+ The library uses signals internally. The signal handler is
+ registered with the SA_RESTART flag. However, these signals may cause
+ some non-restartable system calls to fail with errno = EINTR. Care
+ should be taken to restart system calls manually if they fail with this
+ error. A list of non-restartable system calls may be found in
+ signal(7). To ensure the Userspace RCU library does not use signals,
+ define CONFIG_URCU_AVOID_SIGNALS at compile-time.