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Fix telemetry UUID mutex acquisition #28026

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Merged
Dongbo Wang (daxian-dbw) merged 2 commits into from
Sep 21, 2026
+131 −4
Merged

Fix telemetry UUID mutex acquisition #28026

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ccf329c
Fix telemetry UUID mutex acquisition
Sep 17, 2026
a2d61c0
Bound telemetry mutex acquisition
Sep 18, 2026
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24 changes: 20 additions & 4 deletions src/System.Management.Automation/utils/Telemetry.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -1009,15 +1009,31 @@ private static Guid GetUniqueIdentifier()
try
{
// CreateUniqueIdentifierAndFile shouldn't throw, but the mutex might
using var m = new Mutex(true, "CreateUniqueUserId");
m.WaitOne();
using var mutex = new Mutex(initiallyOwned: false, name: "CreateUniqueUserId");
bool mutexAcquired = false;
try
{
return CreateUniqueIdentifierAndFile(s_uuidPath);
try
{
mutexAcquired = mutex.WaitOne(millisecondsTimeout: 200);
}
catch (AbandonedMutexException)
{
// WaitOne transfers ownership before throwing for an abandoned mutex.
mutexAcquired = true;
}

if (mutexAcquired)
{
return CreateUniqueIdentifierAndFile(s_uuidPath);
}
}
finally
{
m.ReleaseMutex();
if (mutexAcquired)
{
mutex.ReleaseMutex();
}
}
}
catch (Exception)
Expand Down
111 changes: 111 additions & 0 deletions test/powershell/engine/Basic/Telemetry.Tests.ps1
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Original file line number Diff line number Diff line change
Expand Up @@ -65,6 +65,22 @@ Describe "Telemetry for shell startup" -Tag CI {
$PWSH = (Get-Process -Id $PID).MainModule.FileName
$telemetrySet = Test-Path -Path env:POWERSHELL_TELEMETRY_OPTOUT
$SendingTelemetry = $env:POWERSHELL_TELEMETRY_OPTOUT

function Invoke-TelemetryTestProcess {
param(
[Parameter(Mandatory)]
[string[]] $Argument
)

$startInfo = [System.Diagnostics.ProcessStartInfo]::new()
$startInfo.FileName = $PWSH
$startInfo.UseShellExecute = $false
foreach ($argumentValue in $Argument) {
$startInfo.ArgumentList.Add($argumentValue)
}

return [System.Diagnostics.Process]::Start($startInfo)
}
}

AfterAll {
Expand Down Expand Up @@ -108,6 +124,101 @@ Describe "Telemetry for shell startup" -Tag CI {
$uuidPath | Should -Exist
}

It "Should not block concurrent telemetry-enabled shell startup when the uuid file is missing" {
$env:POWERSHELL_TELEMETRY_OPTOUT = "no"
$holderReadyPath = Join-Path -Path $TestDrive -ChildPath "telemetry-holder.ready"
$holderStopPath = Join-Path -Path $TestDrive -ChildPath "telemetry-holder.stop"
$holderScriptPath = Join-Path -Path $TestDrive -ChildPath "telemetry-holder.ps1"
@'
param($ReadyPath, $StopPath)

[void][Microsoft.PowerShell.Telemetry.ApplicationInsightsTelemetry]::CanSendTelemetry
[System.IO.File]::WriteAllText($ReadyPath, "")
while (-not [System.IO.File]::Exists($StopPath)) {
Start-Sleep -Milliseconds 100
}
'@ | Set-Content -LiteralPath $holderScriptPath

$holderProcess = $null
$childProcess = $null
try {
$holderProcess = Invoke-TelemetryTestProcess -Argument @(
"-NoProfile",
"-File",
$holderScriptPath,
$holderReadyPath,
$holderStopPath
)

Wait-UntilTrue -sb { Test-Path -LiteralPath $holderReadyPath } -TimeoutInMilliseconds 15000 -IntervalInMilliseconds 100 |
Should -BeTrue
$uuidPath | Should -Exist
Remove-Item -LiteralPath $uuidPath

$childProcess = Invoke-TelemetryTestProcess -Argument @("-NoProfile", "-Command", "exit")
$childProcess.WaitForExit(15000) | Should -BeTrue
$childProcess.ExitCode | Should -Be 0
$uuidPath | Should -Exist
}
finally {
if ($childProcess -and -not $childProcess.HasExited) {
$childProcess.Kill($true)
$childProcess.WaitForExit()
}

if ($childProcess) {
$childProcess.Dispose()
}

[System.IO.File]::WriteAllText($holderStopPath, "")
if ($holderProcess -and -not $holderProcess.WaitForExit(5000)) {
$holderProcess.Kill($true)
$holderProcess.WaitForExit()
}

if ($holderProcess) {
$holderProcess.Dispose()
}
}
}

It "Should stop creating the uuid file when the telemetry mutex times out" {
$env:POWERSHELL_TELEMETRY_OPTOUT = "no"
$mutex = [System.Threading.Mutex]::new($false, "CreateUniqueUserId")
$mutexAcquired = $false
$childProcess = $null
try {
try {
$mutexAcquired = $mutex.WaitOne(5000)
}
catch [System.Threading.AbandonedMutexException] {
$mutexAcquired = $true
}

$mutexAcquired | Should -BeTrue -Because "the test must own the mutex to force the child to time out"
$childProcess = Invoke-TelemetryTestProcess -Argument @("-NoProfile", "-Command", "exit")
$childProcess.WaitForExit(15000) | Should -BeTrue
$childProcess.ExitCode | Should -Be 0
$uuidPath | Should -Not -Exist
}
finally {
if ($childProcess -and -not $childProcess.HasExited) {
$childProcess.Kill($true)
$childProcess.WaitForExit()
}

if ($childProcess) {
$childProcess.Dispose()
}

if ($mutexAcquired) {
$mutex.ReleaseMutex()
}

$mutex.Dispose()
}
}

It "Should create a uuid file by default" {
if ( Test-Path env:POWERSHELL_TELEMETRY_OPTOUT ) { Remove-Item -Path env:POWERSHELL_TELEMETRY_OPTOUT }
& $PWSH -NoProfile -Command "exit"
Expand Down
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