Merge GH #1245 Restructure Barrier/Semaphore to avoid signed overflow warnings

2 files changed, 9 insertions, 11 deletions

diff --git a/src/lib/utils/barrier.cpp b/src/lib/utils/barrier.cpp
index 3c721d905..ed3878d18 100644
--- a/src/lib/utils/barrier.cpp
+++ b/src/lib/utils/barrier.cpp
@@ -20,9 +20,10 @@ void Barrier::wait(size_t delta)
 void Barrier::sync()
     {
     std::unique_lock<mutex_type> lock(m_mutex);
-    --m_value;
-    if(m_value > 0)
+    
+    if(m_value > 1)
         {
+        --m_value;
         const size_t current_syncs = m_syncs;
         m_cond.wait(lock, [this, &current_syncs] { return m_syncs != current_syncs; });
         }
diff --git a/src/lib/utils/semaphore.cpp b/src/lib/utils/semaphore.cpp
index 62c31d3e3..e990ded41 100644
--- a/src/lib/utils/semaphore.cpp
+++ b/src/lib/utils/semaphore.cpp
@@ -19,9 +19,7 @@ void Semaphore::release(size_t n)
       {
       lock_guard_type<mutex_type> lock(m_mutex);
 
-      ++m_value;
-
-      if(m_value <= 0)
+      if(m_value++ < 0)
          {
          ++m_wakeups;
          m_cond.notify_one();
@@ -32,12 +30,11 @@ void Semaphore::release(size_t n)
 void Semaphore::acquire()
    {
    std::unique_lock<mutex_type> lock(m_mutex);
-   --m_value;
-   if(m_value < 0)
-      {
-      m_cond.wait(lock, [this] { return m_wakeups > 0; });
-      --m_wakeups;
-      }
+   if(m_value-- <= 0)
+       {
+       m_cond.wait(lock, [this] { return m_wakeups > 0; });
+       --m_wakeups;
+       }
    }
 
 }