int main(void) {
pid_t pid, mypid;
if((pid = fork()) < 0)
err_sys("fork error");
else if(pid > 0) { // parent
mypid = getpid();
TELL_WAIT();
printf("%d: WAIT_CHILD()\n", mypid);
WAIT_CHILD();
printf("%d: wake up\n", mypid);
sleep(2);
printf("%d: TELL_CHILD()\n", mypid);
TELL_CHILD(pid);
} else { // child
mypid = getpid();
TELL_WAIT();
sleep(2);
printf("%d: TELL_PARENT()\n", mypid);
TELL_PARENT(getppid());
printf("%d: WAIT_PARENT()\n", mypid);
WAIT_PARENT();
printf("%d: wake up\n", mypid);
}
return 0;
}
int main(void)
{
int fd;
pid_t pid;
if ((fd = creat("templock", FILE_MODE)) < 0)
err_sys("creat error");
if (write(fd, "ab", 2) != 2)
err_sys("write error");
TELL_WAIT();
if ((pid = fork()) < 0){
err_sys("fork error");
}else if(pid == 0){/*child*/
lockabyte("child", fd, 0);
TELL_PARENT(getppid());
WAIT_PARENT();
lockabyte("child", fd, 1);
}else{
lockabyte("parent", fd, 1);
TELL_CHILD(pid);
WAIT_CHILD();
lockabyte("parent", fd, 0);
}
exit(0);
}
int main(int argc, char *argv[])
{
pid_t pid;
TELL_WAIT();
pid = Fork();
if (pid == 0)
{
while ( n < 1000)
{
WAIT_PARENT();
printf(" c%d ", n);
n += 2;
TELL_PARENT(getppid());
//sleep(1);
}
}
else if(pid > 0)
{
while (n < 1000)
{
printf(" p%d ", n);
n += 2;
TELL_CHILD(pid);
// sleep(1);
WAIT_CHILD();
}
}
printf("Hello, world\n");
return 0;
}
int main(int argc, char *argv[])
{
int fd;
pid_t pid;
/*Create a file and write two bytes to it*/
fd = Open("templock", O_RDWR | O_CREAT | O_TRUNC, FILE_MODE) ;
if(write(fd, "ab", 2) != 2)
err_sys("write error");
TELL_WAIT();
pid = Fork();
if(pid == 0)
{
lockabyte("child", fd, 0);
TELL_PARENT(getppid());
WAIT_PARENT();
lockabyte("child", fd, 1);
}else
{
lockabyte("parent", fd, 1);
TELL_CHILD(pid);
WAIT_CHILD();
lockabyte("parent", fd, 0);
}
return 0;
}
/* gcc apue.h apue_err.c figure-14.5.c figure-10.24.c figure-14.7.c */
int
main(void)
{
int fd;
pid_t pid;
/*
* Create a file and write two bytes to it.
*/
if ((fd = creat("templock", FILE_MODE)) < 0)
err_sys("creat error");
if (write(fd, "ab", 2) != 2)
err_sys("write error");
TELL_WAIT(); /* figure-10.24.c */
if ((pid = fork()) < 0) {
err_sys("fork error");
} else if (pid == 0) { /* child */
lockabyte("child", fd, 0);
TELL_PARENT(getppid());
WAIT_PARENT();
lockabyte("child", fd, 1);
} else { /* parent */
lockabyte("parent", fd, 1);
TELL_CHILD(pid);
WAIT_CHILD();
lockabyte("parent", fd, 0);
}
exit(0);
}
/* increment counter in shared memory segment; mmap /dev/zero version */
int main(void)
{
int fd, i, counter;
pid_t pid;
void *area;
if ((fd = open("/dev/zero", O_RDWR)) < 0)
err_sys("open error");
if ((area = mmap(0, SIZE, PROT_READ | PROT_WRITE, MAP_SHARED,
fd, 0)) == MAP_FAILED)
err_sys("mmap error");
close(fd); /* can close /dev/zero now that it is mapped */
TELL_WAIT();
if ((pid = Fork()) > 0) { /* parent */
for (i = 0; i < NLOOPS; i += 2) {
if ((counter = update((long *)area)) != i)
err_quit("parent: expected %d, got %d", i, counter);
TELL_CHILD(pid);
WAIT_CHILD();
}
} else { /* child */
for (i = 1; i < NLOOPS + 1; i += 2) {
WAIT_PARENT();
if ((counter = update((long *)area)) != i)
err_quit("child: expected %d, got %d", i, counter);
TELL_PARENT();
}
}
exit(0);
}
int main(int argc, char* argv[])
{
int fd;
pid_t pid;
if((fd = creat("templock", FILEMODE)) < 0)
printf("creat error");
if(write(fd, "ab", 2) != 2)
printf("write error");
TELL_WAIT();
if((pid = fork()) < 0)
printf("fork error");
else if(pid == 0)
{
lockabyte("child:", fd, 0);
TELL_PARENT(getpid());
WAIT_PARENT();
lockabyte("child:", fd, 1);
}
else
{
lockabyte("parent:", fd, 1);
TELL_CHILD(pid);
