Improve unit test coverage for jemalloc_init, arenas_management, and jemalloc_fork modules

test/unit/jemalloc_init.c

@@ -0,0 +1,74 @@
+#include "test/jemalloc_test.h"
+
+#include "jemalloc/internal/jemalloc_init.h"
+
+TEST_BEGIN(test_malloc_init_hard_idempotent) {
+	expect_false(malloc_init_hard(),
+	    "malloc_init_hard should return false when already initialized");
+	expect_true(malloc_initialized(),
+	    "malloc_initialized should still be true after re-calling "
+	    "malloc_init_hard");
+}
+TEST_END
+
+TEST_BEGIN(test_malloc_initializer_set_idempotent_on_main) {
+	test_skip_if(!malloc_is_initializer());
+
+	malloc_initializer_set();
+
+	expect_true(malloc_is_initializer(),
+	    "malloc_is_initializer should still be true after re-setting "
+	    "from the same thread");
+	expect_true(malloc_initializer_is_set(),
+	    "malloc_initializer_is_set should still be true after re-setting");
+}
+TEST_END
+
+#ifdef JEMALLOC_THREADED_INIT
+static atomic_b_t initializer_worker_done;
+static atomic_b_t initializer_worker_result;
+
+static void *
+is_initializer_worker(void *unused) {
+	atomic_store_b(&initializer_worker_result, malloc_is_initializer(),
+	    ATOMIC_RELEASE);
+	atomic_store_b(&initializer_worker_done, true, ATOMIC_RELEASE);
+	return NULL;
+}
+#endif
+
+TEST_BEGIN(test_malloc_is_initializer_false_in_worker) {
+#ifndef JEMALLOC_THREADED_INIT
+	/*
+	 * Without JEMALLOC_THREADED_INIT (e.g. macOS), malloc_initializer
+	 * is a process-wide bool and malloc_is_initializer() returns true
+	 * for every thread after init.  The per-thread distinction this
+	 * test exercises only exists in threaded-init builds.
+	 */
+	test_skip_if(true);
+#else
+	test_skip_if(!malloc_is_initializer());
+
+	atomic_store_b(&initializer_worker_done, false, ATOMIC_RELEASE);
+	atomic_store_b(&initializer_worker_result, false, ATOMIC_RELEASE);
+
+	thd_t thd;
+	thd_create(&thd, is_initializer_worker, NULL);
+	thd_join(thd, NULL);
+
+	expect_true(
+	    atomic_load_b(&initializer_worker_done, ATOMIC_ACQUIRE),
+	    "Worker should have completed");
+	expect_false(
+	    atomic_load_b(&initializer_worker_result, ATOMIC_ACQUIRE),
+	    "malloc_is_initializer should be false in a non-init thread");
+#endif
+}
+TEST_END
+
+int
+main(void) {
+	return test(test_malloc_init_hard_idempotent,
+	    test_malloc_initializer_set_idempotent_on_main,
+	    test_malloc_is_initializer_false_in_worker);
+}