1 files changed, 111 insertions, 0 deletions
diff --git a/test/test_semaphore.c b/test/test_semaphore.c
new file mode 100644
index 00000000..299273ea
--- /dev/null
+++ b/test/test_semaphore.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright (c) 2019 Richard Braun.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * This test creates a number of threads (at least 2) which wait on a
+ * semaphore, and one that posts the semaphore as many times as there
+ * are threads. All threads are bound to the same processor, and posts
+ * are performed with preemption disabled, to guarantee they occur
+ * back-to-back in order to make sure that they're not missed.
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+
+#include <kern/cpumap.h>
+#include <kern/error.h>
+#include <kern/log.h>
+#include <kern/macros.h>
+#include <kern/semaphore.h>
+#include <kern/thread.h>
+#include <test/test.h>
+
+#define TEST_NR_WAITERS 2
+
+#if TEST_NR_WAITERS < 2
+#error "invalid number of waiters"
+#endif /* TEST_NR_WAITERS < 2 */
+
+static struct semaphore test_semaphore;
+
+static struct thread *test_waiters[TEST_NR_WAITERS];
+
+static void
+test_wait(void *arg)
+{
+    (void)arg;
+
+    semaphore_wait(&test_semaphore);
+}
+
+static void
+test_post(void *arg)
+{
+    int error;
+
+    (void)arg;
+
+    for (size_t i = 0; i < ARRAY_SIZE(test_waiters); i++) {
+        while (thread_state(test_waiters[i]) != THREAD_SLEEPING) {
+            thread_delay(1, false);
+        }
+    }
+
+    thread_preempt_disable();
+
+    for (size_t i = 0; i < ARRAY_SIZE(test_waiters); i++) {
+        error = semaphore_post(&test_semaphore);
+        error_check(error, "semaphore_post");
+    }
+
+    thread_preempt_enable();
+
+    for (size_t i = 0; i < ARRAY_SIZE(test_waiters); i++) {
+        thread_join(test_waiters[i]);
+    }
+
+    log_info("test: done");
+}
+
+void __init
+test_setup(void)
+{
+    char name[THREAD_NAME_SIZE];
+    struct thread_attr attr;
+    struct cpumap *cpumap;
+    int error;
+
+    semaphore_init(&test_semaphore, 0, TEST_NR_WAITERS);
+
+    error = cpumap_create(&cpumap);
+    error_check(error, "cpumap_create");
+    cpumap_zero(cpumap);
+    cpumap_set(cpumap, 0);
+
+    for (size_t i = 0; i < ARRAY_SIZE(test_waiters); i++) {
+        snprintf(name, sizeof(name), THREAD_KERNEL_PREFIX "test_wait:%zu", i);
+        thread_attr_init(&attr, name);
+        thread_attr_set_cpumap(&attr, cpumap);
+        error = thread_create(&test_waiters[i], &attr, test_wait, NULL);
+        error_check(error, "thread_create");
+    }
+
+    thread_attr_init(&attr, THREAD_KERNEL_PREFIX "test_post");
+    thread_attr_set_detached(&attr);
+    thread_attr_set_cpumap(&attr, cpumap);
+    error = thread_create(NULL, &attr, test_post, NULL);
+    error_check(error, "thread_create");
+}