public void ServerStartup_MutexAlreadyAcquired_Fails()
{
// Arrange
var pipeName = Guid.NewGuid().ToString("N");
var mutexName = MutexName.GetServerMutexName(pipeName);
var compilerHost = new Mock <CompilerHost>(MockBehavior.Strict);
var host = new Mock <ConnectionHost>(MockBehavior.Strict);
// Act & Assert
using (var mutex = new Mutex(initiallyOwned: true, name: mutexName, createdNew: out var holdsMutex))
{
Assert.True(holdsMutex);
try
{
var result = ServerUtilities.RunServer(pipeName, host.Object, compilerHost.Object);
// Assert failure
Assert.Equal(1, result);
}
finally
{
mutex.ReleaseMutex();
}
}
}
protected override Task <int> ExecuteCoreAsync()
{
// Make sure there's only one server with the same identity at a time.
using (var mutex = new Mutex(initiallyOwned: true, name: MutexName.GetServerMutexName(Pipe.Value()), createdNew: out var holdsMutex))
{
if (!holdsMutex)
{
// Another server is running, just exit.
Error.Write("Another server already running...");
return(Task.FromResult(1));
}
try
{
var host = ConnectionHost.Create(Pipe.Value());
var compilerHost = CompilerHost.Create();
var dispatcher = RequestDispatcher.Create(host, compilerHost, Cancelled);
dispatcher.Run();
}
finally
{
mutex.ReleaseMutex();
}
}
return(Task.FromResult(0));
}
private bool IsServerRunning()
{
if (Mutex.TryOpenExisting(MutexName.GetServerMutexName(Pipe.Value()), out var mutex))
{
mutex.Dispose();
return(true);
}
return(false);
}
protected override Task <int> ExecuteCoreAsync()
{
// Make sure there's only one server with the same identity at a time.
var serverMutexName = MutexName.GetServerMutexName(Pipe.Value());
Mutex serverMutex = null;
var holdsMutex = false;
try
{
serverMutex = new Mutex(initiallyOwned: true, name: serverMutexName, createdNew: out holdsMutex);
}
catch (Exception ex)
{
// The Mutex constructor can throw in certain cases. One specific example is docker containers
// where the /tmp directory is restricted. In those cases there is no reliable way to execute
// the server and we need to fall back to the command line.
// Example: https://github.com/dotnet/roslyn/issues/24124
Error.Write($"Server mutex creation failed. {ex.Message}");
return(Task.FromResult(-1));
}
if (!holdsMutex)
{
// Another server is running, just exit.
Error.Write("Another server already running...");
return(Task.FromResult(1));
}
try
{
TimeSpan?keepAlive = null;
if (KeepAlive.HasValue() && int.TryParse(KeepAlive.Value(), out var result))
{
// Keep alive times are specified in seconds
keepAlive = TimeSpan.FromSeconds(result);
}
var host = ConnectionHost.Create(Pipe.Value());
var compilerHost = CompilerHost.Create();
ExecuteServerCore(host, compilerHost, Cancelled, eventBus: null, keepAlive: keepAlive);
}
finally
{
serverMutex.ReleaseMutex();
serverMutex.Dispose();
}
return(Task.FromResult(0));
}
internal static ServerData CreateServer(
string pipeName = null,
CompilerHost compilerHost = null,
ConnectionHost connectionHost = null,
Action <object, EventArgs> onListening = null)
{
pipeName = pipeName ?? Guid.NewGuid().ToString();
compilerHost = compilerHost ?? CompilerHost.Create();
connectionHost = connectionHost ?? ConnectionHost.Create(pipeName);
var serverStatsSource = new TaskCompletionSource <ServerStats>();
var serverListenSource = new TaskCompletionSource <bool>();
var cts = new CancellationTokenSource();
var mutexName = MutexName.GetServerMutexName(pipeName);
var thread = new Thread(_ =>
{
var eventBus = new TestableEventBus();
eventBus.Listening += (sender, e) => { serverListenSource.TrySetResult(true); };
if (onListening != null)
{
eventBus.Listening += (sender, e) => onListening(sender, e);
}
try
{
RunServer(
pipeName,
connectionHost,
compilerHost,
cts.Token,
eventBus,
Timeout.InfiniteTimeSpan);
}
finally
{
var serverStats = new ServerStats(connections: eventBus.ConnectionCount, completedConnections: eventBus.CompletedCount);
serverStatsSource.SetResult(serverStats);
}
});
thread.Start();
// The contract of this function is that it will return once the server has started. Spin here until
// we can verify the server has started or simply failed to start.
