several improvements, see #2 for more details
This commit is contained in:
Carl Fredrik Samson
@@ -1,5 +1,5 @@
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<!DOCTYPE HTML>
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<html lang="en" class="sidebar-visible no-js light">
|
||||
<html lang="en" class="sidebar-visible no-js">
|
||||
<head>
|
||||
<!-- Book generated using mdBook -->
|
||||
<meta charset="UTF-8">
|
||||
@@ -32,11 +32,11 @@
|
||||
|
||||
|
||||
</head>
|
||||
<body>
|
||||
<body class="light">
|
||||
<!-- Provide site root to javascript -->
|
||||
<script type="text/javascript">
|
||||
var path_to_root = "";
|
||||
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "light" : "light";
|
||||
var default_theme = "light";
|
||||
</script>
|
||||
|
||||
<!-- Work around some values being stored in localStorage wrapped in quotes -->
|
||||
@@ -60,11 +60,8 @@
|
||||
var theme;
|
||||
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
|
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if (theme === null || theme === undefined) { theme = default_theme; }
|
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var html = document.querySelector('html');
|
||||
html.classList.remove('no-js')
|
||||
html.classList.remove('light')
|
||||
html.classList.add(theme);
|
||||
html.classList.add('js');
|
||||
document.body.className = theme;
|
||||
document.querySelector('html').className = theme + ' js';
|
||||
</script>
|
||||
|
||||
<!-- Hide / unhide sidebar before it is displayed -->
|
||||
@@ -80,8 +77,8 @@
|
||||
</script>
|
||||
|
||||
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
|
||||
<div id="sidebar-scrollbox" class="sidebar-scrollbox">
|
||||
<ol class="chapter"><li class="expanded affix "><a href="introduction.html">Introduction</a></li><li class="expanded "><a href="0_background_information.html" class="active"><strong aria-hidden="true">1.</strong> Background information</a></li><li class="expanded "><a href="1_futures_in_rust.html"><strong aria-hidden="true">2.</strong> Futures in Rust</a></li><li class="expanded "><a href="2_waker_context.html"><strong aria-hidden="true">3.</strong> Waker and Context</a></li><li class="expanded "><a href="3_generators_async_await.html"><strong aria-hidden="true">4.</strong> Generators and async/await</a></li><li class="expanded "><a href="4_pin.html"><strong aria-hidden="true">5.</strong> Pin</a></li><li class="expanded "><a href="6_future_example.html"><strong aria-hidden="true">6.</strong> Implementing Futures</a></li><li class="expanded "><a href="8_finished_example.html"><strong aria-hidden="true">7.</strong> Finished example (editable)</a></li><li class="expanded affix "><a href="conclusion.html">Conclusion and exercises</a></li></ol>
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<div class="sidebar-scrollbox">
|
||||
<ol class="chapter"><li class="affix"><a href="introduction.html">Introduction</a></li><li><a href="0_background_information.html" class="active"><strong aria-hidden="true">1.</strong> Background information</a></li><li><a href="1_futures_in_rust.html"><strong aria-hidden="true">2.</strong> Futures in Rust</a></li><li><a href="2_waker_context.html"><strong aria-hidden="true">3.</strong> Waker and Context</a></li><li><a href="3_generators_async_await.html"><strong aria-hidden="true">4.</strong> Generators and async/await</a></li><li><a href="4_pin.html"><strong aria-hidden="true">5.</strong> Pin</a></li><li><a href="6_future_example.html"><strong aria-hidden="true">6.</strong> Implementing Futures</a></li><li><a href="8_finished_example.html"><strong aria-hidden="true">7.</strong> Finished example (editable)</a></li><li class="affix"><a href="conclusion.html">Conclusion and exercises</a></li></ol>
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</div>
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<div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
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</nav>
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@@ -280,199 +277,199 @@ It's not in any way meant to showcase "best practice". Just so we're o
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the same page.</p>
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</blockquote>