WAIT_CHILD();
lockabyte("parent:", fd, 0);
}
exit(0);
}
int main(void)
{
pid_t pid;
FILE *fp;
int fd;
int i = 0;
char *child = "in child\n";
char *parent = "in parent\n";
if ((fp = fopen("tmp", "a")) == NULL) {
perror("fopen error");
exit(1);
}
fd = fileno(fp);
/* if (write(fd, pi, 1) != 1) { */
/* perror("write error"); */
/* exit(1); */
/* } */
fprintf(fp, "%d\n", i);
fflush(fp);
TELL_WAIT();
if ((pid = fork()) < 0) { /* pid = fork()要用括号括起来 */
perror("fork error");
exit(1);
} else if (pid == 0) {
while (i < 100) {
WAIT_PARENT();
/* if (write(fd, pi, 1) != 1) { */
/* perror("write error"); */
/* exit(1); */
/* } */
i += 2;
fprintf(fp, "%d\t", i);
fflush(fp);
write(fd, child, strlen(child));
TELL_PARENT(getppid());
}
} else {
i++;
while (i < 100) {
/* if (write(fd, pi, 1) != 1) { */
/* perror("write error"); */
/* exit(1); */
/* } */
fprintf(fp, "%d\t", i);
fflush(fp);
i += 2;
write(fd, parent, strlen(parent));
TELL_CHILD(pid);
WAIT_CHILD();
}
}
return 0;
}
int
main(int argc, char *argv[])
{
int fd;
pid_t pid;
char buf[5];
struct stat statbuf;
if (argc != 2) {
fprintf(stderr, "usage: %s filename\n", argv[0]);
exit(1);
}
if ((fd = open(argv[1], O_RDWR | O_CREAT | O_TRUNC, FILE_MODE)) < 0)
err_sys("open error");
if (write(fd, "abcdef", 6) != 6)
err_sys("write error");
/* turn on set-group-ID and turn off group-execute */
if (fstat(fd, &statbuf) < 0)
err_sys("fstat error");
if (fchmod(fd, (statbuf.st_mode & ~S_IXGRP) | S_ISGID) < 0)
err_sys("fchmod error");
TELL_WAIT();
if ((pid = fork()) < 0) {
err_sys("fork error");
} else if (pid > 0) { /* parent */
/* write lock entire file */
if (write_lock(fd, 0, SEEK_SET, 0) < 0)
err_sys("write_lock error");
TELL_CHILD(pid);
if (waitpid(pid, NULL, 0) < 0)
err_sys("waitpid error");
} else { /* child */
WAIT_PARENT(); /* wait for parent to set lock */
set_fl(fd, O_NONBLOCK);
/* first let's see what error we get if region is locked */
if (read_lock(fd, 0, SEEK_SET, 0) != -1) /* no wait */
err_sys("child: read_lock succeeded");
printf("read_lock of already-locked region returns %d\n",
errno);
/* now try to read the mandatory locked file */
if (lseek(fd, 0, SEEK_SET) == -1)
err_sys("lseek error");
if (read(fd, buf, 2) < 0)
err_ret("read failed (mandatory locking works)");
else
printf("read OK (no mandatory locking), buf = %2.2s\n",
buf);
}
exit(0);
}
void init (void)
{
TELL_WAIT ();
file = fopen (FILE_NAME, "w+");
if (file == NULL) {
err_quit ("open file failed\n");
}
fprintf (file, "%d", 0);
fflush (file);
}
int main(int argc,char ** argv)
{
int fd;
pid_t pid;
char buf[5];
struct stat statbuf;
if(argc!=2)
{
fprintf(stderr,"usage:%s filename \n",argv[0]);
exit(1);
}
if((fd=open(argv[1],O_RDWR|O_CREAT|O_TRUNC,FILE_MODE))<0)
err_sys("open error");
if(write(fd,"abcdef",6)<0)
err_sys("write error");
if(fstat(fd,&statbuf)<0)
err_sys("fstat error");
if(fchmod(fd,(statbuf.st_mode & ~S_IXGRP)|S_ISGID)<0)
err_sys("fchmod error");
TELL_WAIT();
if((pid=fork())<0)
err_sys("fork error");
else if(pid>0)
{
if(write_lock(fd,0,SEEK_SET,0)<0)
err_sys("write_lock error");
TELL_CHILD(pid);
if(waitpid(pid,NULL,0)<0)
err_sys("waitpid error");
}
else
{
WAIT_PARENT();
set_fl(fd,O_NONBLOCK);
if(read_lock(fd,0,SEEK_SET,0)!=-1)
err_sys("child read_lock successed ");
printf("read_lock of arleady-locked region return %d \n",errno);
if(lseek(fd,0,SEEK_SET)==-1)
err_sys("lseek error");
if(read(fd,buf,2)<0)
err_ret("read failed (mandatory locking works )");
else
printf("read OK(no mandatory locking ,buf=%2.2s\n)",buf);
exit(0);
}
}
int main(int argc,char *argv[]){
pid_t pid;
