[continued from previous message]

+ If the calling process contains threads in multiple groups,
+ the function returns zero for both affinity masks
+
+ note: tested in Win10: GetProcessAffinityMask() doesn't return 0
+ in (processAffinityMask) and (systemAffinityMask) masks.
+ We need to test it in Win11: how to get mask==0 from GetProcessAffinityMask()?
+ */
+ if (!res)
+ {
+ processAffinityMask = 0;
+ systemAffinityMask = 0;
+ }
+ if (Groups.GroupSizes.Size() > 1 && Groups.NumThreadsTotal)
+ if (// !res ||
+ processAffinityMask == 0 || // to support case described in DOCs and for (!res) case
+ processAffinityMask == systemAffinityMask) // for default nonchanged affinity
+ {
+ // we set IsGroupMode only if processAffinity is default (not changed). + res = TRUE;
+ IsGroupMode = true;
+ }
+ return res;
}


+UInt32 CProcessAffinity::Load_and_GetNumberOfThreads()
+{
+ if (Get())
+ {
+ const UInt32 numProcessors = GetNumProcessThreads();
+ if (numProcessors)
+ return numProcessors;
+ }
+ SYSTEM_INFO systemInfo;
+ GetSystemInfo(&systemInfo);
+ // the number of logical processors in the current group
+ return systemInfo.dwNumberOfProcessors;
+}
+
UInt32 GetNumberOfProcessors()
{
// We need to know how many threads we can use.
// By default the process is assigned to one group.
- // So we get the number of logical processors (threads)
- // assigned to current process in the current group.
- // Group size can be smaller than total number logical processors, for exammple, 2x36
-
CProcessAffinity pa;
-
- if (pa.Get() && pa.processAffinityMask != 0)
- return pa.GetNumProcessThreads();
-
- SYSTEM_INFO systemInfo;
- GetSystemInfo(&systemInfo);
- // the number of logical processors in the current group
- return (UInt32)systemInfo.dwNumberOfProcessors;
+ return pa.Load_and_GetNumberOfThreads();
}

#else
diff -Nru 7zip-24.09+dfsg/CPP/Windows/System.h 7zip-25.00+dfsg/CPP/Windows/System.h
--- 7zip-24.09+dfsg/CPP/Windows/System.h 2024-10-02 10:00:00.000000000 +0200
+++ 7zip-25.00+dfsg/CPP/Windows/System.h 2025-06-30 12:00:00.000000000 +0200
@@ -9,6 +9,7 @@
#endif

#include "../Common/MyTypes.h"
+#include "../Common/MyVector.h"
#include "../Common/MyWindows.h"

namespace NWindows {
@@ -16,6 +17,34 @@

#ifdef _WIN32

+struct CCpuGroups
+{
+ CRecordVector<UInt32> GroupSizes;
+ UInt32 NumThreadsTotal; // sum of threads in all groups
+ // bool Is_Win11_Groups; // useless
+
+ void Get_GroupSize_Min_Max(UInt32 &minSize, UInt32 &maxSize) const
+ {
+ unsigned num = GroupSizes.Size();
+ UInt32 minSize2 = 0, maxSize2 = 0;
+ if (num)
+ {
+ minSize2 = (UInt32)0 - 1;
+ do
+ {
+ const UInt32 v = GroupSizes[--num];
+ if (minSize2 > v) minSize2 = v;
+ if (maxSize2 < v) maxSize2 = v;
+ }
+ while (num);
+ }
+ minSize = minSize2;
+ maxSize = maxSize2;
+ }
+ bool Load();
+ CCpuGroups(): NumThreadsT