if( DEBUG_SYS_SEM < tm_start )
66printk("\n[DBG] %s : thread %x in process %x enter for %s / cycle %d\n",
67__FUNCTION__, this->trdid, process->pid, sys_sem_op_str( operation ), (uint32_t)tm_start );
68#endif
69
70    // check vaddr in user vspace
71        error = vmm_get_vseg( process , (intptr_t)vaddr , &vseg );
72        if( error )
73    {
74
75#if DEBUG_SYSCALLS_ERROR
76printk("\n[ERROR] in %s : unmapped semaphore pointer %x / thread %x in process %x / cycle %d\n",
77__FUNCTION__ , (intptr_t)vaddr, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
78vmm_display( process , false );
79#endif
80        this->errno = EINVAL;
81        return -1;
82    }
83
84    // execute requested operation
85        switch( operation )
86        {
87        //////////////
88            case SEM_INIT:
89        {
90            // call relevant kernel function to initialize semaphore
91            error = remote_sem_create( (intptr_t)vaddr , 
92                                       init_value,
93                                       XPTR( local_cxy , &sem_xp ) );
94
95            if ( error )
96            {
97
98#if DEBUG_SYSCALLS_ERROR
99printk("\n[ERROR] in %s INIT: cannot create semaphore / thread %x in process %x / cycle %d\n",
100__FUNCTION__, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
101#endif
102                this->errno = ENOMEM;
103                return -1;
104            }
105
106            break;
107        }
108        //////////////////
109        case SEM_GETVALUE:
110        {
111            // check current_value buffer in user vspace
112                error = vmm_get_vseg( process , (intptr_t)current_value , &vseg );
113            if( error )
114            {
115
116#if DEBUG_SYSCALLS_ERROR
117printk("\n[ERROR] in %s GETVALUE: unmapped target buffer %x / thread %x in process %x / cycle %d\n",
118__FUNCTION__ , (intptr_t)current_value, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
119vmm_display( process , false );
120#endif
121                this->errno = EINVAL;
122                return -1;
123            }
124
125            // get extended pointer on remote semaphore
126            sem_xp = remote_sem_from_vaddr( (intptr_t)vaddr );
127
128            // check semaphore registered
129            if( sem_xp == XPTR_NULL )
130            {
131
132#if DEBUG_SYSCALLS_ERROR
133printk("\n[ERROR] in %s GETVALUE: semaphore %x not found / thread %x in process %x / cycle %d\n",
134__FUNCTION__ , (intptr_t)vaddr, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
135#endif
136                this->errno = EINVAL;
137                return -1;
138            }
139
140            // call relevant kernel function to get semaphore current value
141                    remote_sem_get_value( sem_xp , &current );
142 
143            // return value to user
144            hal_copy_to_uspace( current_value , &current , sizeof(uint32_t) );
145
146            break;
147        }
148        //////////////
149            case SEM_WAIT:
150        { 
151            // get extended pointer on remote semaphore
152            sem_xp = remote_sem_from_vaddr( (intptr_t)vaddr );
153
154            // check semaphore registered
155            if( sem_xp == XPTR_NULL )
156            {
157
158#if DEBUG_SYSCALLS_ERROR
159printk("\n[ERROR] in %s WAIT: semaphore %x not found / thread %x in process %x / cycle %d\n",
160__FUNCTION__ , (intptr_t)vaddr, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
161vmm_display( process , true );
162#endif
163                this->errno = EINVAL;
164                return -1;
165            }
166
167            // call relevant kernel function to wait semaphore available
168            remote_sem_wait( sem_xp );
169           
170            break;
171        }
172        //////////////
173            case SEM_POST:
174        {
175            // get extended pointer on remote semaphore
176            sem_xp = remote_sem_from_vaddr( (intptr_t)vaddr );
177
178            // check semaphore registered
179            if( sem_xp == XPTR_NULL )
180            {
181
182#if DEBUG_SYSCALLS_ERROR
183printk("\n[ERROR] in %s POST: semaphore %x not found / thread %x in process %x / cycle %d\n",
184__FUNCTION__ , (intptr_t)vaddr, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
185#endif
186                this->errno = EINVAL;
187                return -1;
188            }
189
190            // call relevant kernel function to release semaphore
191            remote_sem_post( sem_xp );
192
193                        break;
194        }
195        /////////////////
196            case SEM_DESTROY:
197        {
198            // get extended pointer on remote semaphore
199            sem_xp = remote_sem_from_vaddr( (intptr_t)vaddr );
200
201            // check semaphore registered
202            if( sem_xp == XPTR_NULL )
203            {
204
205#if DEBUG_SYSCALLS_ERROR
206printk("\n[ERROR] in %s DESTROY: semaphore %x not found / thread %x in process %x / cycle %d\n",
207__FUNCTION__ , (intptr_t)vaddr, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
208#endif
209                this->errno = EINVAL;
210                return -1;
211            }
212
213            // destroy semaphore
214            remote_sem_destroy( sem_xp );
215
216            break;
217            }   
218        ///////
219            default:  // undefined operation                       
220        {
221
222#if DEBUG_SYSCALLS_ERROR
223printk("\n[ERROR] in %s : undefined operation type %d / thread %x in process %x / cycle %d\n",
224__FUNCTION__ , operation, this->trdid, process->pid, (uint32_t)hal_get_cycles() );
225#endif
226            this->errno = EINVAL;
227            return -1;
228        }
229        }
230
231    hal_fence();
232
233#if DEBUG_SYS_SEM
234tm_end = hal_get_cycles();
235if( DEBUG_SYS_SEM < tm_end )
236{
237    cxy_t          sem_cxy = GET_CXY( sem_xp );
238    remote_sem_t * sem_ptr = GET_PTR( sem_xp );
239    uint32_t       value   = hal_remote_lw( XPTR( sem_cxy , &sem_ptr->count ) ); 
240    printk("\n[DBG] %s : thread %x in process %x exit for %s / value %d / cost = %d / cycle %d\n",
241    __FUNCTION__, this->trdid, process->pid, sys_sem_op_str( operation ), value, 
242    (uint32_t)(tm_end - tm_start), (uint32_t)tm_end );
243}
244#endif
245
246    return 0;
247
248}  // end sys_sem()
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