From 4fc6772dc3c2075a28dd572629402f0d34138e9a Mon Sep 17 00:00:00 2001
From: Zlatin Balevsky <zlatinb@gmail.com>
Date: Thu, 17 Mar 2022 14:48:36 +0000
Subject: [PATCH] try 2 to use background priorities on windows, GitHub issue
 #126

---
 .../com/muwire/gui/win/PrioritySetter.groovy      | 15 +++++++++++++--
 .../main/java/com/muwire/gui/win/MWKernel32.java  | 15 ++++++++++++---
 2 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/gui/src/main/groovy/com/muwire/gui/win/PrioritySetter.groovy b/gui/src/main/groovy/com/muwire/gui/win/PrioritySetter.groovy
index 08b90ab6..c87746e4 100644
--- a/gui/src/main/groovy/com/muwire/gui/win/PrioritySetter.groovy
+++ b/gui/src/main/groovy/com/muwire/gui/win/PrioritySetter.groovy
@@ -1,5 +1,7 @@
 package com.muwire.gui.win
 
+import com.sun.jna.platform.win32.BaseTSD
+import com.sun.jna.platform.win32.WinDef
 import com.sun.jna.platform.win32.WinNT.HANDLE
 
 class PrioritySetter {
@@ -9,10 +11,19 @@ class PrioritySetter {
     }
     
     static void enterBackgroundMode() {
-        MWKernel32.INSTANCE.SetPriorityClass(myProcess, 0x00100000)
+        // 1. set BELOW_NORMAL
+        MWKernel32.INSTANCE.SetPriorityClass(myProcess, new WinDef.DWORD(0x00004000L))
+        // 2. enter background mode
+        MWKernel32.INSTANCE.SetPriorityClass(myProcess, new WinDef.DWORD(0x00100000))
+        // 3. increase the process working set to something reasonable 
+        def sizeT = new BaseTSD.SIZE_T(0x1L << 29) // 512 MB
+        MWKernel32.INSTANCE.SetProcessWorkingSetSizeEx(myProcess, sizeT, sizeT, new WinDef.DWORD(0x00000008L))
     }
     
     static void exitBackgroundMode() {
-        MWKernel32.INSTANCE.SetPriorityClass(myProcess, 0x00200000)
+        // 1. exit background mode
+        MWKernel32.INSTANCE.SetPriorityClass(myProcess, new WinDef.DWORD(0x00200000L))
+        // 2. set priority to normal
+        MWKernel32.INSTANCE.SetPriorityClass(myProcess, new WinDef.DWORD(0x00000020L))
     }
 }
diff --git a/gui/src/main/java/com/muwire/gui/win/MWKernel32.java b/gui/src/main/java/com/muwire/gui/win/MWKernel32.java
index 426bc75f..e847a29d 100644
--- a/gui/src/main/java/com/muwire/gui/win/MWKernel32.java
+++ b/gui/src/main/java/com/muwire/gui/win/MWKernel32.java
@@ -1,12 +1,21 @@
 package com.muwire.gui.win;
 
 import com.sun.jna.Native;
-import com.sun.jna.platform.win32.Kernel32;
+import com.sun.jna.platform.win32.BaseTSD;
+import com.sun.jna.platform.win32.WinDef;
+import com.sun.jna.platform.win32.WinNT;
+import com.sun.jna.win32.StdCallLibrary;
 import com.sun.jna.win32.W32APIOptions;
 
-public interface MWKernel32 extends Kernel32 {
+public interface MWKernel32 extends StdCallLibrary {
     
     MWKernel32 INSTANCE = Native.load("kernel32", MWKernel32.class, W32APIOptions.DEFAULT_OPTIONS);
     
-    boolean SetPriorityClass(HANDLE hProcess, int mask);
+    WinDef.BOOL SetPriorityClass(WinNT.HANDLE hProcess, WinDef.DWORD mask);
+    WinNT.HANDLE GetCurrentProcess();
+    
+    WinDef.BOOL SetProcessWorkingSetSizeEx(WinNT.HANDLE hProcess, 
+                                           BaseTSD.SIZE_T minSize,
+                                           BaseTSD.SIZE_T maxSize,
+                                           WinDef.DWORD flags);
 }