Remove armhf/armv7 support from faasd

See notes in: #364

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

vendor/google.golang.org/grpc/internal/grpcsync/callback_serializer.go

@@ -32,10 +32,10 @@ import (
 //
 // This type is safe for concurrent access.
 type CallbackSerializer struct {
-	// Done is closed once the serializer is shut down completely, i.e all
+	// done is closed once the serializer is shut down completely, i.e all
 	// scheduled callbacks are executed and the serializer has deallocated all
 	// its resources.
-	Done chan struct{}
+	done chan struct{}
 
 	callbacks *buffer.Unbounded
 	closedMu  sync.Mutex
@@ -48,12 +48,12 @@ type CallbackSerializer struct {
 // callbacks will be added once this context is canceled, and any pending un-run
 // callbacks will be executed before the serializer is shut down.
 func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
-	t := &CallbackSerializer{
-		Done:      make(chan struct{}),
+	cs := &CallbackSerializer{
+		done:      make(chan struct{}),
 		callbacks: buffer.NewUnbounded(),
 	}
-	go t.run(ctx)
-	return t
+	go cs.run(ctx)
+	return cs
 }
 
 // Schedule adds a callback to be scheduled after existing callbacks are run.
@@ -64,56 +64,62 @@ func NewCallbackSerializer(ctx context.Context) *CallbackSerializer {
 // Return value indicates if the callback was successfully added to the list of
 // callbacks to be executed by the serializer. It is not possible to add
 // callbacks once the context passed to NewCallbackSerializer is cancelled.
-func (t *CallbackSerializer) Schedule(f func(ctx context.Context)) bool {
-	t.closedMu.Lock()
-	defer t.closedMu.Unlock()
+func (cs *CallbackSerializer) Schedule(f func(ctx context.Context)) bool {
+	cs.closedMu.Lock()
+	defer cs.closedMu.Unlock()
 
-	if t.closed {
+	if cs.closed {
 		return false
 	}
-	t.callbacks.Put(f)
+	cs.callbacks.Put(f)
 	return true
 }
 
-func (t *CallbackSerializer) run(ctx context.Context) {
+func (cs *CallbackSerializer) run(ctx context.Context) {
 	var backlog []func(context.Context)
 
-	defer close(t.Done)
+	defer close(cs.done)
 	for ctx.Err() == nil {
 		select {
 		case <-ctx.Done():
 			// Do nothing here. Next iteration of the for loop will not happen,
 			// since ctx.Err() would be non-nil.
-		case callback, ok := <-t.callbacks.Get():
+		case callback, ok := <-cs.callbacks.Get():
 			if !ok {
 				return
 			}
-			t.callbacks.Load()
+			cs.callbacks.Load()
 			callback.(func(ctx context.Context))(ctx)
 		}
 	}
 
 	// Fetch pending callbacks if any, and execute them before returning from
-	// this method and closing t.Done.
-	t.closedMu.Lock()
-	t.closed = true
-	backlog = t.fetchPendingCallbacks()
-	t.callbacks.Close()
-	t.closedMu.Unlock()
+	// this method and closing cs.done.
+	cs.closedMu.Lock()
+	cs.closed = true
+	backlog = cs.fetchPendingCallbacks()
+	cs.callbacks.Close()
+	cs.closedMu.Unlock()
 	for _, b := range backlog {
 		b(ctx)
 	}
 }
 
-func (t *CallbackSerializer) fetchPendingCallbacks() []func(context.Context) {
+func (cs *CallbackSerializer) fetchPendingCallbacks() []func(context.Context) {
 	var backlog []func(context.Context)
 	for {
 		select {
-		case b := <-t.callbacks.Get():
+		case b := <-cs.callbacks.Get():
 			backlog = append(backlog, b.(func(context.Context)))
-			t.callbacks.Load()
+			cs.callbacks.Load()
 		default:
 			return backlog
 		}
 	}
 }
+
+// Done returns a channel that is closed after the context passed to
+// NewCallbackSerializer is canceled and all callbacks have been executed.
+func (cs *CallbackSerializer) Done() <-chan struct{} {
+	return cs.done
+}

vendor/google.golang.org/grpc/internal/grpcsync/pubsub.go

@@ -0,0 +1,121 @@
+/*
+ *
+ * Copyright 2023 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+package grpcsync
+
+import (
+	"context"
+	"sync"
+)
+
+// Subscriber represents an entity that is subscribed to messages published on
+// a PubSub. It wraps the callback to be invoked by the PubSub when a new
+// message is published.
+type Subscriber interface {
+	// OnMessage is invoked when a new message is published. Implementations
+	// must not block in this method.
+	OnMessage(msg any)
+}
+
+// PubSub is a simple one-to-many publish-subscribe system that supports
+// messages of arbitrary type. It guarantees that messages are delivered in
+// the same order in which they were published.
+//
+// Publisher invokes the Publish() method to publish new messages, while
+// subscribers interested in receiving these messages register a callback
+// via the Subscribe() method.
+//
+// Once a PubSub is stopped, no more messages can be published, but any pending
+// published messages will be delivered to the subscribers.  Done may be used
+// to determine when all published messages have been delivered.
+type PubSub struct {
+	cs *CallbackSerializer
+
+	// Access to the below fields are guarded by this mutex.
+	mu          sync.Mutex
+	msg         any
+	subscribers map[Subscriber]bool
+}
+
+// NewPubSub returns a new PubSub instance.  Users should cancel the
+// provided context to shutdown the PubSub.
+func NewPubSub(ctx context.Context) *PubSub {
+	return &PubSub{
+		cs:          NewCallbackSerializer(ctx),
+		subscribers: map[Subscriber]bool{},
+	}
+}
+
+// Subscribe registers the provided Subscriber to the PubSub.
+//
+// If the PubSub contains a previously published message, the Subscriber's
+// OnMessage() callback will be invoked asynchronously with the existing
+// message to begin with, and subsequently for every newly published message.
+//
+// The caller is responsible for invoking the returned cancel function to
+// unsubscribe itself from the PubSub.
+func (ps *PubSub) Subscribe(sub Subscriber) (cancel func()) {
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+
+	ps.subscribers[sub] = true
+
+	if ps.msg != nil {
+		msg := ps.msg
+		ps.cs.Schedule(func(context.Context) {
+			ps.mu.Lock()
+			defer ps.mu.Unlock()
+			if !ps.subscribers[sub] {
+				return
+			}
+			sub.OnMessage(msg)
+		})
+	}
+
+	return func() {
+		ps.mu.Lock()
+		defer ps.mu.Unlock()
+		delete(ps.subscribers, sub)
+	}
+}
+
+// Publish publishes the provided message to the PubSub, and invokes
+// callbacks registered by subscribers asynchronously.
+func (ps *PubSub) Publish(msg any) {
+	ps.mu.Lock()
+	defer ps.mu.Unlock()
+
+	ps.msg = msg
+	for sub := range ps.subscribers {
+		s := sub
+		ps.cs.Schedule(func(context.Context) {
+			ps.mu.Lock()
+			defer ps.mu.Unlock()
+			if !ps.subscribers[s] {
+				return
+			}
+			s.OnMessage(msg)
+		})
+	}
+}
+
+// Done returns a channel that is closed after the context passed to NewPubSub
+// is canceled and all updates have been sent to subscribers.
+func (ps *PubSub) Done() <-chan struct{} {
+	return ps.cs.Done()
+}