I wanted to use threads in my code and thought that the upcoming C++0x

Question

0

Asked: May 18, 20262026-05-18T22:16:43+00:00 2026-05-18T22:16:43+00:00

I wanted to use threads in my code and thought that the upcoming C++0x

0

I wanted to use threads in my code and thought that the upcoming C++0x extensions would be handy as they will become a standard eventually. This seemed to be future-proof without the need to use additional libraries like the boost::thread.
Unfortunately I couldn’t find useful information about which features regarding threads are currently supported by gcc. I’m using unique_locks which seem not to work, yet. This is the output of the linker:

.build_debug/src/core/simulator.o: In function `Simulator::start(int, int, int, int)':
simulator.cpp:(.text+0x1fc): undefined reference to `_ZSt4lockISt11unique_lockISt5mutexES2_IEEvRT_RT0_DpRT1_'
.build_debug/src/core/simulator.o: In function `Simulator::resume()':
simulator.cpp:(.text+0x351): undefined reference to `_ZSt4lockISt11unique_lockISt5mutexES2_IEEvRT_RT0_DpRT1_'
.build_debug/src/core/simulator.o: In function `Simulator::pause()':
simulator.cpp:(.text+0x417): undefined reference to `_ZSt4lockISt11unique_lockISt5mutexES2_IEEvRT_RT0_DpRT1_'
.build_debug/src/core/simulator.o: In function `Simulator::stop()':
simulator.cpp:(.text+0x4cd): undefined reference to `_ZSt4lockISt11unique_lockISt5mutexES2_IEEvRT_RT0_DpRT1_'

Does anybody understand these messages? I guess they are referring to the usage of unique_locks. But why do these errors occur?

My source code resembles this one:
std::unique_lock<std::mutex> lkIntra(intraMtx, std::defer_lock); std::unique_lock<std::mutex> lkInter(interMtx, std::defer_lock); std::lock(lkIntra, lkInter);

EDIT: I tried to compile this with gcc 4.3.X and 4.4.5. The linker was g++ 4.3, 4.4 and 4.5.

EDIT2: I just tried to use the boost equivalents to the std-threads. After adding the compiler flag “-lboost_thread” the compilation worked. Without which the linking process resulted in similar error messages. Now I’m wondering whether I need to do something alike when using standard threads (I already tried “-lpthread”).