Update parking_lot to 0.12.0

Test: cd external/rust/crates && atest --host -c
Change-Id: I8f81aacb68f02b75ebe5ed9964d1da6dacedcae3

9 files changed, 86 insertions, 80 deletions

diff --git a/src/condvar.rs b/src/condvar.rs
index 534b8af..9eaf300 100644
--- a/src/condvar.rs
+++ b/src/condvar.rs
@@ -12,10 +12,9 @@ use core::{
     fmt, ptr,
     sync::atomic::{AtomicPtr, Ordering},
 };
-use instant::Instant;
 use lock_api::RawMutex as RawMutex_;
 use parking_lot_core::{self, ParkResult, RequeueOp, UnparkResult, DEFAULT_PARK_TOKEN};
-use std::time::Duration;
+use std::time::{Duration, Instant};
 
 /// A type indicating whether a timed wait on a condition variable returned
 /// due to a time out or not.
@@ -381,12 +380,6 @@ impl Condvar {
     ///
     /// Like `wait`, the lock specified will be re-acquired when this function
     /// returns, regardless of whether the timeout elapsed or not.
-    ///
-    /// # Panics
-    ///
-    /// Panics if the given `timeout` is so large that it can't be added to the current time.
-    /// This panic is not possible if the crate is built with the `nightly` feature, then a too
-    /// large `timeout` becomes equivalent to just calling `wait`.
     #[inline]
     pub fn wait_for<T: ?Sized>(
         &self,
@@ -414,11 +407,11 @@ impl fmt::Debug for Condvar {
 #[cfg(test)]
 mod tests {
     use crate::{Condvar, Mutex, MutexGuard};
-    use instant::Instant;
     use std::sync::mpsc::channel;
     use std::sync::Arc;
     use std::thread;
     use std::time::Duration;
+    use std::time::Instant;
 
     #[test]
     fn smoke() {
@@ -557,14 +550,7 @@ mod tests {
             let _g = m2.lock();
             c2.notify_one();
         });
-        // Non-nightly panics on too large timeouts. Nightly treats it as indefinite wait.
-        let very_long_timeout = if cfg!(feature = "nightly") {
-            Duration::from_secs(u64::max_value())
-        } else {
-            Duration::from_millis(u32::max_value() as u64)
-        };
-
-        let timeout_res = c.wait_for(&mut g, very_long_timeout);
+        let timeout_res = c.wait_for(&mut g, Duration::from_secs(u64::max_value()));
         assert!(!timeout_res.timed_out());
 
         drop(g);
diff --git a/src/elision.rs b/src/elision.rs
index 68cfa63..8fa229e 100644
--- a/src/elision.rs
+++ b/src/elision.rs
@@ -5,6 +5,8 @@
 // http://opensource.org/licenses/MIT>, at your option. This file may not be
 // copied, modified, or distributed except according to those terms.
 
+#[cfg(all(feature = "hardware-lock-elision", any(target_arch = "x86", target_arch = "x86_64")))]
+use std::arch::asm;
 use std::sync::atomic::AtomicUsize;
 
 // Extension trait to add lock elision primitives to atomic types
@@ -26,14 +28,14 @@ pub trait AtomicElisionExt {
 #[inline]
 pub fn have_elision() -> bool {
     cfg!(all(
-        feature = "nightly",
+        feature = "hardware-lock-elision",
         any(target_arch = "x86", target_arch = "x86_64"),
     ))
 }
 
 // This implementation is never actually called because it is guarded by
 // have_elision().
-#[cfg(not(all(feature = "nightly", any(target_arch = "x86", target_arch = "x86_64"))))]
+#[cfg(not(all(feature = "hardware-lock-elision", any(target_arch = "x86", target_arch = "x86_64"))))]
 impl AtomicElisionExt for AtomicUsize {
     type IntType = usize;
 
@@ -48,37 +50,33 @@ impl AtomicElisionExt for AtomicUsize {
     }
 }
 
-#[cfg(all(feature = "nightly", any(target_arch = "x86", target_arch = "x86_64")))]
+#[cfg(all(feature = "hardware-lock-elision", any(target_arch = "x86", target_arch = "x86_64")))]
 impl AtomicElisionExt for AtomicUsize {
     type IntType = usize;
 
