[dsrouter] improve log message when launched as a subprocess (#5536)

`dotnet-trace collect --dsrouter android` logs an unnecessary message
currently:

Run diagnotic tool connecting application on android device through
dotnet-dsrouter pid=38004:
    dotnet-trace collect -p 38004

`dotnet-trace` is launching and controlling `dotnet-dsrouter`, and so
you would not need to run `dotnet-trace collect -p 38004`.

To solve this:

* Pass `--parentprocess pid:name` when launching `dotnet-dsrouter` from
`dotnet-trace`

* `dotnet-dsrouter` checks `--parentprocess` switch to tell if it is
running as a subprocess

* Only log this message when *not* a subprocess

Author: jonathanpeppers

src/Tools/Common/DsRouterProcessLauncher.cs

@@ -127,8 +127,10 @@ public int Start(string dsrouterCommand, CancellationToken ct)
                 dotnetDsrouterTool = Path.Combine(toolsRoot, dotnetDsrouterTool);
             }
 
+            using Process currentProcess = Process.GetCurrentProcess();
+
             // Block SIGINT and SIGQUIT in child process.
-            dsrouterCommand += " --block-signals SIGINT;SIGQUIT";
+            dsrouterCommand += $" --block-signals SIGINT;SIGQUIT --parentprocess \"{currentProcess.Id}:{currentProcess.ProcessName}\"";
 
             _childProc = new Process();
 

src/Tools/dotnet-dsrouter/DiagnosticsServerRouterCommands.cs

@@ -357,41 +357,41 @@ public async Task<int> RunIpcClientWebSocketServerRouter(CancellationToken token
             }
         }
 
-        public async Task<int> RunIpcServerIOSSimulatorRouter(CancellationToken token, int runtimeTimeout, string verbose, bool info)
+        public async Task<int> RunIpcServerIOSSimulatorRouter(CancellationToken token, int runtimeTimeout, string verbose, bool info, string parentProcess)
         {
             if (info || ParseLogLevel(verbose) <= LogLevel.Information)
             {
-                logRouterUsageInfo("ios simulator", "127.0.0.1:9000", true);
+                logRouterUsageInfo("ios simulator", "127.0.0.1:9000", true, parentProcess);
             }
 
             return await RunIpcServerTcpClientRouter(token, "", "127.0.0.1:9000", runtimeTimeout, verbose, "").ConfigureAwait(false);
         }
 
-        public async Task<int> RunIpcServerIOSRouter(CancellationToken token, int runtimeTimeout, string verbose, bool info)
+        public async Task<int> RunIpcServerIOSRouter(CancellationToken token, int runtimeTimeout, string verbose, bool info, string parentProcess)
         {
             if (info || ParseLogLevel(verbose) <= LogLevel.Information)
             {
-                logRouterUsageInfo("ios device", "127.0.0.1:9000", true);
+                logRouterUsageInfo("ios device", "127.0.0.1:9000", true, parentProcess);
             }
 
             return await RunIpcServerTcpClientRouter(token, "", "127.0.0.1:9000", runtimeTimeout, verbose, "iOS").ConfigureAwait(false);
         }
 
-        public async Task<int> RunIpcServerAndroidEmulatorRouter(CancellationToken token, int runtimeTimeout, string verbose, bool info)
+        public async Task<int> RunIpcServerAndroidEmulatorRouter(CancellationToken token, int runtimeTimeout, string verbose, bool info, string parentProcess)
         {
             if (info || ParseLogLevel(verbose) <= LogLevel.Information)
             {
-                logRouterUsageInfo("android emulator", "10.0.2.2:9000", false);
+                logRouterUsageInfo("android emulator", "10.0.2.2:9000", false, parentProcess);
             }
 
             return await RunIpcServerTcpServerRouter(token, "", "127.0.0.1:9000", runtimeTimeout, verbose, "").ConfigureAwait(false);
         }
 
-        public async Task<int> RunIpcServerAndroidRouter(CancellationToken token, int runtimeTimeout, string verbose, bool info)
+        public async Task<int> RunIpcServerAndroidRouter(CancellationToken token, int runtimeTimeout, string verbose, bool info, string parentProcess)
         {
             if (info || ParseLogLevel(verbose) <= LogLevel.Information)
             {
-                logRouterUsageInfo("android device", "127.0.0.1:9000", false);
+                logRouterUsageInfo("android device", "127.0.0.1:9000", false, parentProcess);
             }
 
             return await RunIpcServerTcpServerRouter(token, "", "127.0.0.1:9001", runtimeTimeout, verbose, "Android").ConfigureAwait(false);
@@ -501,7 +501,7 @@ private static LogLevel ParseLogLevel(string verbose)
             return logLevel;
         }
 
-        private static void logRouterUsageInfo(string deviceName, string deviceTcpIpAddress, bool deviceListenMode)
+        private static void logRouterUsageInfo(string deviceName, string deviceTcpIpAddress, bool deviceListenMode, string parentProcess)
         {
             StringBuilder message = new();
 