//set up for TELL** and WAIT**
TELL_WAIT();
if((pid=fork())<0){
perror("fork error:");
return -1;
}else if(pid>0){
WAIT_CHILD();
charatatime("output from parent\n");
}else{
charatatime("output from child\n");
TELL_PARENT(pid);
}
return 0;
}
int main() {
pid_t pid;
TELL_WAIT();
if ((pid = fork()) < 0) {
err_sys("fork error");
} else if (pid == 0) {
WAIT_PARENT(); /* parent goes first */
charatatime("output from child\n");
} else {
charatatime("output from parent\n");
TELL_CHILD(pid);
}
exit(0);
}
int main()
{
int fd = open(path, O_CREAT|O_TRUNC|O_RDWR, 0644);
write(fd, "0", 1);
char inbuf[20];
char outbuf[20];
int num;
TELL_WAIT();
pid_t pid;
pid = fork();
if(pid<0) {
perror("fork error");
return 1;
} else if(pid == 0) { //child
for(int i=0;i<10;++i) {
lseek(fd, 0, SEEK_SET);
ssize_t len = read(fd, inbuf, 20);
if(len<0) break;
inbuf[len] = 0;
fprintf(stderr, "CHILD read %s\n",inbuf);//debug
sscanf(inbuf,"%d",&num);
++num;
lseek(fd, 0, SEEK_SET);
sprintf(outbuf, "%d", num);
write(fd, outbuf, strlen(outbuf));
fprintf(stderr, "CHILD write %s\n",outbuf);//debug
TELL_PARENT(getppid());
WAIT_PARENT();
}
} else { //parent
for(int i=0;i<10;++i) {
WAIT_CHILD();
lseek(fd, 0, SEEK_SET);
ssize_t len = read(fd, inbuf, 20);
if(len<0) break;
inbuf[len] = 0;
fprintf(stderr, "PARENT read %s\n",inbuf);//debug
sscanf(inbuf,"%d",&num);
++num;
lseek(fd, 0, SEEK_SET);
sprintf(outbuf, "%d", num);
write(fd, outbuf, strlen(outbuf));
fprintf(stderr, "PARENT write %s\n",outbuf);//debug
TELL_CHILD(pid);
}
}
}
int main(void){
pid_t pid;
TELL_WAIT();
if((pid=fork())<0){
err_sys("fork error");
}else if(pid==0){/*child*/
WAIT_PARENT();/*parent goes next*/
char_at_a_time("output from child\n");
/*TELL_PARENT(getppid());*//*child goes first*/
}else{/*parent*/
/*sleep(2);*/
/*WAIT_CHILD();*//*parent goes first*/
char_at_a_time("output from parent\n");
TELL_CHILD(pid);/*child goest next*/
}
exit(0);
}
int main(int argc,char *argv[])
{
pid_t pid;
TELL_WAIT();
if ((pid = fork()) < 0){
perror("fork");
}else if (pid == 0){
TELL_PARENT(getppid());
WAIT_PARENT();
chara("output from child\n");
}else{
chara("output from parent\n");
TELL_CHILD(pid);
}
exit(0);
}
int main(void)
{
pid_t pid;
TELL_WAIT();
if ((pid = fork()) < 0) {
err_sys("fork error");
} else if (pid == 0) {
charactatime("output from child\n");
TELL_PARENT(getppid()); /* child goes first */
} else {
WAIT_CHILD();
charactatime("output from parent\n");
}
exit(0);
}
int main(int argc, char const *argv[])
{
pid_t pid;
TELL_WAIT();
if ((pid = fork()) < 0) {
fprintf(stderr, "fork error\n");
exit(1);
} else if (pid == 0) {
charatatime("output from child\n");
TELL_PARENT(getppid());
} else {
WAIT_CHILD(); /* child goes first */
charatatime("output from parent\n");
}
return 0;
}
int main()
{
int fid;
pid_t pid;
if((fid = open("number.txt", O_WRONLY|O_CREAT|O_TRUNC))<0)
err_sys("create file error...\n");
sprintf(str,"%d",number);
write(fid,str,strlen(str));
close(fid);
TELL_WAIT();
if((pid = fork())<0)
err_sys("fork error");
else if(pid==0)
{
while((getNumber("number.txt")+1)<1000)
{
WAIT_PARENT();
number = getNumber("number.txt");
setNumber("number.txt",number+1);
printf("Pid = %d,Number = %d\n",getpid(),number+1);
TELL_PARENT(getppid());
}
}
else
{
while((getNumber("number.txt")+1)<1000)
{
number = getNumber("number.txt");
setNumber("number.txt",number+1);
printf("Pid = %d,Number = %d\n",getpid(),number+1);
TELL_CHILD(pid);
WAIT_CHILD();
}
}
close(fid);
return 0;
}
int main(void) {
pid_t pid;
TELL_WAIT();
if((pid = fork()) < 0)
err_sys("fork error");
else if (pid == 0) {
