~/Memory Management in Go Insights and Tips

Dec 22, 2019


Memory management in Go combines garbage collection, stack management, and tools for manual allocation and profiling. Proper management ensures performance and reliability in high-concurrency systems.

Go uses a concurrent garbage collector which automatically reclaims unused memory. Memory is allocated on either the stack or the heap using functions like new or make.

Stack memory is managed automatically for goroutines. The runtime grows and shrinks stacks as needed to minimize overhead. Heap allocation is controlled by the allocator.

Use sync.Pool to cache temporary objects and reduce pressure on the garbage collector:

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var bufferPool = sync.Pool{
    New: func() interface{} {
        return make([]byte, 1024)
    },
}

buf := bufferPool.Get().([]byte)
// use buf
bufferPool.Put(buf)

Profiling memory usage is possible with pprof and runtime/debug. Run with GODEBUG flags to inspect GC performance:

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GODEBUG=gctrace=1 go run main.go

Release memory promptly by letting references go out of scope. Setting objects to nil before they exit scope can help, as in:

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data := make([]byte, 1024*1024)
// process data
data = nil // data eligible for GC

Tuning the GC is possible with runtime.GOMAXPROCS and GCPercent settings. Lowering the GC percentage can reduce pause times, but may increase memory usage.

Avoid accidental memory leaks by watching for closures capturing objects, global variables, and long-lived channels. Use finalizers carefully and only when needed.

For large objects or manual release, use unsafe and syscall packages, but this is not recommended for typical applications since it bypasses Go safety.

Review code with go tool pprof for live systems and optimize hot paths and data layout for locality.

Understand memory alignment and padding for custom structs to reduce wasted space.

Learn more about Go internals in Go Memory Management and study the runtime source code for advanced optimization.

Further resources:

Tags: [golang] [memory] [programming]