source: trunk/kernel/syscalls/sys_thread_join.c @ 457

Last change on this file since 457 was 457, checked in by alain, 3 years ago

This version modifies the exec syscall and fixes a large number of small bugs.
The version number has been updated (0.1)

File size: 5.7 KB
RevLine 
[1]1/*
[23]2 * sys_thread_join.c - passive wait on the end of a given thread.
[1]3 *
[23]4 * Authors    Alain Greiner (2016,2017)
5 *
[1]6 * Copyright (c) 2011,2012 UPMC Sorbonne Universites
7 *
[23]8 * This file is part of ALMOS-MKH.
[1]9 *
[23]10 * ALMOS-MKH is free software; you can redistribute it and/or modify it
[1]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 *
[23]14 * ALMOS-MKH is distributed in the hope that it will be useful, but
[1]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
[23]20 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
[1]21 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
[457]24#include <hal_kernel_types.h>
[23]25#include <hal_remote.h>
26#include <hal_special.h>
[436]27#include <hal_irqmask.h>
[1]28#include <thread.h>
[23]29#include <vmm.h>
[1]30#include <scheduler.h>
31#include <errno.h>
[23]32#include <printk.h>
33#include <remote_spinlock.h>
[1]34
[23]35///////////////////////////////////////
36int sys_thread_join ( trdid_t    trdid,
37                      void    ** exit_value )
[1]38{
[436]39    reg_t         save_sr;
[23]40    xptr_t        target_xp;
41    thread_t    * target_ptr;
42    cxy_t         target_cxy;
43    ltid_t        target_ltid;
[436]44    xptr_t        target_join_lock_xp;
45    xptr_t        target_flags_xp;
46    xptr_t        target_blocked_xp;
47    xptr_t        target_join_xp_xp;
48    xptr_t        killer_xp;
49    xptr_t        joining_xp;
50    thread_t    * joining_ptr;
51    process_t   * process;
[1]52
[436]53    // get joining thread pointers
54        joining_ptr = CURRENT_THREAD;
55    joining_xp  = XPTR( local_cxy , joining_ptr );
56    process     = joining_ptr->process;
[1]57
[23]58    // get target thread ltid and cxy
59    target_ltid = LTID_FROM_TRDID( trdid );
60    target_cxy  = CXY_FROM_TRDID( trdid );
61
[438]62#if DEBUG_SYS_THREAD_JOIN
[436]63uint64_t     tm_start;
64uint64_t     tm_end;
65tm_start = hal_get_cycles();
[438]66if( DEBUG_SYS_THREAD_JOIN < tm_start )
[436]67printk("\n[DBG] %s : parent thread %x enter / process %x / target trdid %x / cycle %d\n",
68__FUNCTION__ , joining_ptr , process->pid , trdid , (uint32_t)tm_start );
69#endif
70
[23]71    // check trdid argument
72        if( (target_ltid >= CONFIG_THREAD_MAX_PER_CLUSTER) || cluster_is_undefined( target_cxy ) ) 
[1]73        {
[436]74
[438]75#if DEBUG_SYSCALLS_ERROR
[436]76printk("\n[ERROR] in %s : illegal trdid argument %x\n", __FUNCTION__, trdid );
77#endif
78                joining_ptr->errno = EINVAL;
[23]79                return -1;
[1]80        }
81
[23]82    // check exit_value argument
[436]83        if( exit_value != NULL )
[1]84        {
[436]85
[438]86#if DEBUG_SYSCALLS_ERROR
[436]87printk("\n[ERROR] in %s : exit_value argument must be NULL\n", __FUNCTION__ );
88#endif
89                joining_ptr->errno = EINVAL;
[23]90                return -1;
[1]91        }
92
[23]93    // check target thread != this thread
[436]94    if( joining_ptr->trdid == trdid )
[23]95    {
[436]96
[438]97#if DEBUG_SYSCALLS_ERROR
[436]98printk("\n[ERROR] in %s : this thread == target thread\n", __FUNCTION__ );
99#endif
100        joining_ptr->errno = EDEADLK;
