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| author | Kartik Agaram <vc@akkartik.com> | 2020-07-18 15:56:32 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2020-07-18 15:56:32 -0700 |
| commit | 02b7f9bd89fcae62c118772b1eb907b6c93055f0 (patch) | |
| tree | a62bcbd2e4ed9e3864d13025ec4309fc418d3fc2 /vocabulary.md | |
| parent | 28b25a489338f31f291832e8dc94174619387e95 (diff) | |
| download | mu-02b7f9bd89fcae62c118772b1eb907b6c93055f0.tar.gz | |
6658
Diffstat (limited to 'vocabulary.md')
| -rw-r--r-- | vocabulary.md | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/vocabulary.md b/vocabulary.md index 426ed590..ce3eab23 100644 --- a/vocabulary.md +++ b/vocabulary.md @@ -5,9 +5,9 @@ - Kernel strings: null-terminated regions of memory. Unsafe and to be avoided, but needed for interacting with the kernel. -- Arrays: length-prefixed regions of memory containing multiple elements of a +- Arrays: size-prefixed regions of memory containing multiple elements of a single type. Contents are preceded by 4 bytes (32 bits) containing the - `length` of the array in bytes. + `size` of the array in bytes. - Slices: a pair of 32-bit addresses denoting a [half-open](https://en.wikipedia.org/wiki/Interval_(mathematics)) \[`start`, `end`) interval to live memory with a consistent lifetime. @@ -19,10 +19,10 @@ - offset 0: write index - offset 4: read index - - offset 8: length of array (in bytes) + - offset 8: size of array (in bytes) - offset 12: start of array data - Invariant: 0 <= `read` <= `write` <= `length` + Invariant: 0 <= `read` <= `write` <= `size` - File descriptors (fd): Low-level 32-bit integers that the kernel uses to track files opened by the program. @@ -51,7 +51,7 @@ But those are big goals. Here are the syscalls I have so far: 1. SubX can handle 'fake' file descriptors in tests. - 1. `write()` accepts buffer and its length in separate arguments, which + 1. `write()` accepts buffer and its size in separate arguments, which requires callers to manage the two separately and so can be error-prone. SubX's wrapper keeps the two together to increase the chances that we never accidentally go out of array bounds. @@ -178,7 +178,7 @@ allocated memory for it.)_ - `new-stream`: allocates space for a stream of `n` elements, each occupying `b` bytes. - Will abort the entire program if `n*b` requires more than 32 bits. -- `clear-stream`: resets everything in the stream to `0` (except its `length`). +- `clear-stream`: resets everything in the stream to `0` (except its `size`). - `rewind-stream`: resets the read index of the stream to `0` without modifying its contents. |