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| author | Vivian Lim <[email protected]> | 2021-02-06 22:11:59 -0800 |
|---|---|---|
| committer | Vivian Lim <[email protected]> | 2021-02-06 22:11:59 -0800 |
| commit | 64423f0e34cc4a7d78c15b345b3b8f58243d8286 (patch) | |
| tree | cc20e2e7f0fc35abf470e20e61d3d48f0d954f3b /ctr-std/src/sys/cloudabi/mutex.rs | |
| parent | Support libctru 2.0 (diff) | |
| download | archived-ctru-rs-64423f0e34cc4a7d78c15b345b3b8f58243d8286.tar.xz archived-ctru-rs-64423f0e34cc4a7d78c15b345b3b8f58243d8286.zip | |
Delete ctr-std to use my fork of the rust repo instead
Diffstat (limited to 'ctr-std/src/sys/cloudabi/mutex.rs')
| -rw-r--r-- | ctr-std/src/sys/cloudabi/mutex.rs | 158 |
1 files changed, 0 insertions, 158 deletions
diff --git a/ctr-std/src/sys/cloudabi/mutex.rs b/ctr-std/src/sys/cloudabi/mutex.rs deleted file mode 100644 index d4ba6bc..0000000 --- a/ctr-std/src/sys/cloudabi/mutex.rs +++ /dev/null @@ -1,158 +0,0 @@ -// Copyright 2018 The Rust Project Developers. See the COPYRIGHT -// file at the top-level directory of this distribution and at -// http://rust-lang.org/COPYRIGHT. -// -// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or -// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license -// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your -// option. This file may not be copied, modified, or distributed -// except according to those terms. - -use cell::UnsafeCell; -use mem; -use sync::atomic::{AtomicU32, Ordering}; -use sys::cloudabi::abi; -use sys::rwlock::{self, RWLock}; - -extern "C" { - #[thread_local] - static __pthread_thread_id: abi::tid; -} - -// Implement Mutex using an RWLock. This doesn't introduce any -// performance overhead in this environment, as the operations would be -// implemented identically. -pub struct Mutex(RWLock); - -pub unsafe fn raw(m: &Mutex) -> *mut AtomicU32 { - rwlock::raw(&m.0) -} - -impl Mutex { - pub const fn new() -> Mutex { - Mutex(RWLock::new()) - } - - pub unsafe fn init(&mut self) { - // This function should normally reinitialize the mutex after - // moving it to a different memory address. This implementation - // does not require adjustments after moving. - } - - pub unsafe fn try_lock(&self) -> bool { - self.0.try_write() - } - - pub unsafe fn lock(&self) { - self.0.write() - } - - pub unsafe fn unlock(&self) { - self.0.write_unlock() - } - - pub unsafe fn destroy(&self) { - self.0.destroy() - } -} - -pub struct ReentrantMutex { - lock: UnsafeCell<AtomicU32>, - recursion: UnsafeCell<u32>, -} - -impl ReentrantMutex { - pub unsafe fn uninitialized() -> ReentrantMutex { - mem::uninitialized() - } - - pub unsafe fn init(&mut self) { - self.lock = UnsafeCell::new(AtomicU32::new(abi::LOCK_UNLOCKED.0)); - self.recursion = UnsafeCell::new(0); - } - - pub unsafe fn try_lock(&self) -> bool { - // Attempt to acquire the lock. - let lock = self.lock.get(); - let recursion = self.recursion.get(); - if let Err(old) = (*lock).compare_exchange( - abi::LOCK_UNLOCKED.0, - __pthread_thread_id.0 | abi::LOCK_WRLOCKED.0, - Ordering::Acquire, - Ordering::Relaxed, - ) { - // If we fail to acquire the lock, it may be the case - // that we've already acquired it and may need to recurse. - if old & !abi::LOCK_KERNEL_MANAGED.0 == __pthread_thread_id.0 | abi::LOCK_WRLOCKED.0 { - *recursion += 1; - true - } else { - false - } - } else { - // Success. - assert_eq!(*recursion, 0, "Mutex has invalid recursion count"); - true - } - } - - pub unsafe fn lock(&self) { - if !self.try_lock() { - // Call into the kernel to acquire a write lock. - let lock = self.lock.get(); - let subscription = abi::subscription { - type_: abi::eventtype::LOCK_WRLOCK, - union: abi::subscription_union { - lock: abi::subscription_lock { - lock: lock as *mut abi::lock, - lock_scope: abi::scope::PRIVATE, - }, - }, - ..mem::zeroed() - }; - let mut event: abi::event = mem::uninitialized(); - let mut nevents: usize = mem::uninitialized(); - let ret = abi::poll(&subscription, &mut event, 1, &mut nevents); - assert_eq!(ret, abi::errno::SUCCESS, "Failed to acquire mutex"); - assert_eq!(event.error, abi::errno::SUCCESS, "Failed to acquire mutex"); - } - } - - pub unsafe fn unlock(&self) { - let lock = self.lock.get(); - let recursion = self.recursion.get(); - assert_eq!( - (*lock).load(Ordering::Relaxed) & !abi::LOCK_KERNEL_MANAGED.0, - __pthread_thread_id.0 | abi::LOCK_WRLOCKED.0, - "This mutex is locked by a different thread" - ); - - if *recursion > 0 { - *recursion -= 1; - } else if !(*lock) - .compare_exchange( - __pthread_thread_id.0 | abi::LOCK_WRLOCKED.0, - abi::LOCK_UNLOCKED.0, - Ordering::Release, - Ordering::Relaxed, - ) - .is_ok() - { - // Lock is managed by kernelspace. Call into the kernel - // to unblock waiting threads. - let ret = abi::lock_unlock(lock as *mut abi::lock, abi::scope::PRIVATE); - assert_eq!(ret, abi::errno::SUCCESS, "Failed to unlock a mutex"); - } - } - - pub unsafe fn destroy(&self) { - let lock = self.lock.get(); - let recursion = self.recursion.get(); - assert_eq!( - (*lock).load(Ordering::Relaxed), - abi::LOCK_UNLOCKED.0, - "Attempted to destroy locked mutex" - ); - assert_eq!(*recursion, 0, "Recursion counter invalid"); - } -} |