Sure, I can provide you with a test case generator for the "Deadlock Detection" problem. 

Here's a Python function that generates test cases according to the problem specifications:

```python
import random

def generate_instruction_sequence(n):
    # Generate a random instruction sequence of length n ending with 'u'
    instructions = [random.choice('0123456789') for _ in range(n-1)]
    instructions.append('u')
    return ''.join(instructions)

def deadlock_detection_tcgen():
    # Number of datasets, can be up to 50
    num_datasets = random.randint(1, 50)
    datasets = []
    
    for _ in range(num_datasets):
        # Length of the instruction sequence (1 ≤ n ≤ 10,000)
        n = random.randint(1, 10000)
        
        # Generate the instruction sequence
        instructions = generate_instruction_sequence(n)
        
        datasets.append((n, instructions))
    
    # Append the terminating zero line
    datasets.append((0, ''))
    
    return datasets

# Example of generating test cases
test_cases = deadlock_detection_tcgen()
for (n, instructions) in test_cases:
    if n == 0:
        print(n)
    else:
        print(n)
        print(instructions)
```

Explanation:
1. **generate_instruction_sequence(n)**: This function generates a random instruction sequence of length `n` where each character is either a digit ('0' to '9') or 'u'. It ensures the sequence ends with 'u'.
2. **deadlock_detection_tcgen()**: This function generates up to 50 datasets. Each dataset consists of:
   - An integer `n`, representing the length of the instruction sequence.
   - A string `instructions`, representing the instruction sequence.
3. The function appends the terminating zero line at the end of the datasets to mark the end of input as specified.

You can use the generated test cases to test your implementation of the deadlock detection problem.