## What are the differences between Syscall and RawSyscall in Go, and when should each be used?-Golang-php.cn

Home

Backend Development

Golang

## What are the differences between Syscall and RawSyscall in Go, and when should each be used?

Mary-Kate Olsen

Oct 25, 2024 pm 04:16 PM

## What are the differences between Syscall and RawSyscall in Go, and when should each be used?

Details of Syscall.RawSyscall() and Syscall.Syscall() in Go

Syscall.RawSyscall() and Syscall.Syscall() are functions in the Go syscall package that provide direct access to the operating system's system calls. They allow developers to interact with the operating system at a low level, enabling the creation of custom system calls or interfacing with operating system-specific features.

Parameters and Return Values

Syscall.RawSyscall() takes the following parameters:

trap: The system call number.
a1, a2, a3: Additional arguments passed to the system call.
r1, r2: Return values from the system call.

Syscall.Syscall() takes similar parameters but also includes two additional parameters:

err: An error code returned by the system call.

Assembly Code in Syscall.RawSyscall()

The assembly code for Syscall.RawSyscall() on Darwin/amd64 (located in syscall/asm_darwin_amd64.s) can be summarized as follows:

It creates a system call frame by pushing arguments onto the stack (lines 61-65).
It adds a constant to the AX register, which is the system call number (line 69).
It performs a system call (line 70).
Based on the result of the system call, the program jumps to either line 71 or 76 (label ok1).

Meaning of `ok1:

Label ok1 (line 76) is used to handle successful system call execution. If the system call succeeds, the assembly code jumps to this label and returns the results in registers AX (r1) and DX (r2). Otherwise, it returns -1 in register AX (r1) and 0 in register DX (r2) (lines 72-74).

Zsyscalls

The package syscall/zsyscall_darwin_amd64.go contains "zipped" system calls that do not perform arguments validation. They are typically used in netpoll functions to improve performance.

Syscall vs. RawSyscall

The main difference between Syscall and RawSyscall is that Syscall notifies the Go runtime system that a blocking system call is about to be executed (lines 14, 28, and 34 of syscall.go). This allows the runtime to yield the CPU to other goroutines while the system call is executing. In contrast, RawSyscall does not notify the runtime, meaning that the program will block until the system call completes.

Usage

Syscall and RawSyscall can be used to implement custom system calls or interact with operating system-specific features that are not supported by the standard Go syscall package. For example, you might use Syscall to implement a new file system or access a hardware device directly.

To use Syscall or RawSyscall, you need to first determine the system call number and arguments. You can find this information in the documentation for the specific operating system and architecture you are targeting. Once you have this information, you can use the syscall package to create a system call.

The above is the detailed content of ## What are the differences between Syscall and RawSyscall in Go, and when should each be used?. For more information, please follow other related articles on the PHP Chinese website!

Statement

The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Learn Go String Manipulation: Working with the 'strings' PackageMay 09, 2025 am 12:07 AM

Go's "strings" package provides rich features to make string operation efficient and simple. 1) Use strings.Contains() to check substrings. 2) strings.Split() can be used to parse data, but it should be used with caution to avoid performance problems. 3) strings.Join() is suitable for formatting strings, but for small datasets, looping = is more efficient. 4) For large strings, it is more efficient to build strings using strings.Builder.

Go: String Manipulation with the Standard 'strings' PackageMay 09, 2025 am 12:07 AM

Go uses the "strings" package for string operations. 1) Use strings.Join function to splice strings. 2) Use the strings.Contains function to find substrings. 3) Use the strings.Replace function to replace strings. These functions are efficient and easy to use and are suitable for various string processing tasks.

Mastering Byte Slice Manipulation with Go's 'bytes' Package: A Practical GuideMay 09, 2025 am 12:02 AM

ThebytespackageinGoisessentialforefficientbyteslicemanipulation,offeringfunctionslikeContains,Index,andReplaceforsearchingandmodifyingbinarydata.Itenhancesperformanceandcodereadability,makingitavitaltoolforhandlingbinarydata,networkprotocols,andfileI

Learn Go Binary Encoding/Decoding: Working with the 'encoding/binary' PackageMay 08, 2025 am 12:13 AM

Go uses the "encoding/binary" package for binary encoding and decoding. 1) This package provides binary.Write and binary.Read functions for writing and reading data. 2) Pay attention to choosing the correct endian (such as BigEndian or LittleEndian). 3) Data alignment and error handling are also key to ensure the correctness and performance of the data.

Go: Byte Slice Manipulation with the Standard 'bytes' PackageMay 08, 2025 am 12:09 AM

The"bytes"packageinGooffersefficientfunctionsformanipulatingbyteslices.1)Usebytes.Joinforconcatenatingslices,2)bytes.Bufferforincrementalwriting,3)bytes.Indexorbytes.IndexByteforsearching,4)bytes.Readerforreadinginchunks,and5)bytes.SplitNor

Go encoding/binary package: Optimizing performance for binary operationsMay 08, 2025 am 12:06 AM

Theencoding/binarypackageinGoiseffectiveforoptimizingbinaryoperationsduetoitssupportforendiannessandefficientdatahandling.Toenhanceperformance:1)Usebinary.NativeEndianfornativeendiannesstoavoidbyteswapping.2)BatchReadandWriteoperationstoreduceI/Oover

Go bytes package: short reference and tipsMay 08, 2025 am 12:05 AM

Go's bytes package is mainly used to efficiently process byte slices. 1) Using bytes.Buffer can efficiently perform string splicing to avoid unnecessary memory allocation. 2) The bytes.Equal function is used to quickly compare byte slices. 3) The bytes.Index, bytes.Split and bytes.ReplaceAll functions can be used to search and manipulate byte slices, but performance issues need to be paid attention to.

Go bytes package: practical examples for byte slice manipulationMay 08, 2025 am 12:01 AM

The byte package provides a variety of functions to efficiently process byte slices. 1) Use bytes.Contains to check the byte sequence. 2) Use bytes.Split to split byte slices. 3) Replace the byte sequence bytes.Replace. 4) Use bytes.Join to connect multiple byte slices. 5) Use bytes.Buffer to build data. 6) Combined bytes.Map for error processing and data verification.

See all articles