WAIT_PARENT(); /* parent goes first */
charactatime("output from child\n");
TELL_PARENT(getppid());
}
else {
charactatime("output from parent\n");
TELL_CHILD(pid);
WAIT_CHILD();
}
return 0;
}
int main(void)
{
pid_t pid;
TELL_WAIT();
if ((pid = fork()) < 0)
err_sys("fork error");
else if (pid == 0)
{
WAIT_PARENT();
charatatime("child 12345678901234567890123456\n");
}
else
{
charatatime("parent abcdefghigklmnopqrstuvwxyz\n");
TELL_CHILD(pid);
}
exit(0);
}
/* parent goes first program */
int main()
{
pid_t pid;
TELL_WAIT();
pid = fork();
if(pid < 0) {
printf("fork error\n");
}
else if(pid == 0) {
WAIT_PARENT();
do_task("child task\n");
}
else {
do_task("parent task\n");
TELL_CHILD(pid);
}
return 0;
}
int main(int argc, char *argv[])
{
char line[MAXLINE];
int n;
pid_t pid;
int fd;
if (argc != 2)
err_sys("usage: a.out <pathname>");
if ((fd = open(argv[1], O_RDWR)) < 0)
err_sys("open %s file failed", argv[1]);
memset(line, '\0', MAXLINE);
TELL_WAIT();
pid = fork();
switch (pid) {
case -1://error
err_sys("fork error");
case 0://child
WAIT_PARENT();
lseek(fd, SEEK_SET, 0);
if ((n = read(fd, line, MAXLINE)) < 0)
err_sys("read error form %s", argv[1]);
printf("read %d bytes:", n);
fflush(stdout);
write(STDOUT_FILENO, line, n);
TELL_PARENT(getppid());
break;
default://parent
sleep(2);
n = write(fd, "hello child\n", 13);
printf("write %d bytes\n", n);
fflush(stdout);
TELL_CHILD(pid);
WAIT_CHILD();
break;
}
close(fd);
exit(0);
}
void main()
{
FILE *file;
int pid;
void (*tell)(pid_t);
void (*wait)(void);
TELL_WAIT();
if((file = fopen("file.txt", "w")) == NULL)
{
err_sys("oh crap, unable to open file");
}
fprintf(file, "PARENT initializes the counter to 0\n");
fflush(file);
if ((pid = fork()) < 0)
{
err_sys("unable to fork");
}
if (PARENT)
{
tell = TELL_CHILD;
wait = WAIT_CHILD;
}
else
{
tell = TELL_PARENT;
wait = WAIT_PARENT;
}
increment_file(file, pid, tell, wait);
if (PARENT)
fclose(file);
}
int test_record_lock()
{
int ret;
int fd;
pid_t pid;
char *name;
name = tmpnam(NULL);
if((fd = creat(name, FILE_MODE)) < 0) {
err_sys("create");
}
if (write(fd, "ab", 2) != 2)
err_sys("write");
TELL_WAIT();
if ((pid = fork()) < 0)
err_sys("fork");
else if (pid == 0) {
lockbyte("child", fd, 0);
TELL_PARENT(getpid());
WAIT_PARENT();
lockbyte("child", fd, 1);
sleep(2);
exit(0);
} else {
lockbyte("parent", fd, 1);
TELL_CHILD(getpid());
WAIT_CHILD();
lockbyte("parent", fd, 0);
close(fd);
sleep(1);
unlink(name);
}
return 0;
}
int main(int argc, char const *argv[])
{
pid_t pid;
int fd;
TELL_WAIT();
if((fd = open("luo.txt", O_RDWR)) < 0) {
printf("open file error\n");
}
int data = 0;
if(write(fd, &data, sizeof(data)) == -1) {
printf("write file error\n");
}
//fsync(fd);
/*if((pid = fork()) < 0) {
printf("fork error\n");
}
else if(pid == 0) {
//while(1){
WAIT_PARENT();
int d1 = 0;
lseek(fd, 0, SEEK_SET);
if(read(fd, &d1, sizeof(d1)) == -1) {
printf("read error\n");
}
printf("%d process read %d\n", getpid(), d1);
++d1;
if(write(fd, &d1, sizeof(d1)) == -1)
printf("write error\n");
fsync(fd);
printf("%d process increase to %d\n", getpid(), d1);
TELL_PARENT(getppid());
//}
}
else {
//while(1){
int d2 = 0, read_cnt = 0;
lseek(fd, 0, SEEK_SET);
if((read_cnt = read(fd, &d2, sizeof(d2))) == -1) {
printf("read error\n");
}
else if(read_cnt != sizeof(d2)) {
printf("read error\n");
}
printf("%d process read %d\n", getpid(), d2);
++d2;
if(write(fd, &d2, sizeof(d2)) == -1)
printf("write error\n");
fsync(fd);
printf("%d process increase to %d\n", getpid(), d2);
TELL_CHILD(pid);
WAIT_CHILD();
//}
}*/
if(read(fd, &data, sizeof(data)) == -1)
