740 lines
28 KiB
C#
740 lines
28 KiB
C#
// Copyright (c) Microsoft Corporation.
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// Licensed under the MIT License.
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using System;
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using System.Collections.ObjectModel;
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using System.Diagnostics.CodeAnalysis;
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using System.Linq;
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using System.Management.Automation;
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using System.Management.Automation.Runspaces;
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using Dbg = System.Management.Automation.Diagnostics;
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namespace Microsoft.PowerShell
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{
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/// <summary>
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/// Executor wraps a Pipeline instance, and provides helper methods for executing commands in that pipeline. It is used to
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/// provide bookkeeping and structure to the use of pipeline in such a way that they can be interrupted and cancelled by a
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/// break event handler, and track nesting of pipelines (which happens with interrupted input loops (aka subshells) and use
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/// of tab-completion in prompts. The bookkeeping is necessary because the break handler is static and global, and there is
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/// no means for tying a break handler to an instance of an object.
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///
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/// The class' instance methods manage a single pipeline. The class' static methods track the outstanding instances to
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/// ensure that only one instance is 'active' (and therefore cancellable) at a time.
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/// </summary>
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internal class Executor
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{
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[Flags]
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internal enum ExecutionOptions
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{
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None = 0x0,
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AddOutputter = 0x01,
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AddToHistory = 0x02,
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ReadInputObjects = 0x04
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}
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/// <summary>
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/// Constructs a new instance.
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/// </summary>
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/// <param name="parent">
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/// A reference to the parent ConsoleHost that created this instance.
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/// </param>
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/// <param name="useNestedPipelines">
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/// true if the executor is supposed to use nested pipelines; false if not.
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/// </param>
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/// <param name="isPromptFunctionExecutor">
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/// True if the instance will be used to execute the prompt function, which will delay stopping the pipeline by some
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/// milliseconds. This we prevent us from stopping the pipeline so quickly that when the user leans on the ctrl-c key
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/// that the prompt "stops working" (because it is being stopped faster than it can run to completion).
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/// </param>
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internal Executor(ConsoleHost parent, bool useNestedPipelines, bool isPromptFunctionExecutor)
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{
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Dbg.Assert(parent != null, "parent should not be null");
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_parent = parent;
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this.useNestedPipelines = useNestedPipelines;
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_isPromptFunctionExecutor = isPromptFunctionExecutor;
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Reset();
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}
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#region async
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// called on the pipeline thread
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private void OutputObjectStreamHandler(object sender, EventArgs e)
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{
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// e is just an empty instance of EventArgs, so we ignore it. sender is the PipelineReader that raised it's
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// DataReady event that calls this handler, which is the PipelineReader for the Output object stream.
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PipelineReader<PSObject> reader = (PipelineReader<PSObject>)sender;
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// we use NonBlockingRead instead of Read, as Read would block if the reader has no objects. While it would be
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// inconsistent for this method to be called when there are no objects, since it will be called synchronously on
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// the pipeline thread, blocking in this call until an object is streamed would deadlock the pipeline. So we
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// prefer to take no chance of blocking.
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Collection<PSObject> objects = reader.NonBlockingRead();
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foreach (PSObject obj in objects)
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{
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_parent.OutputSerializer.Serialize(obj);
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}
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}
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// called on the pipeline thread
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private void ErrorObjectStreamHandler(object sender, EventArgs e)
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{
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// e is just an empty instance of EventArgs, so we ignore it. sender is the PipelineReader that raised it's
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// DataReady event that calls this handler, which is the PipelineReader for the Error object stream.
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PipelineReader<object> reader = (PipelineReader<object>)sender;
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// we use NonBlockingRead instead of Read, as Read would block if the reader has no objects. While it would be
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// inconsistent for this method to be called when there are no objects, since it will be called synchronously on
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// the pipeline thread, blocking in this call until an object is streamed would deadlock the pipeline. So we
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// prefer to take no chance of blocking.
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Collection<object> objects = reader.NonBlockingRead();
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foreach (object obj in objects)
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{
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_parent.ErrorSerializer.Serialize(obj);
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}
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}
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/// <summary>
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/// This method handles the failure in executing pipeline asynchronously.
