public MessageQueue(int length, string queueName)
{
int cbMessage = Marshal.SizeOf <T>();
if (cbMessage > 8192)
{
throw new ArgumentOutOfRangeException("By default, Linux limits size of queue messages to 8kb");
}
if (length > 10)
{
throw new ArgumentOutOfRangeException("By default, Linux limits the queue to 10 pending messages");
}
int pid = Process.GetCurrentProcess().Id;
string name = $"/{ queueName }.{ pid }";
MessageQueueAttributes mqa = new MessageQueueAttributes()
{
flags = eMessageQueueFlags.NonBlocking,
maxMessages = length,
messageSize = cbMessage
};
int fd = MQ.mq_open(name, queueFlags, eFileAccess.OwnerAllAccess, ref mqa);
if (fd < 0)
{
throw LibC.exception("mq_open", fd);
}
handle = fd;
this.name = name;
}
public void finalize()
{
if (fd >= 0)
{
LibC.close(fd);
fd = -1;
}
}
public static FileHandle openFile(string path, eFileFlags flags)
{
int fd = LibC.open(path, flags);
if (fd >= 0)
{
return(new FileHandle(fd));
}
throw LibC.exception($"Unable to open the file \"{ path }\"", fd);
}
public static EventHandle create()
{
int fd = LibC.eventfd(0, eEventFdFlags.NonBlocking | eEventFdFlags.DisableHandleInheritance);
if (fd >= 0)
{
return(new EventHandle(fd));
}
throw LibC.exception($"Unable to create an event handle", fd);
}
public static TimerHandle create()
{
int fd = LibC.timerfd_create(eClock.Monotonic, eTimerCreateFlags.DisableHandleInheritance);
if (fd >= 0)
{
return(new TimerHandle(fd));
}
throwError($"Unable to create a timer handle", fd);
throw new ApplicationException();
}
public void reset()
{
unsafe
{
ulong counter = 0;
int res = (int)LibC.read(fd, &counter, (UIntPtr)8);
if (8 == res)
{
return;
}
throw LibC.exception("EventHandle.reset failed", res);
}
}
public void set()
{
unsafe
{
ulong increment = 1;
int res = (int)LibC.write(fd, &increment, (UIntPtr)8);
if (8 == res)
{
return;
}
throw LibC.exception("EventHandle.set failed", res);
}
}
public T read <T>(eControlCode code) where T : unmanaged
{
T result = new T();
unsafe
{
T * pointer = &result;
int res = LibC.ioctl(fd, (uint)code, pointer);
if (0 == res)
{
return(result);
}
handleError(code, res);
return(default);
static void throwError(string what, int returnedValue)
{
if (returnedValue == -1)
{
int errno = Marshal.GetLastWin32Error();
string message = NativeErrorMessages.lookupLinuxError(errno);
if (null != message)
{
throw new COMException($"{ what }: { message }", LibC.hresultFromLinux(errno));
}
throw new COMException($"{ what }: undocumented Linux error code { errno }", LibC.hresultFromLinux(errno));
}
throw new ApplicationException($"{ what }: unexpected result { returnedValue }");
}
public static void mq_send <T>(int fd, T message, uint priority = 0) where T : unmanaged
{
size_t cb = (size_t)Marshal.SizeOf <T>();
unsafe
{
T * ptr = &message;
int res = mq_send(fd, ptr, cb, priority);
if (0 == res)
{
return;
}
throw LibC.exception("mq_send", res);
}
}
public static T mq_receive <T>(int fd, out uint priority) where T : unmanaged
{
size_t cb = (size_t)Marshal.SizeOf <T>();
T result;
unsafe
{
T * ptr = &result;
int res = (int)mq_receive(fd, ptr, cb, out priority);
if (res == (int)cb)
{
return(result);
}
throw LibC.exception("mq_receive", res);
}
}
public void dispose()
{
if (this.fd < 0)
{
return;
}
int fd = this.fd;
this.fd = -1;
int res = LibC.close(fd);
if (0 == res)
{
return;
}
throw LibC.exception($"Error closing file descriptor { fd }", res);
}
public void Dispose()
{
if (handle >= 0)
{
int res = MQ.mq_close(handle);
if (res < 0)
{
throw LibC.exception("mq_close", res);
}
res = MQ.mq_unlink(name);
if (res < 0)
{
throw LibC.exception("mq_unlink", res);
}
}
GC.SuppressFinalize(this);
}
public void dispose()
{
if (this.fd < 0)
{
return;
}
int fd = this.fd;
this.fd = -1;
int res = LibC.close(fd);
if (0 == res)
{
return;
}
throwError($"Error closing timer handle { fd }", res);
}
public void setTimeout(TimeSpan timeout)
{
if (fd < 0)
{
throw new ApplicationException("The timer was not created");
}
if (timeout.Ticks <= 0)
{
throw new ArgumentOutOfRangeException("The time is in the past");
}
sTimerDesc desc = default;
desc.value = timeout;
int res = LibC.timerfd_settime(fd, eTimerSetFlag.Relative, ref desc);
if (res >= 0)
{
return;
}
throwError($"Unable to set the time", res);
throw new ApplicationException();
}