*/
#define RCU_QS_ACTIVE_ATTEMPTS 100
+/*
+ * RCU_MEMBARRIER is only possibly available on Linux.
+ */
+#if defined(RCU_MEMBARRIER) && defined(__linux__)
+#include <syscall.h>
+#endif
+
+/* If the headers do not support SYS_membarrier, fall back on RCU_MB */
+#ifdef SYS_membarrier
+# define membarrier(...) syscall(SYS_membarrier, __VA_ARGS__)
+#else
+# define membarrier(...) -ENOSYS
+#endif
+
+#define MEMBARRIER_EXPEDITED (1 << 0)
+#define MEMBARRIER_DELAYED (1 << 1)
+#define MEMBARRIER_QUERY (1 << 16)
+
#ifdef RCU_MEMBARRIER
static int init_done;
int rcu_has_sys_membarrier;
static void smp_mb_master(int group)
{
if (caa_likely(rcu_has_sys_membarrier))
- membarrier(MEMBARRIER_EXPEDITED);
+ (void) membarrier(MEMBARRIER_EXPEDITED);
else
cmm_smp_mb();
}
void rcu_exit(void)
{
- struct sigaction act;
- int ret;
-
- ret = sigaction(SIGRCU, NULL, &act);
- if (ret)
- urcu_die(errno);
- assert(act.sa_sigaction == sigrcu_handler);
- assert(cds_list_empty(®istry));
+ /*
+ * Don't unregister the SIGRCU signal handler anymore, because
+ * call_rcu threads could still be using it shortly before the
+ * application exits.
+ * Assertion disabled because call_rcu threads are now rcu
+ * readers, and left running at exit.
+ * assert(cds_list_empty(®istry));
+ */
}
#endif /* #ifdef RCU_SIGNAL */