-    #[cfg(target_pointer_width = "32")]
     #[inline]
     fn elision_compare_exchange_acquire(&self, current: usize, new: usize) -> Result<usize, usize> {
         unsafe {
+            use core::arch::asm;
             let prev: usize;
-            llvm_asm!("xacquire; lock; cmpxchgl $2, $1"
-                      : "={eax}" (prev), "+*m" (self)
-                      : "r" (new), "{eax}" (current)
-                      : "memory"
-                      : "volatile");
-            if prev == current {
-                Ok(prev)
-            } else {
-                Err(prev)
-            }
-        }
-    }
-    #[cfg(target_pointer_width = "64")]
-    #[inline]
-    fn elision_compare_exchange_acquire(&self, current: usize, new: usize) -> Result<usize, usize> {
-        unsafe {
-            let prev: usize;
-            llvm_asm!("xacquire; lock; cmpxchgq $2, $1"
-                      : "={rax}" (prev), "+*m" (self)
-                      : "r" (new), "{rax}" (current)
-                      : "memory"
-                      : "volatile");
+            #[cfg(target_pointer_width = "32")]
+            asm!(
+                "xacquire",
+                "lock",
+                "cmpxchg [{:e}], {:e}",
+                in(reg) self,
+                in(reg) new,
+                inout("eax") current => prev,
+            );
+            #[cfg(target_pointer_width = "64")]
+            asm!(
+                "xacquire",
+                "lock",
+                "cmpxchg [{}], {}",
+                in(reg) self,
+                in(reg) new,
+                inout("rax") current => prev,
+            );
             if prev == current {
                 Ok(prev)
             } else {
@@ -87,29 +85,27 @@ impl AtomicElisionExt for AtomicUsize {
         }
     }
 
-    #[cfg(target_pointer_width = "32")]
-    #[inline]
-    fn elision_fetch_sub_release(&self, val: usize) -> usize {
-        unsafe {
-            let prev: usize;
-            llvm_asm!("xrelease; lock; xaddl $2, $1"
-                      : "=r" (prev), "+*m" (self)
-                      : "0" (val.wrapping_neg())
-                      : "memory"
-                      : "volatile");
-            prev
-        }
-    }
-    #[cfg(target_pointer_width = "64")]
     #[inline]
     fn elision_fetch_sub_release(&self, val: usize) -> usize {
         unsafe {
+            use core::arch::asm;
             let prev: usize;
-            llvm_asm!("xrelease; lock; xaddq $2, $1"
-                      : "=r" (prev), "+*m" (self)
-                      : "0" (val.wrapping_neg())
-                      : "memory"
-                      : "volatile");
+            #[cfg(target_pointer_width = "32")]
+            asm!(
+                "xrelease",
+                "lock",
+                "xadd [{:e}], {:e}",
+                in(reg) self,
+                inout(reg) val.wrapping_neg() => prev,
+            );
+            #[cfg(target_pointer_width = "64")]
+            asm!(
+                "xrelease",
+                "lock",
+                "xadd [{}], {}",
+                in(reg) self,
+                inout(reg) val.wrapping_neg() => prev,
+            );
             prev
         }
     }
diff --git a/src/fair_mutex.rs b/src/fair_mutex.rs
index 449c53b..3e4c163 100644
--- a/src/fair_mutex.rs
+++ b/src/fair_mutex.rs
@@ -11,24 +11,21 @@ use lock_api;
 /// A mutual exclusive primitive that is always fair, useful for protecting shared data
 ///
 /// This mutex will block threads waiting for the lock to become available. The
-/// mutex can also be statically initialized or created via a `new`
+/// mutex can be statically initialized or created by the `new`
 /// constructor. Each mutex has a type parameter which represents the data that
 /// it is protecting. The data can only be accessed through the RAII guards
 /// returned from `lock` and `try_lock`, which guarantees that the data is only
 /// ever accessed when the mutex is locked.
 ///
-/// The regular mutex provided by `parking_lot` uses eventual locking fairness
+/// The regular mutex provided by `parking_lot` uses eventual fairness
 /// (after some time it will default to the fair algorithm), but eventual
-/// fairness does not provide the same garantees a always fair method would.
-/// Fair mutexes are generally slower, but sometimes needed. This wrapper was
-/// created to avoid using a unfair protocol when it's forbidden by mistake.
+/// fairness does not provide the same guarantees an always fair method would.
+/// Fair mutexes are generally slower, but sometimes needed.
 ///
-/// In a fair mutex the lock is provided to whichever thread asked first,
-/// they form a queue and always follow the first-in first-out order. This
-/// means some thread in the queue won't be able to steal the lock and use it fast
-/// to increase throughput, at the cost of latency. Since the response time will grow
-/// for some threads that are waiting for the lock and losing to faster but later ones,
-/// but it may make sending more responses possible.
+/// In a fair mutex the waiters form a queue, and the lock is always granted to
+/// the next requester in the queue, in first-in first-out order. This ensures
+/// that one thread cannot starve others by quickly re-acquiring the lock after
+/// releasing it.
 ///
 /// A fair mutex may not be interesting if threads have different priorities (this is known as
 /// priority inversion).
diff --git a/src/lib.rs b/src/lib.rs
index 7ff2c79..03639a6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -11,7 +11,6 @@
 
