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#include <common.h>
#ifndef MAX_CHILDREN
#define MAX_CHILDREN 50
#endif
/**
** User function I: exit, fork, exec, kill, sleep, waitpid, write
**
** Reports, then loops spawing userW, sleeps, kills two children, then
** loops checking the status of all its children
**
** Invoked as: userI [ x [ n ] ]
** where x is the ID character (defaults to 'i')
** n is the number of children to spawn (defaults to 5)
*/
USERMAIN( main ) {
int count = 5; // default child count
char ch = 'i'; // default character to print
int nap = 5; // nap time
char buf[128];
char ch2[] = "*?*";
uint_t children[MAX_CHILDREN];
int nkids = 0;
// process the command-line arguments
switch( argc ) {
case 3: count = str2int( argv[2], 10 );
// FALL THROUGH
case 2: ch = argv[1][0];
break;
case 1: // just use the defaults
break;
default:
sprint( buf, "userI: argc %d, args: ", argc );
cwrites( buf );
for( int i = 0; i <= argc; ++i ) {
sprint( buf, " %s", argv[argc] ? argv[argc] : "(null)" );
cwrites( buf );
}
cwrites( "\n" );
}
// secondary output (for indicating errors)
ch2[1] = ch;
// announce our presence
write( CHAN_SIO, &ch, 1 );
// set up the argument vector
// we run: userW 10 5
char *argsw[] = { "userW", "W", "10", "5", NULL };
for( int i = 0; i < count; ++i ) {
int whom = spawn( ProgW, argsw );
if( whom < 0 ) {
swrites( ch2 );
} else {
swritech( ch );
children[nkids++] = whom;
}
}
// let the children start
sleep( SEC_TO_MS(nap) );
// kill two of them
int32_t status = kill( children[1] );
if( status ) {
sprint( buf, "!! %c: kill(%d) status %d\n", ch, children[1], status );
cwrites( buf );
children[1] = -42;
}
status = kill( children[3] );
if( status ) {
sprint( buf, "!! %c: kill(%d) status %d\n", ch, children[3], status );
cwrites( buf );
children[3] = -42;
}
// collect child information
while( 1 ) {
int n = waitpid( 0, NULL );
if( n == E_NO_CHILDREN ) {
// all done!
break;
}
for( int i = 0; i < count; ++i ) {
if( children[i] == n ) {
sprint( buf, "== %c: child %d (%d)\n", ch, i, children[i] );
cwrites( buf );
}
}
sleep( SEC_TO_MS(nap) );
};
// let init() clean up after us!
exit( 0 );
return( 42 ); // shut the compiler up!
}
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