benches/join.rs

@@ -56,7 +56,7 @@ mod tree {
     }
 }
 
-const TREE_SIZE: usize = 16;
+const TREE_SIZE: usize = 13;
 
 #[bench]
 fn join_melange(b: &mut Bencher) {

src/praetor/mod.rs

@@ -435,7 +435,6 @@ mod job {
         // these cannot be boxes because boxes are noalias.
         head: NonNull<Job>,
         tail: NonNull<Job>,
-        job_count: usize,
     }
 
     impl Debug for JobList {
@@ -489,7 +488,6 @@ mod job {
                 Self {
                     head: NonNull::new_unchecked(head),
                     tail: NonNull::new_unchecked(tail),
-                    job_count: 0,
                 }
             }
         }
@@ -503,7 +501,6 @@ mod job {
 
         /// elem must be valid until it is popped.
         pub unsafe fn push_front<T>(&mut self, elem: *const Job<T>) {
-            self.job_count += 1;
             let head_link = unsafe { self.head.as_ref().link_mut() };
 
             // SAFETY: head will always have a previous element.
@@ -521,7 +518,6 @@ mod job {
 
         /// elem must be valid until it is popped.
         pub unsafe fn push_back<T>(&mut self, elem: *const Job<T>) {
-            self.job_count += 1;
             let tail_link = unsafe { self.tail.as_ref().link_mut() };
 
             // SAFETY: tail will always have a previous element.
@@ -539,7 +535,6 @@ mod job {
 
         #[allow(dead_code)]
         pub fn pop_front(&mut self) -> Option<NonNull<Job>> {
-            self.job_count -= 1;
             let head_link = unsafe { self.head.as_ref().link_mut() };
 
             // SAFETY: head will always have a previous element.
@@ -556,7 +551,6 @@ mod job {
         }
 
         pub fn pop_back(&mut self) -> Option<NonNull<Job>> {
-            self.job_count -= 1;
             // TODO: next and elem might be the same
             let tail_link = unsafe { self.tail.as_ref().link_mut() };
 
@@ -572,15 +566,6 @@ mod job {
 
             Some(elem)
         }
-
-        #[allow(dead_code)]
-        pub fn is_empty(&self) -> bool {
-            self.job_count == 0
-        }
-
-        pub fn len(&self) -> usize {
-            self.job_count
-        }
     }
 
     impl Drop for JobList {
@@ -1287,10 +1272,7 @@ impl WorkerThread {
 
         // TODO: add counter to job queue, check for low job count to decide whether to use heartbeat or seq.
         // see: chili
-
-        // SAFETY: this function runs in a worker thread, so we can access the queue safely.
-        if count == 0 || unsafe { self.queue.as_ref_unchecked().len() } < 3 {
-            cold_path();
+        if self.join_count.get() == 1 {
             self.join_heartbeat(a, b)
         } else {
             self.join_seq(a, b)
@@ -1964,32 +1946,15 @@ fn worker(ctx: Arc<Context>, barrier: Arc<std::sync::Barrier>) {
     barrier.wait();
 
     let mut job = ctx.shared.lock().pop_job();
-    'outer: loop {
-        let mut guard = loop {
-            if let Some(job) = job {
-                worker.execute(job);
-            }
+    loop {
+        if let Some(job) = job {
+            worker.execute(job);
+        }
 
-            let mut guard = ctx.shared.lock();
-            if guard.should_stop {
-                // if the context is stopped, break out of the outer loop which
-                // will exit the thread.
-                break 'outer;
-            }
-
-            match guard.pop_job() {
-                Some(job) => {
-                    tracing::trace!("worker: popping job: {:?}", job);
-                    // found job, continue inner loop
-                    continue;
-                }
-                None => {
-                    tracing::trace!("worker: no job, waiting for shared job");
-                    // no more jobs, break out of inner loop and wait for shared job
-                    break guard;
-                }
-            }
-        };
+        let mut guard = ctx.shared.lock();
+        if guard.should_stop {
+            break;
+        }
 
         ctx.shared_job.wait(&mut guard);
         job = guard.pop_job();