source: trunk/kernel/syscalls/sys_exit.c @ 436

Last change on this file since 436 was 436, checked in by alain, 4 years ago

1) improve the threads and process destruction mechanism.
2) introduce FIFOs in the soclib_tty driver.

File size: 3.8 KB
Line 
1/*
2 * sys_exit.c - Kernel function implementing the "exit" system call.
3 *
4 * Author    Alain Greiner (2016,2017)
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 <kernel_config.h>
25#include <hal_types.h>
26#include <hal_irqmask.h>
27#include <errno.h>
28#include <thread.h>
29#include <printk.h>
30#include <process.h>
31#include <shared_syscalls.h>
32#include <cluster.h>
33#include <rpc.h>
34
35///////////////////////////////
36int sys_exit( uint32_t status )
37{
38    reg_t       save_sr;       // required to enable IRQs
39
40    thread_t  * this    = CURRENT_THREAD;
41    process_t * process = this->process;
42    pid_t       pid     = process->pid;
43    trdid_t     trdid   = this->trdid;
44
45#if CONFIG_DEBUG_SYS_EXIT
46uint64_t    tm_start;
47uint64_t    tm_end;
48tm_start = hal_get_cycles();
49if( CONFIG_DEBUG_SYS_EXIT < tm_start )
50printk("\n[DBG] %s : thread %x enter / process %x / status %x / cycle %d\n",
51__FUNCTION__ , this, pid , status , (uint32_t)tm_start );
52#endif
53
54    // get owner cluster
55    cxy_t  owner_cxy = CXY_FROM_PID( pid );
56
57    // exit must be called by the main thread
58    if( (owner_cxy != local_cxy) || (LTID_FROM_TRDID( trdid ) != 0) )
59    {
60
61#if CONFIG_DEBUG_SYSCALLS_ERROR
62printk("\n[ERROR] in %s : calling thread %x is not thread 0 in owner cluster %x\n",
63__FUNCTION__, trdid, owner_cxy );
64#endif
65         this->errno = EINVAL;
66         return -1;
67    }
68
69    // enable IRQs
70    hal_enable_irq( &save_sr );
71
72    // register exit_status in owner process descriptor
73    process->term_state = status;
74
75#if( CONFIG_DEBUG_SYS_EXIT & 1)
76printk("\n[DBG] %s : set exit status in process term_state\n", __FUNCTION__);
77#endif
78
79    // remove process from TXT list
80    process_txt_detach( XPTR( local_cxy , process ) );
81
82#if( CONFIG_DEBUG_SYS_EXIT & 1)
83printk("\n[DBG] %s : removed from TXT list\n", __FUNCTION__);
84#endif
85
86    // mark for delete all process threads in all clusters (but the main)
87    process_sigaction( pid , DELETE_ALL_THREADS );
88
89#if( CONFIG_DEBUG_SYS_EXIT & 1)
90printk("\n[DBG] %s : deleted all other threads than main\n", __FUNCTION__);
91#endif
92
93    // restore IRQs
94    hal_restore_irq( save_sr );
95
96    // block the main thread itself
97    thread_block( XPTR( local_cxy , this ) , THREAD_BLOCKED_GLOBAL );
98
99#if( CONFIG_DEBUG_SYS_EXIT & 1)
100printk("\n[DBG] %s : blocked the main thread\n", __FUNCTION__);
101#endif
102
103    // atomically update owner process descriptor term_state to ask
104    // the parent process sys_wait() function to delete this main thread
105    hal_remote_atomic_or( XPTR( local_cxy , &process->term_state ) ,
106                          PROCESS_TERM_EXIT );
107
108#if( CONFIG_DEBUG_SYS_EXIT & 1)
109printk("\n[DBG] %s : set EXIT flag in process term_state\n", __FUNCTION__);
110#endif
111
112    hal_fence();
113
114#if CONFIG_DEBUG_SYS_EXIT
115tm_end = hal_get_cycles();
116if( CONFIG_DEBUG_SYS_EXIT < tm_end )
117printk("\n[DBG] %s : thread %x exit / process %x / status %x / cost = %d / cycle %d\n",
118__FUNCTION__, this, pid, status, (uint32_t)(tm_end - tm_start), (uint32_t)tm_end );
119#endif
120
121    // main thread deschedule
122    sched_yield( "process exit" );
123
124    // this code should never be executed
125    assert( false , __FUNCTION__ , "this code should not be executed...\n" );
126        return 0;
127
128}  // end sys_exit()
129
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