diff --git a/libc/src/pthread/pthread_mutexattr_destroy.h b/libc/src/pthread/pthread_mutexattr_destroy.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for pthread_mutexattr_destroy -----*- 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_PTHREAD_PTHREAD_MUTEXATTR_DESTROY_H
+#define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_DESTROY_H
+
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+int pthread_mutexattr_destroy(pthread_mutexattr_t *attr);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_DESTROY_H
diff --git a/libc/src/pthread/pthread_mutexattr_getpshared.cpp b/libc/src/pthread/pthread_mutexattr_getpshared.cpp
@@ -0,0 +1,26 @@
+//===-- Implementation of the pthread_mutexattr_getpshared ----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "pthread_mutexattr_getpshared.h"
+#include "pthread_mutexattr.h"
+
+#include "src/__support/common.h"
+
+#include <errno.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, pthread_mutexattr_getpshared,
+                   (const pthread_mutexattr_t *__restrict attr,
+                    int *__restrict pshared)) {
+  *pshared = (*attr & unsigned(PThreadMutexAttrPos::PSHARED_MASK)) >>
+             unsigned(PThreadMutexAttrPos::PSHARED_SHIFT);
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/pthread/pthread_mutexattr_getpshared.h b/libc/src/pthread/pthread_mutexattr_getpshared.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for pthread_mutexattr_getpshared --*- 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_PTHREAD_PTHREAD_MUTEXATTR_GETPSHARED_H
+#define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_GETPSHARED_H
+
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+int pthread_mutexattr_getpshared(const pthread_mutexattr_t *__restrict attr,
+                                 int *__restrict pshared);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_GETPSHARED_H
diff --git a/libc/src/pthread/pthread_mutexattr_getrobust.cpp b/libc/src/pthread/pthread_mutexattr_getrobust.cpp
@@ -0,0 +1,26 @@
+//===-- Implementation of the pthread_mutexattr_getrobust -----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "pthread_mutexattr_getrobust.h"
+#include "pthread_mutexattr.h"
+
+#include "src/__support/common.h"
+
+#include <errno.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, pthread_mutexattr_getrobust,
+                   (const pthread_mutexattr_t *__restrict attr,
+                    int *__restrict robust)) {
+  *robust = (*attr & unsigned(PThreadMutexAttrPos::ROBUST_MASK)) >>
+            unsigned(PThreadMutexAttrPos::ROBUST_SHIFT);
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/pthread/pthread_mutexattr_getrobust.h b/libc/src/pthread/pthread_mutexattr_getrobust.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for pthread_mutexattr_getrobust ---*- 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_PTHREAD_PTHREAD_MUTEXATTR_GETROBUST_H
+#define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_GETROBUST_H
+
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+int pthread_mutexattr_getrobust(const pthread_mutexattr_t *__restrict attr,
+                                int *__restrict robust);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_GETROBUST_H
diff --git a/libc/src/pthread/pthread_mutexattr_gettype.cpp b/libc/src/pthread/pthread_mutexattr_gettype.cpp
@@ -0,0 +1,26 @@
+//===-- Implementation of the pthread_mutexattr_gettype -------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "pthread_mutexattr_gettype.h"
+#include "pthread_mutexattr.h"
+
+#include "src/__support/common.h"
+
+#include <errno.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, pthread_mutexattr_gettype,
+                   (const pthread_mutexattr_t *__restrict attr,
+                    int *__restrict type)) {
+  *type = (*attr & unsigned(PThreadMutexAttrPos::TYPE_MASK)) >>
+          unsigned(PThreadMutexAttrPos::TYPE_SHIFT);
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/pthread/pthread_mutexattr_gettype.h b/libc/src/pthread/pthread_mutexattr_gettype.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for pthread_mutexattr_gettype -----*- 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_PTHREAD_PTHREAD_MUTEXATTR_GETTYPE_H
+#define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_GETTYPE_H
+
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+int pthread_mutexattr_gettype(const pthread_mutexattr_t *__restrict attr,
+                              int *__restrict type);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_GETTYPE_H
diff --git a/libc/src/pthread/pthread_mutexattr_init.cpp b/libc/src/pthread/pthread_mutexattr_init.cpp
@@ -0,0 +1,23 @@
+//===-- Implementation of the pthread_mutexattr_init ----------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "pthread_mutexattr_init.h"
+#include "pthread_mutexattr.h"
+
+#include "src/__support/common.h"
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, pthread_mutexattr_init, (pthread_mutexattr_t * attr)) {
+  // Set the default attributes and mark the attribute object as initiliazed
+  // by setting the first bit.
