void assert_single_threaded_at(const char *where);
#define assert_single_threaded() assert_single_threaded_at(SOURCE_LOCATOR)
+#ifndef _WIN32
pid_t xfork_at(const char *where);
#define xfork() xfork_at(SOURCE_LOCATOR)
+#endif
void forbid_forking(const char *reason);
bool may_fork(void);