printf("read error\n");
printf("%d\n", data);
++data;
write(fd, &data, sizeof(data));
read(fd, &data, sizeof(data));
printf("%d\n", data);
close(fd);
return 0;
}
int servopen(char* host, char* port)
{
int fd, newfd, i, on, pid;
const char* protocol;
struct in_addr inaddr;
struct servent* sp;
protocol = udp ? "udp" : "tcp";
/* Initialize the socket address structure */
bzero(&servaddr, sizeof(servaddr));
servaddr.sin_family = AF_INET;
/* Caller normally wildcards the local Internet address, meaning
a connection will be accepted on any connected interface.
We only allow an IP address for the "host", not a name. */
if (host == NULL)
servaddr.sin_addr.s_addr = htonl(INADDR_ANY); /* wildcard */
else {
if (inet_aton(host, &inaddr) == 0)
err_quit("invalid host name for server: %s", host);
servaddr.sin_addr = inaddr;
}
/* See if "port" is a service name or number */
if ((i = atoi(port)) == 0) {
if ((sp = getservbyname(port, protocol)) == NULL)
err_ret("getservbyname() error for: %s/%s", port, protocol);
servaddr.sin_port = sp->s_port;
} else
servaddr.sin_port = htons(i);
if ((fd = socket(AF_INET, udp ? SOCK_DGRAM : SOCK_STREAM, 0)) < 0)
err_sys("socket() error");
if (reuseaddr) {
on = 1;
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
err_sys("setsockopt of SO_REUSEADDR error");
}
#ifdef SO_REUSEPORT
if (reuseport) {
on = 1;
if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &on, sizeof(on)) < 0)
err_sys("setsockopt of SO_REUSEPORT error");
}
#endif
/* Bind our well-known port so the client can connect to us. */
if (bind(fd, (struct sockaddr*)&servaddr, sizeof(servaddr)) < 0)
err_sys("can't bind local address");
join_mcast(fd, &servaddr);
if (udp) {
buffers(fd);
if (foreignip[0] != 0) { /* connect to foreignip/port# */
bzero(&cliaddr, sizeof(cliaddr));
if (inet_aton(foreignip, &cliaddr.sin_addr) == 0)
err_quit("invalid IP address: %s", foreignip);
cliaddr.sin_family = AF_INET;
cliaddr.sin_port = htons(foreignport);
/* connect() for datagram socket doesn't appear to allow
wildcarding of either IP address or port number */
if (connect(fd, (struct sockaddr*)&cliaddr, sizeof(cliaddr)) < 0)
err_sys("connect() error");
}
sockopts(fd, 1);
return (fd); /* nothing else to do */
}
buffers(fd); /* may set receive buffer size; must do here to get
correct window advertised on SYN */
sockopts(fd, 0); /* only set some socket options for fd */
listen(fd, listenq);
if (pauselisten)
sleep_us(pauselisten * 1000); /* lets connection queue build up */
if (dofork) TELL_WAIT(); /* initialize synchronization primitives */
for (;;) {
i = sizeof(cliaddr);
if ((newfd = accept(fd, (struct sockaddr*)&cliaddr, &i)) < 0)
err_sys("accept() error");
if (dofork) {
if ((pid = fork()) < 0) err_sys("fork error");
if (pid > 0) {
close(newfd); /* parent closes connected socket */
WAIT_CHILD(); /* wait for child to output to terminal */
continue; /* and back to for(;;) for another accept() */
} else {
close(fd); /* child closes listening socket */
}
}
/* child (or iterative server) continues here */
if (verbose) {
/* Call getsockname() to find local address bound to socket:
local internet address is now determined (if multihomed). */
i = sizeof(servaddr);
if (getsockname(newfd, (struct sockaddr*)&servaddr, &i) < 0)
err_sys("getsockname() error");
/* Can't do one fprintf() since inet_ntoa() stores
the result in a static location. */
fprintf(stderr, "connection on %s.%d ",
INET_NTOA(servaddr.sin_addr), ntohs(servaddr.sin_port));
fprintf(stderr, "from %s.%d\n", INET_NTOA(cliaddr.sin_addr),
ntohs(cliaddr.sin_port));
}
