1344909 - mingw build broken with VideoDecoder.cpp error: 'std::thread' has not been declared

Status: RESOLVED FIXED

(Core :: Audio/Video: GMP, defect, P2)

Description

[Tom Ritter [:tjr]]

mingw does not understand std::thread:

> 0:13.12 In file included from /tmp/workspace/mingw-w64-build/mozilla-mingw/media/gmp-clearkey/0.1/Unified_cpp_gmp-clearkey_0.10.cpp:74:0:
> 0:13.12 /tmp/workspace/mingw-w64-build/firefox/media/gmp-clearkey/0.1/VideoDecoder.cpp: In constructor 'VideoDecoder::VideoDecoder(cdm::Host_8*)':
> 0:13.12 /tmp/workspace/mingw-w64-build/firefox/media/gmp-clearkey/0.1/VideoDecoder.cpp:40:38: error: 'std::thread' has not been declared
> 0:13.12    uint32_t cores = std::max(1u, std::thread::hardware_concurrency());

In a related bug (https://bugzilla.mozilla.org/show_bug.cgi?id=1317642) we commented out the code on MinGW because it was in Error Reporting and not strictly necessary. Here we could use something like the below, or just hardcode it.

> #ifdef _WIN32
>     SYSTEM_INFO sysinfo;
>     GetSystemInfo(&sysinfo);
>     return sysinfo.dwNumberOfProcessors;

Comment 1

[Tom Ritter [:tjr]]

Attachment: Bug 1344909 When compiled with MinGW, use only a single core in gmp-clearkey

Review commit: https://reviewboard.mozilla.org/r/123184/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/123184/

Comment 2

[Chris Pearce [:cpearce (Not reading bugmail)]]

Comment on attachment 8850640 [details]
Bug 1344909 When compiled with MinGW, use only a single core in gmp-clearkey

https://reviewboard.mozilla.org/r/123184/#review127122

Thanks for the patch. It's a shame mingw doesn't have std::thread yet. I'd be happy to for us to get the number of processors from a call to GetSystemInfo() as well, as it would mean mingw builds would have better parallelism for ClearKey video. There's very little ClearKey content out there through, so it's not super important.

Comment 3

[Tom Ritter [:tjr]]

(In reply to Chris Pearce (:cpearce) from comment #2)
> Comment on attachment 8850640 [details]
> Bug 1344909 When compiled with MinGW, use only a single core in gmp-clearkey
> 
> https://reviewboard.mozilla.org/r/123184/#review127122
> 
> Thanks for the patch. It's a shame mingw doesn't have std::thread yet. I'd
> be happy to for us to get the number of processors from a call to
> GetSystemInfo() as well, as it would mean mingw builds would have better
> parallelism for ClearKey video. There's very little ClearKey content out
> there through, so it's not super important.

Thanks! The plan is to add pthreads in mingw to get std::thread support at which point I'll be undoing the few patches like these we've accumulated, so the GetSystemInfo() approach isn't really worth the complexity of having that code in FF without it being exercised by our tests right now.

Comment 4

[Ian Moody [:Kwan] (UTC+1)]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/142baaabe917
When compiled with MinGW, use only a single core in gmp-clearkey r=cpearce

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/142baaabe917

Comment 6

[Julien Cristau [:jcristau]]

Guessing this is wontfix for 54 as tor builds aren't based off that version.