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Comprehensive Rust v2 (#1073) I've taken some work by @fw-immunant and others on the new organization of the course and condensed it into a form amenable to a text editor and some computational analysis. You can see the inputs in `course.py` but the interesting bits are the output: `outline.md` and `slides.md`. The idea is to break the course into more, smaller segments with exercises at the ends and breaks in between. So `outline.md` lists the segments, their duration, and sums those durations up per-day. It shows we're about an hour too long right now! There are more details of the segments in `slides.md`, or you can see mostly the same stuff in `course.py`. This now contains all of the content from the v1 course, ensuring both that we've covered everything and that we'll have somewhere to redirect every page. Fixes #1082. Fixes #1465. --------- Co-authored-by: Nicole LeGare <dlegare.1001@gmail.com> Co-authored-by: Martin Geisler <mgeisler@google.com>
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---
minutes: 10
---
# Approaches to Memory Management
Traditionally, languages have fallen into two broad categories:
Format all Markdown files with `dprint` (#1157) This is the result of running `dprint fmt` after removing `src/` from the list of excluded directories. This also reformats the Rust code: we might want to tweak this a bit in the future since some of the changes removes the hand-formatting. Of course, this formatting can be seen as a mis-feature, so maybe this is good overall. Thanks to mdbook-i18n-helpers 0.2, the POT file is nearly unchanged after this, meaning that all existing translations remain valid! A few messages were changed because of stray whitespace characters: msgid "" "Slices always borrow from another object. In this example, `a` has to remain " -"'alive' (in scope) for at least as long as our slice. " +"'alive' (in scope) for at least as long as our slice." msgstr "" The formatting is enforced in CI and we will have to see how annoying this is in practice for the many contributors. If it becomes annoying, we should look into fixing dprint/check#11 so that `dprint` can annotate the lines that need fixing directly, then I think we can consider more strict formatting checks. I added more customization to `rustfmt.toml`. This is to better emulate the dense style used in the course: - `max_width = 85` allows lines to take up the full width available in our code blocks (when taking margins and the line numbers into account). - `wrap_comments = true` ensures that we don't show very long comments in the code examples. I edited some comments to shorten them and avoid unnecessary line breaks — please trim other unnecessarily long comments when you see them! Remember we're writing code for slides :smile: - `use_small_heuristics = "Max"` allows for things like struct literals and if-statements to take up the full line width configured above. The formatting settings apply to all our Rust code right now — I think we could improve this with https://github.com/dprint/dprint/issues/711 which lets us add per-directory `dprint` configuration files. However, the `inherit: true` setting is not yet implemented (as far as I can tell), so a nested configuration file will have to copy most or all of the top-level file.
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- Full control via manual memory management: C, C++, Pascal, ...
- Programmer decides when to allocate or free heap memory.
- Programmer must determine whether a pointer still points to valid memory.
- Studies show, programmers make mistakes.
- Full safety via automatic memory management at runtime: Java, Python, Go,
Haskell, ...
- A runtime system ensures that memory is not freed until it can no longer be
referenced.
Update approaches.md (#2317) I might be missing something, but RAII is generally associated with programming languages with manual memory management (prominently with C++, where it originated), so I think it is not very appropriate to have it mentioned here.
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- Typically implemented with reference counting or garbage collection.
