X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=mpmc-queue%2Fmpmc-queue.h;h=47af8eab37b7509ca8e257e118c5b7e38ec8278a;hb=5ab6d890042234648c0baec333ed65e90ca055cf;hp=bef0f324cfc368e94533eb67e509b5787074f354;hpb=1261596fb5b7aa16bc7bc98489d470c3d24fa849;p=model-checker-benchmarks.git

diff --git a/mpmc-queue/mpmc-queue.h b/mpmc-queue/mpmc-queue.h
index bef0f32..47af8ea 100644
--- a/mpmc-queue/mpmc-queue.h
+++ b/mpmc-queue/mpmc-queue.h
@@ -7,7 +7,7 @@ struct mpmc_boundq_1_alt
 private:
 
 	// elements should generally be cache-line-size padded :
-	nonatomic<t_element>  m_array[t_size];
+	t_element               m_array[t_size];
 
 	// rdwr counts the reads & writes that have started
 	atomic<unsigned int>    m_rdwr;
@@ -17,13 +17,16 @@ private:
 
 public:
 
-	mpmc_boundq_1_alt() : m_rdwr(0), m_read(0), m_written(0)
+	mpmc_boundq_1_alt()
 	{
+		m_rdwr = 0;
+		m_read = 0;
+		m_written = 0;
 	}
 
 	//-----------------------------------------------------
 
-	nonatomic<t_element> * read_fetch() {
+	t_element * read_fetch() {
 		unsigned int rdwr = m_rdwr.load(mo_acquire);
 		unsigned int rd,wr;
 		for(;;) {
@@ -31,19 +34,21 @@ public:
 			wr = rdwr & 0xFFFF;
 
 			if ( wr == rd ) // empty
-				return false;
+				return NULL;
 
 			if ( m_rdwr.compare_exchange_weak(rdwr,rdwr+(1<<16),mo_acq_rel) )
 				break;
+			else
+				thrd_yield();
 		}
 
 		// (*1)
 		rl::backoff bo;
 		while ( (m_written.load(mo_acquire) & 0xFFFF) != wr ) {
-			bo.yield();
+			thrd_yield();
 		}
 
-		nonatomic<t_element> * p = & ( m_array[ rd % t_size ] );
+		t_element * p = & ( m_array[ rd % t_size ] );
 
 		return p;
 	}
@@ -54,7 +59,7 @@ public:
 
 	//-----------------------------------------------------
 
-	nonatomic<t_element> * write_prepare() {
+	t_element * write_prepare() {
 		unsigned int rdwr = m_rdwr.load(mo_acquire);
 		unsigned int rd,wr;
 		for(;;) {
@@ -66,15 +71,17 @@ public:
 
 			if ( m_rdwr.compare_exchange_weak(rdwr,(rd<<16) | ((wr+1)&0xFFFF),mo_acq_rel) )
 				break;
+			else
+				thrd_yield();
 		}
 
 		// (*1)
 		rl::backoff bo;
 		while ( (m_read.load(mo_acquire) & 0xFFFF) != rd ) {
-			bo.yield();
+			thrd_yield();
 		}
 
-		nonatomic<t_element> * p = & ( m_array[ wr % t_size ] );
+		t_element * p = & ( m_array[ wr % t_size ] );
 
 		return p;
 	}