C MultiThread Value not printed - c

Question

First, Here is an entire code.
Read the file
Input file content into structure value
Begin Multithread
$ cat sunje.conf
{
DSN:GOLDILOCKS
UID:TEST
PWD:test
COMMIT INTERVAL:1
}
$ cat sh.c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <sys/time.h>
//EXEC SQL INCLUDE SQLCA;
typedef struct thread
{
char *dsn;
char *uid;
char *pwd;
char mode;
int num;
int start;
int end;
int interval;
} thread;
pthread_mutex_t mutex;
void *MultiThread(void* threadInfo);
int main(int argc, char **argv)
{
char s[1024];
FILE *fp;
char conn[4][1024];
int i = 0;
int session = 0;
int record = 0;
char mode = NULL;
//int interval;
fp = fopen("sunje.conf", "r");
while(!feof(fp))
{
fgets(s, 1024, fp);
char *ptr = strchr(s, ':');
if (ptr != NULL)
{
strcpy(conn[i], ptr + 1);
conn[i][strlen(conn[i]) - 1] = '\0';
//printf("conn[%d]=\"%s\"\n", i, conn[i]);
i++;
}
}
fclose(fp);
session = atoi(argv[1]);
record = atoi(argv[2]);
mode = argv[4][0];
printf("=========================================\n");
printf("DSN = [%s]\n"
"ID = [%s]\n"
"PW = [%s]\n"
"Commit Interval = [%s]\n"
"\n"
"Total Session = %d\n"
"Total Record = %d\n"
"Mode = %c\n", conn[0], conn[1], conn[2], conn[3], session, record, mode);
printf("=========================================\n");
int init = 1;
int init_div = record / session ;
int init_mod = record % session ;
if (mode == 's')
{
init = record;
init_div = 0;
}
pthread_mutex_init(&mutex, NULL);
thread threadInfo[session];
pthread_t threadCount[session];
i = 0;
for ( i = 0 ; i < session ; i ++)
{
pthread_mutex_lock(&mutex);
if( i != ( session - 1 ) )
{
threadInfo[i].dsn = conn[0];
threadInfo[i].uid = conn[1];
threadInfo[i].pwd = conn[2];
threadInfo[i].interval = atoi(conn[3]);
threadInfo[i].mode = mode;
threadInfo[i].num = i;
threadInfo[i].start = init;
threadInfo[i].end = init + init_div - 1;
}else
{
threadInfo[i].dsn = conn[0];
threadInfo[i].uid = conn[1];
threadInfo[i].pwd = conn[2];
threadInfo[i].interval = atoi(conn[3]);
threadInfo[i].mode = mode;
threadInfo[i].num = i;
threadInfo[i].start = init;
threadInfo[i].end = init + init_div + init_mod - 1;
}
pthread_mutex_unlock(&mutex);
printf("Thread Num = [%d]\n"
"Mode = [%c]\n"
"Start = [%d]\n"
"End = [%d]\n"
"Interval = [%d]\n"
"DSN = [%s]\n\n"
,threadInfo[i].num, threadInfo[i].mode, threadInfo[i].start, threadInfo[i].end, threadInfo[i].interval, threadInfo[i].dsn);
pthread_create ( &threadCount[i], NULL, MultiThread, (void*)&threadInfo[i] );
init = init + init_div;
}
int result;
i = 0;
for ( i = 0 ; i < session ; i ++)
{
pthread_join ( threadCount[i], (void *)&result );
}
printf("Thread Success\n");
return 0;
}
void *MultiThread(void* threadInfo)
{
thread* info = (thread*)threadInfo;
// struct timeval st, et;
char mode;
int num;
int start;
int end;
int interval;
mode = info->mode;
num = info->num;
start = info->start;
end = info->end;
interval = info->interval;
printf("num[%d] dsn[%s] uid[%s] pwd[%s] mode[%c] interval[%d] start[%d] end[%d]\n", num, info->dsn, info->uid, info->pwd, mode, interval, start, end);
return NULL;
}
Now, I ask a question..
I want to print last thread's value. But only "dsn" value not printed..
I used mutex of pthread to solve this problem. But it was not.
$ ./sh 3 300 2 i
=========================================
DSN = [GOLDILOCKS]
ID = [TEST]
PW = [test]
Commit Interval = [1]
Total Session = 3
Total Record = 300
Mode = i
=========================================
Thread Num = [0]
Mode = [i]
Start = [1]
End = [100]
Interval = [1]
DSN = [GOLDILOCKS]
Thread Num = [1]
Mode = [i]
Start = [101]
End = [200]
Interval = [1]
DSN = [GOLDILOCKS]
num[0] dsn[GOLDILOCKS] uid[TEST] pwd[test] mode[i] interval[1] start[1] end[100]
Thread Num = [2]
Mode = [i]
Start = [201]
End = [300]
Interval = [1]
DSN = [GOLDILOCKS]
num[1] dsn[GOLDILOCKS] uid[TEST] pwd[test] mode[i] interval[1] start[101] end[200]
num[2] dsn[] uid[TEST] pwd[test] mode[i] interval[1] start[201] end[300]
Thread Success
Could you help me?
I can't understand why num[2]'s dsn is not show

Answer 1

int result is 4 bytes.
(void *)&result is 8 bytes.
If the memory structure made like [ int 4 byte result ][ conn[0][0] .. ] .. on first time,
the return will be like [ 8 byte (void **)&result ][ conn[0][4] .. ] ..
Where is conn[0][0] ~ conn[0][3] ? this location covered with NULL(\000).
This program doesn't read after NULL value.
Here is gdb result.
Breakpoint 1, main (argc=5, argv=0x7fffffffdbf8) at sh.gc:131
131 pthread_join ( threadCount[i], (void **)&result );
1: conn[0] = "\000\000\000\000GOLDILOCKS", '\000' <repeats 26 times>, "\364G\336\367\377\177\000\000\000"
(gdb) p &conn[0]
$1 = (char (*)[50]) 0x7fffffffd5c0
(gdb) p &result
$2 = (int *) 0x7fffffffd5bc
(gdb)