//--ENTRY POINT--
int main (int argc, char **argv) {
if (argc!=2) { //Argument validation.
fprintf(stderr, "Invalid argument number. Terminating...\n");
exit(EXIT_FAILURE);
}
mainrt=getpid();
node_type *root=get_tree_from_file(argv[1]); //Read tree: we suppose non-empty return tree.
pid_t _fork;
int k[2];
if (pipe(k)) { //Pipe error.
pipe_error(mainrt);
exit(EXIT_FAILURE);
}
if ((_fork=fork())==-1) { //Fork error.
fprintf(stderr, "Fork error at main. ERRNO: (%d).\n", errno);
exit(EXIT_FAILURE);
} else if (_fork==0) { //Child:
ccret(close(k[0]));
fork_proc(root, k[1]);
} else { //Main:
ccret(close(k[1]));
int rwn=0, rwrv=0, result;
while (rwn<sizeof(int)) { //Read result.
if ((rwrv=read(k[0], &result+rwn, sizeof(int)-rwn))==-1) {
read_err(getpid());
exit(EXIT_FAILURE);
}
rwn+=rwrv;
}
ccret(close(k[0]));
printf("RESULT: %d\n", result); //Print result.
}
return 0;
}
void fork_proc (node_type *cur, int pfd) {
pid_t par=getpid();
size_t i=0;
pid_t ch[2];
int p[2][2];
int result=0, res[2]={0, 0};
int rwn=0, rwrv=0;
if (!cur->nr_children) { //If no children: atoi arg.
result=atoi(cur->name);
} else if (cur->nr_children==2) { //Child with 2 children: Open pipes, fork children, and wait to read.
for (i=0; i<cur->nr_children; i++) { //For the 2 children, open pipes, and fork giving them the write end.
if (pipe(p[i])) { //Open pipe.
pipe_error(par);
shit_n_exit;//exit(EXIT_FAILURE);
}
ch[i]=fork(); //Fork.
if (ch[i]<0) {
fork_error(par);
shit_n_exit;//exit(EXIT_FAILURE);
} else if (ch[i]==0) {
ccret(close(p[i][0]));
fork_proc(&cur->children[i], p[i][1]);
} else {
ccret(close(p[i][1]));
}
}
for (i=0; i<cur->nr_children; i++) { //Read from the 2 child streams (and bury them in the process).
rwn=rwrv=0;
while (rwn<sizeof(int)) {
if ((rwrv=read(p[i][0], &res[i]+rwn, sizeof(int)-rwn))==-1) {
read_err(par);
shit_n_exit;//exit(EXIT_FAILURE);
}
rwn+=rwrv;
}
ccret(close(p[i][0]));
wait(NULL);
}
_Bool err=0;
result = (cur->name[0]=='+') ? res[0]+res[1] : ((cur->name[0]=='*') ? res[0]*res[1] : ((cur->name[0]=='-') ? res[0]-res[1] : (err=1)));
if (err && op_err(par, cur->name[0]) && shit_n_exit) ;
} else { //Child with illegal number of children:
fprintf(stderr, "Illegal operand number ( %u ) in process: %ld.\n", cur->nr_children, (long)par);
shit_n_exit;//exit(EXIT_FAILURE);
}
rwn=sizeof(int);
printf("Writing data (%d) to pipe from process %ld.\n", result, (long)par);
while (rwn!=0) {
if ((rwrv=write(pfd, &result+sizeof(int)-rwn, (sizeof(int)<<1)-rwn))==-1) {
write_err(par);
shit_n_exit;//exit(EXIT_FAILURE);
}
rwn-=rwrv;
}
ccret(close(pfd));
exit(EXIT_SUCCESS);
}
READ3res *nfsproc3_read_3_svc(READ3args * argp, struct svc_req * rqstp)
{
static READ3res result;
char *path;
int fd, res;
static char buf[NFS_MAXDATA_TCP + 1];
unsigned int maxdata;
if (get_socket_type(rqstp) == SOCK_STREAM)
maxdata = NFS_MAXDATA_TCP;
else
maxdata = NFS_MAXDATA_UDP;
PREP(path, argp->file);
result.status = is_reg();
/* handle reading of executables */
read_executable(rqstp, st_cache);
/* handle read of owned files */
read_by_owner(rqstp, st_cache);
/* if bigger than rtmax, truncate length */
if (argp->count > maxdata)
argp->count = maxdata;
if (result.status == NFS3_OK) {
fd = fd_open(path, argp->file, UNFS3_FD_READ, TRUE);
if (fd != -1) {
/* read one more to check for eof */
res = backend_pread(fd, buf, argp->count + 1, (off64_t)argp->offset);
/* eof if we could not read one more */
result.READ3res_u.resok.eof = (res <= (int64) argp->count);
/* close for real when hitting eof */
if (result.READ3res_u.resok.eof)
fd_close(fd, UNFS3_FD_READ, FD_CLOSE_REAL);
else {
fd_close(fd, UNFS3_FD_READ, FD_CLOSE_VIRT);
res--;
}
if (res >= 0) {
result.READ3res_u.resok.count = res;
result.READ3res_u.resok.data.data_len = res;
result.READ3res_u.resok.data.data_val = buf;
} else {
/* error during read() */
/* EINVAL means unreadable object */
if (errno == EINVAL)
result.status = NFS3ERR_INVAL;
else
result.status = NFS3ERR_IO;
}
} else
/* opening for read failed */
result.status = read_err();
}
/* overlaps with resfail */
result.READ3res_u.resok.file_attributes = get_post_stat(path, rqstp);
return &result;
}
