feature: support terminate clone/fetch/pull/push gracefully on macOS

Signed-off-by: leo <longshuang@msn.cn>

Author: love-linger

build/scripts/package.osx-app.sh

@@ -13,5 +13,6 @@ cp resources/app/App.icns SourceGit.app/Contents/Resources/App.icns
 sed "s/SOURCE_GIT_VERSION/$VERSION/g" resources/app/App.plist > SourceGit.app/Contents/Info.plist
 rm -rf SourceGit.app/Contents/MacOS/SourceGit.dsym
 rm -f SourceGit.app/Contents/MacOS/*.pdb
+clang ../tools/setsid-macos/setsid.c -o SourceGit.app/Contents/MacOS/setsid -mmacosx-version-min=13.0
 
 zip "sourcegit_$VERSION.$RUNTIME.zip" -r SourceGit.app

src/Commands/Command.cs

@@ -158,7 +158,7 @@ protected async Task<Result> ReadToEndAsync()
 
         protected ProcessStartInfo CreateGitStartInfo(bool redirect)
         {
-            var useSetSid = OperatingSystem.IsLinux() && CancellationToken.CanBeCanceled;
+            var useSetSid = CancellationToken.CanBeCanceled && Native.OS.SupportSetSid();
             var selfExecFile = Environment.ProcessPath;
             var builder = new StringBuilder(2048);
 
@@ -186,7 +186,7 @@ protected ProcessStartInfo CreateGitStartInfo(bool redirect)
             builder.Append(Args);
 
             var start = new ProcessStartInfo();
-            start.FileName = useSetSid ? "setsid" : Native.OS.GitExecutable;
+            start.FileName = useSetSid ? Native.OS.GetSetSidExecutable() : Native.OS.GitExecutable;
             start.Arguments = builder.ToString();
             start.UseShellExecute = false;
             start.CreateNoWindow = true;

src/Native/Linux.cs

@@ -177,6 +177,16 @@ public void OpenWithDefaultEditor(string file)
             }
         }
 
+        public bool SupportSetSid()
+        {
+            return true;
+        }
+
+        public string GetSetSidExecutable()
+        {
+            return "setsid";
+        }
+
         public void TerminateProcess(Process proc)
         {
             if (kill(-proc.Id, 15) != 0)

src/Native/MacOS.cs

@@ -15,6 +15,14 @@ namespace SourceGit.Native
     [SupportedOSPlatform("macOS")]
     internal class MacOS : OS.IBackend
     {
+        [DllImport("/usr/lib/libSystem.B.dylib", SetLastError = true)]
+        private static extern int kill(int pid, int sig);
+
+        public MacOS()
+        {
+            _setsidExecutable = Path.Combine(Path.GetDirectoryName(Environment.ProcessPath), "setsid");
+        }
+
         public void SetupApp(AppBuilder builder)
         {
             builder.With(new MacOSPlatformOptions()
@@ -122,10 +130,46 @@ public void OpenWithDefaultEditor(string file)
             Process.Start("open", file.Quoted());
         }
 
+        public bool SupportSetSid()
+        {
+            return File.Exists(_setsidExecutable);
+        }
+
+        public string GetSetSidExecutable()
+        {
+            return _setsidExecutable;
+        }
+
         public void TerminateProcess(Process proc)
         {
-            proc.Kill(true);
+            if (!SupportSetSid())
+            {
+                proc.Kill(true);
+                return;
+            }
+
+            if (kill(-proc.Id, 15) != 0)
+            {
+                // If the process already exited, we can just ignore the error.
+                if (Marshal.GetLastPInvokeError() == 3 /* ESRCH */)
+                    return;
+
+                // Actually, this will not be called since the process is
+                // spawned by us (EPERM will not happen), and SIGTERM (15)
+                // is a valid signal (EINVAL will not happen).
+                // See https://www.man7.org/linux/man-pages/man2/kill.2.html
+                try
+                {
+                    proc.Kill(true);
+                }
+                catch
+                {
+                    // Ignore any errors when trying to kill the process
+                }
+            }
         }
+
+        private string _setsidExecutable = null;
     }
 
     [SupportedOSPlatform("macOS")]

src/Native/OS.cs

@@ -35,6 +35,8 @@ public interface IBackend
             void OpenBrowser(string url);
             void OpenWithDefaultEditor(string file);
 
+            bool SupportSetSid();
+            string GetSetSidExecutable();
             void TerminateProcess(Process proc);
         }
 
@@ -303,9 +305,19 @@ public static string GetRelativePathToHome(string path)
             return path;
         }
 
+        public static bool SupportSetSid()
+        {
+            return _backend.SupportSetSid();
+        }
+
+        public static string GetSetSidExecutable()
+        {
+            return _backend.GetSetSidExecutable();
+        }
+
         public static void TerminateProcess(Process proc)
         {
-            _backend?.TerminateProcess(proc);
+            _backend.TerminateProcess(proc);
         }
 
         private static void UpdateGitVersion()

src/Native/Windows.cs

@@ -222,6 +222,16 @@ public void OpenWithDefaultEditor(string file)
             Process.Start(start);
         }
 
+        public bool SupportSetSid()
+        {
+            return false;
+        }
+
+        public string GetSetSidExecutable()
+        {
+            return null;
+        }
+
         public void TerminateProcess(Process proc)
         {
             var pid = proc.Id;

src/ViewModels/Popup.cs

@@ -12,8 +12,7 @@ public bool CanTerminate
             get => _canTerminate;
             protected set
             {
-                // Terminating a process is only supported on Windows/Linux.
-                if (!OperatingSystem.IsMacOS())
+                if (OperatingSystem.IsWindows() || Native.OS.SupportSetSid())
                     SetProperty(ref _canTerminate, value);
             }
         }

tools/setsid-macos/setsid.c

@@ -0,0 +1,16 @@
+#include <stdlib.h>
+#include <unistd.h>
+#include <err.h>
+
+int main(int argc, char* argv[]) {
+    if (argc < 2) {
+        err(EXIT_FAILURE, "Usage: setsid <program> [arguments ...]");
+    }
+
+    if (setsid() < 0) {
+        err(EXIT_FAILURE, "setsid failed");
+    }
+
+    execvp(argv[1], argv + 1);
+    err(EXIT_FAILURE, "Failed to execute %s", argv[1]);
+}