[libc-commits] [libc] [libc][semaphore] Add unnamed semaphore implementation (PR #190851)

[Michael Jones via libc-commits]

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@@ -0,0 +1,31 @@
+//===-- Implementation of sem_getvalue -----------------------------------===//
+//
+// 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/semaphore/sem_getvalue.h"
+
+#include "src/semaphore/posix_semaphore.h"
+
+#include "hdr/errno_macros.h"
+#include "src/__support/common.h"
+#include "src/__support/libc_errno.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, sem_getvalue,
+                   (sem_t *__restrict sem, int *__restrict sval)) {
+  auto *s = reinterpret_cast<Semaphore *>(sem);
+  if (sem == nullptr || !s->is_valid() || sval == nullptr) {
+    libc_errno = EINVAL;
+    return -1;
+  }
+
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michaelrj-google wrote:

add a todo to handle the case where the semaphore is locked.

https://github.com/llvm/llvm-project/pull/190851