Class ExecutionContext

Represents an execution context, which is used to manage the execution of WebAssembly functions. It contains a stack of frames and behaves like a thread of execution.

Assembly: WaaS.Core.dll

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Declaration

public class ExecutionContext : IDisposable

Implements:
System.IDisposable

Properties

Fuel

The remaining fuel, or null if the fuel is unlimited (default). Each executed WebAssembly instruction consumes one unit of fuel, and WaaS.Runtime.FuelExhaustedException is thrown when an instruction is about to be executed with no fuel left. The host can refill the fuel at any time, e.g. between invocations or while the execution is suspended.

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Declaration

public ulong? Fuel { get; set; }

FuelPerResume

If set, WaaS.Runtime.ExecutionContext.Fuel is reset to this value each time the execution starts or resumes, that is, at the start of an invocation and after each suspension on an asynchronous host function. This limits the number of instructions executed between two suspensions.

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Declaration

public ulong? FuelPerResume { get; set; }

MaxMemoryPages

If set, "memory.grow" executed on this context fails once the memory would exceed this number of pages, in addition to the maximum declared by the module.

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Declaration

public uint? MaxMemoryPages { get; set; }

CancellationToken

The token to abort the execution on this context. It is observed while WebAssembly code is running (at branches and calls) and while the execution is suspended on an asynchronous host function. When cancellation is requested, System.OperationCanceledException is thrown from the invocation and the frames of the invocation are discarded.

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Declaration

public CancellationToken CancellationToken { get; set; }

DefaultDebugger

The debugger attached to the contexts when they are created, such as a debugger connected from an IDE.

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Declaration

public static IWasmDebugger DefaultDebugger { get; set; }

Debugger

The debugger observing the execution, or null. While a debugger is attached, the interpreter calls it before every instruction, which makes the execution several times slower.

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Declaration

public IWasmDebugger Debugger { get; set; }

LastFrame

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Declaration

public StackFrame LastFrame { get; }

ResultLength

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Declaration

public int ResultLength { get; }

Methods

Dispose()

Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.

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Declaration

public void Dispose()

Invoke(IInvocableFunction, ReadOnlySpan<StackValueItem>)

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Declaration

public void Invoke(IInvocableFunction function, ReadOnlySpan<StackValueItem> inputValues)

Parameters

Type	Name
WaaS.Runtime.IInvocableFunction	function
System.ReadOnlySpan<WaaS.Runtime.StackValueItem>	inputValues

InvokeAsync(IInvocableFunction, ReadOnlySpan<StackValueItem>)

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Declaration

public ValueTask InvokeAsync(IInvocableFunction function, ReadOnlySpan<StackValueItem> inputValues)

Returns

System.Threading.Tasks.ValueTask

Parameters

Type	Name
WaaS.Runtime.IInvocableFunction	function
System.ReadOnlySpan<WaaS.Runtime.StackValueItem>	inputValues

TakeResults(Span<StackValueItem>)

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Declaration

public void TakeResults(Span<StackValueItem> results)

Parameters

Type	Name
System.Span<WaaS.Runtime.StackValueItem>	results

Implements

• System.IDisposable