1 files changed, 32 insertions, 15 deletions

diff --git a/std/atomic/queue.zig b/std/atomic/queue.zig
index 1aab4c32de..183c434dc5 100644
--- a/std/atomic/queue.zig
+++ b/std/atomic/queue.zig
@@ -170,20 +170,36 @@ test "std.atomic.Queue" {
         .get_count = 0,
     };
 
-    var putters: [put_thread_count]*std.os.Thread = undefined;
-    for (putters) |*t| {
-        t.* = try std.os.spawnThread(&context, startPuts);
-    }
-    var getters: [put_thread_count]*std.os.Thread = undefined;
-    for (getters) |*t| {
-        t.* = try std.os.spawnThread(&context, startGets);
-    }
+    if (builtin.single_threaded) {
+        {
+            var i: usize = 0;
+            while (i < put_thread_count) : (i += 1) {
+                std.debug.assertOrPanic(startPuts(&context) == 0);
+            }
+        }
+        context.puts_done = 1;
+        {
+            var i: usize = 0;
+            while (i < put_thread_count) : (i += 1) {
+                std.debug.assertOrPanic(startGets(&context) == 0);
+            }
+        }
+    } else {
+        var putters: [put_thread_count]*std.os.Thread = undefined;
+        for (putters) |*t| {
+            t.* = try std.os.spawnThread(&context, startPuts);
+        }
+        var getters: [put_thread_count]*std.os.Thread = undefined;
+        for (getters) |*t| {
+            t.* = try std.os.spawnThread(&context, startGets);
+        }
 
-    for (putters) |t|
-        t.wait();
-    _ = @atomicRmw(u8, &context.puts_done, builtin.AtomicRmwOp.Xchg, 1, AtomicOrder.SeqCst);
-    for (getters) |t|
-        t.wait();
+        for (putters) |t|
+            t.wait();
+        _ = @atomicRmw(u8, &context.puts_done, builtin.AtomicRmwOp.Xchg, 1, AtomicOrder.SeqCst);
+        for (getters) |t|
+            t.wait();
+    }
 
     if (context.put_sum != context.get_sum) {
         std.debug.panic("failure\nput_sum:{} != get_sum:{}", context.put_sum, context.get_sum);
@@ -205,11 +221,12 @@ fn startPuts(ctx: *Context) u8 {
     while (put_count != 0) : (put_count -= 1) {
         std.os.time.sleep(1); // let the os scheduler be our fuzz
         const x = @bitCast(i32, r.random.scalar(u32));
-        const node = ctx.allocator.create(Queue(i32).Node{
+        const node = ctx.allocator.create(Queue(i32).Node) catch unreachable;
+        node.* = Queue(i32).Node{
             .prev = undefined,
             .next = undefined,
             .data = x,
-        }) catch unreachable;
+        };
         ctx.queue.put(node);
         _ = @atomicRmw(isize, &ctx.put_sum, builtin.AtomicRmwOp.Add, x, AtomicOrder.SeqCst);
     }