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<p><em><strong>Press the expand icon in the top right corner to show the example code.</strong></em> </p>
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<pre><pre class="playpen"><code class="language-rust edition2018"><span class="boring">#![feature(asm, naked_functions)]
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||||
</span><span class="boring">use std::ptr;
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">const DEFAULT_STACK_SIZE: usize = 1024 * 1024 * 2;
|
||||
</span><span class="boring">const MAX_THREADS: usize = 4;
|
||||
</span><span class="boring">static mut RUNTIME: usize = 0;
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">pub struct Runtime {
|
||||
</span><span class="boring"> threads: Vec<Thread>,
|
||||
</span><span class="boring"> current: usize,
|
||||
</span><span class="boring">}
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">#[derive(PartialEq, Eq, Debug)]
|
||||
</span><span class="boring">enum State {
|
||||
</span><span class="boring"> Available,
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||||
</span><span class="boring"> Running,
|
||||
</span><span class="boring"> Ready,
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||||
</span><span class="boring">}
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">struct Thread {
|
||||
</span><span class="boring"> id: usize,
|
||||
</span><span class="boring"> stack: Vec<u8>,
|
||||
</span><span class="boring"> ctx: ThreadContext,
|
||||
</span><span class="boring"> state: State,
|
||||
</span><span class="boring"> task: Option<Box<dyn Fn()>>,
|
||||
</span><span class="boring">}
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">#[derive(Debug, Default)]
|
||||
</span><span class="boring">#[repr(C)]
|
||||
</span><span class="boring">struct ThreadContext {
|
||||
</span><span class="boring"> rsp: u64,
|
||||
</span><span class="boring"> r15: u64,
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||||
</span><span class="boring"> r14: u64,
|
||||
</span><span class="boring"> r13: u64,
|
||||
</span><span class="boring"> r12: u64,
|
||||
</span><span class="boring"> rbx: u64,
|
||||
</span><span class="boring"> rbp: u64,
|
||||
</span><span class="boring"> thread_ptr: u64,
|
||||
</span><span class="boring">}
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||||
</span><span class="boring">
|
||||
</span><span class="boring">impl Thread {
|
||||
</span><span class="boring"> fn new(id: usize) -> Self {
|
||||
</span><span class="boring"> Thread {
|
||||
</span><span class="boring"> id,
|
||||
</span><span class="boring"> stack: vec![0_u8; DEFAULT_STACK_SIZE],
|
||||
</span><span class="boring"> ctx: ThreadContext::default(),
|
||||
</span><span class="boring"> state: State::Available,
|
||||
</span><span class="boring"> task: None,
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">}
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">impl Runtime {
|
||||
</span><span class="boring"> pub fn new() -> Self {
|
||||
</span><span class="boring"> let base_thread = Thread {
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||||
</span><span class="boring"> id: 0,
|
||||
</span><span class="boring"> stack: vec![0_u8; DEFAULT_STACK_SIZE],
|
||||
</span><span class="boring"> ctx: ThreadContext::default(),
|
||||
</span><span class="boring"> state: State::Running,
|
||||
</span><span class="boring"> task: None,
|
||||
</span><span class="boring"> };
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> let mut threads = vec![base_thread];
|
||||
</span><span class="boring"> threads[0].ctx.thread_ptr = &threads[0] as *const Thread as u64;
|
||||
</span><span class="boring"> let mut available_threads: Vec<Thread> = (1..MAX_THREADS).map(|i| Thread::new(i)).collect();
|
||||
</span><span class="boring"> threads.append(&mut available_threads);
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> Runtime {
|
||||
</span><span class="boring"> threads,
|
||||
</span><span class="boring"> current: 0,
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> pub fn init(&self) {
|
||||
</span><span class="boring"> unsafe {
|
||||
</span><span class="boring"> let r_ptr: *const Runtime = self;
|
||||
</span><span class="boring"> RUNTIME = r_ptr as usize;
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> pub fn run(&mut self) -> ! {
