public VariableSubscription Subscribe(
int frameIndex,
string variableExpression,
Action<DebugEvaluationResult> executeAction) {
var token = new VariableSubscriptionToken(frameIndex, variableExpression);
var subscription = new VariableSubscription(
token,
executeAction,
Unsubscribe);
lock (_subscribers) {
List<VariableSubscription> subscriptions;
if (_subscribers.TryGetValue(subscription.Token, out subscriptions)) {
subscriptions.Add(subscription);
} else {
_subscribers.Add(
token,
new List<VariableSubscription>() { subscription });
}
}
return subscription;
}
public VariableSubscription(
VariableSubscriptionToken token,
Action<DebugEvaluationResult> executeAction,
Action<VariableSubscription> unsubscribeAction) {
Token = token;
_weakReference = new WeakReference(executeAction.Target);
_method = executeAction.Method;
_delegateType = executeAction.GetType();
_unsubscribe = unsubscribeAction;
}
private async Task PublishAsync(VariableSubscriptionToken token, IList<VariableSubscription> subscriptions) {
if (subscriptions.Count == 0) {
return;
}
Debug.Assert(_debugSession != null);
var stackFrames = await _debugSession.GetStackFramesAsync();
var stackFrame = stackFrames.FirstOrDefault(f => f.Index == token.FrameIndex);
if (stackFrame != null) {
const DebugEvaluationResultFields fields = DebugEvaluationResultFields.Classes
| DebugEvaluationResultFields.Expression
| DebugEvaluationResultFields.TypeName
| (DebugEvaluationResultFields.Repr | DebugEvaluationResultFields.ReprStr)
| DebugEvaluationResultFields.Dim
| DebugEvaluationResultFields.Length;
DebugEvaluationResult evaluation = await stackFrame.EvaluateAsync(token.Expression, fields: fields);
foreach (var sub in subscriptions) {
try {
var action = sub.GetExecuteAction();
if (action != null) {
action(evaluation);
}
} catch (Exception e) {
Debug.Fail(e.ToString());
// swallow exception and continue
}
}
}
}
