Is there a way to get benchmark arguments from GlobalSetup for currently running benchmark?

[PsykerUdot]

I have already looked through issues and discussions but found nothing relevant so far.
The problem is that there are no legal means to get argument from inside Setup method when current benchmark is running.

What am I looking for is following:

private BenchmarkArgument _actualBenchmarkArgument;

[GlobalSetup]
public void Setup()
{
  // Here we want to create actual benchmark argument from value specified by generated benchmark code.
  _actualBenchmarkArgument = GenerateArgumentFromFile(GetCurrentBenchmarkArgument());
}

[Benchmark]
[ArgumentsSource(nameof(GetFileNames))]
public void SomeBenchmark(string _)
{
  // Some code using _actualBenchmarkArgument
}

public IEnumerable<string> GetFileNames()
{
  // Discover files for benchmarks. We don't want to create actual benchmark arguments for all files over and over for every benchmark.
}

I have a workaround though, but it involves reflection performed on generated benchmarker code - it traverses Runnable_ constructor IL code and extracts required data. The workaround fits well for my needs but it's poorly maintainable and smells horribly.

[timcassell]

Can you explain what you're trying to do? Fields assigned in GlobalSetup are usable in the benchmark, just read the field directly instead of trying to pass it in as an argument. ArgumentsSource, however, does not interact with GlobalSetup (and tbh it should be static to make that more obvious). See #1408

[PsykerUdot]

My benchmarks use a large set of complex objects as argument values. The objects are constructed from data stored as files. Creating all objects at once (in a method that is referenced by ArgumentsSource) for every benchmark run is pretty time and resource consuming.

So what I want to implement:

• The method referenced by ArgumentsSource returns a collection of file names.
• During each benchmark run, GlobalSetup method gets current argument value (specific file name) provided by Runnable_ class to create actual object and store it (as class property).
• Benchmark method uses constructed object from the property.

So now it is not possible to access current benchmark argument values before work delegate is called (to which they are indeed passed).

[timcassell]

Try this instead:

[ParamsSource(nameof(GetFileNames))]
public string FileName { get; set; }

private BenchmarkArgument _actualBenchmarkArgument;

[GlobalSetup]
public void Setup()
{
  _actualBenchmarkArgument = GenerateArgumentFromFile(FileName);
}

[PsykerUdot]

It works! Appreciate it, thank you!
Somehow I overlooked ParamsSource...