Comprehensive Rust v2 (#1073) I've taken some work by @fw-immunant and others on the new organization of the course and condensed it into a form amenable to a text editor and some computational analysis. You can see the inputs in `course.py` but the interesting bits are the output: `outline.md` and `slides.md`. The idea is to break the course into more, smaller segments with exercises at the ends and breaks in between. So `outline.md` lists the segments, their duration, and sums those durations up per-day. It shows we're about an hour too long right now! There are more details of the segments in `slides.md`, or you can see mostly the same stuff in `course.py`. This now contains all of the content from the v1 course, ensuring both that we've covered everything and that we'll have somewhere to redirect every page. Fixes #1082. Fixes #1465. --------- Co-authored-by: Nicole LeGare <dlegare.1001@gmail.com> Co-authored-by: Martin Geisler <mgeisler@google.com>
2023-11-29 10:39:24 -05:00
Rust offers a new mix:
Format all Markdown files with `dprint` (#1157) This is the result of running `dprint fmt` after removing `src/` from the list of excluded directories. This also reformats the Rust code: we might want to tweak this a bit in the future since some of the changes removes the hand-formatting. Of course, this formatting can be seen as a mis-feature, so maybe this is good overall. Thanks to mdbook-i18n-helpers 0.2, the POT file is nearly unchanged after this, meaning that all existing translations remain valid! A few messages were changed because of stray whitespace characters: msgid "" "Slices always borrow from another object. In this example, `a` has to remain " -"'alive' (in scope) for at least as long as our slice. " +"'alive' (in scope) for at least as long as our slice." msgstr "" The formatting is enforced in CI and we will have to see how annoying this is in practice for the many contributors. If it becomes annoying, we should look into fixing dprint/check#11 so that `dprint` can annotate the lines that need fixing directly, then I think we can consider more strict formatting checks. I added more customization to `rustfmt.toml`. This is to better emulate the dense style used in the course: - `max_width = 85` allows lines to take up the full width available in our code blocks (when taking margins and the line numbers into account). - `wrap_comments = true` ensures that we don't show very long comments in the code examples. I edited some comments to shorten them and avoid unnecessary line breaks — please trim other unnecessarily long comments when you see them! Remember we're writing code for slides :smile: - `use_small_heuristics = "Max"` allows for things like struct literals and if-statements to take up the full line width configured above. The formatting settings apply to all our Rust code right now — I think we could improve this with https://github.com/dprint/dprint/issues/711 which lets us add per-directory `dprint` configuration files. However, the `inherit: true` setting is not yet implemented (as far as I can tell), so a nested configuration file will have to copy most or all of the top-level file.
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> Full control _and_ safety via compile time enforcement of correct memory
Comprehensive Rust v2 (#1073) I've taken some work by @fw-immunant and others on the new organization of the course and condensed it into a form amenable to a text editor and some computational analysis. You can see the inputs in `course.py` but the interesting bits are the output: `outline.md` and `slides.md`. The idea is to break the course into more, smaller segments with exercises at the ends and breaks in between. So `outline.md` lists the segments, their duration, and sums those durations up per-day. It shows we're about an hour too long right now! There are more details of the segments in `slides.md`, or you can see mostly the same stuff in `course.py`. This now contains all of the content from the v1 course, ensuring both that we've covered everything and that we'll have somewhere to redirect every page. Fixes #1082. Fixes #1465. --------- Co-authored-by: Nicole LeGare <dlegare.1001@gmail.com> Co-authored-by: Martin Geisler <mgeisler@google.com>
2023-11-29 10:39:24 -05:00
> management.
It does this with an explicit ownership concept.
<details>
This slide is intended to help students coming from other languages to put Rust
in context.
Format all Markdown files with `dprint` (#1157) This is the result of running `dprint fmt` after removing `src/` from the list of excluded directories. This also reformats the Rust code: we might want to tweak this a bit in the future since some of the changes removes the hand-formatting. Of course, this formatting can be seen as a mis-feature, so maybe this is good overall. Thanks to mdbook-i18n-helpers 0.2, the POT file is nearly unchanged after this, meaning that all existing translations remain valid! A few messages were changed because of stray whitespace characters: msgid "" "Slices always borrow from another object. In this example, `a` has to remain " -"'alive' (in scope) for at least as long as our slice. " +"'alive' (in scope) for at least as long as our slice." msgstr "" The formatting is enforced in CI and we will have to see how annoying this is in practice for the many contributors. If it becomes annoying, we should look into fixing dprint/check#11 so that `dprint` can annotate the lines that need fixing directly, then I think we can consider more strict formatting checks. I added more customization to `rustfmt.toml`. This is to better emulate the dense style used in the course: - `max_width = 85` allows lines to take up the full width available in our code blocks (when taking margins and the line numbers into account). - `wrap_comments = true` ensures that we don't show very long comments in the code examples. I edited some comments to shorten them and avoid unnecessary line breaks — please trim other unnecessarily long comments when you see them! Remember we're writing code for slides :smile: - `use_small_heuristics = "Max"` allows for things like struct literals and if-statements to take up the full line width configured above. The formatting settings apply to all our Rust code right now — I think we could improve this with https://github.com/dprint/dprint/issues/711 which lets us add per-directory `dprint` configuration files. However, the `inherit: true` setting is not yet implemented (as far as I can tell), so a nested configuration file will have to copy most or all of the top-level file.
