From f27db333052aa24a0aad135c09ce7969bf31bc56 Mon Sep 17 00:00:00 2001 From: Simon Ser Date: Sun, 19 May 2019 09:50:19 +0000 Subject: [PATCH] worker/types/worker: make ID allocation atomic Message IDs are allocated for both messages from UI to workers and the other way around. Hence, the global nextId variable is accessed from multiple goroutines. Instead, use atomic to access the global counter. --- worker/types/messages.go | 10 +++++----- worker/types/worker.go | 11 ++++++----- 2 files changed, 11 insertions(+), 10 deletions(-) diff --git a/worker/types/messages.go b/worker/types/messages.go index 0cb6eeb..eb54a15 100644 --- a/worker/types/messages.go +++ b/worker/types/messages.go @@ -12,13 +12,13 @@ import ( type WorkerMessage interface { InResponseTo() WorkerMessage - getId() int - setId(id int) + getId() int64 + setId(id int64) } type Message struct { inResponseTo WorkerMessage - id int + id int64 } func RespondTo(msg WorkerMessage) Message { @@ -31,11 +31,11 @@ func (m Message) InResponseTo() WorkerMessage { return m.inResponseTo } -func (m Message) getId() int { +func (m Message) getId() int64 { return m.id } -func (m Message) setId(id int) { +func (m Message) setId(id int64) { m.id = id } diff --git a/worker/types/worker.go b/worker/types/worker.go index 5647ae3..2ca142b 100644 --- a/worker/types/worker.go +++ b/worker/types/worker.go @@ -3,9 +3,10 @@ package types import ( "log" "sync" + "sync/atomic" ) -var nextId int = 1 +var lastId int64 = 1 // access via atomic type Backend interface { Run() @@ -17,7 +18,7 @@ type Worker struct { Messages chan WorkerMessage Logger *log.Logger - callbacks map[int]func(msg WorkerMessage) // protected by mutex + callbacks map[int64]func(msg WorkerMessage) // protected by mutex mutex sync.Mutex } @@ -26,13 +27,13 @@ func NewWorker(logger *log.Logger) *Worker { Actions: make(chan WorkerMessage, 50), Messages: make(chan WorkerMessage, 50), Logger: logger, - callbacks: make(map[int]func(msg WorkerMessage)), + callbacks: make(map[int64]func(msg WorkerMessage)), } } func (worker *Worker) setId(msg WorkerMessage) { - msg.setId(nextId) - nextId++ + id := atomic.AddInt64(&lastId, 1) + msg.setId(id) } func (worker *Worker) setCallback(msg WorkerMessage,