go-mutexasserts

A small library that allows to check if Go mutexes are locked. It can be used to verify invariants/assumptions about [un]locking mutexes within certain functions.

Also, read the "How to check if a mutex is locked in Go" blog post on that topic.

Installation

Use go get github.com/trailofbits/go-mutexasserts to install this into your project and you can then import it with github.com/trailofbits/go-mutexasserts and use the mutexasserts package.

Then, add assertions to your program and compile it with a debug tag (e.g., go build -tags debug) to enable mutex assertions.

API

Assertion functions

The Assert* functions print stack trace and exit program when they are called with an object that won't pass assertion. We decided to use exit(1) instead of panic() because panics are sometimes (mis?)used for exception handling and we want to generate a fatal error.

The mutexasserts.Assert* functions will only check assertions if program is build with the debug tag (so e.g. go build -tags debug). Otherwise, those functions will be empty and optimized out by the compiler.

• mutexasserts.AssertMutexLocked(m *sync.Mutex)
• mutexasserts.AssertRWMutexLocked(m *sync.RWMutex)
• mutexasserts.AssertRWMutexRLocked(m *sync.RWMutex)

Getting mutex locked state functions

• mutexasserts.MutexLocked(m *sync.Mutex) bool
• mutexasserts.RWMutexLocked(rw *sync.RWMutex) bool
• mutexasserts.RWMutexRLocked(rw *sync.RWMutex) bool