2023-12-31 00:15:07 +01:00
- C must manage heap manually with `malloc` and `free`. Common errors include
forgetting to call `free`, calling it multiple times for the same pointer, or
dereferencing a pointer after the memory it points to has been freed.
Comprehensive Rust v2 (#1073) I've taken some work by @fw-immunant and others on the new organization of the course and condensed it into a form amenable to a text editor and some computational analysis. You can see the inputs in `course.py` but the interesting bits are the output: `outline.md` and `slides.md`. The idea is to break the course into more, smaller segments with exercises at the ends and breaks in between. So `outline.md` lists the segments, their duration, and sums those durations up per-day. It shows we're about an hour too long right now! There are more details of the segments in `slides.md`, or you can see mostly the same stuff in `course.py`. This now contains all of the content from the v1 course, ensuring both that we've covered everything and that we'll have somewhere to redirect every page. Fixes #1082. Fixes #1465. --------- Co-authored-by: Nicole LeGare <dlegare.1001@gmail.com> Co-authored-by: Martin Geisler <mgeisler@google.com>
2023-11-29 10:39:24 -05:00
Format all Markdown files with `dprint` (#1157) This is the result of running `dprint fmt` after removing `src/` from the list of excluded directories. This also reformats the Rust code: we might want to tweak this a bit in the future since some of the changes removes the hand-formatting. Of course, this formatting can be seen as a mis-feature, so maybe this is good overall. Thanks to mdbook-i18n-helpers 0.2, the POT file is nearly unchanged after this, meaning that all existing translations remain valid! A few messages were changed because of stray whitespace characters: msgid "" "Slices always borrow from another object. In this example, `a` has to remain " -"'alive' (in scope) for at least as long as our slice. " +"'alive' (in scope) for at least as long as our slice." msgstr "" The formatting is enforced in CI and we will have to see how annoying this is in practice for the many contributors. If it becomes annoying, we should look into fixing dprint/check#11 so that `dprint` can annotate the lines that need fixing directly, then I think we can consider more strict formatting checks. I added more customization to `rustfmt.toml`. This is to better emulate the dense style used in the course: - `max_width = 85` allows lines to take up the full width available in our code blocks (when taking margins and the line numbers into account). - `wrap_comments = true` ensures that we don't show very long comments in the code examples. I edited some comments to shorten them and avoid unnecessary line breaks — please trim other unnecessarily long comments when you see them! Remember we're writing code for slides :smile: - `use_small_heuristics = "Max"` allows for things like struct literals and if-statements to take up the full line width configured above. The formatting settings apply to all our Rust code right now — I think we could improve this with https://github.com/dprint/dprint/issues/711 which lets us add per-directory `dprint` configuration files. However, the `inherit: true` setting is not yet implemented (as far as I can tell), so a nested configuration file will have to copy most or all of the top-level file.
2023-12-31 00:15:07 +01:00
- C++ has tools like smart pointers (`unique_ptr`, `shared_ptr`) that take
advantage of language guarantees about calling destructors to ensure memory is
freed when a function returns. It is still quite easy to mis-use these tools
and create similar bugs to C.
