+e_xbt_parmap_mode_t Context::parallel_mode = XBT_PARMAP_DEFAULT;
+int Context::parallel_contexts = 1;
+unsigned Context::stack_size;
+unsigned Context::guard_size;
+thread_local Context* Context::current_context_ = nullptr;
+
+/* Install or disable alternate signal stack, for SIGSEGV handler. */
+int Context::install_sigsegv_stack(bool enable)
+{
+ static std::vector<unsigned char> sigsegv_stack(SIGSTKSZ);
+ stack_t stack;
+ stack.ss_sp = sigsegv_stack.data();
+ stack.ss_size = sigsegv_stack.size();
+ stack.ss_flags = enable ? 0 : SS_DISABLE;
+ return sigaltstack(&stack, nullptr);
+}
+