Par2: Set Processor Affinity 2007-03-02 -- Bjorn Holm I have added this code to my programs:
MAP
Module('winapi')
SetProcessAffinityMask(UNSIGNED,LONG),LONG,PASCAL,RAW
GetCurrentProcess(),LONG,PASCAL,RAW
GetSystemInfo(LONG),PASCAL,RAW
End
End
SYSTEM_INFO GROUP,TYPE
dwOemId LONG
dwPageSize LONG
pMinimumApplicationAddress ULONG
lpMaximumApplicationAddress ULONG
dwActiveProcessorMask LONG
dwNumberOfProcessors LONG
dwProcessorType LONG
dwAllocationGranularity LONG
dwReserved LONG
wProcessorLevel USHORT
wProcessorRevision USHORT
wProcessorArchitecture USHORT
END
SystemInfo LIKE(SYSTEM_INFO),AUTO
Loc:ProcCount Long
Loc:ProcNo Long
GetSystemInfo(ADDRESS(SystemInfo))
Loc:ProcCount = SystemInfo.dwNumberOfProcessors
If Loc:ProcCount > 1 Then
Loc:ProcNo = Random(1, Loc:ProcCount)
A# = SetProcessAffinityMask(GetCurrentProcess(),Loc:ProcNo)
End
takes care of multiprocessor systems for me. : )
Carl Barnes notes:
Your code is wrong if there are more then 2 processores. It's a "bit-mask" and
not processor number. So if there are 4 processors and you pick processor 3 you
are using a mask of 3 which is 011b and you are assigning your EXE to
processors 1 and 2. Or if you pick 4 which is 0100b you are asigning processor
3. You'll never assign to processor 4 since that mask value is 8.
Your code should be (untested)
BSHIFT long
Loc:ProcNo = Random(1, Loc:ProcCount)
CPUBM = BSHIFT(1,Loc:ProcNo-1) !or 2^(Loc:ProcNo-1)
A# = SetProcessAffinityMask(GetCurrentProcess(),CPUBM)
If your going to add runtime affinity code to the EXE that way IMO the right
way is to use GetProcessorAffinity() and not GetSystemInfo(). Then select a
processor from the affinity mask your Process has been assigned, not the system
mask.
Assigning processor affinity at runtime from dwNumberOfProcessors will ignore
an affinity assigned in the EXE header (by the compiler or ImageCfg.exe) or by
the Windows loader that already is a subset of the maximum processors in the
system.
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