Merge pull request #14878 from vespa-engine/balder/modernize-barrier

vespalib::Monitor -> std:.mutex/std::condition_variable

2 files changed, 22 insertions, 11 deletions

diff --git a/vespalib/src/vespa/vespalib/util/barrier.cpp b/vespalib/src/vespa/vespalib/util/barrier.cpp
index d20298ffada..32f63424ae1 100644
--- a/vespalib/src/vespa/vespalib/util/barrier.cpp
+++ b/vespalib/src/vespa/vespalib/util/barrier.cpp
@@ -4,10 +4,19 @@
 
 namespace vespalib {
 
+Barrier::Barrier(size_t n)
+  : _n(n),
+    _lock(),
+    _cond(),
+    _count(0),
+    _next(0)
+{}
+Barrier::~Barrier() = default;
+
 bool
 Barrier::await()
 {
-    MonitorGuard guard(_monitor);
+    std::unique_lock guard(_lock);
     if (_n == 0) {
         return false;
     }
@@ -15,14 +24,14 @@ Barrier::await()
         _next += _n;
     }
     if (++_count == _next) {
-        guard.broadcast();
+        _cond.notify_all();
     } else {
         size_t limit = _next;
         while ((_count - limit) > _n) {
             if (_n == 0) {
                 return false;
             }
-            guard.wait();
+            _cond.wait(guard);
         }
     }
     return true;
@@ -31,9 +40,9 @@ Barrier::await()
 void
 Barrier::destroy()
 {
-    MonitorGuard guard(_monitor);
+    std::lock_guard guard(_lock);
     _n = 0;
-    guard.broadcast();
+    _cond.notify_all();
 }
 
 } // namespace vespalib
diff --git a/vespalib/src/vespa/vespalib/util/barrier.h b/vespalib/src/vespa/vespalib/util/barrier.h
index 20768c3abcf..3eeb0cb5837 100644
--- a/vespalib/src/vespa/vespalib/util/barrier.h
+++ b/vespalib/src/vespa/vespalib/util/barrier.h
@@ -2,7 +2,7 @@
 
 #pragma once
 
-#include "sync.h"
+#include <condition_variable>
 
 namespace vespalib {
 
@@ -12,10 +12,11 @@ namespace vespalib {
 class Barrier
 {
 private:
-    size_t  _n;
-    Monitor _monitor;
-    size_t  _count;
-    size_t  _next;
+    size_t                  _n;
+    std::mutex              _lock;
+    std::condition_variable _cond;
+    size_t                  _count;
+    size_t                  _next;
 
 public:
     /**
@@ -23,7 +24,8 @@ public:
      *
      * @param n number of participants
      **/
-    Barrier(size_t n) : _n(n), _monitor(), _count(0), _next(0) {}
+    Barrier(size_t n);
+    ~Barrier();
 
     /**
      * Wait for the (n - 1) other participants to call this