runtime: clarify the behavior of Handle::block_on
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This commit adds documentation to the `Handle::block_on`` method to clarify its behavior when called from within a Tokio runtime's asynchronous context, and how it can be used along with `block_in_place` to re-enter the runtime. closes tokio-rs#7387
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tokio/src/runtime/handle.rs
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| /// # } | ||
| /// ``` | ||
| /// | ||
| /// `Handle::block_on` may use [`task::block_in_place`] to re-enter the async context of a multi-thread scheduler runtime: |
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| /// `Handle::block_on` may use [`task::block_in_place`] to re-enter the async context of a multi-thread scheduler runtime: | |
| /// `Handle::block_on` may be combined with [`task::block_in_place`] to re-enter the async context of a multi-thread scheduler runtime: |
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Oh, also reflow the text with a line break at 80 or 100 chars (whatever the rest of the file is using).
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Handle::block_on behavior with block_in_placeHandle::block_on behavior with block_in_place
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Handle::block_on behavior with block_in_placeHandle::block_on
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Motivation
See: #7387
Solution
This commit adds documentation to the
Handle::block_onmethod to clarify its behavior when called from within a Tokio runtime's asynchronous context, and how it can be used along withblock_in_placeto re-enter the runtime.Note: the issue proposes updating the Cannot start a runtime from within a runtime error message. I chose not to change it here, since a more detailed explanation would make the message too verbose. I'm happy to adjust it if maintainers think it's worth including in this PR.
closes: #7387