 #![warn(missing_docs)]
 #![warn(rust_2018_idioms)]
-#![cfg_attr(feature = "nightly", feature(llvm_asm))]
 
 mod condvar;
 mod elision;
diff --git a/src/mutex.rs b/src/mutex.rs
index 9f63cb9..71bc351 100644
--- a/src/mutex.rs
+++ b/src/mutex.rs
@@ -11,7 +11,7 @@ use lock_api;
 /// A mutual exclusion primitive useful for protecting shared data
 ///
 /// This mutex will block threads waiting for the lock to become available. The
-/// mutex can also be statically initialized or created via a `new`
+/// mutex can be statically initialized or created by the `new`
 /// constructor. Each mutex has a type parameter which represents the data that
 /// it is protecting. The data can only be accessed through the RAII guards
 /// returned from `lock` and `try_lock`, which guarantees that the data is only
diff --git a/src/raw_mutex.rs b/src/raw_mutex.rs
index 06667d3..b1ae7ee 100644
--- a/src/raw_mutex.rs
+++ b/src/raw_mutex.rs
@@ -10,9 +10,9 @@ use core::{
     sync::atomic::{AtomicU8, Ordering},
     time::Duration,
 };
-use instant::Instant;
 use lock_api::RawMutex as RawMutex_;
 use parking_lot_core::{self, ParkResult, SpinWait, UnparkResult, UnparkToken, DEFAULT_PARK_TOKEN};
+use std::time::Instant;
 
 // UnparkToken used to indicate that that the target thread should attempt to
 // lock the mutex again as soon as it is unparked.
diff --git a/src/raw_rwlock.rs b/src/raw_rwlock.rs
index 19b61c8..21d338b 100644
--- a/src/raw_rwlock.rs
+++ b/src/raw_rwlock.rs
@@ -12,12 +12,11 @@ use core::{
     cell::Cell,
     sync::atomic::{AtomicUsize, Ordering},
 };
-use instant::Instant;
 use lock_api::{RawRwLock as RawRwLock_, RawRwLockUpgrade};
 use parking_lot_core::{
     self, deadlock, FilterOp, ParkResult, ParkToken, SpinWait, UnparkResult, UnparkToken,
 };
-use std::time::Duration;
+use std::time::{Duration, Instant};
 
 // This reader-writer lock implementation is based on Boost's upgrade_mutex:
 // https://github.com/boostorg/thread/blob/fc08c1fe2840baeeee143440fba31ef9e9a813c8/include/boost/thread/v2/shared_mutex.hpp#L432
@@ -144,6 +143,12 @@ unsafe impl lock_api::RawRwLock for RawRwLock {
         let state = self.state.load(Ordering::Relaxed);
         state & (WRITER_BIT | READERS_MASK) != 0
     }
+
+    #[inline]
+    fn is_locked_exclusive(&self) -> bool {
+        let state = self.state.load(Ordering::Relaxed);
+        state & (WRITER_BIT) != 0
+    }
 }
 
 unsafe impl lock_api::RawRwLockFair for RawRwLock {
diff --git a/src/rwlock.rs b/src/rwlock.rs
index 70e1b1a..512114c 100644
--- a/src/rwlock.rs
+++ b/src/rwlock.rs
@@ -408,6 +408,8 @@ mod tests {
                 write_result.is_none(),
                 "try_write should fail while read_guard is in scope"
             );
+            assert!(lock.is_locked());
+            assert!(!lock.is_locked_exclusive());
 
             drop(read_guard);
         }
@@ -419,6 +421,8 @@ mod tests {
                 write_result.is_none(),
                 "try_write should fail while upgrade_guard is in scope"
             );
+            assert!(lock.is_locked());
+            assert!(!lock.is_locked_exclusive());
 
             drop(upgrade_guard);
         }
@@ -430,6 +434,8 @@ mod tests {
                 write_result.is_none(),
                 "try_write should fail while write_guard is in scope"
             );
+            assert!(lock.is_locked());
+            assert!(lock.is_locked_exclusive());
 
             drop(write_guard);
         }
@@ -615,4 +621,22 @@ mod tests {
         .join()
         .unwrap();
     }
+
+    #[test]
+    fn test_rw_write_is_locked() {
+        let lock = RwLock::new(0isize);
+        {
+            let _read_guard = lock.read();
+
+            assert!(lock.is_locked());
+            assert!(!lock.is_locked_exclusive());
+        }
+
+        {
+            let _write_guard = lock.write();
+
+            assert!(lock.is_locked());
+            assert!(lock.is_locked_exclusive());
+        }
+    }
 }
diff --git a/src/util.rs b/src/util.rs
index 19cc2c2..c5496fc 100644
--- a/src/util.rs
+++ b/src/util.rs
@@ -5,8 +5,7 @@
 // http://opensource.org/licenses/MIT>, at your option. This file may not be
 // copied, modified, or distributed except according to those terms.
 
-use instant::Instant;
-use std::time::Duration;
+use std::time::{Duration, Instant};
 
 // Option::unchecked_unwrap
 pub trait UncheckedOptionExt<T> {