source: trunk/kernel/syscalls/sys_thread_join.c@ 640

Last change on this file since 640 was 637, checked in by alain, 7 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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