public static int DoFutex(Thread current, ref Arch.ExceptionRegisters regs, UserPtr uaddr, int op, int val, UserPtr timeoutPtr, UserPtr uaddr2, uint val3)
{
var cmd = op & FUTEX_CMD_MASK;
var flags = ToFlags(op, cmd);
timespec ts;
ts.tv_sec = ts.tv_nsec = 0;
// Don't care about shared mutex
if ((flags & FLAGS_SHARED) != 0)
{
return DoFutexShared(current, ref regs, uaddr, op, val, timeoutPtr, uaddr2, val3);
}
bool hasTimeout = timeoutPtr != UserPtr.Zero;
if (hasTimeout && timeoutPtr.Read(current, out ts) != 0)
return -ErrorCode.EFAULT;
switch (cmd)
{
case FUTEX_WAIT:
return Wait(current, ref regs, uaddr, flags, val, hasTimeout, ts, FUTEX_BITSET_MATCH_ANY);
case FUTEX_WAIT_BITSET:
return Wait(current, ref regs, uaddr, flags, val, hasTimeout, ts, val3);
case FUTEX_WAKE:
return Wake(current, uaddr, flags, val, FUTEX_BITSET_MATCH_ANY);
case FUTEX_WAKE_BITSET:
return Wake(current, uaddr, flags, val, val3);
default:
Arch.Console.Write("futex: unknown primitives ");
Arch.Console.Write(cmd);
Arch.Console.WriteLine();
return -ErrorCode.ENOSYS;
}
}
// Forward the futex request to Linux helper
private static int DoFutexShared(Thread current, ref Arch.ExceptionRegisters regs, UserPtr uaddr, int op, int val, UserPtr timeoutPtr, UserPtr uaddr2, uint val3)
{
// Some local test
var cmd = op & FUTEX_CMD_MASK;
timespec ts = new timespec();
bool hasTimeout = timeoutPtr != UserPtr.Zero;
if (hasTimeout && timeoutPtr.Read(current, out ts) != 0)
return -ErrorCode.EFAULT;
if (cmd == FUTEX_WAIT || cmd == FUTEX_WAIT_BITSET)
{
int old_val;
if (uaddr.Read(current, out old_val) != 0)
return -ErrorCode.EFAULT;
if (old_val != val)
return -ErrorCode.EWOULDBLOCK;
var bitset = cmd == FUTEX_WAIT ? FUTEX_BITSET_MATCH_ANY : val3;
var shadowAddr = FindShadowAddr(current, uaddr);
if (shadowAddr == Pointer.Zero)
{
Arch.Console.WriteLine("FutexShared: Don't know how to deal with shared_wait");
return 0;
}
var futex_entry = new FutexCompletionEntry(current, uaddr, bitset);
Arch.IPCStubs.linux_sys_futex_wait(current.Parent.helperPid, current.impl._value.thread._value, op, shadowAddr, val, ts, bitset);
Globals.CompletionQueue.Enqueue(futex_entry);
current.SaveState(ref regs);
current.AsyncReturn = true;
return 0;
}
else if (cmd == FUTEX_WAKE || cmd == FUTEX_WAKE_BITSET)
{
var bitset = cmd == FUTEX_WAKE ? FUTEX_BITSET_MATCH_ANY : val3;
if (bitset == 0)
return -ErrorCode.EINVAL;
var shadowAddr = FindShadowAddr(current, uaddr);
if (shadowAddr == Pointer.Zero)
{
Arch.Console.WriteLine("FutexShared: Don't know how to deal with shared_wake");
return 0;
}
var c = new BridgeCompletion(current, new ByteBufferRef());
Arch.IPCStubs.linux_sys_futex_wake(current.Parent.helperPid, current.impl._value.thread._value, op, shadowAddr, bitset);
Globals.CompletionQueue.Enqueue(c);
current.SaveState(ref regs);
current.AsyncReturn = true;
return 0;
}
return 0;
}
private static int Wait(Thread current, ref Arch.ExceptionRegisters regs, UserPtr uaddr, int flags, int val, bool hasTimeout, timespec ts, uint bitset)
{
int old_val;
if (uaddr.Read(current, out old_val) != 0)
return -ErrorCode.EFAULT;
if (old_val != val)
return -ErrorCode.EWOULDBLOCK;
//Arch.Console.Write("wait: addr=");
//Arch.Console.Write(uaddr.Value.ToUInt32());
//Arch.Console.Write(" thr=");
//Arch.Console.Write(current.Tid);
//Arch.Console.WriteLine();
TimerQueueNode node;
var futex_entry = new FutexCompletionEntry(current, uaddr, bitset);
Globals.FutexLists.InsertAtTail(futex_entry);
if (hasTimeout)
{
node = Globals.TimeoutQueue.Enqueue(ts.ToMilliseconds(), current);
futex_entry.timeoutNode = node;
}
Globals.CompletionQueue.Enqueue(futex_entry);
current.SaveState(ref regs);
current.AsyncReturn = true;
return 0;
}
