std: pass hint to id-based parking functions

Author: joboet

library/std/src/sys/sgx/thread_parking.rs

@@ -7,17 +7,17 @@ pub type ThreadId = fortanix_sgx_abi::Tcs;
 
 pub use super::abi::thread::current;
 
-pub fn park() {
+pub fn park(_hint: usize) {
     usercalls::wait(EV_UNPARK, WAIT_INDEFINITE).unwrap();
 }
 
-pub fn park_timeout(dur: Duration) {
+pub fn park_timeout(dur: Duration, _hint: usize) {
     let timeout = u128::min(dur.as_nanos(), WAIT_INDEFINITE as u128 - 1) as u64;
     if let Err(e) = usercalls::wait(EV_UNPARK, timeout) {
         assert!(matches!(e.kind(), ErrorKind::TimedOut | ErrorKind::WouldBlock))
     }
 }
 
-pub fn unpark(tid: ThreadId) {
+pub fn unpark(tid: ThreadId, _hint: usize) {
     let _ = usercalls::send(EV_UNPARK, Some(tid));
 }

library/std/src/sys/unix/thread_parking/netbsd.rs

@@ -1,7 +1,7 @@
 #![cfg(target_os = "netbsd")]
 
 use crate::ffi::{c_int, c_void};
-use crate::ptr::{null, null_mut};
+use crate::ptr;
 use crate::time::Duration;
 use libc::{_lwp_self, clockid_t, lwpid_t, time_t, timespec, CLOCK_MONOTONIC};
 
@@ -25,13 +25,13 @@ pub fn current() -> ThreadId {
 }
 
 #[inline]
-pub fn park() {
+pub fn park(hint: usize) {
     unsafe {
-        ___lwp_park60(0, 0, null_mut(), 0, null(), null());
+        ___lwp_park60(0, 0, ptr::null_mut(), 0, ptr::invalid(hint), ptr::null());
     }
 }
 
-pub fn park_timeout(dur: Duration) {
+pub fn park_timeout(dur: Duration, hint: usize) {
     let mut timeout = timespec {
         // Saturate so that the operation will definitely time out
         // (even if it is after the heat death of the universe).
@@ -42,13 +42,13 @@ pub fn park_timeout(dur: Duration) {
     // Timeout needs to be mutable since it is modified on NetBSD 9.0 and
     // above.
     unsafe {
-        ___lwp_park60(CLOCK_MONOTONIC, 0, &mut timeout, 0, null(), null());
+        ___lwp_park60(CLOCK_MONOTONIC, 0, &mut timeout, 0, ptr::invalid(hint), ptr::null());
     }
 }
 
 #[inline]
-pub fn unpark(tid: ThreadId) {
+pub fn unpark(tid: ThreadId, hint: usize) {
     unsafe {
-        _lwp_unpark(tid, null());
+        _lwp_unpark(tid, ptr::invalid(hint));
     }
 }

library/std/src/sys_common/thread_parking/id.rs

@@ -56,7 +56,7 @@ impl Parker {
         if state == PARKED {
             // Loop to guard against spurious wakeups.
             while state == PARKED {
-                park();
+                park(self.state.as_mut_ptr().addr());
                 state = self.state.load(Acquire);
             }
 
@@ -72,7 +72,7 @@ impl Parker {
 
         let state = self.state.fetch_sub(1, Acquire).wrapping_sub(1);
         if state == PARKED {
-            park_timeout(dur);
+            park_timeout(dur, self.state.as_mut_ptr().addr());
             // Swap to ensure that we observe all state changes with acquire
             // ordering, even if the state has been changed after the timeout
             // occured.
@@ -95,7 +95,7 @@ impl Parker {
             // and terminated before this call is made. This call then returns an
             // error or wakes up an unrelated thread. The platform API and
             // environment does allow this, however.
-            unpark(tid);
+            unpark(tid, self.state.as_mut_ptr().addr());
         }
     }
 }