[23]101        return -1;
102    }
[1]103
[436]104    // get pointers on target thread
[23]105        target_xp  = thread_get_xptr( process->pid , trdid );
[436]106    target_ptr = GET_PTR( target_xp );
[1]107
[23]108    if( target_xp == XPTR_NULL )
109    {
[436]110
[438]111#if DEBUG_SYSCALLS_ERROR
[436]112printk("\n[ERROR] in %s : target thread %x not found\n", __FUNCTION__, trdid );
113#endif
114        joining_ptr->errno = ESRCH;
[23]115        return -1;
116    }
[1]117
[436]118    // get extended pointers on various fields in target thread
119    target_join_lock_xp = XPTR( target_cxy , &target_ptr->join_lock );
120    target_flags_xp     = XPTR( target_cxy , &target_ptr->flags );
121    target_blocked_xp   = XPTR( target_cxy , &target_ptr->blocked );
122    target_join_xp_xp   = XPTR( target_cxy , &target_ptr->join_xp );
[1]123
[23]124    // check target thread joinable
[436]125    if( (hal_remote_lw( target_flags_xp ) & THREAD_FLAG_DETACHED) == 0 )
[23]126    {
[436]127
[438]128#if DEBUG_SYSCALLS_ERROR
[436]129printk("\n[ERROR] in %s : target thread %x not joinable\n", __FUNCTION__, trdid );
130#endif
131        joining_ptr->errno = EINVAL; 
[23]132        return -1;
133    }
[1]134
[436]135    // mask IRQs
136    hal_disable_irq( &save_sr );
[1]137
[409]138    // get the lock protecting the join in target thread
[436]139    remote_spinlock_lock( target_join_lock_xp );
[409]140
[436]141    // test the kill_done flag from the target thread
142    if( hal_remote_lw( target_flags_xp ) & THREAD_FLAG_KILL_DONE )  // killer thread is first
[23]143    {
[436]144        // get pointers on killer thread
145        killer_xp  = (xptr_t)hal_remote_lwd( target_join_xp_xp );
[1]146
[436]147        // reset the kill_done flag in target thread
148        hal_remote_atomic_and( target_flags_xp , ~THREAD_FLAG_KILL_DONE );
[1]149
[436]150        // unblock the killer thread
151        thread_unblock( killer_xp , THREAD_BLOCKED_JOIN );
152
153        // release the lock protecting join     
154        remote_spinlock_unlock( target_join_lock_xp );
155
156        // restore IRQs
157        hal_restore_irq( save_sr );
[409]158    }
[436]159    else                                                          // joining thread is first
[409]160    {
[436]161        // set the join_done flag in target thread
162        hal_remote_atomic_or( target_flags_xp , THREAD_FLAG_JOIN_DONE );
[23]163
[436]164        // block joining thread on BLOCKED_JOIN
165        thread_block( joining_xp , THREAD_BLOCKED_JOIN );
[23]166
[436]167        // register the joining thread extended pointer in target thread
168        hal_remote_swd( target_join_xp_xp , joining_xp );
[23]169
[436]170        // release the lock protecting the join     
171        remote_spinlock_unlock( target_join_lock_xp );
[23]172
[409]173        // deschedule
[436]174        sched_yield( "joining thread waiting killer thread" );
[409]175   
[436]176        // restore IRQs
177        hal_restore_irq( save_sr );
[23]178    }
179
[438]180#if DEBUG_SYS_THREAD_JOIN
[436]181tm_end = hal_get_cycles();
[438]182if( DEBUG_SYS_THREAD_JOIN < tm_end )
[436]183printk("\n[DBG] %s : parent thread %x exit / process %x / target trdid %x / cycle %d\n",
184__FUNCTION__, joining_ptr, process->pid, trdid, (uint32_t)tm_end );
185#endif
186
[23]187    return 0;
188
189}  // end sys_thread_join()
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