windows internals!

[kunjachan]

Hi!!

am trying to figure out answers to following qns in a windows environment:

-how many threads are allowed per process , any known limitations?
-what is the process space/address space/stack size allocated per process?
-whats the max. memory that could be available for allocation per process/thread?

I am just finding myself curious with windows internals. Could somebody answer me...also some nice kool links on relevant topics?!

Thanks! :wave:

[googler]

-how many threads are allowed per process , any known limitations?
There is no hardwired limit. You're limited by the amount of system memory. It's also possible to enable quotas on NT/XP, so that may limit you but I don't know the details. Quotas are not usually on.


-what is the process space/address space/stack size allocated per process?

I don't know what you mean by process space. The user-mode address space size on 32-bit Windows is 2GB. You can raise it to 3GB with a boot-time switch. On 64-bit Windows the sky is the limit.

To get the current size of the stack for the current thread, use
((PNT_TIB)NtCurrentTeb())->StackBase
((PNT_TIB)NtCurrentTeb())->StackLimit

The system grows the stack as needed, so the size may change. The maximum size for the stack is given in the header of the executable file,
see
IMAGE_NT_HEADERS::IMAGE_OPTIONAL_HEADER::SizeOfStackReserve


-whats the max. memory that could be available for allocation per process/thread?

If quotas are not enabled, then any thread in any process can allocate all of the memory remaining in the pagefile. If quotas are enabled, it's up to the quotas.

[wildfrog]

-how many threads are allowed per process , any known limitations?There is a limit of 2^24 kernel object handles per process, but as googler said, the actual amount is limited by memory. In addition, the default stack size for a thread is 1MB, giving a default limit of ~2000 threads per process.

- petter