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/// </summary>
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/// <param name="ex"></param>
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private void AsyncPipelineFailureHandler(Exception ex)
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{
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ErrorRecord er = null;
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IContainsErrorRecord cer = ex as IContainsErrorRecord;
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if (cer != null)
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{
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er = cer.ErrorRecord;
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// Exception inside the error record is ParentContainsErrorRecordException which
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// doesn't have stack trace. Replace it with top level exception.
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er = new ErrorRecord(er, ex);
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}
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if (er == null)
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{
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er = new ErrorRecord(ex, "ConsoleHostAsyncPipelineFailure", ErrorCategory.NotSpecified, null);
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}
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_parent.ErrorSerializer.Serialize(er);
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}
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private sealed class PipelineFinishedWaitHandle
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{
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internal PipelineFinishedWaitHandle(Pipeline p)
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{
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p.StateChanged += PipelineStateChangedHandler;
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}
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internal void Wait()
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{
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_eventHandle.WaitOne();
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}
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private void PipelineStateChangedHandler(object sender, PipelineStateEventArgs e)
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{
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if (
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e.PipelineStateInfo.State == PipelineState.Completed
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|| e.PipelineStateInfo.State == PipelineState.Failed
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|| e.PipelineStateInfo.State == PipelineState.Stopped)
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{
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_eventHandle.Set();
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}
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}
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private readonly System.Threading.ManualResetEvent _eventHandle = new System.Threading.ManualResetEvent(false);
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}
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internal void ExecuteCommandAsync(string command, out Exception exceptionThrown, ExecutionOptions options)
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{
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Dbg.Assert(!useNestedPipelines, "can't async invoke a nested pipeline");
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Dbg.Assert(!string.IsNullOrEmpty(command), "command should have a value");
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bool addToHistory = (options & ExecutionOptions.AddToHistory) > 0;
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Pipeline tempPipeline = _parent.RunspaceRef.CreatePipeline(command, addToHistory, false);
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ExecuteCommandAsyncHelper(tempPipeline, out exceptionThrown, options);
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}
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/// <summary>
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/// Executes a pipeline in the console when we are running asnyc.
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/// </summary>
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/// <param name="tempPipeline">
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/// The pipeline to execute.
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/// </param>
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/// <param name="exceptionThrown">
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/// Any exception thrown trying to run the pipeline.
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/// </param>
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/// <param name="options">
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/// The options to use to execute the pipeline.
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/// </param>
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internal void ExecuteCommandAsyncHelper(Pipeline tempPipeline, out Exception exceptionThrown, ExecutionOptions options)
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{
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Dbg.Assert(!_isPromptFunctionExecutor, "should not async invoke the prompt");
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exceptionThrown = null;
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Executor oldCurrent = CurrentExecutor;
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CurrentExecutor = this;
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lock (_instanceStateLock)
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{
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Dbg.Assert(_pipeline == null, "no other pipeline should exist");
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_pipeline = tempPipeline;
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}
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try
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{
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if ((options & ExecutionOptions.AddOutputter) > 0 && _parent.OutputFormat == Serialization.DataFormat.Text)
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{
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// Tell the script command to merge it's output and error streams
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if (tempPipeline.Commands.Count == 1)
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{
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tempPipeline.Commands[0].MergeMyResults(PipelineResultTypes.Error, PipelineResultTypes.Output);
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}
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// then add out-default to the pipeline to render everything...