@@ -514,8 +514,11 @@ private static void logRouterUsageInfo(string deviceName, string deviceTcpIpAddr
             message.AppendLine($"DOTNET_DiagnosticPorts={deviceTcpIpAddress},nosuspend,{listenMode}");
             message.AppendLine("[Startup Tracing]");
             message.AppendLine($"DOTNET_DiagnosticPorts={deviceTcpIpAddress},suspend,{listenMode}");
-            message.AppendLine($"Run diagnotic tool connecting application on {deviceName} through dotnet-dsrouter pid={pid}:");
-            message.AppendLine($"dotnet-trace collect -p {pid}");
+            if (string.IsNullOrEmpty(parentProcess))
+            {
+                message.AppendLine($"Run diagnotic tool connecting application on {deviceName} through dotnet-dsrouter pid={pid}:");
+                message.AppendLine($"dotnet-trace collect -p {pid}");
+            }
             message.AppendLine($"See https://learn.microsoft.com/en-us/dotnet/core/diagnostics/dotnet-dsrouter for additional details and examples.");
 
             ConsoleColor currentColor = Console.ForegroundColor;

src/Tools/dotnet-dsrouter/Program.cs

@@ -156,14 +156,15 @@ private static Command IOSSimulatorRouterCommand()
                                 "Router is configured using an IPC server (connecting to by diagnostic tools) " +
                                 "and a TCP/IP server (accepting runtime TCP client).")
             {
-                RuntimeTimeoutOption, VerboseOption, InfoOption, BlockedSignalsOption
+                RuntimeTimeoutOption, VerboseOption, InfoOption, BlockedSignalsOption, ParentProcessOption
             };
 
             command.SetAction((parseResult, ct) => new DiagnosticsServerRouterCommands().RunIpcServerIOSSimulatorRouter(
                 ct,
                 runtimeTimeout: parseResult.GetValue(RuntimeTimeoutOption),
                 verbose: parseResult.GetValue(VerboseOption),
-                info: parseResult.GetValue(InfoOption)
+                info: parseResult.GetValue(InfoOption),
+                parentProcess: parseResult.GetValue(ParentProcessOption)
             ));
 
             return command;
@@ -177,14 +178,15 @@ private static Command IOSRouterCommand()
                                 "Router is configured using an IPC server (connecting to by diagnostic tools) " +
                                 "and a TCP/IP client (connecting runtime TCP server over usbmux).")
             {
-                RuntimeTimeoutOption, VerboseOption, InfoOption, BlockedSignalsOption
+                RuntimeTimeoutOption, VerboseOption, InfoOption, BlockedSignalsOption, ParentProcessOption
             };
 
             command.SetAction((parseResult, ct) => new DiagnosticsServerRouterCommands().RunIpcServerIOSRouter(
                 ct,
                 runtimeTimeout: parseResult.GetValue(RuntimeTimeoutOption),
                 verbose: parseResult.GetValue(VerboseOption),
-                info: parseResult.GetValue(InfoOption)
+                info: parseResult.GetValue(InfoOption),
+                parentProcess: parseResult.GetValue(ParentProcessOption)
             ));
 
             return command;
@@ -198,14 +200,16 @@ private static Command AndroidEmulatorRouterCommand()
                                 "Router is configured using an IPC server (connecting to by diagnostic tools) " +
                                 "and a TCP/IP server (accepting runtime TCP client).")
             {
-                RuntimeTimeoutOption, VerboseOption, InfoOption, BlockedSignalsOption
+                RuntimeTimeoutOption, VerboseOption, InfoOption, BlockedSignalsOption, ParentProcessOption
             };
 
             command.SetAction((parseResult, ct) => new DiagnosticsServerRouterCommands().RunIpcServerAndroidEmulatorRouter(
                 ct,
                 runtimeTimeout: parseResult.GetValue(RuntimeTimeoutOption),
                 verbose: parseResult.GetValue(VerboseOption),
-                info: parseResult.GetValue(InfoOption)));
+                info: parseResult.GetValue(InfoOption),
+                parentProcess: parseResult.GetValue(ParentProcessOption)
+            ));
 
             return command;
         }
@@ -218,14 +222,16 @@ private static Command AndroidRouterCommand()
                                 "Router is configured using an IPC server (connecting to by diagnostic tools) " +
                                 "and a TCP/IP server (accepting runtime TCP client).")
             {
-                RuntimeTimeoutOption, VerboseOption, InfoOption, BlockedSignalsOption
+                RuntimeTimeoutOption, VerboseOption, InfoOption, BlockedSignalsOption, ParentProcessOption
             };
 
             command.SetAction((parseResult, ct) => new DiagnosticsServerRouterCommands().RunIpcServerAndroidRouter(
                 ct,
                 runtimeTimeout: parseResult.GetValue(RuntimeTimeoutOption),
                 verbose: parseResult.GetValue(VerboseOption),
-                info: parseResult.GetValue(InfoOption)));
+                info: parseResult.GetValue(InfoOption),
+                parentProcess: parseResult.GetValue(ParentProcessOption)
+            ));
 
             return command;
         }
@@ -304,6 +310,14 @@ private static Command AndroidRouterCommand()
                 Description = "Print info on how to use current dotnet-dsrouter instance with application and diagnostic tooling."
             };
 
+        private static readonly Option<string> ParentProcessOption =
+            new("--parentprocess")
+            {
+                Description = "If dsrouter was launched from dotnet-trace or another .NET diagnostic tool, contains the parent process ID and name: --parentprocess pid:name",
+                DefaultValueFactory = _ => "",
+                Hidden = true
+            };
+
         private static Task<int> Main(string[] args)
         {
             RootCommand rootCommand = new()