source: trunk/kernel/syscalls/sys_thread_exit.c

Last change on this file was 670, checked in by alain, 2 weeks ago

1) Introduce up to 4 command lines arguments in the KSH "load" command.
These arguments are transfered to the user process through the
argc/argv mechanism, using the user space "args" vseg.

2) Introduce the named and anonymous "pipes", for inter-process communication
through the pipe() and mkfifo() syscalls.

3) Introduce the "chat" application to validate the two above mechanisms.

4) Improve printk() and assert() fonctions in printk.c.

File size: 3.5 KB
Line 
1/*
2 * sys_thread_exit.c - terminates the execution of calling 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_irqmask.h>
26#include <thread.h>
27#include <process.h>
28#include <core.h>
29#include <vmm.h>
30#include <scheduler.h>
31#include <printk.h>
32
33#include <syscalls.h>
34
35/////////////////////////////////////////
36int sys_thread_exit( void * exit_status )
37{
38    error_t     error;
39    vseg_t    * vseg;
40
41        thread_t  * this      = CURRENT_THREAD;
42    trdid_t     trdid     = this->trdid;
43    process_t * process   = this->process;
44    pid_t       pid       = process->pid;
45   
46    // check exit_value pointer in user space if required
47    if( exit_status != NULL )
48    {
49        error = vmm_get_vseg( process , (intptr_t)exit_status  , &vseg );
50
51        if( error )
52            {
53
54#if DEBUG_SYSCALLS_ERROR
55printk("\n[ERROR] in %s : exit_status buffer %x unmapped / thread[%x,%x]\n",
56__FUNCTION__, (intptr_t)exit_status, process->pid, this->trdid );
57#endif
58            this->errno = EINVAL;
59                return -1;
60        }
61    }
62
63        // check busylocks
64    uint32_t count = this->busylocks;
65        if( count )
66        {
67
68#if DEBUG_SYSCALLS_ERROR
69printk("\n[ERROR] in %s : busylocks count = %d  / thread[%x,%x]\n",
70__FUNCTION__ , count, process->pid, this->trdid );
71#endif
72            this->errno = EINVAL;
73                return -1;
74    }
75
76    // If calling thread is the main thread, the process must be deleted.
77    // => delete all process threads and synchronize with parent process.
78    // If calling thread is not the main thread, only this thread must be deleted.
79    // => register exit_status in thread descriptor, block the thread,
80    //    mark it for delete, and synchronize with joining thread.
81
82    if( (CXY_FROM_PID( pid ) == local_cxy) && (LTID_FROM_TRDID(trdid) == 0) )  // main
83    {
84
85#if DEBUG_SYS_THREAD_EXIT
86uint64_t     tm_start = hal_get_cycles();
87if( DEBUG_SYS_THREAD_EXIT < tm_start )
88printk("\n[%s] thread[%x,%x] is main => delete process / cycle %d\n",
89__FUNCTION__ , pid , trdid , (uint32_t)tm_start );
90#endif
91        // delete process
92        sys_exit( 0 );
93    }
94    else                                                             // not the main
95    {
96
97#if DEBUG_SYS_THREAD_EXIT
98uint64_t     tm_start = hal_get_cycles();
99if( DEBUG_SYS_THREAD_EXIT < tm_start )
100printk("\n[%s] thread[%x,%x] is not main => delete thread / cycle %d\n",
101__FUNCTION__ , pid , trdid , (uint32_t)tm_start );
102#endif
103        // register exit_status in thread descriptor
104        this->exit_status = exit_status;
105
106        // block calling thread and mark it for delete,
107        thread_delete_request( XPTR( local_cxy , this ) , false );   // not forced
108
109        // deschedule
110        sched_yield( "suicide after thread_exit" );
111    }
112
113    return 0;   // never executed but required by compiler
114
115}  // end sys_thread exit
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