LLVM and Pthreads

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1

Hello,

I know clang supports -pthread option (here). Does this mean I can call pthread routines inside llvm code and which pthread library is used, the one for Linux OS or the one for Windows?

Thank you.
Iulia

2

I know clang supports -pthread option (here). Does this mean I can call
pthread routines inside llvm code

LLVM itself can run when pthreads isn't available, so while some parts
do use pthreads they have alternative implementations for other
systems. Take a look at Mutex.cpp for example: the default is Posix
but there's a Windows specific version in lib/Support/Windows.

and which pthread library is used, the one for Linux OS or the one for Windows?

There's never (to my knowledge) a situation where both of those are
valid answers: if you're running on Linux you'll use a Linux library,
if you're running on Windows you'll use a Windows library.

Tim.

3

I know clang supports -pthread option (here). Does this mean I can call
pthread routines inside llvm code

LLVM itself can run when pthreads isn’t available, so while some parts
do use pthreads they have alternative implementations for other
systems. Take a look at Mutex.cpp for example: the default is Posix
but there’s a Windows specific version in lib/Support/Windows.

and which pthread library is used, the one for Linux OS or the one for Windows?

There’s never (to my knowledge) a situation where both of those are
valid answers: if you’re running on Linux you’ll use a Linux library,
if you’re running on Windows you’ll use a Windows library.

Thank you. My question was: is PThreads library for Windows supported by LLVM?

Tim.

4

No, you cannot use pthreads in windows.

If you want to write multithreaded code you need to use (or create) a portable abstraction

5

Hello all,

I am returning to this subject after a while and I was looking for CBuilder::CreatePThreadCreateCall function below. I cannot find it anywere and I guess it has been rename or changed into a more generic one. I would want to insert a phtread call into the input source code. Which builder class to use for that instead of CBuilder class? If I insert the call into IR representation, do I need to insert the call also into machine representation?

Kind regards,

6

Hi Iulia,

The declaration Rob has shared was never part of mainline LLVM (afaik).
The implementation Rob provided should however still work.
Have you tried it?

There is no need to add/change anything in the machine representation.

Cheers,
  Johannes