【Rust日报】 2020-01-06 tomaka / redshirt:在0环中运行的WASM二进制的操作系统原型

2020年1月7日 373点热度 0人点赞 0条评论

tomaka / redshirt:在0环中运行的WASM二进制的操作系统原型

redshirt操作系统是建立某种形式与操作系统类似环境的实验,其中的可执行文件都在WASM并从类似IPFS的去中心化网络被加载。

此存储库中有两种二进制文件:

  • “托管内核”是执行WASM程序并使用主机操作系统的常规二进制文件。

  • 独立式内核是兼容multiboot2的内核,可以与GRUB2或任何兼容的引导程序一起加载。

对于托管内核:

# You need the WASI target installed:
rustup target add wasm32-wasi

# Then:
cargo run

对于独立内核:

rustup target add wasm32-wasi

# From the root directory of this repository (where the `arm-freestanding.json` file is located):
RUST_TARGET_PATH=`pwd` cargo +nightly build -Z build-std=core,alloc --target arm-freestanding --package redshirt-standalone-kernel

# You now have a `target/arm-freestanding/debug/redshirt-standalone-kernel`.
# It can be loaded directly by QEMU:
qemu-system-arm -M raspi2 -m 2048 -serial stdio -kernel ./target/arm-freestanding/debug/redshirt-standalone-kernel

支持x86_64的独立内核:

RUST_TARGET_PATH=`pwd` cargo +nightly build -Z build-std=core,alloc --target x86_64-multiboot2 --package redshirt-standalone-kernel

前往GitHub了解更多。

Rust官方发布:任务监视器扩展task_scope

task_scope crates是一个运行时用于向现有运行时添加对结构化并发的支持的扩展。

什么是结构化并发?

结构化并发是一种编程范例,它允许异步操作仅在特定范围内运行,以便它们像常规函数调用堆栈一样形成操作堆栈。当父操作等待所有子代完成时,结构化并发有助于并发程序的本地引导。

可撤回点

task_scope要求任务定期通过一个可撤回点才能有效地工作。

use tokio::io::*;

let mut read = repeat(42); // very fast input
let mut write = sink(); // very fast output

copy(&mut read, &mut write).await.unwrap();

实际上,该程序回进入无限循环,因为read并且write永远不会终止。更糟糕的是,程序无法从外部关闭,因为I / O操作始终会成功,并且copy功能会尝试尽可能继续。因此,产生的任务必须协同检查取消或定期循环执行以保持结构良好。

task_scope提供便利功能cancelable以自动处理取消。它封装给特定的Future/ AsyncRead/ AsyncWrite并在进行内部计算之前检查取消。

use futures::pin_mut;
use tokio::io::*;

use task_scope::cancelable;

let read = cancelable(repeat(42)); // very fast, but cancelable input
pin_mut!(read); // needed for Unpin bound of copy
let mut write = sink(); // very fast output

// this will terminate with an error on cancellation
copy(&mut read, &mut write).await.unwrap();

如果这个取消逻辑比较复杂,则可以使用Cancellation手动轮询以检查取消信号。

详细信息前往Rust官方博客浏览

新版本sysinfo(OSX性能改进)

sysinfo用于创建系统信息(支持Linux,Windows,OSX,Android和raspberry pi)。

此版本是性能改进系列的最后一个版本,专注于OSX。

关于sysinfo前往GitHub了解更多。

前往https://blog.guillaume-gomez.fr/articles/2020-01-06+New+sysinfo+release+(OSX+performance+improvements) 查看更新日志。

restq-一种适用于rest api的紧凑型查询语言

/person?age=lt.42&(student=eq.true|gender=eq.'M')&group_by=sum(age),grade,gender&having=min(age)=gt.42&order_by=age.desc,height.asc&page=20&page_size=100

大致转换成sql即为:

SELECT * FROM person
WHERE age < 42
AND (student = true OR gender = 'M')
GROUP BY sum(age), grade, gender
HAVING min(age) > 42
ORDER BY age DESC, height ASC
LIMIT 100 OFFSET 1900 ROWS

RestQ的语句/语法

create  = table, column_def_list, "\n", csv

select = table, [join_table], column_list, [ "?", condition]

delete = table, [ "?", condition ]

update = table, set_expr_list, [ "?", condition]

drop = "-", table

alter = table, { drop_column | add_column | alter_column }

drop_column = "-", column

add_column = "+", column_def

alter_column = column, "=", column_def


column_def_list = "{", { column_def }, "}"
| "(", { column_def }, ")"

column_def = [ { column_attributes } ], column, [ "(" foreign ")" ], ":", data_type, [ "(" default_value ")" ]

column_attributes = primary | index | unique

primary = "*"

index = "@"

unique = "&"

data_type = "bool" | "s8" | "s16" | "s32" | "s64" | "u8" | "u16", etc

default_value = value

value = number | string | bool ,..etc

column = string, ".", string
| string

table = string

foreign = table

insert = table, column_list ,"\n", csv

column_list = "{", { column }, "}"
| "(", { column }, ")"


join_table = table, join_type, table

join_type = right_join | left_join | inner_join | full_join

right_join = "->" | "-^"

left_join = "<-" | "^-"

inner_join = "-><-" | "-^^-"

full_join = "<-->" | "^--^"

condition = expr

expr = column | value | binary_operation

binary_operation = expr, operator, expr

operator = "and" | "or" | "eq" | "gte" | "lte" ,..etc

更多详细功能与用法前往GitHub查看。


From 日报小组 @Lance

41030【Rust日报】 2020-01-06 tomaka / redshirt:在0环中运行的WASM二进制的操作系统原型

这个人很懒,什么都没留下

文章评论