From 9f2a28f12f61001be2bd5adc74964acf5e8e6721 Mon Sep 17 00:00:00 2001
From: Brian Demsky <bdemsky@uci.edu>
Date: Thu, 14 Mar 2013 00:10:19 -0700
Subject: [PATCH] Fix all benchmarks to use yield

All benchmarks now call thrd_yield when appropriate so that they terminate with the -y option.
---
 barrier/barrier.h              |  2 +-
 bench.sh                       |  2 +-
 dekker-fences/dekker-fences.cc |  8 ++++++--
 linuxrwlocks/linuxrwlocks.c    | 12 ++++++------
 mcs-lock/mcs-lock.h            |  4 ++--
 mpmc-queue/mpmc-queue.h        |  4 ++--
 6 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/barrier/barrier.h b/barrier/barrier.h
index 6970816..dd5d39c 100644
--- a/barrier/barrier.h
+++ b/barrier/barrier.h
@@ -18,7 +18,7 @@ class spinning_barrier {
 		} else {
 			/* Run in circles and scream like a little girl.  */
 			while (step_.load () == step)
-				;
+				thrd_yield();
 			return false;
 		}
 	}
diff --git a/bench.sh b/bench.sh
index c32924b..94d041f 100755
--- a/bench.sh
+++ b/bench.sh
@@ -26,7 +26,7 @@ TESTS+=" mpmc-queue/mpmc-1r2w-noinit"
 TESTS+=" mpmc-queue/mpmc-queue-noinit"
 TESTS+=" linuxrwlocks/linuxrwlocks"
 
-MODEL_ARGS="-f 10 -m 2 -e 1"
+MODEL_ARGS="-y -m 2"
 COUNT=0
 
 function run_test {
diff --git a/dekker-fences/dekker-fences.cc b/dekker-fences/dekker-fences.cc
index 81f6098..eb38d5c 100644
--- a/dekker-fences/dekker-fences.cc
+++ b/dekker-fences/dekker-fences.cc
@@ -27,10 +27,12 @@ void p0(void *arg)
 			flag0.store(false,std::memory_order_relaxed);
 			while (turn.load(std::memory_order_relaxed) != 0)
 			{
+				thrd_yield();
 			}
 			flag0.store(true,std::memory_order_relaxed);
 			std::atomic_thread_fence(std::memory_order_seq_cst);
-		}
+		} else
+			thrd_yield();
 	}
 	std::atomic_thread_fence(std::memory_order_acquire);
 
@@ -54,10 +56,12 @@ void p1(void *arg)
 			flag1.store(false,std::memory_order_relaxed);
 			while (turn.load(std::memory_order_relaxed) != 1)
 			{
+				thrd_yield();
 			}
 			flag1.store(true,std::memory_order_relaxed);
 			std::atomic_thread_fence(std::memory_order_seq_cst);
-		}
+		} else
+			thrd_yield();
 	}
 	std::atomic_thread_fence(std::memory_order_acquire);
 
diff --git a/linuxrwlocks/linuxrwlocks.c b/linuxrwlocks/linuxrwlocks.c
index 7e317aa..be3550e 100644
--- a/linuxrwlocks/linuxrwlocks.c
+++ b/linuxrwlocks/linuxrwlocks.c
@@ -29,9 +29,9 @@ static inline void read_lock(rwlock_t *rw)
 	int priorvalue = atomic_fetch_sub_explicit(&rw->lock, 1, memory_order_acquire);
 	while (priorvalue <= 0) {
 		atomic_fetch_add_explicit(&rw->lock, 1, memory_order_relaxed);
-		do {
-			priorvalue = atomic_load_explicit(&rw->lock, memory_order_relaxed);
-		} while (priorvalue <= 0);
+		while (atomic_load_explicit(&rw->lock, memory_order_relaxed) <= 0) {
+			thrd_yield();
+		}
 		priorvalue = atomic_fetch_sub_explicit(&rw->lock, 1, memory_order_acquire);
 	}
 }
@@ -41,9 +41,9 @@ static inline void write_lock(rwlock_t *rw)
 	int priorvalue = atomic_fetch_sub_explicit(&rw->lock, RW_LOCK_BIAS, memory_order_acquire);
 	while (priorvalue != RW_LOCK_BIAS) {
 		atomic_fetch_add_explicit(&rw->lock, RW_LOCK_BIAS, memory_order_relaxed);
-		do {
-			priorvalue = atomic_load_explicit(&rw->lock, memory_order_relaxed);
-		} while (priorvalue != RW_LOCK_BIAS);
+		while (atomic_load_explicit(&rw->lock, memory_order_relaxed) != RW_LOCK_BIAS) {
+			thrd_yield();
+		}
 		priorvalue = atomic_fetch_sub_explicit(&rw->lock, RW_LOCK_BIAS, memory_order_acquire);
 	}
 }
diff --git a/mcs-lock/mcs-lock.h b/mcs-lock/mcs-lock.h
index 2d39f2f..4b808f7 100644
--- a/mcs-lock/mcs-lock.h
+++ b/mcs-lock/mcs-lock.h
@@ -57,7 +57,7 @@ public:
 			// wait on predecessor setting my flag -
 			rl::linear_backoff bo;
 			while ( me->gate.load(std::mo_acquire) ) {
-				bo.yield();
+				thrd_yield();
 			}
 		}
 	}
@@ -80,7 +80,7 @@ public:
 				next = me->next.load(std::mo_acquire);
 				if ( next != NULL )
 					break;
-				bo.yield();
+				thrd_yield();
 			}
 		}
 
diff --git a/mpmc-queue/mpmc-queue.h b/mpmc-queue/mpmc-queue.h
index f73ab99..dc2b561 100644
--- a/mpmc-queue/mpmc-queue.h
+++ b/mpmc-queue/mpmc-queue.h
@@ -43,7 +43,7 @@ public:
 		// (*1)
 		rl::backoff bo;
 		while ( (m_written.load(mo_acquire) & 0xFFFF) != wr ) {
-			bo.yield();
+			thrd_yield();
 		}
 
 		t_element * p = & ( m_array[ rd % t_size ] );
@@ -74,7 +74,7 @@ public:
 		// (*1)
 		rl::backoff bo;
 		while ( (m_read.load(mo_acquire) & 0xFFFF) != rd ) {
-			bo.yield();
+			thrd_yield();
 		}
 
 		t_element * p = & ( m_array[ wr % t_size ] );
-- 
2.34.1