while (ServerConnection.WasServerMutexOpen(mutexName) != true && thread.IsAlive)
{
Thread.Yield();
}
return(new ServerData(cts, pipeName, serverStatsSource.Task, serverListenSource.Task));
}
public void ServerStartup_SuccessfullyAcquiredMutex()
{
// Arrange, Act & Assert
var pipeName = Guid.NewGuid().ToString("N");
var mutexName = MutexName.GetServerMutexName(pipeName);
var compilerHost = new Mock <CompilerHost>(MockBehavior.Strict);
var host = new Mock <ConnectionHost>(MockBehavior.Strict);
host
.Setup(x => x.WaitForConnectionAsync(It.IsAny <CancellationToken>()))
.Returns(() =>
{
// Use a thread instead of Task to guarantee this code runs on a different
// thread and we can validate the mutex state.
var source = new TaskCompletionSource <bool>();
var thread = new Thread(_ =>
{
Mutex mutex = null;
try
{
Assert.True(Mutex.TryOpenExisting(mutexName, out mutex));
Assert.False(mutex.WaitOne(millisecondsTimeout: 0));
source.SetResult(true);
}
catch (Exception ex)
{
source.SetException(ex);
throw;
}
finally
{
mutex?.Dispose();
}
});
// Synchronously wait here. Don't returned a Task value because we need to
// ensure the above check completes before the server hits a timeout and
// releases the mutex.
thread.Start();
source.Task.Wait();
return(new TaskCompletionSource <Connection>().Task);
});
var result = ServerUtilities.RunServer(pipeName, host.Object, compilerHost.Object, keepAlive: TimeSpan.FromSeconds(1));
Assert.Equal(0, result);
}
protected override Task <int> ExecuteCoreAsync()
{
// Make sure there's only one server with the same identity at a time.
using (var mutex = new Mutex(initiallyOwned: true, name: MutexName.GetServerMutexName(Pipe.Value()), createdNew: out var holdsMutex))
{
if (!holdsMutex)
{
// Another server is running, just exit.
Error.Write("Another server already running...");
return(Task.FromResult(1));
}
try
{
TimeSpan?keepAlive = null;
if (KeepAlive.HasValue())
{
var value = KeepAlive.Value();
if (int.TryParse(value, out var result))
{
// Keep alive times are specified in seconds
keepAlive = TimeSpan.FromSeconds(result);
}
}
var host = ConnectionHost.Create(Pipe.Value());
var compilerHost = CompilerHost.Create();
ExecuteServerCore(host, compilerHost, Cancelled, eventBus: null, keepAlive: keepAlive);
}
finally
{
mutex.ReleaseMutex();
}
}
return(Task.FromResult(0));
}
private static async Task <ServerResponse> RunOnServerCore(
IList <string> arguments,
ServerPaths serverPaths,
string pipeName,
string keepAlive,
int?timeoutOverride,
TryCreateServerCoreDelegate <string, string, int?, bool, bool> tryCreateServerFunc,
CancellationToken cancellationToken,
bool debug)
{
if (pipeName == null)
{
return(new RejectedServerResponse());
}
if (serverPaths.TempDirectory == null)
{
return(new RejectedServerResponse());
}
var clientDir = serverPaths.ClientDirectory;
var timeoutNewProcess = timeoutOverride ?? TimeOutMsNewProcess;
var timeoutExistingProcess = timeoutOverride ?? TimeOutMsExistingProcess;
var clientMutexName = MutexName.GetClientMutexName(pipeName);
Task <Client> pipeTask = null;
Mutex clientMutex = null;
var holdsMutex = false;
try
{
try
{
clientMutex = new Mutex(initiallyOwned: true, name: clientMutexName, createdNew: out holdsMutex);
}
catch (Exception ex)
{
// The Mutex constructor can throw in certain cases. One specific example is docker containers
// where the /tmp directory is restricted. In those cases there is no reliable way to execute
// the server and we need to fall back to the command line.
