opt: shrink the poll event list when it need to

panjf2000 · Jan 30, 2021 · 1587638 · 1587638
1 parent 9d86c92
commit 1587638
Show file tree

Hide file tree

Showing 5 changed files with 19 additions and 5 deletions.
diff --git a/internal/netpoll/epoll.go b/internal/netpoll/epoll.go
@@ -138,7 +138,9 @@ func (p *Poller) Polling(callback func(fd int, ev uint32) error) error {
 		}
 
 		if n == el.size {
-			el.increase()
+			el.expand()
+		} else if n < el.size>>1 {
+			el.shrink()
 		}
 	}
 }

diff --git a/internal/netpoll/epoll_events.go b/internal/netpoll/epoll_events.go
@@ -45,7 +45,12 @@ func newEventList(size int) *eventList {
 	return &eventList{size, make([]unix.EpollEvent, size)}
 }
 
-func (el *eventList) increase() {
+func (el *eventList) expand() {
 	el.size <<= 1
 	el.events = make([]unix.EpollEvent, el.size)
 }
+
+func (el *eventList) shrink() {
+	el.size >>= 1
+	el.events = make([]unix.EpollEvent, el.size)
+}
diff --git a/internal/netpoll/kqueue.go b/internal/netpoll/kqueue.go
@@ -136,7 +136,9 @@ func (p *Poller) Polling(callback func(fd int, filter int16) error) error {
 		}
 
 		if n == el.size {
-			el.increase()
+			el.expand()
+		} else if n < el.size>>1 {
+			el.shrink()
 		}
 	}
 }

diff --git a/internal/netpoll/kqueue_events.go b/internal/netpoll/kqueue_events.go
@@ -45,7 +45,12 @@ func newEventList(size int) *eventList {
 	return &eventList{size, make([]unix.Kevent_t, size)}
 }
 
-func (el *eventList) increase() {
+func (el *eventList) expand() {
 	el.size <<= 1
 	el.events = make([]unix.Kevent_t, el.size)
 }
+
+func (el *eventList) shrink() {
+	el.size >>= 1
+	el.events = make([]unix.Kevent_t, el.size)
+}
diff --git a/ringbuffer/ring_buffer.go b/ringbuffer/ring_buffer.go
@@ -371,7 +371,7 @@ func (r *RingBuffer) Reset() {
 	r.r, r.w = 0, 0
 
 	// Shrink the internal buffer for saving memory.
-	newCap := r.size / 2
+	newCap := r.size >> 1
 	newBuf := make([]byte, newCap)
 	r.buf = newBuf
 	r.size = newCap