Comprehensive Rust v2 (#1073) I've taken some work by @fw-immunant and others on the new organization of the course and condensed it into a form amenable to a text editor and some computational analysis. You can see the inputs in `course.py` but the interesting bits are the output: `outline.md` and `slides.md`. The idea is to break the course into more, smaller segments with exercises at the ends and breaks in between. So `outline.md` lists the segments, their duration, and sums those durations up per-day. It shows we're about an hour too long right now! There are more details of the segments in `slides.md`, or you can see mostly the same stuff in `course.py`. This now contains all of the content from the v1 course, ensuring both that we've covered everything and that we'll have somewhere to redirect every page. Fixes #1082. Fixes #1465. --------- Co-authored-by: Nicole LeGare <dlegare.1001@gmail.com> Co-authored-by: Martin Geisler <mgeisler@google.com>
2023-11-29 10:39:24 -05:00
Format all Markdown files with `dprint` (#1157) This is the result of running `dprint fmt` after removing `src/` from the list of excluded directories. This also reformats the Rust code: we might want to tweak this a bit in the future since some of the changes removes the hand-formatting. Of course, this formatting can be seen as a mis-feature, so maybe this is good overall. Thanks to mdbook-i18n-helpers 0.2, the POT file is nearly unchanged after this, meaning that all existing translations remain valid! A few messages were changed because of stray whitespace characters: msgid "" "Slices always borrow from another object. In this example, `a` has to remain " -"'alive' (in scope) for at least as long as our slice. " +"'alive' (in scope) for at least as long as our slice." msgstr "" The formatting is enforced in CI and we will have to see how annoying this is in practice for the many contributors. If it becomes annoying, we should look into fixing dprint/check#11 so that `dprint` can annotate the lines that need fixing directly, then I think we can consider more strict formatting checks. I added more customization to `rustfmt.toml`. This is to better emulate the dense style used in the course: - `max_width = 85` allows lines to take up the full width available in our code blocks (when taking margins and the line numbers into account). - `wrap_comments = true` ensures that we don't show very long comments in the code examples. I edited some comments to shorten them and avoid unnecessary line breaks — please trim other unnecessarily long comments when you see them! Remember we're writing code for slides :smile: - `use_small_heuristics = "Max"` allows for things like struct literals and if-statements to take up the full line width configured above. The formatting settings apply to all our Rust code right now — I think we could improve this with https://github.com/dprint/dprint/issues/711 which lets us add per-directory `dprint` configuration files. However, the `inherit: true` setting is not yet implemented (as far as I can tell), so a nested configuration file will have to copy most or all of the top-level file.
2023-12-31 00:15:07 +01:00
- Java, Go, and Python rely on the garbage collector to identify memory that is
no longer reachable and discard it. This guarantees that any pointer can be
dereferenced, eliminating use-after-free and other classes of bugs. But, GC
has a runtime cost and is difficult to tune properly.
Comprehensive Rust v2 (#1073) I've taken some work by @fw-immunant and others on the new organization of the course and condensed it into a form amenable to a text editor and some computational analysis. You can see the inputs in `course.py` but the interesting bits are the output: `outline.md` and `slides.md`. The idea is to break the course into more, smaller segments with exercises at the ends and breaks in between. So `outline.md` lists the segments, their duration, and sums those durations up per-day. It shows we're about an hour too long right now! There are more details of the segments in `slides.md`, or you can see mostly the same stuff in `course.py`. This now contains all of the content from the v1 course, ensuring both that we've covered everything and that we'll have somewhere to redirect every page. Fixes #1082. Fixes #1465. --------- Co-authored-by: Nicole LeGare <dlegare.1001@gmail.com> Co-authored-by: Martin Geisler <mgeisler@google.com>
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Rust's ownership and borrowing model can, in many cases, get the performance of
C, with alloc and free operations precisely where they are required -- zero
cost. It also provides tools similar to C++'s smart pointers. When required,
other options such as reference counting are available, and there are even
Remove the phrase "third-party" (#2512) "Third-party" is a Googleism that doesn't make much sense otherwise. Most references to crates just say "crate", implying that they are open-source packages available on https://crates.io, so this updates a few additional locations to do the same.
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crates available to support runtime garbage collection (not covered in this
class).
Comprehensive Rust v2 (#1073) I've taken some work by @fw-immunant and others on the new organization of the course and condensed it into a form amenable to a text editor and some computational analysis. You can see the inputs in `course.py` but the interesting bits are the output: `outline.md` and `slides.md`. The idea is to break the course into more, smaller segments with exercises at the ends and breaks in between. So `outline.md` lists the segments, their duration, and sums those durations up per-day. It shows we're about an hour too long right now! There are more details of the segments in `slides.md`, or you can see mostly the same stuff in `course.py`. This now contains all of the content from the v1 course, ensuring both that we've covered everything and that we'll have somewhere to redirect every page. Fixes #1082. Fixes #1465. --------- Co-authored-by: Nicole LeGare <dlegare.1001@gmail.com> Co-authored-by: Martin Geisler <mgeisler@google.com>
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</details>
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