buffers(newfd); /* setsockopt() again, in case it didn't propagate
from listening socket to connected socket */
sockopts(newfd, 1); /* can set all socket options for this socket */
if (dofork)
TELL_PARENT(getppid()); /* tell parent we're done with terminal */
return (newfd);
}
}
/**
* main()
*
* This program comprises two processes. First, the "brain" which
* communicates with a supervisor-client. The brain receives
* high-level control commands from the supervisor-client and then
* conveys any resulting sensor data back. The second process is the
* "nerves"; this process translates high-level commands into
* low-level iRobot SCI commands, executes them on the iRobot, and
* then obtains any resulting sensor data.
*
*/
int main(int argc, char* argv[])
{
/* Create a message queue using O_CREAT so that if the queue doesn't
* already exist, it will be created. When using mq_open with
* O_CREAT, one must supply four arguments. The first "name"
* argument must begin with a slash. The third "mode" argument is
* derived from the symbolic constants is <sys/stat.h>.
*/
mqd_t mqd_cmd = mq_open("/q_cmd",
O_RDWR | O_CREAT ,
S_IRWXU | S_IRWXG | S_IRWXO,
NULL);
mqd_t mqd_sns = mq_open("/q_sns",
O_RDWR | O_CREAT,
S_IRWXU | S_IRWXG | S_IRWXO,
NULL);
printf("The message queue id is: %d\n", mqd_cmd);
/* Determine the size of messages for this message queue
*/
struct mq_attr a;
mq_getattr(mqd_cmd,&a);
printf("The default message size is: %d\n", a.mq_msgsize);
if( mqd_cmd == -1)
{
perror("mq_open():");
return -1;
}
if( mqd_sns == -1)
{
perror("mq_open():");
return -1;
}
int check = 0;
char addresses[3][13];
if ((check = checkArgName(argc, argv, addresses)) == -1)
{
printf("Not correct name entered. Exiting.\n");
exit(0);
}
int i, counter, serverID, clientSock, numBytes;
pid_t pid, pid2;
// Arrays to hold most recent command sent by the
// supervisor-client and the most recent command sent to the iRobot.
char commandFromSupervisor[MAXDATASIZE] = {'\0'};
char commandToRobot[MAXDATASIZE] = {'\0'};
// An array to hold sensor data sent to the supervisor-client and
// obtained from the iRobot.
char sensDataToSupervisor[MAXDATASIZE] = {'\0'};
char sensDataFromRobot[MAXDATASIZE] = {'\0'};
char emptyDataToSupervisor[MAXDATASIZE] = "0000000000 ";
char rawTimeString[12] = {'\0'};
// An array to hold the timestamp.
char currTime[100];
// Create pipe to communicate between parent and child
int fd[2];
if(pipe(fd) < 0)
perror("pipe error");
//------------------------------------------------------------------------
// Added Code to implement client
//------------------------------------------------------------------------
int sockfd, numbytes;
//buffer to store sensor information
char sensorBuf[MAXDATASIZE];
char msgBuf[MAXDATASIZE];
struct addrinfo hints, *servinfo, *p;
int rv;
char s[INET6_ADDRSTRLEN];
//array to hold the command sent
char cmd[1];
//initialize the input to NULL char
char input = '\0';
//------------------------------------------------------------------------
// End of added section
//------------------------------------------------------------------------
// Create a socket-based server
if((serverID = createServer()) == -1)
{
perror("createServer()");
return -1;
}
printf("brainstem: waiting for connections...\n");
// Establish a client-connection for the socket-based server
if((clientSock = establishConnection(serverID)) == -1)
{
perror("establishConnection(serverID)");
return -1;
}
// Set up signal-based communication between the child
// (brain) and parent (nervous system) to avoid possible
// race conditions.
