Disabling OpenMP for Windows & Linux

[Belval]

Environment

• Tesseract Version: Latest / cloned from master
• Platform: Windows 10 x64 with VS2017

Current Behavior:

The compiling section does not explain how to compile under Windows without OpenMP (neither under Linux mind you). How can it be done?

Expected Behavior:

The compiling section of the wiki should include such informations as they are quite important if the binaries are to be used in a heavily threaded environnement.

Suggested Fix:

For Linux, add a line in the wiki about using ./configure --disable-openmp flag (although you can simply use ./configure --help)

For Windows, add a line explaining how it can be done (I haven't figured out that one yet)

I am more than willing to make a PR for this if you consider it necessary, if not, how can it be achieved under Windows?

[stweil]

The option --disable-openmp works for Windows with Mingw-w64, too. You don't need it neither for Linux nor for Windows, because it is possible to tell OpenMP not to create any threads:

export OMP_THREAD_LIMIT=1
tesseract ...

or

OMP_THREAD_LIMIT=1 tesseract ...

You can help improving the Wiki by adding any important information which is currently missing.

[Belval]

@stweil Thank you for the quick response. I am using MSVC. Any parameter for that one? Also how can I set OMP_THREAD_LIMIT in Windows?

Doing SET OMP_THREAD_LIMIT=1 then calling tesseract.exe works