// Example: https://github.com/dotnet/roslyn/issues/24124
ServerLogger.LogException(ex, "Client mutex creation failed.");
return(new RejectedServerResponse());
}
if (!holdsMutex)
{
try
{
holdsMutex = clientMutex.WaitOne(timeoutNewProcess);
if (!holdsMutex)
{
return(new RejectedServerResponse());
}
}
catch (AbandonedMutexException)
{
holdsMutex = true;
}
}
// Check for an already running server
var serverMutexName = MutexName.GetServerMutexName(pipeName);
var wasServerRunning = WasServerMutexOpen(serverMutexName);
var timeout = wasServerRunning ? timeoutExistingProcess : timeoutNewProcess;
if (wasServerRunning || tryCreateServerFunc(clientDir, pipeName, out var _, debug))
{
pipeTask = Client.ConnectAsync(pipeName, TimeSpan.FromMilliseconds(timeout), cancellationToken);
}
}
finally
{
if (holdsMutex)
{
clientMutex?.ReleaseMutex();
}
clientMutex?.Dispose();
}
if (pipeTask != null)
{
var client = await pipeTask.ConfigureAwait(false);
if (client != null)
{
var request = ServerRequest.Create(
serverPaths.WorkingDirectory,
serverPaths.TempDirectory,
arguments,
keepAlive);
return(await TryProcessRequest(client, request, cancellationToken).ConfigureAwait(false));
}
}
return(new RejectedServerResponse());
}
private static async Task <ServerResponse> RunOnServerCore(
IList <string> arguments,
ServerPaths buildPaths,
string pipeName,
string keepAlive,
int?timeoutOverride,
Func <string, string, bool, bool> tryCreateServerFunc,
CancellationToken cancellationToken,
bool debug)
{
if (pipeName == null)
{
return(new RejectedServerResponse());
}
if (buildPaths.TempDirectory == null)
{
return(new RejectedServerResponse());
}
var clientDir = buildPaths.ClientDirectory;
var timeoutNewProcess = timeoutOverride ?? TimeOutMsNewProcess;
var timeoutExistingProcess = timeoutOverride ?? TimeOutMsExistingProcess;
var clientMutexName = MutexName.GetClientMutexName(pipeName);
Task <Client> pipeTask = null;
using (var clientMutex = new Mutex(initiallyOwned: true, name: clientMutexName, createdNew: out var holdsMutex))
{
try
{
if (!holdsMutex)
{
try
{
holdsMutex = clientMutex.WaitOne(timeoutNewProcess);
if (!holdsMutex)
{
return(new RejectedServerResponse());
}
}
catch (AbandonedMutexException)
{
holdsMutex = true;
}
}
// Check for an already running server
var serverMutexName = MutexName.GetServerMutexName(pipeName);
var wasServerRunning = WasServerMutexOpen(serverMutexName);
var timeout = wasServerRunning ? timeoutExistingProcess : timeoutNewProcess;
if (wasServerRunning || tryCreateServerFunc(clientDir, pipeName, debug))
{
pipeTask = Client.ConnectAsync(pipeName, TimeSpan.FromMilliseconds(timeout), cancellationToken);
}
}
finally
{
if (holdsMutex)
{
clientMutex.ReleaseMutex();
}
}
}
if (pipeTask != null)
{
var client = await pipeTask.ConfigureAwait(false);
if (client != null)
{
var request = ServerRequest.Create(
buildPaths.WorkingDirectory,
buildPaths.TempDirectory,
arguments,
keepAlive);
return(await TryProcessRequest(client, request, cancellationToken).ConfigureAwait(false));
}
}
return(new RejectedServerResponse());
}
