关于linux下多线程处理informix

[jody_go]

我有如下测试程序，主函数中创建2个线程，
分别调用函数foo1和foo2，都向testtable表中写入数据，foo1,直接COMMIT,foo2睡眠一秒后，进行ROLLBACK，
可是为什么数据还是写入到testtable中了啊!
还有，就是多线程连接informix的时候，我想并发处理，该用什么办法诶？

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/stat.h>
#include <unistd.h>
#include <pthread.h> 


void *foo1(void* arg)
{
    EXEC SQL BEGIN DECLARE SECTION;
      char  acc[10];
    EXEC SQL END   DECLARE SECTION;
  
    strcat(acc, "yyy");

    EXEC SQL set connection 'conn1';
  
    EXEC SQL BEGIN WORK;
  
	EXEC SQL
	 insert into testtable
	  values(:acc, 'N', 100);
 	
    EXEC SQL COMMIT WORK;	
    //EXEC SQL ROLLBACK WORK;  
}

void *foo2(void* arg)
{
    EXEC SQL BEGIN DECLARE SECTION;
      char  acc[10];
    EXEC SQL END   DECLARE SECTION;
  
    strcat(acc, "xxx");

    EXEC SQL set connection 'conn2';
 
    EXEC SQL BEGIN WORK;
  
    sleep(1);
  
	EXEC SQL
	 insert into testtable
	  values(:acc, 'M', 200);
  
	//EXEC SQL COMMIT WORK;
	EXEC SQL ROLLBACK WORK;  
}

int main()
{
    pthread_t    tid[10];

    EXEC SQL CONNECT TO "root@ol_informix1170" as "conn1";
    EXEC SQL CONNECT TO "root@ol_informix1170" as "conn2";
  
    pthread_create(&tid[0], NULL, foo1, NULL);
    pthread_create(&tid[1], NULL, foo2, NULL);

    pthread_join(tid[0], NULL);  	
    pthread_join(tid[1], NULL);  	
	
    EXEC SQL DISCONNECT "conn1";
    EXEC SQL DISCONNECT "conn2";

    return 0;
}

[jody_go]

都没有人啊！！！