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Command outDefault = new Command("Out-Default", /* isScript */false, /* useLocalScope */ true);
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tempPipeline.Commands.Add(outDefault);
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}
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tempPipeline.Output.DataReady += OutputObjectStreamHandler;
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tempPipeline.Error.DataReady += ErrorObjectStreamHandler;
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PipelineFinishedWaitHandle pipelineWaiter = new PipelineFinishedWaitHandle(tempPipeline);
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// close the input pipeline so the command will do something
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// if we are not reading input
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if ((options & Executor.ExecutionOptions.ReadInputObjects) == 0)
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{
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tempPipeline.Input.Close();
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}
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tempPipeline.InvokeAsync();
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if ((options & ExecutionOptions.ReadInputObjects) > 0 && Console.IsInputRedirected)
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{
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// read input objects from stdin
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WrappedDeserializer des = new WrappedDeserializer(_parent.InputFormat, "Input", _parent.ConsoleIn.Value);
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while (!des.AtEnd)
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{
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object o = des.Deserialize();
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if (o == null)
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{
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break;
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}
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try
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{
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tempPipeline.Input.Write(o);
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}
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catch (PipelineClosedException)
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{
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// This exception can occurs when input is closed. This can happen
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// for various reasons. For ex:Command in the pipeline is invalid and
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// command discovery throws exception which closes the pipeline and
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// hence the Input pipe.
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break;
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}
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}
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des.End();
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}
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tempPipeline.Input.Close();
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pipelineWaiter.Wait();
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// report error if pipeline failed
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if (tempPipeline.PipelineStateInfo.State == PipelineState.Failed && tempPipeline.PipelineStateInfo.Reason != null)
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{
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if (_parent.OutputFormat == Serialization.DataFormat.Text)
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{
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// Report the exception using normal error reporting
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exceptionThrown = tempPipeline.PipelineStateInfo.Reason;
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}
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else
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{
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// serialize the error record
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AsyncPipelineFailureHandler(tempPipeline.PipelineStateInfo.Reason);
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}
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}
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}
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catch (Exception e)
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{
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exceptionThrown = e;
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}
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finally
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{
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// Once we have the results, or an exception is thrown, we throw away the pipeline.
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_parent.ui.ResetProgress();
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CurrentExecutor = oldCurrent;
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Reset();
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}
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}
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#endregion async
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internal Pipeline CreatePipeline()
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{
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if (useNestedPipelines)
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{
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return _parent.RunspaceRef.CreateNestedPipeline();
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}
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else
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{
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return _parent.RunspaceRef.CreatePipeline();
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}
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}
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internal Pipeline CreatePipeline(string command, bool addToHistory)
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{
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Dbg.Assert(!string.IsNullOrEmpty(command), "command should have a value");
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return _parent.RunspaceRef.CreatePipeline(command, addToHistory, useNestedPipelines);
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}
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/// <summary>
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/// All calls to the Runspace to execute a command line must be done with this function, which properly synchronizes
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/// access to the running pipeline between the main thread and the break handler thread. This synchronization is
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/// necessary so that executions can be aborted with Ctrl-C (including evaluation of the prompt and collection of
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/// command-completion candidates.
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///
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/// On any given Executor instance, ExecuteCommand should be called at most once at a time by any one thread. It is NOT
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/// reentrant.
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/// </summary>
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/// <param name="command">
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/// The command line to be executed. Must be non-null.
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/// </param>
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/// <param name="exceptionThrown">
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/// Receives the Exception thrown by the execution of the command, if any. If no exception is thrown, then set to null.
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/// Can be tested to see if the execution was successful or not.
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/// </param>
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/// <param name="options">
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/// options to govern the execution
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/// </param>
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/// <returns>
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/// the object stream resulting from the execution. May be null.
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/// </returns>
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internal Collection<PSObject> ExecuteCommand(string command, out Exception exceptionThrown, ExecutionOptions options)
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{
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Dbg.Assert(!string.IsNullOrEmpty(command), "command should have a value");
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// Experimental:
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// Check for implicit remoting commands that can be batched, and execute as batched if able.
