source: trunk/user/init/init.c @ 635

Last change on this file since 635 was 635, checked in by alain, 18 months ago

This version is a major evolution: The physical memory allocators,
defined in the kmem.c, ppm.c, and kcm.c files have been modified
to support remote accesses. The RPCs that were previously user
to allocate physical memory in a remote cluster have been removed.
This has been done to cure a dead-lock in case of concurrent page-faults.

This version 2.2 has been tested on a (4 clusters / 2 cores per cluster)
TSAR architecture, for both the "sort" and the "fft" applications.

File size: 6.1 KB
Line 
1///////////////////////////////////////////////////////////////////////////////////////
2// File   :  init.c
3// Date   :  January 2018
4// Author :  Alain Greiner
5///////////////////////////////////////////////////////////////////////////////////////
6// This single thread application implement the "init" process for ALMOS-MKH.
7// It uses the fork/exec syscalls to create N KSH child processes
8// (one child process per user terminal).
9// Then calls the wait() function to block, and reactivate any child KSH process
10// that has been deleted, using a new fork/exec.
11// It includes the hard_config.h file to get th NB_TXT_CHANNELS parameter.
12///////////////////////////////////////////////////////////////////////////////////////
13
14#include <hard_config.h>
15#include <unistd.h>
16#include <stdlib.h>
17#include <stdio.h>
18#include <pthread.h>
19#include <almosmkh.h>
20#include <hal_macros.h>
21#include <sys/wait.h>
22
23#define DEBUG_PROCESS_INIT    0
24
25// TODO improve the get_config() syscall to return nb_txt_channels
26// and avoid the hard_config include [AG]
27
28////////////////
29int main( void )
30{
31    int           i;
32    int           ret_fork;      // fork return value 
33    int           ret_exec;      // exec return value 
34    int           rcv_pid;       // pid received from the wait syscall
35    int           status;        // used by the wait syscall
36    char          string[64];    // log messages on kernel TXT0
37
38#if DEBUG_PROCESS_INIT
39display_string("[init] process enters");
40#endif
41
42    // check number of TXT channels
43    if( NB_TXT_CHANNELS < 2 )
44    {
45        printf("\n[ERROR] in init process : number of TXT channels must be larger than 1\n");
46        exit( EXIT_FAILURE );
47    }
48
49    // create the KSH processes (one per user terminal)
50    for( i = 1 ; i <  NB_TXT_CHANNELS ; i++ )
51    {
52        // INIT process fork process CHILD[i]
53        ret_fork = fork();
54
55        if( ret_fork < 0 )   // error in fork
56        {
57            // INIT display error message 
58            snprintf( string , 64 , "[init ERROR] cannot fork child[%d] => suicide" , i );
59            display_string( string );
60
61            // INIT suicide
62            exit( 0 );
63        }
64        else if( ret_fork == 0 )                    // we are in CHILD[i] process
65        {
66            // CHILD[i] process exec process KSH[i]
67            ret_exec = execve( "/bin/user/ksh.elf" , NULL , NULL ); 
68
69            if ( ret_exec )   // error in exec             
70            {
71                // CHILD[i] display error message
72                snprintf( string , 64 , 
73                "[init ERROR] CHILD[%d] cannot exec KSH / ret_exec = %d" , i , ret_exec );
74                display_string( string );
75            }
76        }
77        else                                      // we are in INIT process
78        {
79            // INIT display CHILD[i] process PID
80            snprintf( string , 64 , "[init] (pid 0x1) created ksh[%d] (pid %x)", i , ret_fork ); 
81            display_string( string );
82
83            // wait signal from KSH[i]
84            pause();
85        }
86    } 
87 
88#if DEBUG_PROCESS_INIT
89{
90    unsigned int  x_size;        // number of clusters in a row
91    unsigned int  y_size;        // number of clusters in a column
92    unsigned int  ncores;        // number of cores per cluster
93    unsigned int  x;             // cluster x coordinate
94    unsigned int  y;             // cluster y coordinate
95    unsigned int  cxy;           // cluster identifier
96    unsigned int  lid;           // core local index
97
98    // get hardware config
99    get_config( &x_size , &y_size , &ncores );
100
101    // INIT displays processes and threads in all clusters
102    for( x = 0 ; x < x_size ; x++ )
103    {
104        for( y = 0 ; y < y_size ; y++ )
105        {
106            cxy = HAL_CXY_FROM_XY( x , y );
107            display_cluster_processes( cxy , 0 );
108            for( lid = 0 ; lid < ncores ; lid++ )
109            { 
110                display_sched( cxy , lid );
111            }
112        }
113    }
114}
115#endif
116
117    // This loop detects the termination of the KSH[i] processes,
118    // and recreate a new KSH[i] process when required.
119    while( 1 )
120    {
121        // block on child processes termination
122        rcv_pid = wait( &status );
123
124        if( WIFSTOPPED( status ) )                         // stopped => unblock it
125        {
126            // display string to report unexpected KSH process block
127            snprintf( string , 64 , "[init] KSH process %x stopped => unblock it" , rcv_pid );
128            display_string( string ); 
129
130            // TODO : unblock KSH [AG]
131
132        }  // end KSH stopped handling
133
134        if( WIFSIGNALED( status ) || WIFEXITED( status ) )  // killed => recreate it
135        {
136            // display string to report KSH process termination
137            snprintf( string , 64 , "[init] KSH process %x terminated => recreate", rcv_pid );
138            display_string( string ); 
139
140            // INIT process fork a new CHILD process
141            ret_fork = fork();
142
143            if( ret_fork < 0 )                          // error in fork
144            {
145                // INIT display error message
146                snprintf( string , 64 , "[init ERROR] cannot fork child => suicide");
147                display_string( string );
148
149                // INIT suicide
150                exit( 0 );
151            }
152            else if( ret_fork == 0 )                    // we are in CHILD process
153            {
154                // CHILD process exec process KSH
155                ret_exec = execve( "/bin/user/ksh.elf" , NULL , NULL ); 
156
157                if ( ret_exec )   // error in exec             
158                {
159                    // CHILD display error message on TXT0 terminal
160                    snprintf( string , 64 , "[init ERROR] CHILD cannot exec KSH" );
161                    display_string( string );
162                }
163            }
164            else                                       // we are in INIT process
165            {
166                // INIT display new KSH process PID
167                snprintf( string , 64 , "[init] re-created KSH / pid = %x", ret_fork ); 
168                display_string( string );
169            }
170        } // end KSH kill handling
171
172    }  // end while waiting KSH[i] termination
173
174} // end main()
175
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