From 650879eaa7fc800f453f65c717ccd8c30aa1089b Mon Sep 17 00:00:00 2001
From: Brian Norris <banorris@uci.edu>
Date: Wed, 10 Oct 2012 16:15:56 -0700
Subject: [PATCH] mpmc-queue: driver fixes

* Initialize queue with at least one item

* Instrument some racy accesses in driver

* Print a little information to see what kind of loops we're stuck in
---
 mpmc-queue/mpmc-queue.cc | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/mpmc-queue/mpmc-queue.cc b/mpmc-queue/mpmc-queue.cc
index b6af7ef..146f11e 100644
--- a/mpmc-queue/mpmc-queue.cc
+++ b/mpmc-queue/mpmc-queue.cc
@@ -1,3 +1,4 @@
+#include <inttypes.h>
 #include <threads.h>
 #include <stdio.h>
 
@@ -5,29 +6,37 @@
 
 #include "mpmc-queue.h"
 
-void threadA(struct mpmc_boundq_1_alt<int, sizeof(int)> *queue)
+void threadA(struct mpmc_boundq_1_alt<int32_t, sizeof(int32_t)> *queue)
 {
-	int *bin = queue->write_prepare();
-	*bin = 1;
+	int32_t *bin = queue->write_prepare();
+	store_32(bin, 1);
 	queue->write_publish();
 }
 
-void threadB(struct mpmc_boundq_1_alt<int, sizeof(int)> *queue)
+void threadB(struct mpmc_boundq_1_alt<int32_t, sizeof(int32_t)> *queue)
 {
-	int *bin = queue->read_fetch();
-	printf("Read: %d\n", *bin);
+	int32_t *bin = queue->read_fetch();
+	printf("Read: %d\n", load_32(bin));
 	queue->read_consume();
 }
 
 int user_main(int argc, char **argv)
 {
-	struct mpmc_boundq_1_alt<int, sizeof(int)> queue;
+	struct mpmc_boundq_1_alt<int32_t, sizeof(int32_t)> queue;
 	thrd_t A, B;
 
+	int32_t *bin = queue.write_prepare();
+	store_32(bin, 17);
+	queue.write_publish();
+
+	printf("Start threads\n");
+
 	thrd_create(&A, (thrd_start_t)&threadA, &queue);
 	thrd_create(&B, (thrd_start_t)&threadB, &queue);
 	thrd_join(A);
 	thrd_join(B);
 
+	printf("Threads complete\n");
+
 	return 0;
 }
-- 
2.34.1