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if (ExperimentalFeature.IsEnabled("PSImplicitRemotingBatching"))
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{
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var addOutputter = ((options & ExecutionOptions.AddOutputter) > 0);
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if (addOutputter &&
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!_parent.RunspaceRef.IsRunspaceOverridden &&
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_parent.RunspaceRef.Runspace.ExecutionContext.Modules != null &&
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_parent.RunspaceRef.Runspace.ExecutionContext.Modules.IsImplicitRemotingModuleLoaded &&
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Utils.TryRunAsImplicitBatch(command, _parent.RunspaceRef.Runspace))
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{
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exceptionThrown = null;
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return null;
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}
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}
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Pipeline tempPipeline = CreatePipeline(command, (options & ExecutionOptions.AddToHistory) > 0);
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return ExecuteCommandHelper(tempPipeline, out exceptionThrown, options);
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}
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private static Command GetOutDefaultCommand(bool endOfStatement)
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{
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return new Command(command: "Out-Default",
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isScript: false,
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useLocalScope: true,
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mergeUnclaimedPreviousErrorResults: true)
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{
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IsEndOfStatement = endOfStatement
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};
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}
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internal Collection<PSObject> ExecuteCommandHelper(Pipeline tempPipeline, out Exception exceptionThrown, ExecutionOptions options)
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{
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Dbg.Assert(tempPipeline != null, "command should have a value");
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exceptionThrown = null;
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Collection<PSObject> results = null;
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if ((options & ExecutionOptions.AddOutputter) > 0)
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{
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if (tempPipeline.Commands.Count < 2)
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{
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if (tempPipeline.Commands.Count == 1)
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{
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// Tell the script command to merge it's output and error streams.
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tempPipeline.Commands[0].MergeMyResults(PipelineResultTypes.Error, PipelineResultTypes.Output);
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}
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// Add Out-Default to the pipeline to render.
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tempPipeline.Commands.Add(GetOutDefaultCommand(endOfStatement: false));
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}
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else
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{
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// For multiple commands/scripts we need to insert Out-Default at the end of each statement.
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CommandCollection executeCommands = new CommandCollection();
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foreach (var cmd in tempPipeline.Commands)
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{
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executeCommands.Add(cmd);
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if (cmd.IsEndOfStatement)
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{
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// End of statement needs to pipe to Out-Default.
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cmd.IsEndOfStatement = false;
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executeCommands.Add(GetOutDefaultCommand(endOfStatement: true));
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}
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}
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var lastCmd = executeCommands.Last();
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if (!((lastCmd.CommandText != null) &&
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(lastCmd.CommandText.Equals("Out-Default", StringComparison.OrdinalIgnoreCase)))
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)
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{
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// Ensure pipeline output goes to Out-Default.
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executeCommands.Add(GetOutDefaultCommand(endOfStatement: false));
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}
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tempPipeline.Commands.Clear();
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foreach (var cmd in executeCommands)
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{
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tempPipeline.Commands.Add(cmd);
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}
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}
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}
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Executor oldCurrent = CurrentExecutor;
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CurrentExecutor = this;
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lock (_instanceStateLock)
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{
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Dbg.Assert(_pipeline == null, "no other pipeline should exist");
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_pipeline = tempPipeline;
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}
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try
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{
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// blocks until all results are retrieved.
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results = tempPipeline.Invoke();
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}
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catch (Exception e)
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{
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exceptionThrown = e;
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}
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finally
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{
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// Once we have the results, or an exception is thrown, we throw away the pipeline.
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_parent.ui.ResetProgress();
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CurrentExecutor = oldCurrent;
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Reset();
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}
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return results;
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}
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[SuppressMessage("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode", Justification = "Needed by ProfileTests as mentioned in bug 140572")]
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internal Collection<PSObject> ExecuteCommand(string command)
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{
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Collection<PSObject> result = null;
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Exception e = null;
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do
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{
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result = ExecuteCommand(command, out e, ExecutionOptions.None);
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if (e != null)
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{
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break;
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}
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if (result == null)
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{
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break;
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}
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} while (false);
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return result;
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}
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/// <summary>
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/// Executes a command (by calling this.ExecuteCommand), and coerces the first result object to a string. Any Exception
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/// thrown in the course of execution is returned thru the exceptionThrown parameter.
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/// </summary>
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/// <param name="command">
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/// The command to execute. May be any valid monad command.
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/// </param>
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/// <param name="exceptionThrown">
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/// Receives the Exception thrown by the execution of the command, if any. If no exception is thrown, then set to null.
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/// Can be tested to see if the execution was successful or not.
