From d865678b8057332c6df13d895214dffbf83e499c Mon Sep 17 00:00:00 2001
From: NextTurn <45985406+nxtn@users.noreply.github.com>
Date: Sun, 12 Jul 2020 00:00:00 +0800
Subject: [PATCH] Internal updates

---
 src/WinSW.Core/Native/Service.cs | 29 +++++++++++++++--
 src/WinSW/Program.cs             | 55 +++++++++++---------------------
 2 files changed, 45 insertions(+), 39 deletions(-)

diff --git a/src/WinSW.Core/Native/Service.cs b/src/WinSW.Core/Native/Service.cs
index 66e5467..944f083 100644
--- a/src/WinSW.Core/Native/Service.cs
+++ b/src/WinSW.Core/Native/Service.cs
@@ -100,7 +100,7 @@ namespace WinSW.Native
         }
 
         /// <exception cref="CommandException" />
-        internal unsafe (IntPtr Services, int Count) EnumerateServices()
+        internal ServiceEnumerator EnumerateServices()
         {
             int resume = 0;
             _ = EnumServicesStatus(
@@ -129,7 +129,7 @@ namespace WinSW.Native
                     Throw.Command.Win32Exception("Failed to enumerate services.");
                 }
 
-                return (services, count);
+                return new(services, count);
             }
             catch
             {
@@ -183,6 +183,31 @@ namespace WinSW.Native
 
             this.handle = IntPtr.Zero;
         }
+
+        internal ref struct ServiceEnumerator
+        {
+            private readonly IntPtr services;
+            private readonly int count;
+
+            private int index;
+
+            internal ServiceEnumerator(IntPtr services, int count)
+            {
+                this.services = services;
+                this.count = count;
+                this.index = -1;
+            }
+
+            public unsafe ENUM_SERVICE_STATUS* Current => (ENUM_SERVICE_STATUS*)this.services + this.index;
+
+            public void Dispose() => Marshal.FreeHGlobal(this.services);
+
+            public ServiceEnumerator GetEnumerator() => this;
+
+            public bool MoveNext() => ++this.index < this.count;
+
+            public void Reset() => throw new NotImplementedException();
+        }
     }
 
     internal ref struct Service
diff --git a/src/WinSW/Program.cs b/src/WinSW/Program.cs
index d2eb6c9..5cc7b06 100644
--- a/src/WinSW/Program.cs
+++ b/src/WinSW/Program.cs
@@ -10,7 +10,6 @@ using System.IO;
 using System.IO.Pipes;
 using System.Linq;
 using System.Reflection;
-using System.Runtime.InteropServices;
 using System.Security.AccessControl;
 using System.Security.Principal;
 using System.ServiceProcess;
@@ -889,39 +888,30 @@ namespace WinSW
                 if (all)
                 {
                     using var scm = ServiceManager.Open(ServiceManagerAccess.EnumerateService);
-                    (var services, int count) = scm.EnumerateServices();
-                    try
+                    int prevProcessId = -1;
+                    foreach (var status in scm.EnumerateServices())
                     {
-                        int prevProcessId = -1;
-                        for (int i = 0; i < count; i++)
+                        using var sc = scm.OpenService(status->ServiceName, ServiceAccess.QueryConfig | ServiceAccess.QueryStatus);
+                        if (sc.ExecutablePath.StartsWith($"\"{ExecutablePath}\""))
                         {
-                            var status = (ENUM_SERVICE_STATUS*)services + i;
-                            using var sc = scm.OpenService(status->ServiceName, ServiceAccess.QueryConfig | ServiceAccess.QueryStatus);
-                            if (sc.ExecutablePath.StartsWith($"\"{ExecutablePath}\""))
+                            int processId = sc.ProcessId;
+                            if (processId >= 0)
                             {
-                                int processId = sc.ProcessId;
-                                if (processId >= 0)
+                                if (prevProcessId >= 0)
                                 {
-                                    if (prevProcessId >= 0)
-                                    {
-                                        using var process = Process.GetProcessById(prevProcessId);
-                                        Draw(process, string.Empty, false);
-                                    }
+                                    using var process = Process.GetProcessById(prevProcessId);
+                                    Draw(process, string.Empty, false);
                                 }
-
-                                prevProcessId = processId;
                             }
-                        }
 
-                        if (prevProcessId >= 0)
-                        {
-                            using var process = Process.GetProcessById(prevProcessId);
-                            Draw(process, string.Empty, true);
+                            prevProcessId = processId;
                         }
                     }
-                    finally
+
+                    if (prevProcessId >= 0)
                     {
-                        Marshal.FreeHGlobal(services);
+                        using var process = Process.GetProcessById(prevProcessId);
+                        Draw(process, string.Empty, true);
                     }
                 }
                 else
@@ -996,23 +986,14 @@ namespace WinSW
             static unsafe void DevList()
             {
                 using var scm = ServiceManager.Open(ServiceManagerAccess.EnumerateService);
-                (var services, int count) = scm.EnumerateServices();
-                try
+                foreach (var status in scm.EnumerateServices())
                 {
-                    for (int i = 0; i < count; i++)
+                    using var sc = scm.OpenService(status->ServiceName, ServiceAccess.QueryConfig);
+                    if (sc.ExecutablePath.StartsWith($"\"{ExecutablePath}\""))
                     {
-                        var status = (ENUM_SERVICE_STATUS*)services + i;
-                        using var sc = scm.OpenService(status->ServiceName, ServiceAccess.QueryConfig);
-                        if (sc.ExecutablePath.StartsWith($"\"{ExecutablePath}\""))
-                        {
-                            Console.WriteLine(status->ToString());
-                        }
+                        Console.WriteLine(status->ToString());
                     }
                 }
-                finally
-                {
-                    Marshal.FreeHGlobal(services);
-                }
             }
 
             static void Customize(string output, string manufacturer)