|
||||
</span><span class="boring"> while self.t_yield() {}
|
||||
</span><span class="boring"> std::process::exit(0);
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> fn t_return(&mut self) {
|
||||
</span><span class="boring"> if self.current != 0 {
|
||||
</span><span class="boring"> self.threads[self.current].state = State::Available;
|
||||
</span><span class="boring"> self.t_yield();
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> fn t_yield(&mut self) -> bool {
|
||||
</span><span class="boring"> let mut pos = self.current;
|
||||
</span><span class="boring"> while self.threads[pos].state != State::Ready {
|
||||
</span><span class="boring"> pos += 1;
|
||||
</span><span class="boring"> if pos == self.threads.len() {
|
||||
</span><span class="boring"> pos = 0;
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring"> if pos == self.current {
|
||||
</span><span class="boring"> return false;
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> if self.threads[self.current].state != State::Available {
|
||||
</span><span class="boring"> self.threads[self.current].state = State::Ready;
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> self.threads[pos].state = State::Running;
|
||||
</span><span class="boring"> let old_pos = self.current;
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||||
</span><span class="boring"> self.current = pos;
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||||
</span><span class="boring">
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||||
</span><span class="boring"> unsafe {
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||||
</span><span class="boring"> switch(&mut self.threads[old_pos].ctx, &self.threads[pos].ctx);
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||||
</span><span class="boring"> }
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||||
</span><span class="boring"> true
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||||
</span><span class="boring"> }
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||||
</span><span class="boring">
|
||||
</span><span class="boring"> pub fn spawn<F: Fn() + 'static>(f: F){
|
||||
</span><span class="boring"> unsafe {
|
||||
</span><span class="boring"> let rt_ptr = RUNTIME as *mut Runtime;
|
||||
</span><span class="boring"> let available = (*rt_ptr)
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||||
</span><span class="boring"> .threads
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||||
</span><span class="boring"> .iter_mut()
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||||
</span><span class="boring"> .find(|t| t.state == State::Available)
|
||||
</span><span class="boring"> .expect("no available thread.");
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||||
</span><span class="boring">
|
||||
</span><span class="boring"> let size = available.stack.len();
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||||
</span><span class="boring"> let s_ptr = available.stack.as_mut_ptr();
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||||
</span><span class="boring"> available.task = Some(Box::new(f));
|
||||
</span><span class="boring"> available.ctx.thread_ptr = available as *const Thread as u64;
|
||||
</span><span class="boring"> ptr::write(s_ptr.offset((size - 8) as isize) as *mut u64, guard as u64);
|
||||
</span><span class="boring"> ptr::write(s_ptr.offset((size - 16) as isize) as *mut u64, call as u64);
|
||||
</span><span class="boring"> available.ctx.rsp = s_ptr.offset((size - 16) as isize) as u64;
|
||||
</span><span class="boring"> available.state = State::Ready;
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">}
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">fn call(thread: u64) {
|
||||
</span><span class="boring"> let thread = unsafe { &*(thread as *const Thread) };
|
||||
</span><span class="boring"> if let Some(f) = &thread.task {
|
||||
</span><span class="boring"> f();
|
||||
</span><span class="boring"> }
|
||||
</span><span class="boring">}
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">#[naked]
|
||||
</span><span class="boring">fn guard() {
|
||||
</span><span class="boring"> unsafe {
|
||||
</span><span class="boring"> let rt_ptr = RUNTIME as *mut Runtime;
|
||||
