On Sun, Jul 31, 2016 at 07:36:26PM +0200, Guillaume Munch wrote:
> commit 22d7ba642415f576e9553b174166d8c17b945f39
> Author: Guillaume Munch <g...@lyx.org>
> Date: Sat Jul 30 20:46:29 2016 +0100
>
> Use call_once to ensure something is only called once
>
> This is thread-safe.
This does not compile with mingw (g++ 4.9.2):
i686-w64-mingw32-g++ -DHAVE_CONFIG_H -I. -I../../src -I.. -I../../src
-I../../3rdparty/boost -I/c/MinGW/include/hunspell -DQT_NO_STL
-DQT_NO_KEYWORDS -I/c/MinGW/Qt/5.7.0/include/QtCore -I/c/MinGW/Qt/5.7.0/include
-pipe -fno-keep-inline-dllexport -I/c/MinGW/include -O2 -std=c++14 -MT
graphics/PreviewLoader.o -MD -MP -MF graphics/.deps/PreviewLoader.Tpo -c -o
graphics/PreviewLoader.o ../../src/graphics/PreviewLoader.cpp
../../src/graphics/PreviewLoader.cpp: In function ‘const lyx::Converter*
{anonymous}::setConverter(const string&)’:
../../src/graphics/PreviewLoader.cpp:96:9: error: ‘once_flag’ does not name a
type
static once_flag flag;
^
../../src/graphics/PreviewLoader.cpp:97:12: error: ‘flag’ was not declared in
this scope
call_once(flag, [&](){
^
../../src/graphics/PreviewLoader.cpp:101:4: error: ‘call_once’ was not declared
in this scope
});
^
> ---
> src/graphics/PreviewLoader.cpp | 15 ++++++++-------
> 1 files changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/src/graphics/PreviewLoader.cpp b/src/graphics/PreviewLoader.cpp
> index 1240771..f8c1d7e 100644
> --- a/src/graphics/PreviewLoader.cpp
> +++ b/src/graphics/PreviewLoader.cpp
> @@ -45,6 +45,7 @@
> #include <fstream>
> #include <iomanip>
> #include <memory>
> +#include <mutex>
> #include <sstream>
>
> #include <QTimer>
> @@ -91,13 +92,13 @@ lyx::Converter const * setConverter(string const & from)
> return ptr;
> }
>
> - // FIXME THREAD
> - static bool first = true;
> - if (first) {
> - first = false;
> - LYXERR0("PreviewLoader::startLoading()\n"
> - << "No converter from \"" << from << "\" format has
> been defined.");
> - }
> + // Show the error only once
> + static once_flag flag;
> + call_once(flag, [&](){
> + LYXERR0("PreviewLoader::startLoading()\n"
> + << "No converter from \"" << from
> + << "\" format has been defined.");
> + });
> return 0;
> }
>
--
Enrico
