Advance Go Coding — defer

Mastering Resource Management and Error Handling with defer in Go

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A “defer” statement invokes a function whose execution is deferred to the moment the surrounding function returns — from Go spec

As one of the most distinctive features of Go, the defer statement provides a concise and efficient solution for resource cleanup, error recovery, and debugging. The defer statement is used in line with the Go specification to “call a function whose execution is deferred until the surrounding functions return”, acting as the “gatekeeper” of the Go program, like the finally in Java, to ensure that operations like file closing, lock release, and temporary resource cleanup are performed even if errors occur. In this article, we will explore in depth the underlying implementation, usage scenarios, and best practices of defer to continue on our journey of advanced Go coding.

Implementation

Generally, defer statement calls the functions in order according to LIFO when the functions are about to return, but the relevant parameters are determined when they are created.

Each defer creates a stack to store the executed functions and parameters in the compilation phase, and the deferproc function in the runtime for each defer is parsed into the corresponding _defer…