If I am using channels properly should I need to use mutexes?

by

You don’t need mutex if you use channels correctly. In some cases a solution with mutex might be simpler though.

Just make sure the variable(s) holding the channel values are properly initialized before multiple goroutines try to access the channel variables. Once this is done, accessing the channels (e.g. sending values to or receiving values from them) is safe by design.

Supporting documents with references (emphases added by me):

Spec: Channel types:

A single channel may be used in send statements, receive operations, and calls to the built-in functions cap and len by any number of goroutines without further synchronization. Channels act as first-in-first-out queues. For example, if one goroutine sends values on a channel and a second goroutine receives them, the values are received in the order sent.

Effective Go: Concurrency: Share by communicating

Concurrent programming in many environments is made difficult by the subtleties required to implement correct access to shared variables. Go encourages a different approach in which shared values are passed around on channels and, in fact, never actively shared by separate threads of execution. Only one goroutine has access to the value at any given time. Data races cannot occur, by design. To encourage this way of thinking we have reduced it to a slogan:

Do not communicate by sharing memory; instead, share memory by communicating.

This approach can be taken too far. Reference counts may be best done by putting a mutex around an integer variable, for instance. But as a high-level approach, using channels to control access makes it easier to write clear, correct programs.

This article is also very helpful: The Go Memory Model

Also quoting from the package doc of sync:

Package sync provides basic synchronization primitives such as mutual exclusion locks. Other than the Once and WaitGroup types, most are intended for use by low-level library routines. Higher-level synchronization is better done via channels and communication.

More Related Contents:

  1. How to broadcast message using channel
  2. Goroutine does not execute if time.Sleep included
  3. Closing channel of unknown length
  4. No output from goroutine
  5. Is it safe to read a function pointer concurrently without a lock?
  6. How does a non initialized channel behave?
  7. Can I concurrently write different slice elements
  8. Is it OK to leave a channel open?
  9. Prevent the main() function from terminating before goroutines finish in Golang
  10. How safe are Golang maps for concurrent Read/Write operations?
  11. What are channels used for?
  12. Terminating function execution if a context is cancelled
  13. Multiple goroutines listening on one channel
  14. How to collect values from N goroutines executed in a specific order?
  15. When do you embed mutex in struct in Go?
  16. What is channel buffer size?
  17. anonymous struct and empty struct
  18. Do buffered channels maintain order?
  19. Iterate through the fields of a struct in Go
  20. How to set default values in Go structs
  21. Cross compile Go on OSX?
  22. What does an underscore in front of an import statement mean?
  23. How to cross compile from Windows to Linux?
  24. How to compile Go program consisting of multiple files?
  25. Reason for huge size of compiled executable of Go
  26. Why does golang compiler think the variable is declared but not used?
  27. Why can’t I append to a slice that’s the property of a struct in golang?
  28. Testing a gRPC service
  29. Force priority of go select statement
  30. Go exec.Command() – run command which contains pipe

Leave a Comment