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c++multithreadingcgo

C++ and Go <thread> header is Throwing an Error


Afer reading How To Use C++ In Go, I started to need threads in my c++ programs. Recently when i tried using it it gave me this compiler error:

error: 'thread' was not declared in this scope
                 thread parsed(parser, var["ExpAct"], calc_params, sendVars, dir, true, line, false);
                 ^~~~~~
parser/parser.hpp:299:17: note: 'std::thread' is defined in header '<thread>'; did you forget to '#include <thread>'?
parser/parser.hpp:17:1:
+#include <thread>
 using namespace std;
parser/parser.hpp:299:17:

but I am include the <thread> library in my code. I am using mingw-64 and when I run gcc -v I get

Using built-in specs.
COLLECT_GCC=C:\Program Files\mingw-w64\x86_64-8.1.0-win32-seh-rt_v6-rev0\mingw64\bin\gcc.exe
COLLECT_LTO_WRAPPER=C:/Program\ Files/mingw-w64/x86_64-8.1.0-win32-seh-rt_v6-rev0/mingw64/bin/../libexec/gcc/x86_64-w64-mingw32/8.1.0/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../../../src/gcc-8.1.0/configure --host=x86_64-w64-mingw32 --build=x86_64-w64-mingw32 --target=x86_64-w64-mingw32 --prefix=/mingw64 --with-sysroot=/c/mingw810/x86_64-810-win32-seh-rt_v6-rev0/mingw64 --enable-shared --enable-static --disable-multilib --enable-languages=c,c++,fortran,lto --enable-libstdcxx-time=yes --enable-threads=win32 --enable-libgomp --enable-libatomic --enable-lto --enable-graphite --enable-checking=release --enable-fully-dynamic-string --enable-version-specific-runtime-libs --disable-libstdcxx-pch --disable-libstdcxx-debug --enable-bootstrap --disable-rpath --disable-win32-registry --disable-nls --disable-werror --disable-symvers --with-gnu-as --with-gnu-ld --with-arch=nocona --with-tune=core2 --with-libiconv --with-system-zlib --with-gmp=/c/mingw810/prerequisites/x86_64-w64-mingw32-static --with-mpfr=/c/mingw810/prerequisites/x86_64-w64-mingw32-static --with-mpc=/c/mingw810/prerequisites/x86_64-w64-mingw32-static --with-isl=/c/mingw810/prerequisites/x86_64-w64-mingw32-static --with-pkgversion='x86_64-win32-seh-rev0, Built by MinGW-W64 project' --with-bugurl=https://sourceforge.net/projects/mingw-w64 CFLAGS='-O2 -pipe -fno-ident -I/c/mingw810/x86_64-810-win32-seh-rt_v6-rev0/mingw64/opt/include -I/c/mingw810/prerequisites/x86_64-zlib-static/include -I/c/mingw810/prerequisites/x86_64-w64-mingw32-static/include' CXXFLAGS='-O2 -pipe -fno-ident -I/c/mingw810/x86_64-810-win32-seh-rt_v6-rev0/mingw64/opt/include -I/c/mingw810/prerequisites/x86_64-zlib-static/include -I/c/mingw810/prerequisites/x86_64-w64-mingw32-static/include' CPPFLAGS=' -I/c/mingw810/x86_64-810-win32-seh-rt_v6-rev0/mingw64/opt/include -I/c/mingw810/prerequisites/x86_64-zlib-static/include -I/c/mingw810/prerequisites/x86_64-w64-mingw32-static/include' LDFLAGS='-pipe -fno-ident -L/c/mingw810/x86_64-810-win32-seh-rt_v6-rev0/mingw64/opt/lib -L/c/mingw810/prerequisites/x86_64-zlib-static/lib -L/c/mingw810/prerequisites/x86_64-w64-mingw32-static/lib '
Thread model: win32
gcc version 8.1.0 (x86_64-win32-seh-rev0, Built by MinGW-W64 project)

Solution

  • I found the solution to my problem. It was not a cgo issue, but rather an installation issue. Instead of selecting posix style threads, i installed win32 threads. This style does not allow for multithreading. To fix this, I re-installed mingw-w64 with posix threads.