X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11concurrency-benchmarks.git;a=blobdiff_plain;f=cdschecker_modified_benchmarks%2Fms-queue-tsan11%2Fmy_queue.cc;fp=cdschecker_modified_benchmarks%2Fms-queue-tsan11%2Fmy_queue.cc;h=be84c7d7b10a5e9bd6c01f62cf6765acb5e214aa;hp=0000000000000000000000000000000000000000;hb=cfa242fc641a6f27e60980e06b3ea8afea9189c4;hpb=933ce4328bcaa98851474a5c2e2f29ab48a07322

diff --git a/cdschecker_modified_benchmarks/ms-queue-tsan11/my_queue.cc b/cdschecker_modified_benchmarks/ms-queue-tsan11/my_queue.cc
new file mode 100755
index 0000000..be84c7d
--- /dev/null
+++ b/cdschecker_modified_benchmarks/ms-queue-tsan11/my_queue.cc
@@ -0,0 +1,161 @@
+#include "cds_threads.h"
+#include <stdlib.h>
+#include "librace.h"
+#include "model-assert.h"
+
+#include "my_queue.h"
+
+#define relaxed memory_order_relaxed
+#define release memory_order_release
+#define acquire memory_order_acquire
+
+#define MAX_FREELIST 4 /* Each thread can own up to MAX_FREELIST free nodes */
+#define INITIAL_FREE 2 /* Each thread starts with INITIAL_FREE free nodes */
+
+#define POISON_IDX 0x666
+
+static unsigned int (*free_lists)[MAX_FREELIST];
+
+/* Search this thread's free list for a "new" node */
+static unsigned int new_node()
+{
+	int i;
+	int t = get_thread_num();
+	for (i = 0; i < MAX_FREELIST; i++) {
+		unsigned int node = load_32(&free_lists[t][i]);
+		if (node) {
+			store_32(&free_lists[t][i], 0);
+			return node;
+		}
+	}
+	/* free_list is empty? */
+	MODEL_ASSERT(0);
+	return 0;
+}
+
+/* Place this node index back on this thread's free list */
+static void reclaim(unsigned int node)
+{
+	int i;
+	int t = get_thread_num();
+
+	/* Don't reclaim NULL node */
+	MODEL_ASSERT(node);
+
+	for (i = 0; i < MAX_FREELIST; i++) {
+		/* Should never race with our own thread here */
+		unsigned int idx = load_32(&free_lists[t][i]);
+
+		/* Found empty spot in free list */
+		if (idx == 0) {
+			store_32(&free_lists[t][i], node);
+			return;
+		}
+	}
+	/* free list is full? */
+	MODEL_ASSERT(0);
+}
+
+void init_queue(queue_t *q, int num_threads)
+{
+	int i, j;
+
+	/* Initialize each thread's free list with INITIAL_FREE pointers */
+	/* The actual nodes are initialized with poison indexes */
+	free_lists = (unsigned (*)[MAX_FREELIST])malloc(num_threads * sizeof(*free_lists));
+	for (i = 0; i < num_threads; i++) {
+		for (j = 0; j < INITIAL_FREE; j++) {
+			free_lists[i][j] = 2 + i * MAX_FREELIST + j;
+			atomic_init(&q->nodes[free_lists[i][j]].next, MAKE_POINTER(POISON_IDX, 0));
+		}
+	}
+
+	/* initialize queue */
+	atomic_init(&q->head, MAKE_POINTER(1, 0));
+	atomic_init(&q->tail, MAKE_POINTER(1, 0));
+	atomic_init(&q->nodes[1].next, MAKE_POINTER(0, 0));
+}
+
+void enqueue(queue_t *q, unsigned int val)
+{
+	int success = 0;
+	unsigned int node;
+	pointer tail;
+	pointer next;
+	pointer tmp;
+
+	node = new_node();
+	store_32(&q->nodes[node].value, val);
+	tmp = atomic_load_explicit(&q->nodes[node].next, relaxed);
+	set_ptr(&tmp, 0); // NULL
+	atomic_store_explicit(&q->nodes[node].next, tmp, relaxed);
+
+	while (!success) {
+		tail = atomic_load_explicit(&q->tail, acquire);
+		next = atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire);
+		if (tail == atomic_load_explicit(&q->tail, relaxed)) {
+
+			/* Check for uninitialized 'next' */
+			MODEL_ASSERT(get_ptr(next) != POISON_IDX);
+
+			if (get_ptr(next) == 0) { // == NULL
+				pointer value = MAKE_POINTER(node, get_count(next) + 1);
+				success = atomic_compare_exchange_strong_explicit(&q->nodes[get_ptr(tail)].next,
+						&next, value, release, release);
+			}
+			if (!success) {
+				unsigned int ptr = get_ptr(atomic_load_explicit(&q->nodes[get_ptr(tail)].next, acquire));
+				pointer value = MAKE_POINTER(ptr,
+						get_count(tail) + 1);
+				atomic_compare_exchange_strong_explicit(&q->tail,
+						&tail, value,
+						release, release);
+				thrd_yield();
+			}
+		}
+	}
+	atomic_compare_exchange_strong_explicit(&q->tail,
+			&tail,
+			MAKE_POINTER(node, get_count(tail) + 1),
+			release, release);
+}
+
+bool dequeue(queue_t *q, unsigned int *retVal)
+{
+	int success = 0;
+	pointer head;
+	pointer tail;
+	pointer next;
+
+	while (!success) {
+		head = atomic_load_explicit(&q->head, acquire);
+		tail = atomic_load_explicit(&q->tail, relaxed);
+		next = atomic_load_explicit(&q->nodes[get_ptr(head)].next, acquire);
+		if (atomic_load_explicit(&q->head, relaxed) == head) {
+			if (get_ptr(head) == get_ptr(tail)) {
+
+				/* Check for uninitialized 'next' */
+				MODEL_ASSERT(get_ptr(next) != POISON_IDX);
+
+				if (get_ptr(next) == 0) { // NULL
+					return false; // NULL
+				}
+				atomic_compare_exchange_strong_explicit(&q->tail,
+						&tail,
+						MAKE_POINTER(get_ptr(next), get_count(tail) + 1),
+						release, release);
+				thrd_yield();
+			} else {
+				*retVal = load_32(&q->nodes[get_ptr(next)].value);
+				success = atomic_compare_exchange_strong_explicit(&q->head,
+						&head,
+						MAKE_POINTER(get_ptr(next), get_count(head) + 1),
+						release, release);
+				if (!success)
+					thrd_yield();
+			}
+		}
+	}
+	reclaim(get_ptr(head));
+	return true;
+}