[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2201:DoNotRaiseReservedExceptionTypes")] // TODO: fix
public TValue GetOrCreateValue(TKey key, Func <TValue> create)
{
bool lockTaken = false;
try {
MonitorUtils.Enter(data, ref lockTaken);
PublishInfo <TValue> pubValue;
if (data.TryGetValue(key, out pubValue))
{
if (pubValue.Value == null && pubValue.Exception == null)
{
pubValue.PrepareForWait();
MonitorUtils.Exit(data, ref lockTaken);
try {
pubValue.WaitForPublish();
} finally {
MonitorUtils.Enter(data, ref lockTaken);
pubValue.FinishWait();
}
}
if (pubValue.Exception != null)
{
throw new Exception("Error", pubValue.Exception);
}
return(pubValue.Value);
}
TValue ret;
// publish the empty PublishInfo
data[key] = pubValue = new PublishInfo <TValue>();
// release our lock while we create the new value
// then re-acquire the lock and publish the info.
MonitorUtils.Exit(data, ref lockTaken);
try {
try {
ret = create();
Debug.Assert(ret != null, "Can't publish a null value");
} finally {
MonitorUtils.Enter(data, ref lockTaken);
}
} catch (Exception e) {
pubValue.PublishError(e);
throw;
}
pubValue.PublishValue(ret);
return(ret);
} finally {
if (lockTaken)
{
Monitor.Exit(data);
}
}
}
