private/Start-LoggingManager.ps1
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function Start-LoggingManager { [CmdletBinding()] param( [TimeSpan]$ConsumerStartupTimeout = "00:00:10" ) New-Variable -Name LoggingEventQueue -Scope Script -Value ([System.Collections.Concurrent.BlockingCollection[hashtable]]::new(100)) New-Variable -Name LoggingRunspace -Scope Script -Option ReadOnly -Value ([hashtable]::Synchronized(@{ })) New-Variable -Name TargetsInitSync -Scope Script -Option ReadOnly -Value ([System.Threading.ManualResetEventSlim]::new($false)) $Script:InitialSessionState = [initialsessionstate]::CreateDefault() if ($Script:InitialSessionState.psobject.Properties['ApartmentState']) { $Script:InitialSessionState.ApartmentState = [System.Threading.ApartmentState]::MTA } # Importing variables into runspace foreach ($sessionVariable in 'ScriptRoot', 'LevelNames', 'Logging', 'LoggingEventQueue', 'TargetsInitSync') { $Value = Get-Variable -Name $sessionVariable -ErrorAction Continue -ValueOnly Write-Verbose "Importing variable $sessionVariable`: $Value into runspace" $v = New-Object System.Management.Automation.Runspaces.SessionStateVariableEntry -ArgumentList $sessionVariable, $Value, '', ([System.Management.Automation.ScopedItemOptions]::AllScope) $Script:InitialSessionState.Variables.Add($v) } # Importing functions into runspace foreach ($Function in 'Replace-Token', 'Initialize-LoggingTarget', 'Get-LevelNumber') { Write-Verbose "Importing function $($Function) into runspace" $Body = Get-Content Function:\$Function $f = New-Object System.Management.Automation.Runspaces.SessionStateFunctionEntry -ArgumentList $Function, $Body $Script:InitialSessionState.Commands.Add($f) } #Setup runspace $Script:LoggingRunspace.Runspace = [runspacefactory]::CreateRunspace($Script:InitialSessionState) $Script:LoggingRunspace.Runspace.Name = 'LoggingQueueConsumer' $Script:LoggingRunspace.Runspace.Open() $Script:LoggingRunspace.Runspace.SessionStateProxy.SetVariable('ParentHost', $Host) $Script:LoggingRunspace.Runspace.SessionStateProxy.SetVariable('VerbosePreference', $VerbosePreference) # Spawn Logging Consumer $Consumer = { Initialize-LoggingTarget $TargetsInitSync.Set(); # Signal to the parent runspace that logging targets have been loaded foreach ($Log in $Script:LoggingEventQueue.GetConsumingEnumerable()) { if ($Script:Logging.EnabledTargets) { $ParentHost.NotifyBeginApplication() try { #Enumerating through a collection is intrinsically not a thread-safe procedure for ($targetEnum = $Script:Logging.EnabledTargets.GetEnumerator(); $targetEnum.MoveNext(); ) { [string] $LoggingTarget = $targetEnum.Current.key [hashtable] $TargetConfiguration = $targetEnum.Current.Value $Logger = [scriptblock] $Script:Logging.Targets[$LoggingTarget].Logger $targetLevelNo = Get-LevelNumber -Level $TargetConfiguration.Level if ($Log.LevelNo -ge $targetLevelNo) { Invoke-Command -ScriptBlock $Logger -ArgumentList @($Log.PSObject.Copy(), $TargetConfiguration) } } } catch { $ParentHost.UI.WriteErrorLine($_) } finally { $ParentHost.NotifyEndApplication() } } } } $Script:LoggingRunspace.Powershell = [Powershell]::Create().AddScript($Consumer, $true) $Script:LoggingRunspace.Powershell.Runspace = $Script:LoggingRunspace.Runspace $Script:LoggingRunspace.Handle = $Script:LoggingRunspace.Powershell.BeginInvoke() #region Handle Module Removal $OnRemoval = { $Module = Get-Module Logging if ($Module) { $Module.Invoke({ Wait-Logging Stop-LoggingManager }) } [System.GC]::Collect() } # This scriptblock would be called within the module scope $ExecutionContext.SessionState.Module.OnRemove += $OnRemoval # This scriptblock would be called within the global scope and wouldn't have access to internal module variables and functions that we need $Script:LoggingRunspace.EngineEventJob = Register-EngineEvent -SourceIdentifier ([System.Management.Automation.PsEngineEvent]::Exiting) -Action $OnRemoval #endregion Handle Module Removal if(-not $TargetsInitSync.Wait($ConsumerStartupTimeout)){ throw 'Timed out while waiting for logging consumer to start up' } } |