[libc] Add a definition of pthread_attr_t and its getters and setters.

Not all attributes have been added to phtread_attr_t in this patch. They
will be added gradually in future patches.

Reviewed By: lntue

Differential Revision: https://reviews.llvm.org/D123423

1 files changed, 28 insertions, 0 deletions

diff --git a/libc/src/pthread/pthread_attr_init.cpp b/libc/src/pthread/pthread_attr_init.cpp
new file mode 100644
index 000000000000..84b352022874
--- /dev/null
+++ b/libc/src/pthread/pthread_attr_init.cpp
@@ -0,0 +1,28 @@
+//===-- Implementation of the pthread_attr_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_attr_init.h"
+
+#include "src/__support/common.h"
+
+#include <linux/param.h> // For EXEC_PAGESIZE.
+#include <pthread.h>
+
+namespace __llvm_libc {
+
+LLVM_LIBC_FUNCTION(int, pthread_attr_init, (pthread_attr_t * attr)) {
+  *attr = pthread_attr_t{
+      false,         // Not detached
+      nullptr,       // Let the thread manage its stack
+      1 << 16,       // 64KB stack size
+      EXEC_PAGESIZE, // Default page size for the guard size.
+  };
+  return 0;
+}
+
+} // namespace __llvm_libc