fix: netpollmux shard index overflow

chyroc · Oct 18, 2021 · c394eba · c394eba
1 parent c1c542f
commit c394eba
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Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/pkg/remote/trans/netpollmux/shared_map.go b/pkg/remote/trans/netpollmux/shared_map.go
@@ -56,7 +56,7 @@ func newSharedMap(size int32) *sharedMap {
 
 // getShard returns shard under given seq id
 func (m *sharedMap) getShard(seqID int32) *shared {
-	return m.shared[seqID%m.size]
+	return m.shared[abs(seqID)%m.size]
 }
 
 // store stores msg under given seq id.
@@ -104,3 +104,10 @@ func (m *sharedMap) rangeMap(fn func(seqID int32, msg EventHandler)) {
 		shard.Unlock()
 	}
 }
+
+func abs(n int32) int32 {
+	if n < 0 {
+		return -n
+	}
+	return n
+}
diff --git a/pkg/remote/trans/netpollmux/shared_map_test.go b/pkg/remote/trans/netpollmux/shared_map_test.go
@@ -44,6 +44,10 @@ func TestSharedMap(t *testing.T) {
 	msg, ok := m.load(key)
 	test.Assert(t, msg == nil)
 	test.Assert(t, ok == false)
+	// check key<0
+	msg, ok = m.load(-1)
+	test.Assert(t, msg == nil)
+	test.Assert(t, ok == false)
 	// check key>0
 	for i := int32(1); i <= mod; i++ {
 		key := i