</span><span class="boring"> let rt = &mut *rt_ptr;
|
||||
</span><span class="boring"> println!("THREAD {} FINISHED.", rt.threads[rt.current].id);
|
||||
</span><span class="boring"> rt.t_return();
|
||||
</span><span class="boring"> };
|
||||
</span><span class="boring">}
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">pub fn yield_thread() {
|
||||
</span><span class="boring"> unsafe {
|
||||
</span><span class="boring"> let rt_ptr = RUNTIME as *mut Runtime;
|
||||
</span><span class="boring"> (*rt_ptr).t_yield();
|
||||
</span><span class="boring"> };
|
||||
</span><span class="boring">}
|
||||
</span><span class="boring">
|
||||
</span><span class="boring">#[naked]
|
||||
</span><span class="boring">#[inline(never)]
|
||||
</span><span class="boring">unsafe fn switch(old: *mut ThreadContext, new: *const ThreadContext) {
|
||||
</span><span class="boring"> asm!("
|
||||
</span><span class="boring"> mov %rsp, 0x00($0)
|
||||
</span><span class="boring"> mov %r15, 0x08($0)
|
||||
</span><span class="boring"> mov %r14, 0x10($0)
|
||||
</span><span class="boring"> mov %r13, 0x18($0)
|
||||
</span><span class="boring"> mov %r12, 0x20($0)
|
||||
</span><span class="boring"> mov %rbx, 0x28($0)
|
||||
</span><span class="boring"> mov %rbp, 0x30($0)
|
||||
</span><span class="boring">
|
||||
</span><span class="boring"> mov 0x00($1), %rsp
|
||||
</span><span class="boring"> mov 0x08($1), %r15
|
||||
</span><span class="boring"> mov 0x10($1), %r14
|
||||
</span><span class="boring"> mov 0x18($1), %r13
|
||||
</span><span class="boring"> mov 0x20($1), %r12
|
||||
</span><span class="boring"> mov 0x28($1), %rbx
|
||||
</span><span class="boring"> mov 0x30($1), %rbp
|
||||
</span><span class="boring"> mov 0x38($1), %rdi
|
||||
</span><span class="boring"> ret
|
||||
</span><span class="boring"> "
|
||||
</span><span class="boring"> :
|
||||
</span><span class="boring"> : "r"(old), "r"(new)
|
||||
</span><span class="boring"> :
|
||||
</span><span class="boring"> : "alignstack"
|
||||
</span><span class="boring"> );
|
||||
</span><span class="boring">}
|
||||
</span><span class="boring">#[cfg(not(windows))]
|
||||
</span>fn main() {
|
||||
<pre><pre class="playpen"><code class="language-rust edition2018"># #![feature(asm, naked_functions)]
|
||||
# use std::ptr;
|
||||
#
|
||||
# const DEFAULT_STACK_SIZE: usize = 1024 * 1024 * 2;
|
||||
# const MAX_THREADS: usize = 4;
|
||||
# static mut RUNTIME: usize = 0;
|
||||
#
|
||||
# pub struct Runtime {
|
||||
# threads: Vec<Thread>,
|
||||
# current: usize,
|
||||
# }
|
||||
#
|
||||
# #[derive(PartialEq, Eq, Debug)]
|
||||
# enum State {
|
||||
# Available,
|
||||
# Running,
|
||||
# Ready,
|
||||
# }
|
||||
#
|
||||
# struct Thread {
|
||||
# id: usize,
|
||||
# stack: Vec<u8>,
|
||||
# ctx: ThreadContext,
|
||||
# state: State,
|
||||
# task: Option<Box<dyn Fn()>>,
|
||||
# }
|
||||
#
|
||||
# #[derive(Debug, Default)]
|
||||
# #[repr(C)]
|
||||
# struct ThreadContext {
|
||||
# rsp: u64,
|
||||
# r15: u64,
|
||||
# r14: u64,
|
||||
# r13: u64,
|
||||
# r12: u64,
|
||||
# rbx: u64,
|
||||
# rbp: u64,
|
||||
# thread_ptr: u64,
|
||||
# }
|
||||
#
|
||||
# impl Thread {
|
||||
# fn new(id: usize) -> Self {
|
||||
# Thread {
|
||||
# id,
|
||||
# stack: vec![0_u8; DEFAULT_STACK_SIZE],
|
||||
# ctx: ThreadContext::default(),
|
||||
# state: State::Available,
|
||||
# task: None,
|
||||
# }
|
||||
# }
|
||||
# }
|
||||
#
|
||||
# impl Runtime {
|
||||
# pub fn new() -> Self {
|
||||
# let base_thread = Thread {
|
||||
# id: 0,
|
||||
# stack: vec![0_u8; DEFAULT_STACK_SIZE],
|
||||
# ctx: ThreadContext::default(),
|
||||
# state: State::Running,
|
||||
# task: None,
|
||||
# };
|
||||
#
|
||||
# let mut threads = vec![base_thread];
|
||||
# threads[0].ctx.thread_ptr = &threads[0] as *const Thread as u64;
|
||||
# let mut available_threads: Vec<Thread> = (1..MAX_THREADS).map(|i| Thread::new(i)).collect();
|
||||
# threads.append(&mut available_threads);
|
||||
#
|
||||
# Runtime {
|
||||
# threads,
|
||||
# current: 0,
|
||||
# }
|
||||
# }
|
||||
#
|
||||
# pub fn init(&self) {
|
||||
# unsafe {
|
||||
# let r_ptr: *const Runtime = self;
|
||||
# RUNTIME = r_ptr as usize;
|
||||
# }
|
||||
# }
|
||||
#
|
||||
# pub fn run(&mut self) -> ! {
|
||||
# while self.t_yield() {}
|
||||
# std::process::exit(0);
|
||||
# }
|
||||