TELL_WAIT();
// Fork a child process. This process will handle the "brain"
// activities: communicating sensor data to the client
// and receiving control commands from the client.
if(( pid = fork()) < 0)
{
perror("fork error");
}
//------------------------------------------------------------------------
// Code for parent (nerves)
//------------------------------------------------------------------------
else if (pid > 0)
{
// Close the client socket since this parent won't be using it.
close(clientSock);
//TELL_CHILD(pid);
// Open the serial port to the robot. If this is unsuccessful,
// there is no point in continuing.
if(openPort() == 0)
{
printf("Port failed to open \n");
exit(-1);
}
// Initialize the robot, prepare it to receive commands. Wait
// for a second to give this some time to take effect.
initialize();
sleep(1);
#ifdef TARGET_WEBBY
// Initialize the compass device.
initializeCompass();
// This is temporary until turn() works.
// Turn Left 10 degrees
turn(TURN_LEFT, 10);
#endif
// Turn on the LED to indicate the robot is ready and listening.
// It's a nice sanity check.
setLED(RED, PLAY_ON, ADVANCE_ON);
//------------------------------------------------------------------------
// Added Code to implement client
//------------------------------------------------------------------------
if(check == 1)
{
#ifdef DEBUG
printf("%s %d \n", __FILE__, __LINE__);
#endif
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
if ((rv = getaddrinfo(addresses[1], PORT, &hints, &servinfo)) != 0)
{
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
return 1;
}
// loop through all the results and connect to the first we can
for(p = servinfo; p != NULL; p = p->ai_next)
{
if ((sockfd = socket(p->ai_family, p->ai_socktype,
p->ai_protocol)) == -1) {
perror("client: socket");
continue;
}
if (connect(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
close(sockfd);
perror("client: connect");
continue;
}
break;
}
if (p == NULL)
{
fprintf(stderr, "client: failed to connect\n");
return 2;
}
inet_ntop(p->ai_family, get_in_addr((struct sockaddr *)p->ai_addr),
s, sizeof s);
printf("client: connecting to %s\n", s);
freeaddrinfo(servinfo); // all done with this structure
//if the client does not recieve anything from server then exit
if ((numbytes = recv(sockfd, msgBuf, MAXDATASIZE-1, 0)) == -1)
{
perror("recv");
exit(1);
}
}
//------------------------------------------------------------------------
// End of added section
//------------------------------------------------------------------------
while(commandToRobot[0] != ssQuit)
{
commandToRobot[0] = 'z';
// Wait until a valid command is received.
while(commandToRobot[0] == 'z')
{
commandToRobot[0] = readFromMessageQueueAndExecute(mqd_cmd);
}
printf("commandToRobot: %d\n", commandToRobot[0]);
//------------------------------------------------------------------------
// Added Code to implement client
//------------------------------------------------------------------------
if(check == 1)
{
if(send(sockfd, &commandToRobot[0], 1, 0) == -1)
perror("send");
printf(" the command code sent was: %d\n", commandToRobot[0]);
}
//------------------------------------------------------------------------
// End of added section
//------------------------------------------------------------------------
receiveGroupOneSensorData(sensDataFromRobot);
// check if any of the sensor data indicates a
// sensor has been activated. If so, react be
// driving backwards briefly and then stopping.
int sensData = 0;
// Check sensor data first to stop ramming into wall.
sensData = checkSensorData(sensDataFromRobot);
#ifdef DEBUG
printf("%s %d \n", __FILE__, __LINE__);
#endif
// Wait until child has sent previous sensor data.
//WAIT_CHILD();
#ifdef DEBUG
printf("%s %d \n", __FILE__, __LINE__);
printf("%d \n", sensData);
#endif
if(sensData)
{
#ifdef DEBUG
printf("%s %d \n", __FILE__, __LINE__);
#endif
// Drive backwards and then stop.
driveBackwardsUntil(EIGHTH_SECOND, MED);
STOP_MACRO;
// Convey sensorData back to the child.
writeSensorDataToMessageQueue(sensDataFromRobot, mqd_sns, getTime(), getRawTime());
}
// Done writing sensor data, tell child to proceed reading sensor data.
TELL_CHILD(pid);
// Reset the array; fill it again in the next loop.
for(i = 0; i <= 6; i++)
{
sensDataFromRobot[i]= FALSE;
}
}
if (closePort() == -1)
{
perror("Port failed to close \n");
exit(-1);
}
send(sockfd, &input, 1, 0);
close(sockfd);
kill(0, SIGTERM);
mq_close(mqd_cmd);
exit(0);
}
//------------------------------------------------------------------------
// Code for child (brain)
//------------------------------------------------------------------------
else
{
// Child process doesn't need the listener.
close(serverID);
// Initially tell the parent to proceed and write sensor data.
