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26 lines
1.2 KiB
Markdown
26 lines
1.2 KiB
Markdown
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# Session leader
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A session leader is a linux process, which is forked from [init](init.md) after receiving a `LxInitMessageCreateSession` message (see `src/linux/init.cpp`)
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## Creating linux processes
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Session leaders are used to create linux processes on behalf of the user. Each linux session leader is associated to a Windows console.
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To create a user process, [wslservice.exe](wslservice.exe.md) sends a `LxInitMessageCreateProcess` message (WSL1) or a `LxInitMessageCreateProcessUtilityVm` message (WSL2), which contains details about the process to create such as:
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- Command line
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- Current directory
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- Environment variables
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- User name
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### Creating a WSL1 process
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When running in a WSL1 distribution, the session leader forks(), and uses the child process to `exec()` into the user linux process. Before calling `exec()`, child configures various settings such as:
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- The user and group id
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- The current directory
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- The standard file descriptors (stdin, stdout, stderr)
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## Creating a WSL2 process
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When running in a WSL2 distribution, the session leaders forks() to create a [relay](relay.md) process, which is responsible for creating the user process and relaying its output back to [wsl.exe](wsl.exe.md)
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