Use _Thread_local for thread-local storage #358
Conversation
|
cc @compnerd |
src/init.c
Outdated
| #if defined(_WIN32) | ||
| __declspec(thread) struct dispatch_tsd __dispatch_tsd; |
There was a problem hiding this comment.
would using _Thread_local work instead? I would assume it maps to the right thing on both platforms, and libdispatch otherwise already requires C11
There was a problem hiding this comment.
MSVC actually doesn't support C11 threads, so using __declspec(thread) is the canonical method of declaring thread-local variables in Windows code. I agree that using _Thread_local everywhere would be best if we don't care about building with MSVC (I don't).
There was a problem hiding this comment.
by MSVC you mean the MSFT C compiler as opposed to clang, correct? Not MSFT Visual Studio?
libdispatch needs clang (which is I'm told supported on Windows nowadays?) for blocks support anyway (and more). So yeah I don't think we care about MSVC in this instance, if _Thread_local does the job, we should use it, __thread really is a gcc-ism and C11 has the right thing.
There was a problem hiding this comment.
by MSVC you mean the MSFT C compiler as opposed to clang, correct?
Right.
I updated this to use _Thread_local now. Thanks for the guidance.
init.c currently does not compile for Windows with newer versions of Clang because it declares `__dispatch_tsd` with `__thread` but shims/tsd.h declares it with `__declspec(thread)`. Use the standard `_Thread_local` instead.
adierking
changed the title
|
I think that using |
|
@swift-ci please test |
1 similar comment
|
@swift-ci please test |
Use _Thread_local for thread-local storage Signed-off-by: Kim Topley <[email protected]>
When building for Windows, shims/tsd.h declares __dispatch_tsd with
__declspec(thread). init.c needs to match this or else it will not compile with
newer versions of Clang.