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/// </param>
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/// <returns>
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/// The string representation of the first result object returned, or null if an exception was thrown or no objects were
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/// returned by the command.
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/// </returns>
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internal string ExecuteCommandAndGetResultAsString(string command, out Exception exceptionThrown)
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{
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exceptionThrown = null;
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string result = null;
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do
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{
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Collection<PSObject> streamResults = ExecuteCommand(command, out exceptionThrown, ExecutionOptions.None);
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if (exceptionThrown != null)
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{
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break;
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}
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if (streamResults == null || streamResults.Count == 0)
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{
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break;
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}
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// we got back one or more objects. Pick off the first result.
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if (streamResults[0] == null)
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return string.Empty;
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// And convert the base object into a string. We can't use the proxied
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// ToString() on the PSObject because there is no default runspace
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// available.
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PSObject msho = streamResults[0] as PSObject;
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if (msho != null)
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result = msho.BaseObject.ToString();
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else
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result = streamResults[0].ToString();
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}
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while (false);
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return result;
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}
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/// <summary>
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/// Executes a command (by calling this.ExecuteCommand), and coerces the first result object to a bool. Any Exception
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/// thrown in the course of execution is caught and ignored.
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/// </summary>
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/// <param name="command">
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/// The command to execute. May be any valid monad command.
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/// </param>
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/// <returns>
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/// The Nullable`bool representation of the first result object returned, or null if an exception was thrown or no
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/// objects were returned by the command.
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/// </returns>
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internal bool? ExecuteCommandAndGetResultAsBool(string command)
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{
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Exception unused = null;
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bool? result = ExecuteCommandAndGetResultAsBool(command, out unused);
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return result;
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}
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/// <summary>
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/// Executes a command (by calling this.ExecuteCommand), and coerces the first result object to a bool. Any Exception
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/// thrown in the course of execution is returned thru the exceptionThrown parameter.
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/// </summary>
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/// <param name="command">
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/// The command to execute. May be any valid monad command.
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/// </param>
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/// <param name="exceptionThrown">
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/// Receives the Exception thrown by the execution of the command, if any. If no exception is thrown, then set to null.
|
|
/// Can be tested to see if the execution was successful or not.
|
|
/// </param>
|
|
/// <returns>
|
|
/// The Nullable`bool representation of the first result object returned, or null if an exception was thrown or no
|
|
/// objects were returned by the command.
|
|
/// </returns>
|
|
internal bool? ExecuteCommandAndGetResultAsBool(string command, out Exception exceptionThrown)
|
|
{
|
|
exceptionThrown = null;
|
|
|
|
Dbg.Assert(!string.IsNullOrEmpty(command), "command should have a value");
|
|
|
|
bool? result = null;
|
|
|
|
do
|
|
{
|
|
Collection<PSObject> streamResults = ExecuteCommand(command, out exceptionThrown, ExecutionOptions.None);
|
|
|
|
if (exceptionThrown != null)
|
|
{
|
|
break;
|
|
}
|
|
|
|
if (streamResults == null || streamResults.Count == 0)
|
|
{
|
|
break;
|
|
}
|
|
|
|
// we got back one or more objects.
|
|
|
|
result = (streamResults.Count > 1) || (LanguagePrimitives.IsTrue(streamResults[0]));
|
|
}
|
|
while (false);
|
|
|
|
return result;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Cancels execution of the current instance. If the current instance is not running, then does nothing. Called in
|
|
/// response to a break handler, by the static Executor.Cancel method.
|
|
/// </summary>
|
|
private void Cancel()
|
|
{
|
|
// if there's a pipeline running, stop it.
|
|
|
|
lock (_instanceStateLock)
|
|
{
|
|
if (_pipeline != null && !_cancelled)
|
|
{
|
|
_cancelled = true;
|
|
|
|
if (_isPromptFunctionExecutor)
|
|
{
|
|
System.Threading.Thread.Sleep(100);
|
|
}
|
|
|
|
_pipeline.Stop();
|
|
}
|
|
}
|
|
}
|
|
|
|
internal void BlockCommandOutput()
|
|
{
|
|
RemotePipeline remotePipeline = _pipeline as RemotePipeline;
|
|
if (remotePipeline != null)
|
|
{
|
|
// Waits until queued data is handled.