#
|
||||
# fn t_return(&mut self) {
|
||||
# if self.current != 0 {
|
||||
# self.threads[self.current].state = State::Available;
|
||||
# self.t_yield();
|
||||
# }
|
||||
# }
|
||||
#
|
||||
# fn t_yield(&mut self) -> bool {
|
||||
# let mut pos = self.current;
|
||||
# while self.threads[pos].state != State::Ready {
|
||||
# pos += 1;
|
||||
# if pos == self.threads.len() {
|
||||
# pos = 0;
|
||||
# }
|
||||
# if pos == self.current {
|
||||
# return false;
|
||||
# }
|
||||
# }
|
||||
#
|
||||
# if self.threads[self.current].state != State::Available {
|
||||
# self.threads[self.current].state = State::Ready;
|
||||
# }
|
||||
#
|
||||
# self.threads[pos].state = State::Running;
|
||||
# let old_pos = self.current;
|
||||
# self.current = pos;
|
||||
#
|
||||
# unsafe {
|
||||
# switch(&mut self.threads[old_pos].ctx, &self.threads[pos].ctx);
|
||||
# }
|
||||
# true
|
||||
# }
|
||||
#
|
||||
# pub fn spawn<F: Fn() + 'static>(f: F){
|
||||
# unsafe {
|
||||
# let rt_ptr = RUNTIME as *mut Runtime;
|
||||
# let available = (*rt_ptr)
|
||||
# .threads
|
||||
# .iter_mut()
|
||||
# .find(|t| t.state == State::Available)
|
||||
# .expect("no available thread.");
|
||||
#
|
||||
# let size = available.stack.len();
|
||||
# let s_ptr = available.stack.as_mut_ptr();
|
||||
# available.task = Some(Box::new(f));
|
||||
# available.ctx.thread_ptr = available as *const Thread as u64;
|
||||
# ptr::write(s_ptr.offset((size - 8) as isize) as *mut u64, guard as u64);
|
||||
# ptr::write(s_ptr.offset((size - 16) as isize) as *mut u64, call as u64);
|
||||
# available.ctx.rsp = s_ptr.offset((size - 16) as isize) as u64;
|
||||
# available.state = State::Ready;
|
||||
# }
|
||||
# }
|
||||
# }
|
||||
#
|
||||
# fn call(thread: u64) {
|
||||
# let thread = unsafe { &*(thread as *const Thread) };
|
||||
# if let Some(f) = &thread.task {
|
||||
# f();
|
||||
# }
|
||||
# }
|
||||
#
|
||||
# #[naked]
|
||||
# fn guard() {
|
||||
# unsafe {
|
||||
# let rt_ptr = RUNTIME as *mut Runtime;
|
||||
# let rt = &mut *rt_ptr;
|
||||
# println!("THREAD {} FINISHED.", rt.threads[rt.current].id);
|
||||
# rt.t_return();
|
||||
# };
|
||||
# }
|
||||
#
|
||||
# pub fn yield_thread() {
|
||||
# unsafe {
|
||||
# let rt_ptr = RUNTIME as *mut Runtime;
|
||||
# (*rt_ptr).t_yield();
|
||||
# };
|
||||
# }
|
||||
#
|
||||
# #[naked]
|
||||
# #[inline(never)]
|
||||
# unsafe fn switch(old: *mut ThreadContext, new: *const ThreadContext) {
|
||||
# asm!("
|
||||
# mov %rsp, 0x00($0)
|
||||
# mov %r15, 0x08($0)
|
||||
# mov %r14, 0x10($0)
|
||||
# mov %r13, 0x18($0)
|
||||
# mov %r12, 0x20($0)
|
||||
# mov %rbx, 0x28($0)
|
||||
# mov %rbp, 0x30($0)
|
||||
#
|
||||
# mov 0x00($1), %rsp
|
||||
# mov 0x08($1), %r15
|
||||
# mov 0x10($1), %r14
|
||||
# mov 0x18($1), %r13
|
||||
# mov 0x20($1), %r12
|
||||
# mov 0x28($1), %rbx
|
||||
# mov 0x30($1), %rbp
|
||||
# mov 0x38($1), %rdi
|
||||
# ret
|
||||
# "
|
||||
# :
|
||||
# : "r"(old), "r"(new)
|
||||
# :
|
||||
# : "alignstack"
|
||||
# );
|
||||
# }
|
||||
# #[cfg(not(windows))]
|
||||
fn main() {
|
||||
let mut runtime = Runtime::new();
|
||||
runtime.init();
|
||||
Runtime::spawn(|| {
|
||||
@@ -488,9 +485,9 @@ the same page.</p>
|
||||
});
|
||||
runtime.run();
|
||||
}
|
||||
<span class="boring">#[cfg(windows)]
|
||||
</span><span class="boring">fn main() { }
|
||||
</span></code></pre></pre>
|
||||
# #[cfg(windows)]
|
||||
# fn main() { }
|
||||
</code></pre></pre>
|
||||
<p>Still hanging in there? Good. Don't get frustrated if the code above is
|
||||
difficult to understand. If I hadn't written it myself I would probably feel
|
||||
the same. You can always go back and read the book which explains it later.</p>
|
||||
@@ -738,18 +735,6 @@ need to be polled once before they do any work.</p>
|
||||
|
||||
|
||||
|
||||
<script type="text/javascript">
|
||||
window.playpen_line_numbers = true;
|
||||
</script>
|
||||
|
||||
|
||||
|
||||
<script type="text/javascript">
|
||||
window.playpen_copyable = true;
|
||||
</script>
|
||||
|
||||
|
||||
|
||||
<script src="ace.js" type="text/javascript" charset="utf-8"></script>
|
||||
<script src="editor.js" type="text/javascript" charset="utf-8"></script>
|
||||
<script src="mode-rust.js" type="text/javascript" charset="utf-8"></script>
|
||||
|
||||
Reference in New Issue
Block a user