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authorRickard Green <[email protected]>2010-06-01 13:50:50 +0000
committerErlang/OTP <[email protected]>2010-06-01 13:50:50 +0000
commitb53f8a67649a371a38dc6d97b0dfe52111236a3e (patch)
treeae954fdc12817e287dab6cdce7030c9d54e83219 /erts/emulator/sys/common/erl_poll.c
parent6999e909a9ad22d90b64263fd5edd186ac93a990 (diff)
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OTP-8658 Add missing memory barriers in erts_poll()
Missing memory barriers in erts_poll() could cause the runtime system to hang indefinitely.
Diffstat (limited to 'erts/emulator/sys/common/erl_poll.c')
-rw-r--r--erts/emulator/sys/common/erl_poll.c58
1 files changed, 41 insertions, 17 deletions
diff --git a/erts/emulator/sys/common/erl_poll.c b/erts/emulator/sys/common/erl_poll.c
index d268547e1a..09fb6337f7 100644
--- a/erts/emulator/sys/common/erl_poll.c
+++ b/erts/emulator/sys/common/erl_poll.c
@@ -130,13 +130,18 @@
#define ERTS_POLLSET_IS_POLLED(PS) \
((int) erts_smp_atomic_read(&(PS)->polled))
-#define ERTS_POLLSET_SET_POLLER_WOKEN_CHK(PS) \
- ((int) erts_smp_atomic_xchg(&(PS)->woken, (long) 1))
-#define ERTS_POLLSET_SET_POLLER_WOKEN(PS) \
- erts_smp_atomic_set(&(PS)->woken, (long) 1)
-#define ERTS_POLLSET_UNSET_POLLER_WOKEN(PS) \
- erts_smp_atomic_set(&(PS)->woken, (long) 0)
-#define ERTS_POLLSET_IS_POLLER_WOKEN(PS) \
+#define ERTS_POLLSET_SET_POLLER_WOKEN_CHK(PS) set_poller_woken_chk((PS))
+#define ERTS_POLLSET_SET_POLLER_WOKEN(PS) \
+do { \
+ ERTS_THR_MEMORY_BARRIER; \
+ erts_smp_atomic_set(&(PS)->woken, (long) 1); \
+} while (0)
+#define ERTS_POLLSET_UNSET_POLLER_WOKEN(PS) \
+do { \
+ erts_smp_atomic_set(&(PS)->woken, (long) 0); \
+ ERTS_THR_MEMORY_BARRIER; \
+} while (0)
+#define ERTS_POLLSET_IS_POLLER_WOKEN(PS) \
((int) erts_smp_atomic_read(&(PS)->woken))
#else
@@ -194,13 +199,18 @@
#else
-#define ERTS_POLLSET_UNSET_INTERRUPTED_CHK(PS) \
- ((int) erts_smp_atomic_xchg(&(PS)->interrupt, (long) 0))
-#define ERTS_POLLSET_UNSET_INTERRUPTED(PS) \
- erts_smp_atomic_set(&(PS)->interrupt, (long) 0)
-#define ERTS_POLLSET_SET_INTERRUPTED(PS) \
- erts_smp_atomic_set(&(PS)->interrupt, (long) 1)
-#define ERTS_POLLSET_IS_INTERRUPTED(PS) \
+#define ERTS_POLLSET_UNSET_INTERRUPTED_CHK(PS) unset_interrupted_chk((PS))
+#define ERTS_POLLSET_UNSET_INTERRUPTED(PS) \
+do { \
+ erts_smp_atomic_set(&(PS)->interrupt, (long) 0); \
+ ERTS_THR_MEMORY_BARRIER; \
+} while (0)
+#define ERTS_POLLSET_SET_INTERRUPTED(PS) \
+do { \
+ ERTS_THR_MEMORY_BARRIER; \
+ erts_smp_atomic_set(&(PS)->interrupt, (long) 1); \
+} while (0)
+#define ERTS_POLLSET_IS_INTERRUPTED(PS) \
((int) erts_smp_atomic_read(&(PS)->interrupt))
#endif
@@ -336,16 +346,30 @@ struct ErtsPollSet_ {
#endif
};
-#if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT && !defined(ERTS_SMP)
-
static ERTS_INLINE int
unset_interrupted_chk(ErtsPollSet ps)
{
+ int res;
+#if ERTS_POLL_ASYNC_INTERRUPT_SUPPORT && !defined(ERTS_SMP)
/* This operation isn't atomic, but we have no need at all for an
atomic operation here... */
- int res = ps->interrupt;
+ res = ps->interrupt;
ps->interrupt = 0;
+#else
+ res = (int) erts_smp_atomic_xchg(&ps->interrupt, (long) 0);
+ ERTS_THR_MEMORY_BARRIER;
+#endif
return res;
+
+}
+
+#ifdef ERTS_SMP
+
+static ERTS_INLINE int
+set_poller_woken_chk(ErtsPollSet ps)
+{
+ ERTS_THR_MEMORY_BARRIER;
+ return (int) erts_smp_atomic_xchg(&ps->woken, (long) 1);
}
#endif