libgo: update to go1.9

    
    Reviewed-on: https://go-review.googlesource.com/63753


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@252767 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 151 insertions, 0 deletions

diff --git a/libgo/go/sync/map_reference_test.go b/libgo/go/sync/map_reference_test.go
new file mode 100644
index 00000000000..9f27b07c329
--- /dev/null
+++ b/libgo/go/sync/map_reference_test.go
@@ -0,0 +1,151 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package sync_test
+
+import (
+	"sync"
+	"sync/atomic"
+)
+
+// This file contains reference map implementations for unit-tests.
+
+// mapInterface is the interface Map implements.
+type mapInterface interface {
+	Load(interface{}) (interface{}, bool)
+	Store(key, value interface{})
+	LoadOrStore(key, value interface{}) (actual interface{}, loaded bool)
+	Delete(interface{})
+	Range(func(key, value interface{}) (shouldContinue bool))
+}
+
+// RWMutexMap is an implementation of mapInterface using a sync.RWMutex.
+type RWMutexMap struct {
+	mu    sync.RWMutex
+	dirty map[interface{}]interface{}
+}
+
+func (m *RWMutexMap) Load(key interface{}) (value interface{}, ok bool) {
+	m.mu.RLock()
+	value, ok = m.dirty[key]
+	m.mu.RUnlock()
+	return
+}
+
+func (m *RWMutexMap) Store(key, value interface{}) {
+	m.mu.Lock()
+	if m.dirty == nil {
+		m.dirty = make(map[interface{}]interface{})
+	}
+	m.dirty[key] = value
+	m.mu.Unlock()
+}
+
+func (m *RWMutexMap) LoadOrStore(key, value interface{}) (actual interface{}, loaded bool) {
+	m.mu.Lock()
+	actual, loaded = m.dirty[key]
+	if !loaded {
+		actual = value
+		if m.dirty == nil {
+			m.dirty = make(map[interface{}]interface{})
+		}
+		m.dirty[key] = value
+	}
+	m.mu.Unlock()
+	return actual, loaded
+}
+
+func (m *RWMutexMap) Delete(key interface{}) {
+	m.mu.Lock()
+	delete(m.dirty, key)
+	m.mu.Unlock()
+}
+
+func (m *RWMutexMap) Range(f func(key, value interface{}) (shouldContinue bool)) {
+	m.mu.RLock()
+	keys := make([]interface{}, 0, len(m.dirty))
+	for k := range m.dirty {
+		keys = append(keys, k)
+	}
+	m.mu.RUnlock()
+
+	for _, k := range keys {
+		v, ok := m.Load(k)
+		if !ok {
+			continue
+		}
+		if !f(k, v) {
+			break
+		}
+	}
+}
+
+// DeepCopyMap is an implementation of mapInterface using a Mutex and
+// atomic.Value.  It makes deep copies of the map on every write to avoid
+// acquiring the Mutex in Load.
+type DeepCopyMap struct {
+	mu    sync.Mutex
+	clean atomic.Value
+}
+
+func (m *DeepCopyMap) Load(key interface{}) (value interface{}, ok bool) {
+	clean, _ := m.clean.Load().(map[interface{}]interface{})
+	value, ok = clean[key]
+	return value, ok
+}
+
+func (m *DeepCopyMap) Store(key, value interface{}) {
+	m.mu.Lock()
+	dirty := m.dirty()
+	dirty[key] = value
+	m.clean.Store(dirty)
+	m.mu.Unlock()
+}
+
+func (m *DeepCopyMap) LoadOrStore(key, value interface{}) (actual interface{}, loaded bool) {
+	clean, _ := m.clean.Load().(map[interface{}]interface{})
+	actual, loaded = clean[key]
+	if loaded {
+		return actual, loaded
+	}
+
+	m.mu.Lock()
+	// Reload clean in case it changed while we were waiting on m.mu.
+	clean, _ = m.clean.Load().(map[interface{}]interface{})
+	actual, loaded = clean[key]
+	if !loaded {
+		dirty := m.dirty()
+		dirty[key] = value
+		actual = value
+		m.clean.Store(dirty)
+	}
+	m.mu.Unlock()
+	return actual, loaded
+}
+
+func (m *DeepCopyMap) Delete(key interface{}) {
+	m.mu.Lock()
+	dirty := m.dirty()
+	delete(dirty, key)
+	m.clean.Store(dirty)
+	m.mu.Unlock()
+}
+
+func (m *DeepCopyMap) Range(f func(key, value interface{}) (shouldContinue bool)) {
+	clean, _ := m.clean.Load().(map[interface{}]interface{})
+	for k, v := range clean {
+		if !f(k, v) {
+			break
+		}
+	}
+}
+
+func (m *DeepCopyMap) dirty() map[interface{}]interface{} {
+	clean, _ := m.clean.Load().(map[interface{}]interface{})
+	dirty := make(map[interface{}]interface{}, len(clean)+1)
+	for k, v := range clean {
+		dirty[k] = v
+	}
+	return dirty
+}