+  *attr = DEFAULT_MUTEXATTR;
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/pthread/pthread_mutexattr_init.h b/libc/src/pthread/pthread_mutexattr_init.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for pthread_mutexattr_init --------*- 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_PTHREAD_PTHREAD_MUTEXATTR_INIT_H
+#define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_INIT_H
+
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+int pthread_mutexattr_init(pthread_mutexattr_t *attr);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_INIT_H
diff --git a/libc/src/pthread/pthread_mutexattr_setpshared.cpp b/libc/src/pthread/pthread_mutexattr_setpshared.cpp
@@ -0,0 +1,29 @@
+//===-- Implementation of the pthread_mutexattr_setpshared ----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "pthread_mutexattr_setpshared.h"
+#include "pthread_mutexattr.h"
+
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, pthread_mutexattr_setpshared,
+                   (pthread_mutexattr_t *__restrict attr, int pshared)) {
+  if (pshared != PTHREAD_PROCESS_PRIVATE && pshared != PTHREAD_PROCESS_SHARED)
+    return EINVAL;
+  pthread_mutexattr_t old = *attr;
+  old &= ~unsigned(PThreadMutexAttrPos::PSHARED_MASK);
+  *attr = old | (pshared << unsigned(PThreadMutexAttrPos::PSHARED_SHIFT));
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/pthread/pthread_mutexattr_setpshared.h b/libc/src/pthread/pthread_mutexattr_setpshared.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for pthread_mutexattr_setpshared --*- 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_PTHREAD_PTHREAD_MUTEXATTR_SETpshared_H
+#define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_SETpshared_H
+
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+int pthread_mutexattr_setpshared(pthread_mutexattr_t *__restrict attr,
+                                 int pshared);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_SETpshared_H
diff --git a/libc/src/pthread/pthread_mutexattr_setrobust.cpp b/libc/src/pthread/pthread_mutexattr_setrobust.cpp
@@ -0,0 +1,29 @@
+//===-- Implementation of the pthread_mutexattr_setrobust -----------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "pthread_mutexattr_setrobust.h"
+#include "pthread_mutexattr.h"
+
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, pthread_mutexattr_setrobust,
+                   (pthread_mutexattr_t *__restrict attr, int robust)) {
+  if (robust != PTHREAD_MUTEX_STALLED && robust != PTHREAD_MUTEX_ROBUST)
+    return EINVAL;
+  pthread_mutexattr_t old = *attr;
+  old &= ~unsigned(PThreadMutexAttrPos::ROBUST_MASK);
+  *attr = old | (robust << unsigned(PThreadMutexAttrPos::ROBUST_SHIFT));
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/pthread/pthread_mutexattr_setrobust.h b/libc/src/pthread/pthread_mutexattr_setrobust.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for pthread_mutexattr_setrobust ---*- 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_PTHREAD_PTHREAD_MUTEXATTR_SETROBUST_H
+#define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_SETROBUST_H
+
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+int pthread_mutexattr_setrobust(pthread_mutexattr_t *__restrict attr,
+                                int robust);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_SETROBUST_H
diff --git a/libc/src/pthread/pthread_mutexattr_settype.cpp b/libc/src/pthread/pthread_mutexattr_settype.cpp
@@ -0,0 +1,31 @@
+//===-- Implementation of the pthread_mutexattr_settype -------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "pthread_mutexattr_settype.h"
+#include "pthread_mutexattr.h"
+
+#include "src/__support/common.h"
+
+#include <errno.h>
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, pthread_mutexattr_settype,
+                   (pthread_mutexattr_t *__restrict attr, int type)) {
+  if (type != PTHREAD_MUTEX_NORMAL && type != PTHREAD_MUTEX_ERRORCHECK &&
+      type != PTHREAD_MUTEX_RECURSIVE) {
+    return EINVAL;
+  }
+  pthread_mutexattr_t old = *attr;
+  old &= ~unsigned(PThreadMutexAttrPos::TYPE_MASK);
+  *attr = old | (type << unsigned(PThreadMutexAttrPos::TYPE_SHIFT));
+  return 0;
+}
+
+} // namespace __llvm_libc
diff --git a/libc/src/pthread/pthread_mutexattr_settype.h b/libc/src/pthread/pthread_mutexattr_settype.h
@@ -0,0 +1,20 @@
+//===-- Implementation header for pthread_mutexattr_settype -----*- 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_PTHREAD_PTHREAD_MUTEXATTR_SETTYPE_H
+#define LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_SETTYPE_H
+
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+int pthread_mutexattr_settype(pthread_mutexattr_t *__restrict attr, int type);
+
+} // namespace __llvm_libc