|
|
remotePipeline.DrainIncomingData();
|
|
|
|
// Blocks any new data.
|
|
remotePipeline.SuspendIncomingData();
|
|
}
|
|
}
|
|
|
|
internal void ResumeCommandOutput()
|
|
{
|
|
RemotePipeline remotePipeline = _pipeline as RemotePipeline;
|
|
if (remotePipeline != null)
|
|
{
|
|
// Resumes data flow.
|
|
remotePipeline.ResumeIncomingData();
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Resets the instance to its post-ctor state. Does not cancel execution.
|
|
/// </summary>
|
|
private void Reset()
|
|
{
|
|
lock (_instanceStateLock)
|
|
{
|
|
_pipeline = null;
|
|
_cancelled = false;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Makes the given instance the "current" instance, that is, the instance that will receive a Cancel call if the break
|
|
/// handler is triggered and calls the static Cancel method.
|
|
/// </summary>
|
|
/// <value>
|
|
/// The instance to make current. Null is allowed.
|
|
/// </value>
|
|
/// <remarks>
|
|
/// Here are some state-transition cases to illustrate the use of CurrentExecutor
|
|
///
|
|
/// null is current
|
|
/// p1.ExecuteCommand
|
|
/// set p1 as current
|
|
/// promptforparams
|
|
/// tab complete
|
|
/// p2.ExecuteCommand
|
|
/// set p2 as current
|
|
/// p2.Execute completes
|
|
/// restore old current to p1
|
|
/// p1.Execute completes
|
|
/// restore null as current
|
|
///
|
|
/// Here's another case:
|
|
/// null is current
|
|
/// p1.ExecuteCommand
|
|
/// set p1 as current
|
|
/// ShouldProcess - suspend
|
|
/// EnterNestedPrompt
|
|
/// set null as current so that break does not exit the subshell
|
|
/// evaluate prompt
|
|
/// p2.ExecuteCommand
|
|
/// set p2 as current
|
|
/// Execute completes
|
|
/// restore null as current
|
|
/// nested loop exit
|
|
/// restore p1 as current
|
|
///
|
|
/// Summary:
|
|
/// ExecuteCommand always saves/sets/restores CurrentExecutor
|
|
/// Host.EnterNestedPrompt always saves/clears/restores CurrentExecutor
|
|
/// </remarks>
|
|
internal static Executor CurrentExecutor
|
|
{
|
|
get
|
|
{
|
|
Executor result = null;
|
|
|
|
lock (s_staticStateLock)
|
|
{
|
|
result = s_currentExecutor;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
set
|
|
{
|
|
lock (s_staticStateLock)
|
|
{
|
|
// null is acceptable.
|
|
|
|
s_currentExecutor = value;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Cancels the execution of the current instance (the instance last passed to PushCurrentExecutor), if any. If no
|
|
/// instance is Current, then does nothing.
|
|
/// </summary>
|
|
internal static void CancelCurrentExecutor()
|
|
{
|
|
Executor temp = null;
|
|
|
|
lock (s_staticStateLock)
|
|
{
|
|
temp = s_currentExecutor;
|
|
}
|
|
|
|
if (temp != null)
|
|
{
|
|
temp.Cancel();
|
|
}
|
|
}
|
|
|
|
// These statics are threadsafe, as there can be only one instance of ConsoleHost in a process at a time, and access
|
|
// to currentExecutor is guarded by staticStateLock, and static initializers are run by the CLR at program init time.
|
|
|
|
private static Executor s_currentExecutor;
|
|
private static readonly object s_staticStateLock = new object();
|
|
|
|
private readonly ConsoleHost _parent;
|
|
private Pipeline _pipeline;
|
|
private bool _cancelled;
|
|
internal bool useNestedPipelines;
|
|
private readonly object _instanceStateLock = new object();
|
|
private readonly bool _isPromptFunctionExecutor;
|
|
}
|
|
} // namespace
|