source: trunk/kernel/syscalls/sys_thread_join.c @ 637

Last change on this file since 637 was 637, checked in by alain, 3 years ago

Introduce the non-standard pthread_parallel_create() system call
and re-write the <fft> and <sort> applications to improve the
intrinsic paralelism in applications.

File size: 6.2 KB
Line 
1/*
2 * sys_thread_join.c - passive wait on the end of a given thread.
3 *
4 * Authors    Alain Greiner (2016,2017,2018,2019)
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_remote.h>
26#include <hal_special.h>
27#include <hal_irqmask.h>
28#include <thread.h>
29#include <vmm.h>
30#include <scheduler.h>
31#include <errno.h>
32#include <printk.h>
33#include <remote_busylock.h>
34
35#include <syscalls.h>
36
37///////////////////////////////////////
38int sys_thread_join ( trdid_t    trdid,
39                      void    ** exit_value )
40{
41    reg_t         save_sr;
42    xptr_t        target_xp;
43    thread_t    * target_ptr;
44    cxy_t         target_cxy;
45    ltid_t        target_ltid;
46    xptr_t        target_join_lock_xp;
47    xptr_t        target_flags_xp;
48    xptr_t        target_join_xp_xp;
49    xptr_t        killer_xp;
50    xptr_t        joining_xp;
51    thread_t    * joining_ptr;
52    process_t   * process;
53
54    // get joining thread pointers
55        joining_ptr = CURRENT_THREAD;
56    joining_xp  = XPTR( local_cxy , joining_ptr );
57    process     = joining_ptr->process;
58
59    // get target thread ltid and cxy
60    target_ltid = LTID_FROM_TRDID( trdid );
61    target_cxy  = CXY_FROM_TRDID( trdid );
62
63#if DEBUG_SYS_THREAD_JOIN
64uint64_t     tm_start;
65uint64_t     tm_end;
66tm_start = hal_get_cycles();
67if( DEBUG_SYS_THREAD_JOIN < tm_start )
68printk("\n[DBG] %s : joining thread[%x,%x] enter / target thread[%x,%x] / cycle %d\n",
69__FUNCTION__ , process->pid, joining_ptr->trdid,
70process->pid, trdid, (uint32_t)tm_start );
71#endif
72
73    // check trdid argument
74        if( (target_ltid >= CONFIG_THREADS_MAX_PER_CLUSTER) || 
75        (cluster_is_active(target_cxy) == false) )
76        {
77
78#if DEBUG_SYSCALLS_ERROR
79printk("\n[ERROR] in %s : illegal trdid argument %x\n",
80__FUNCTION__, trdid );
81#endif
82                joining_ptr->errno = EINVAL;
83                return -1;
84        }
85
86    // check exit_value argument
87        if( exit_value != NULL )
88        {
89
90#if DEBUG_SYSCALLS_ERROR
91printk("\n[ERROR] in %s : exit_value argument must be NULL\n",
92__FUNCTION__ );
93#endif
94                joining_ptr->errno = EINVAL;
95                return -1;
96        }
97
98    // check target thread != this thread
99    if( joining_ptr->trdid == trdid )
100    {
101
102#if DEBUG_SYSCALLS_ERROR
103printk("\n[ERROR] in %s : this thread (%x) == target thread(%x)\n",
104__FUNCTION__, joining_ptr->trdid, trdid );
105#endif
106        joining_ptr->errno = EDEADLK;
107        return -1;
108    }
109
110    // get pointers on target thread
111        target_xp  = thread_get_xptr( process->pid , trdid );
112    target_ptr = GET_PTR( target_xp );
113
114    if( target_xp == XPTR_NULL )
115    {
116
117#if DEBUG_SYSCALLS_ERROR
118printk("\n[ERROR] in %s : target thread %x not found\n",
119__FUNCTION__, trdid );
120#endif
121        joining_ptr->errno = ESRCH;
122        return -1;
123    }
124
125    // get extended pointers on various fields in target thread
126    target_join_lock_xp = XPTR( target_cxy , &target_ptr->join_lock );
127    target_flags_xp     = XPTR( target_cxy , &target_ptr->flags );
128    target_join_xp_xp   = XPTR( target_cxy , &target_ptr->join_xp );
129
130    // check target thread joinable
131    if( (hal_remote_l32( target_flags_xp ) & THREAD_FLAG_DETACHED) != 0 )
132    {
133
134#if DEBUG_SYSCALLS_ERROR
135printk("\n[ERROR] in %s : target thread %x not joinable\n", __FUNCTION__, trdid );
136#endif
137        joining_ptr->errno = EINVAL; 
138        return -1;
139    }
140
141    // mask IRQs
142    hal_disable_irq( &save_sr );
143
144    // get the lock protecting the join in target thread
145    remote_busylock_acquire( target_join_lock_xp );
146
147    // test the kill_done flag from the target thread
148    if( hal_remote_l32( target_flags_xp ) & THREAD_FLAG_KILL_DONE )  // killer thread is first
149    {
150        // get pointers on killer thread
151        killer_xp  = (xptr_t)hal_remote_l64( target_join_xp_xp );
152
153        // reset the kill_done flag in target thread
154        hal_remote_atomic_and( target_flags_xp , ~THREAD_FLAG_KILL_DONE );
155
156        // unblock the killer thread
157        thread_unblock( killer_xp , THREAD_BLOCKED_JOIN );
158
159        // release the lock protecting join     
160        remote_busylock_release( target_join_lock_xp );
161
162#if DEBUG_SYS_THREAD_JOIN
163tm_end = hal_get_cycles();
164if( DEBUG_SYS_THREAD_JOIN < tm_end )
165printk("\n[DBG] %s : joining thread[%x,%x] exit / target thread[%x,%x] completed / cycle %d\n",
166__FUNCTION__, process->pid, joining_ptr->trdid, process->pid, trdid, (uint32_t)tm_end );
167#endif
168
169    }
170    else                                                          // joining thread is first
171    {
172        // set the join_done flag in target thread
173        hal_remote_atomic_or( target_flags_xp , THREAD_FLAG_JOIN_DONE );
174
175        // block joining thread on BLOCKED_JOIN
176        thread_block( joining_xp , THREAD_BLOCKED_JOIN );
177
178        // register the joining thread extended pointer in target thread
179        hal_remote_s64( target_join_xp_xp , joining_xp );
180
181        // release the lock protecting the join     
182        remote_busylock_release( target_join_lock_xp );
183
184#if DEBUG_SYS_THREAD_JOIN
185if( DEBUG_SYS_THREAD_JOIN < tm_start )
186printk("\n[DBG] %s : joining thread[%x,%x] deschedules / target thread[%x,%x] not completed\n",
187__FUNCTION__ , process->pid, joining_ptr->trdid, process->pid, trdid );
188#endif
189        // deschedule
190        sched_yield( "joining thread waiting killer thread" );
191   
192#if DEBUG_SYS_THREAD_JOIN
193tm_end = hal_get_cycles();
194if( DEBUG_SYS_THREAD_JOIN < tm_end )
195printk("\n[DBG] %s : joining thread[%x,%x] exit / target thread[%x,%x] completed / cycle %d\n",
196__FUNCTION__ , process->pid, joining_ptr->trdid, process->pid, trdid, (uint32_t)tm_end );
197#endif
198
199    }
200
201    // restore IRQs
202    hal_restore_irq( save_sr );
203
204    return 0;
205
206}  // end sys_thread_join()
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