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(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;
}
/* 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);
}
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;
}
/* 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 (void)
{
pid_t pid = 0, ppid = 0, childpid = 0;
int i = 0;
init ();
if ((pid = fork ()) < 0) {
err_sys ("fork error");
} else if (pid == 0) { /* child block */
pid = getpid ();
ppid = getppid ();
for (i = 0; i < 100; i ++) {
WAIT_PARENT ();
increment (pid);
TELL_PARENT (ppid);
}
} else { /* parent block */
childpid = pid;
pid = getpid ();
for (i = 0; i < 100; i ++) {
increment (pid);
TELL_CHILD (childpid);
WAIT_CHILD ();
}
}
exit (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[])
{
int fd;
pid_t pid, cpid;
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");
if ((pid = fork()) < 0) {
err_sys("fork error");
} else if (pid > 0) {
WAIT_CHILD();
if (write_lock(fd, 0, SEEK_SET, 1) < 0)
err_sys("write_lock error");
printf("gain write lock\n");
} else {
if (read_lock(fd, 0, SEEK_SET, 1) < 0)
err_sys("read_lock error");
printf("gain read lock 1\n");
TELL_PARENT(getppid());
if ((cpid = fork()) < 0) {
err_sys("fork error");
} else if (cpid > 0) {
if (read_lock(fd, 0, SEEK_SET, 1) < 0)
err_sys("read_lock error");
printf("gain read lock 2\n");
}
}
return 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[]){
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()
{
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) {
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;
}
/* child goes first program*/
int main()
{
pid_t pid;
TELL_WAIT();
pid = fork();
if(pid < 0) {
printf("fork error\n");
}
else if(pid == 0) {
do_task("child task\n");
TELL_PARENT(getppid());
}
else {
WAIT_CHILD();
do_task("parent task\n");
}
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);
}
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 *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;
}
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);
}
}
