About an instead function of sigtimedwait under darwin

I want to use the sigtimedwait function on my mac.

But it seems like not work under darwin.

So i want to find a function like that under the blow env or it's ok to change the version of gcc.

Is there anyone know one? Thanks.

COLLECT_GCC=g++-7
COLLECT_LTO_WRAPPER=/usr/local/Cellar/gcc@7/7.5.0_1/libexec/gcc/x86_64-apple-darwin19.2.0/7.5.0/lto-wrapper
Target: x86_64-apple-darwin19.2.0
Configured with: ../configure --build=x86_64-apple-darwin19.2.0 --prefix=/usr/local/Cellar/gcc@7/7.5.0_1 --libdir=/usr/local/Cellar/gcc@7/7.5.0_1/lib/gcc/7 --enable-languages=c,c++,objc,obj-c++,fortran --program-suffix=-7 --with-gmp=/usr/local/opt/gmp --with-mpfr=/usr/local/opt/mpfr --with-mpc=/usr/local/opt/libmpc --with-isl=/usr/local/opt/isl --with-system-zlib --enable-checking=release --with-pkgversion='Homebrew GCC 7.5.0_1' --with-bugurl=https://github.com/Homebrew/homebrew-core/issues --disable-nls --disable-multilib --with-native-system-header-dir=/usr/include --with-sysroot=/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk
Thread model: posix
gcc version 7.5.0 (Homebrew GCC 7.5.0_1) ```