Rwlock #181
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Rwlock #181
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fslongjin
requested changes
Mar 4, 2023
kernel/src/libs/rwlock.rs
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| #[inline] | ||
| /// @brief 获取实时的读者数并尝试加1,如果增加值成功则返回增加1后的读者数,否则panic | ||
| fn current_reader(&self) -> Result<u32, u32> { | ||
| const MAX_READERS: u32 = core::u32::MAX / READER / 2; //右移3位 |
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歧义，加括号。
然后，所有用乘除法实现的位运算功能，直接改为位运算即可。
kernel/src/libs/rwlock.rs
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| /// @brief 获取读者+UPGRADER的数量, 不能保证能否获得同步值 | ||
| pub fn reader_count(&self) -> u32 { | ||
| let state = self.lock.load(Ordering::Relaxed); | ||
| state / READER + (state & UPGRADED) / UPGRADED |
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kernel/src/libs/rwlock.rs
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| /// @brief 尝试获得UPGRADER守卫 | ||
| pub fn try_upgradeable_read(&self) -> Option<RwLockUpgradableGuard<T>> { | ||
| //获得UPGRADER守卫不需要查看读者位 | ||
| //如果获得读者锁失败,不撤回fetch_or的原子操作 |
kernel/src/libs/rwlock.rs
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| #[inline] | ||
| pub fn downgrade(self) -> RwLockReadGuard<'rwlock, T> { | ||
| while { | ||
| let res = self.inner.current_reader(); |
added 3 commits
March 4, 2023 17:20
fslongjin
approved these changes
Mar 4, 2023
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