--- tests/dispatch_workqueue.c.orig	2022-11-07 10:43:31 UTC
+++ tests/dispatch_workqueue.c
@@ -0,0 +1,72 @@
+#include <bsdtests.h>
+#include "dispatch_test.h"
+
+struct test_context {
+	uint32_t ncpu;
+	int flag;
+};
+
+static void
+timeout(void *context)
+{
+	struct test_context *ctx = (struct test_context *)context;
+	sleep(2);  // Give the monitor the best chance of firing.
+	test_int32_format(ctx->flag, 1, "flag");
+	test_stop();
+}
+
+static void
+raise_flag(void *context)
+{
+	struct test_context *ctx = (struct test_context *)context;
+	ctx->flag++;
+}
+
+static void
+spin(void *context)
+{
+	struct test_context *ctx = (struct test_context *)context;
+	sleep(ctx->ncpu * 2);
+}
+
+static uint32_t
+activecpu(void)
+{
+        uint32_t activecpu;
+#if defined(__linux__) || defined(__FreeBSD__)
+        activecpu = (uint32_t)sysconf(_SC_NPROCESSORS_ONLN);
+#elif defined(_WIN32)
+        SYSTEM_INFO si;
+        GetSystemInfo(&si);
+        activecpu = si.dwNumberOfProcessors;
+#else
+        size_t s = sizeof(activecpu);
+        sysctlbyname("hw.activecpu", &activecpu, &s, NULL, 0);
+#endif
+	return activecpu;
+}
+
+int
+main(void)
+{
+	uint32_t ncpu = activecpu();
+
+	dispatch_test_start("Dispatch workqueue");
+
+	dispatch_queue_t global = dispatch_get_global_queue(0, 0);
+	test_ptr_notnull("dispatch_get_global_queue", global);
+
+	struct test_context ctx = {ncpu, 0};
+	dispatch_async_f(global, &ctx, timeout);
+
+	for(int i = 0; i < (int)ncpu - 1; i++) {
+		dispatch_async_f(global, &ctx, spin);
+	}
+
+	// All cpus are tied up at this point. Workqueue
+	// should execute this function by overcommit.
+	dispatch_async_f(global, &ctx, raise_flag);
+
+	dispatch_main();
+	return 0;
+}