int vm::start() {
if(!mem)
return -1;
//some temporary addresses some instructions might need
ADDR_TYPE addr1;
for(;;) {
//load next instruction
char *inst = MEM(pc);
//prints the current instruction
//just for debugging purposes
//std::cout << (int)*inst << std::endl;
switch(*inst) {
case NOP:
break;
case ADD:
//adds the two integers on top of the stack
_ADD();
case DUP:
//duplicates the integer on top of the stack
_DUP();
case GETBASIC:
//replaces a pointer to a data object with the object
_GETBASIC();
case HALT:
//Stops the vm
return 0;
case JUMP:
//Jumps to an address
pc = *(ADDR_TYPE*)(inst + sizeof(INST_TYPE));
continue;
case JUMPZ:
//Jumps if the long long on top of the stack is 0
_JUMPZ();
case LOADC:
//loads a INTEGER constant on the stack
_LOADC();
case STORE:
//pushes the value on top of the stack to the adress lying at pos 2 of the stack
//there is no check, if the destination address is allocated or of the right type
_STORE();
case MKBASIC:
//Takes the INTEGER from the stack and stores it on the heap
_MKBASIC();
default:
std::cerr << "Unrecognized Opcode " << (int)*inst << std::endl;
}
pc += sizeof(INST_TYPE);
}
return 0;
}
int
fcntl(int fd, int cmd, ...)
{
int arg, i, ans, err;
Fdinfo *fi, *fans;
va_list va;
unsigned long oflags;
err = 0;
ans = 0;
va_start(va, cmd);
arg = va_arg(va, int);
va_end(va);
fi = &_fdinfo[fd];
if(fd<0 || fd>=OPEN_MAX || !(fi->flags&FD_ISOPEN))
err = EBADF;
else switch(cmd){
case F_DUPFD:
if(fi->flags&(FD_BUFFERED|FD_BUFFEREDX)){
err = EGREG; /* dup of buffered fd not implemented */
break;
}
oflags = fi->oflags;
for(i = (arg>0)? arg : 0; i<OPEN_MAX; i++)
if(!(_fdinfo[i].flags&FD_ISOPEN))
break;
if(i == OPEN_MAX)
err = EMFILE;
else {
ans = _DUP(fd, i);
if(ans != i){
if(ans < 0){
_syserrno();
err = errno;
}else
err = EBADF;
}else{
fans = &_fdinfo[ans];
fans->flags = fi->flags&~FD_CLOEXEC;
fans->oflags = oflags;
fans->uid = fi->uid;
fans->gid = fi->gid;
}
}
break;
case F_GETFD:
ans = fi->flags&FD_CLOEXEC;
break;
case F_SETFD:
fi->flags = (fi->flags&~FD_CLOEXEC)|(arg&FD_CLOEXEC);
break;
case F_GETFL:
ans = fi->oflags&OFL;
break;
case F_SETFL:
fi->oflags = (fi->oflags&~OFL)|(arg&OFL);
break;
case F_GETLK:
case F_SETLK:
case F_SETLKW:
err = EINVAL;
break;
}
if(err){
errno = err;
ans = -1;
}
return ans;
}