+
+#endif // LLVM_LIBC_SRC_PTHREAD_PTHREAD_MUTEXATTR_SETTYPE_H
diff --git a/libc/test/src/CMakeLists.txt b/libc/test/src/CMakeLists.txt
@@ -52,6 +52,10 @@ add_subdirectory(stdio)
 add_subdirectory(threads)
 add_subdirectory(time)
 
+if(${LIBC_TARGET_OS} STREQUAL "linux")
+  add_subdirectory(pthread)
+endif()
+
 set(public_test ${CMAKE_CURRENT_BINARY_DIR}/public_api_test.cpp)
 
 set(entrypoints_name_list "")

diff --git a/libc/test/src/pthread/CMakeLists.txt b/libc/test/src/pthread/CMakeLists.txt
@@ -0,0 +1,20 @@
+add_libc_testsuite(libc_pthread_unittests)
+
+add_libc_unittest(
+  pthread_mutexattr_test
+  SUITE
+    libc_pthread_unittests
+  SRCS
+    pthread_mutexattr_test.cpp
+  DEPENDS
+    libc.include.errno
+    libc.include.pthread
+    libc.src.pthread.pthread_mutexattr_destroy
+    libc.src.pthread.pthread_mutexattr_init
+    libc.src.pthread.pthread_mutexattr_getpshared
+    libc.src.pthread.pthread_mutexattr_getrobust
+    libc.src.pthread.pthread_mutexattr_gettype
+    libc.src.pthread.pthread_mutexattr_setpshared
+    libc.src.pthread.pthread_mutexattr_setrobust
+    libc.src.pthread.pthread_mutexattr_settype
+)
diff --git a/libc/test/src/pthread/pthread_mutexattr_test.cpp b/libc/test/src/pthread/pthread_mutexattr_test.cpp
@@ -0,0 +1,91 @@
+//===-- Unittests for pthread_mutexattr_t ---------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/pthread/pthread_mutexattr_destroy.h"
+#include "src/pthread/pthread_mutexattr_getpshared.h"
+#include "src/pthread/pthread_mutexattr_getrobust.h"
+#include "src/pthread/pthread_mutexattr_gettype.h"
+#include "src/pthread/pthread_mutexattr_init.h"
+#include "src/pthread/pthread_mutexattr_setpshared.h"
+#include "src/pthread/pthread_mutexattr_setrobust.h"
+#include "src/pthread/pthread_mutexattr_settype.h"
+#include "utils/UnitTest/Test.h"
+
+#include <errno.h>
+#include <pthread.h>
+
+TEST(LlvmLibcPThreadMutexAttrTest, InitAndDestroy) {
+  pthread_mutexattr_t attr;
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_init(&attr), 0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_destroy(&attr), 0);
+}
+
+TEST(LlvmLibcPThreadMutexAttrTest, SetAndGetType) {
+  int type;
+  pthread_mutexattr_t attr;
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_init(&attr), 0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_gettype(&attr, &type), 0);
+  ASSERT_EQ(type, int(PTHREAD_MUTEX_DEFAULT));
+
+  ASSERT_EQ(
+      __llvm_libc::pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE),
+      0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_gettype(&attr, &type), 0);
+  ASSERT_EQ(type, int(PTHREAD_MUTEX_RECURSIVE));
+
+  ASSERT_EQ(
+      __llvm_libc::pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK),
+      0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_gettype(&attr, &type), 0);
+  ASSERT_EQ(type, int(PTHREAD_MUTEX_ERRORCHECK));
+
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_settype(&attr, 0xBAD), EINVAL);
+}
+
+TEST(LlvmLibcPThreadMutexAttrTest, SetAndGetRobust) {
+  int robust;
+  pthread_mutexattr_t attr;
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_init(&attr), 0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_getrobust(&attr, &robust), 0);
+  ASSERT_EQ(robust, int(PTHREAD_MUTEX_STALLED));
+
+  ASSERT_EQ(
+      __llvm_libc::pthread_mutexattr_setrobust(&attr, PTHREAD_MUTEX_ROBUST), 0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_getrobust(&attr, &robust), 0);
+  ASSERT_EQ(robust, int(PTHREAD_MUTEX_ROBUST));
+
+  ASSERT_EQ(
+      __llvm_libc::pthread_mutexattr_setrobust(&attr, PTHREAD_MUTEX_STALLED),
+      0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_getrobust(&attr, &robust), 0);
+  ASSERT_EQ(robust, int(PTHREAD_MUTEX_STALLED));
+
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_setrobust(&attr, 0xBAD), EINVAL);
+}
+
+TEST(LlvmLibcPThreadMutexAttrTest, SetAndGetPShared) {
+  int pshared;
+  pthread_mutexattr_t attr;
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_init(&attr), 0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_getpshared(&attr, &pshared), 0);
+  ASSERT_EQ(pshared, int(PTHREAD_PROCESS_PRIVATE));
+
+  ASSERT_EQ(
+      __llvm_libc::pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED),
+      0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_getpshared(&attr, &pshared), 0);
+  ASSERT_EQ(pshared, int(PTHREAD_PROCESS_SHARED));
+
+  ASSERT_EQ(
+      __llvm_libc::pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_PRIVATE),
+      0);
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_getpshared(&attr, &pshared), 0);
+  ASSERT_EQ(pshared, int(PTHREAD_PROCESS_PRIVATE));
+
+  ASSERT_EQ(__llvm_libc::pthread_mutexattr_setpshared(&attr, 0xBAD), EINVAL);
+}