X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=chase-lev-deque-bugfix%2Fdeque.c;fp=chase-lev-deque-bugfix%2Fdeque.c;h=63284465b1217c0eb19585e2944ec64257da584d;hb=595a5a86d894685c1b39ee467599654f8c2a46b5;hp=0000000000000000000000000000000000000000;hpb=a3b1bb7758e8213a6a9972311664d98ca17b1ecf;p=model-checker-benchmarks.git

diff --git a/chase-lev-deque-bugfix/deque.c b/chase-lev-deque-bugfix/deque.c
new file mode 100644
index 0000000..6328446
--- /dev/null
+++ b/chase-lev-deque-bugfix/deque.c
@@ -0,0 +1,85 @@
+#include <stdatomic.h>
+#include <inttypes.h>
+#include "deque.h"
+#include <stdlib.h>
+#include <stdio.h>
+
+Deque * create() {
+	Deque * q = (Deque *) calloc(1, sizeof(Deque));
+	Array * a = (Array *) calloc(1, sizeof(Array)+2*sizeof(atomic_int));
+	atomic_store_explicit(&q->array, a, memory_order_relaxed);
+	atomic_store_explicit(&q->top, 0, memory_order_relaxed);
+	atomic_store_explicit(&q->bottom, 0, memory_order_relaxed);
+	atomic_store_explicit(&a->size, 2, memory_order_relaxed);
+	return q;
+}
+
+int take(Deque *q) {
+	size_t b = atomic_load_explicit(&q->bottom, memory_order_relaxed) - 1;
+	Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
+	atomic_store_explicit(&q->bottom, b, memory_order_relaxed);
+	atomic_thread_fence(memory_order_seq_cst);
+	size_t t = atomic_load_explicit(&q->top, memory_order_relaxed);
+	int x;
+	if (t <= b) {
+		/* Non-empty queue. */
+		x = atomic_load_explicit(&a->buffer[b % atomic_load_explicit(&a->size,memory_order_relaxed)], memory_order_relaxed);
+		if (t == b) {
+			/* Single last element in queue. */
+			if (!atomic_compare_exchange_strong_explicit(&q->top, &t, t + 1, memory_order_seq_cst, memory_order_relaxed))
+				/* Failed race. */
+				x = EMPTY;
+			atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
+		}
+	} else { /* Empty queue. */
+		x = EMPTY;
+		atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
+	}
+	return x;
+}
+
+void resize(Deque *q) {
+	Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
+	size_t size=atomic_load_explicit(&a->size, memory_order_relaxed);
+	size_t new_size=size << 1;
+	Array *new_a = (Array *) calloc(1, new_size * sizeof(atomic_int) + sizeof(Array));
+	size_t top=atomic_load_explicit(&q->top, memory_order_relaxed);
+	size_t bottom=atomic_load_explicit(&q->bottom, memory_order_relaxed);
+	atomic_store_explicit(&new_a->size, new_size, memory_order_relaxed);
+	size_t i;
+	for(i=top; i < bottom; i++) {
+		atomic_store_explicit(&new_a->buffer[i % new_size], atomic_load_explicit(&a->buffer[i % size], memory_order_relaxed), memory_order_relaxed);
+	}
+	atomic_store_explicit(&q->array, new_a, memory_order_release);
+	printf("resize\n");
+}
+
+void push(Deque *q, int x) {
+	size_t b = atomic_load_explicit(&q->bottom, memory_order_relaxed);
+	size_t t = atomic_load_explicit(&q->top, memory_order_acquire);
+	Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
+	if (b - t > atomic_load_explicit(&a->size, memory_order_relaxed) - 1) /* Full queue. */ {
+		resize(q);
+		//Bug in paper...should have next line...
+		a = (Array *) atomic_load_explicit(&q->array, memory_order_relaxed);
+	}
+	atomic_store_explicit(&a->buffer[b % atomic_load_explicit(&a->size, memory_order_relaxed)], x, memory_order_relaxed);
+	atomic_thread_fence(memory_order_release);
+	atomic_store_explicit(&q->bottom, b + 1, memory_order_relaxed);
+}
+
+int steal(Deque *q) {
+	size_t t = atomic_load_explicit(&q->top, memory_order_acquire);
+	atomic_thread_fence(memory_order_seq_cst);
+	size_t b = atomic_load_explicit(&q->bottom, memory_order_acquire);
+	int x = EMPTY;
+	if (t < b) {
+		/* Non-empty queue. */
+		Array *a = (Array *) atomic_load_explicit(&q->array, memory_order_acquire);
+		x = atomic_load_explicit(&a->buffer[t % atomic_load_explicit(&a->size, memory_order_relaxed)], memory_order_relaxed);
+		if (!atomic_compare_exchange_strong_explicit(&q->top, &t, t + 1, memory_order_seq_cst, memory_order_relaxed))
+			/* Failed race. */
+			return ABORT;
+	}
+	return x;
+}