Noa
86 lines
2.0 KiB
Rust
86 lines
2.0 KiB
Rust
use core::num::NonZeroU32;
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pub struct Barrier {
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original_count: NonZeroU32,
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// 4
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lock: crate::sync::Mutex<Inner>,
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// 16
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cvar: crate::header::pthread::RlctCond,
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// 24
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}
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#[derive(Debug)]
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struct Inner {
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count: u32,
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// TODO: Overflows might be problematic... 64-bit?
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gen_id: u32,
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}
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pub enum WaitResult {
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Waited,
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NotifiedAll,
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}
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impl Barrier {
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pub fn new(count: NonZeroU32) -> Self {
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Self {
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original_count: count,
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lock: crate::sync::Mutex::new(Inner {
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count: 0,
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gen_id: 0,
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}),
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cvar: crate::header::pthread::RlctCond::new(),
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}
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}
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pub fn wait(&self) -> WaitResult {
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let mut guard = self.lock.lock();
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let gen_id = guard.gen_id;
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guard.count += 1;
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if guard.count == self.original_count.get() {
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guard.gen_id = guard.gen_id.wrapping_add(1);
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guard.count = 0;
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self.cvar.broadcast();
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drop(guard);
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WaitResult::NotifiedAll
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} else {
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while guard.gen_id == gen_id {
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guard = self.cvar.wait_inner_typedmutex(guard);
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}
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WaitResult::Waited
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}
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/*
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let mut guard = self.lock.lock();
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let Inner { count, gen_id } = *guard;
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let last = self.original_count.get() - 1;
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if count == last {
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eprintln!("last {:?}", *guard);
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guard.gen_id = guard.gen_id.wrapping_add(1);
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guard.count = 0;
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drop(guard);
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self.cvar.broadcast();
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WaitResult::NotifiedAll
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} else {
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guard.count += 1;
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while guard.count != last && guard.gen_id == gen_id {
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eprintln!("before {:?}", *guard);
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guard = self.cvar.wait_inner_typedmutex(guard);
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eprintln!("after {:?}", *guard);
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}
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WaitResult::Waited
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}
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*/
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}
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}
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static LOCK: crate::sync::Mutex<()> = crate::sync::Mutex::new(());
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