golang execution process

Golang is a modern high-level programming language, developed by Google, with high operating efficiency and two major characteristics: functional programming and object-oriented programming. The execution process of Golang may be slightly different compared to other programming languages. This article will explain to you the execution process of Golang and help you better understand the operating mechanism of Golang.

1. Overview of Golang compilation and execution process

The execution process of Golang mainly includes two stages: compilation and execution. The compilation stage is divided into front-end compilation and back-end compilation. Front-end compilation converts source code into AST (Abstract Syntax Tree) and performs lexical analysis and syntax analysis; back-end compilation converts AST into machine code. The execution phase directly runs the machine code.

2. Golang compilation process

Golang’s front-end compilation process mainly includes the following steps:

1. lexical analysis

lexical analysis The analyzer converts the user code into a token sequence, that is, splits the code into individual units according to keywords, identifiers, operators, etc., to facilitate subsequent syntax analysis.

2. Grammar analysis

The grammar analyzer converts the token sequence into AST, that is, it parses the code according to the grammar rules and builds a grammar tree.

3. Semantic analysis

The semantic analyzer will scan the AST and check whether its syntax is legal, such as whether variables are defined, etc.

4. Type Check

The type checker will check the data type of the code, including type compatibility, type conversion, etc.

The above four steps constitute the main process of Golang front-end compilation.

Back-end compilation mainly converts AST into machine code. Golang's compiler uses SSA (Static Single Assignment) form for code generation, dividing the code into multiple blocks to facilitate subsequent optimization and parallel running. Golang will perform some pre-compilation optimizations during compilation, such as inlining functions, eliminating dead code, etc.

3. Golang execution process

The execution process of Golang is mainly to run the compiled machine code directly. The program entry point of Golang is the main function, and all programs start executing from the main function. Golang also performs some initialization operations when the program starts, such as setting the number of CPU cores, virtual memory initialization, etc. Golang's concurrency model is very good. It can easily implement goroutine and channel, making Golang's concurrent programming very simple and easy to use.

During program execution, Golang uses the garbage collection mechanism (GC) to automatically manage memory. Golang's garbage collector uses the mark-and-sweep algorithm to efficiently recycle memory. In addition, Golang also supports using pointers for memory operations, and you need to pay attention to the use and release of memory.

Finally, when the program execution ends, Golang will recycle and clean up resources, such as closing files, releasing memory, etc.

4. Summary

Modern programming languages ​​have their own execution processes, and Golang is no exception. Golang's compilation and execution process is relatively simple and has high execution efficiency. Golang's concurrency model and garbage collection mechanism are excellent, allowing Golang to easily implement high concurrency and automatic memory management. Mastering the Golang execution process is very important to deeply understand the underlying mechanism of Golang.

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