[libc] Call mtx_init in mtx_test.

[sivachandra]

Summary

A typo which was caught has also been fixed.

libc/src/threads/mtx_init.h

 //===-- Implementation header for mtx_init function -------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_LIBC_SRC_THREADS_LINUX_MTX_INIT_H
 #define LLVM_LIBC_SRC_THREADS_LINUX_MTX_INIT_H
 
 #include "include/threads.h"
 
 namespace __llvm_libc {
 
-int mtx_int(mtx_t *mutex, int type);
+int mtx_init(mtx_t *mutex, int type);
 
 } // namespace __llvm_libc
 
 #endif // LLVM_LIBC_SRC_THREADS_LINUX_MTX_INIT_H

libc/test/src/threads/mtx_test.cpp

while (true) {
     __llvm_libc::mtx_unlock(&mutex);
     if (last_count >= MAX)
       break;
   }
   return 0;
 }
 
 TEST(MutexTest, RelayCounter) {
+  ASSERT_EQ(__llvm_libc::mtx_init(&mutex, mtx_plain),
+            static_cast<int>(thrd_success));
+
   // The idea of this test is that two competing threads will update
   // a counter only if the other thread has updated it.
   thrd_t thread;
   __llvm_libc::thrd_create(&thread, counter, nullptr);
 
   int last_count = START;
   while (true) {
-    ASSERT_EQ(__llvm_libc::mtx_lock(&mutex), (int)thrd_success);
+    ASSERT_EQ(__llvm_libc::mtx_lock(&mutex), static_cast<int>(thrd_success));
     if (shared_int == START) {
       ++shared_int;
       last_count = shared_int;
     } else if (shared_int != last_count) {
       ASSERT_EQ(shared_int, last_count + 1);
       ++shared_int;
       last_count = shared_int;
     }
-    ASSERT_EQ(__llvm_libc::mtx_unlock(&mutex), (int)thrd_success);
+    ASSERT_EQ(__llvm_libc::mtx_unlock(&mutex), static_cast<int>(thrd_success));
     if (last_count > MAX)
       break;
   }
 
   int retval = 123;
   __llvm_libc::thrd_join(&thread, &retval);
   ASSERT_EQ(retval, 0);
 }
 
 mtx_t start_lock, step_lock;
 bool start, step;
 
 int stepper(void *arg) {
   __llvm_libc::mtx_lock(&start_lock);
   start = true;
   __llvm_libc::mtx_unlock(&start_lock);
 
   __llvm_libc::mtx_lock(&step_lock);
   step = true;
   __llvm_libc::mtx_unlock(&step_lock);
   return 0;
 }
 
 TEST(MutexTest, WaitAndStep) {
+  ASSERT_EQ(__llvm_libc::mtx_init(&start_lock, mtx_plain),
+            static_cast<int>(thrd_success));
+  ASSERT_EQ(__llvm_libc::mtx_init(&step_lock, mtx_plain),
+            static_cast<int>(thrd_success));
+
   // In this test, we start a new thread but block it before it can make a
   // step. Once we ensure that the thread is blocked, we unblock it.
   // After unblocking, we then verify that the thread was indeed unblocked.
   step = false;
   start = false;
-  ASSERT_EQ(__llvm_libc::mtx_lock(&step_lock), (int)thrd_success);
+  ASSERT_EQ(__llvm_libc::mtx_lock(&step_lock), static_cast<int>(thrd_success));
 
   thrd_t thread;
   __llvm_libc::thrd_create(&thread, stepper, nullptr);
 
   while (true) {
     // Make sure the thread actually started.
-    ASSERT_EQ(__llvm_libc::mtx_lock(&start_lock), (int)thrd_success);
+    ASSERT_EQ(__llvm_libc::mtx_lock(&start_lock),
+              static_cast<int>(thrd_success));
     bool s = start;
-    ASSERT_EQ(__llvm_libc::mtx_unlock(&start_lock), (int)thrd_success);
+    ASSERT_EQ(__llvm_libc::mtx_unlock(&start_lock),
+              static_cast<int>(thrd_success));
     if (s)
       break;
   }
 
   // Since |step_lock| is still locked, |step| should be false.
   ASSERT_FALSE(step);
 
   // Unlock the step lock and wait until the step is made.
-  ASSERT_EQ(__llvm_libc::mtx_unlock(&step_lock), (int)thrd_success);
+  ASSERT_EQ(__llvm_libc::mtx_unlock(&step_lock),
+            static_cast<int>(thrd_success));
 
   while (true) {
-    ASSERT_EQ(__llvm_libc::mtx_lock(&step_lock), (int)thrd_success);
+    ASSERT_EQ(__llvm_libc::mtx_lock(&step_lock),
+              static_cast<int>(thrd_success));
     bool current_step_value = step;
-    ASSERT_EQ(__llvm_libc::mtx_unlock(&step_lock), (int)thrd_success);
+    ASSERT_EQ(__llvm_libc::mtx_unlock(&step_lock),
+              static_cast<int>(thrd_success));
     if (current_step_value)
       break;
   }
 
   int retval = 123;
   __llvm_libc::thrd_join(&thread, &retval);
   ASSERT_EQ(retval, 0);
 }