//TELL_PARENT(getppid());
// Send the client the initial connection message.
if(send(clientSock, MSG, sizeof(MSG), 0) == -1)
perror("send");
// At the request of the supervisor implementation team, The
// brain follows a strict alternation of 'receive control
// command' then 'send sensor data'. If the control command
// sent by the supervisor-client is 'turn left' and the iRobot
// happens to bump into something, then the subsequent message
// to the supervisor-client will indicate which bumper was activated.
// Similarly, if the control command sent by the supervisor is
// 'turn left' and the iRobot experiences no sensory input, the
// subsequent message to the supervisor will indicate that no sensors
// were activated.
// As long as the quit command 'q' has not been sent by the
// supervisor-client, receive a control command and send the
// subsequent sensor data.
while(commandFromSupervisor[0] != ssQuit)
{
// Wait to receive command from supervisor-client; read the command
// into cmdBuf.
if ((numBytes = recv(clientSock, commandFromSupervisor, MAXDATASIZE-1, 0)) == -1)
{
perror("recv");
return -1;
}
// Write the read command into shared memory so that the
// parent (nerves) may read and execute it.
//writeCommandToSharedMemory(commandFromSupervisor, cmdArea,mqd_cmd);
writeCommandToMessageQueue(commandFromSupervisor,mqd_cmd);
// Wait until parent has written sensor data.
WAIT_PARENT();
#ifdef DEBUG
printf("%s %d \n", __FILE__, __LINE__);
#endif
// If there is sensor data available, send it to the
// supervisor-client.
if(readSensorDataFromMessageQueue(sensDataToSupervisor, mqd_sns))
{
printf("\nsensDataToSupervisor: %s \n", sensDataToSupervisor);
if(send(clientSock, sensDataToSupervisor, strlen(sensDataToSupervisor)-1 , 0) == -1)
perror("send");
}
// Otherwise, assume no sensor was activated. Send an empty
// sensor message to the supervisor-client.
else
{
itoa(getRawTime(), rawTimeString);
// Construct an empty sensor data message and send it to
// the supervisor-client.
strncat(emptyDataToSupervisor, rawTimeString, MAXDATASIZE-SIZE_OF_EMPTY_DATA);
strncat(emptyDataToSupervisor, " ", 1);
strncat(emptyDataToSupervisor, getTime(), MAXDATASIZE-SIZE_OF_EMPTY_DATA);
printf("\nemptySensDataToSupervisor: %s \n", emptyDataToSupervisor);
if(send(clientSock, emptyDataToSupervisor, MAXDATASIZE-1, 0) == -1)
perror("send");
emptyDataToSupervisor[SIZE_OF_EMPTY_DATA] = '\0';
}
// Done reading sensor data, allow parent to write more sensor data.
TELL_PARENT(getppid());
}
// All done. Clean up the toys and go home.
printf("Closing socket and terminating processes.\nHave a nice day!\n");
kill(pid, SIGTERM);
close(clientSock);
mq_close(mqd_cmd);
exit(0);
}
// Added following code to implement communication between roomba's
}
int main(int argc, char *argv[])
{
int fd;
pid_t pid;
void *addr = NULL;
fd = open("/dev/zero", O_RDWR);
if (fd < 0)
{
perror("open failure: ");
return EXIT_FAILURE;
}
addr = mmap(NULL, sizeof(int), PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_SHARED, fd, 0);
if (addr == NULL)
{
perror("mmap failure: ");
return EXIT_FAILURE;
}
close(fd); // mmap success and close fd
TELL_WAIT();
if ((pid = fork()) < 0)
{
perror("fork failure: ");
return EXIT_FAILURE;
}
else if (pid == 0)
{
int i = 0;
pid = getpid();
for (i = 0; i < 1000; i+=2)
{
if (update((int *)addr) != i)
{
fprintf(stderr, "child process sync failure, i = %d\n", i);
return EXIT_FAILURE;
}
printf("child start ##############\n");
TELL_PARENT(pid);
WAIT_PARENT();
}
}
else
{
int i = 0;
pid = getpid();
for (i = 1; i < 1000; i+=2)
{
WAIT_CHILD();
printf("parent start @@@@@@@@@@@@@@\n");
if (update((int *)addr) != i)
{
fprintf(stderr, "parent process sync failure, i = %d\n", i);
return EXIT_FAILURE;
}
TELL_CHILD(pid);
}
}
munmap(addr, sizeof(int));
return EXIT_SUCCESS;
}
