port to the new log api

This involves:

* creating a `Logger` object (always)
* using `logger.log(|| ...)` instead of a macro
    * if logs are not compiled in, this should be optimized away
* the logger tracks the number of active threads in various states etc
* some log event names were "normalized" to be more consistent

rayon-core/Cargo.toml

@@ -18,6 +18,7 @@ categories = ["concurrency"]
 [dependencies]
 num_cpus = "1.2"
 lazy_static = "1"
+crossbeam-channel = "0.3.9"
 crossbeam-deque = "0.7.2"
 crossbeam-queue = "0.2"
 crossbeam-utils = "0.7"

rayon-core/src/join/mod.rs

@@ -131,10 +131,6 @@ where
     }
 
     registry::in_worker(|worker_thread, injected| unsafe {
-        log!(Join {
-            worker: worker_thread.index()
-        });
-
         // Create virtual wrapper for task b; this all has to be
         // done here so that the stack frame can keep it all live
         // long enough.
@@ -160,23 +156,20 @@ where
                     // Found it! Let's run it.
                     //
                     // Note that this could panic, but it's ok if we unwind here.
-                    log!(PoppedRhs {
+                    worker_thread.log(|| JobPoppedRhs {
                         worker: worker_thread.index()
                     });
                     let result_b = job_b.run_inline(injected);
                     return (result_a, result_b);
                 } else {
-                    log!(PoppedJob {
+                    worker_thread.log(|| JobPopped {
                         worker: worker_thread.index()
                     });
                     worker_thread.execute(job);
                 }
             } else {
                 // Local deque is empty. Time to steal from other
                 // threads.
-                log!(LostJob {
-                    worker: worker_thread.index()
-                });
                 worker_thread.wait_until(&job_b.latch);
                 debug_assert!(job_b.latch.probe());
                 break;