[UCRT] Import Microsoft.Windows.SDK.CRTSource version 10.0.22621.3

Imported from https://www.nuget.org/packages/Microsoft.Windows.SDK.CRTSource/10.0.22621.3
License: MIT

sdk/lib/ucrt/stdio/fclose.cpp

@@ -0,0 +1,86 @@
+//
+// fclose.cpp
+//
+//      Copyright (c) Microsoft Corporation.  All rights reserved.
+//
+// Defines fclose(), which closes a stdio stream.
+//
+#include <corecrt_internal_stdio.h>
+#include <corecrt_internal_ptd_propagation.h>
+
+
+
+// Closes a stdio stream after flushing the stream and freeing any buffer
+// associated with the stream (unless the buffer was set with setbuf).  Returns
+// zero on success; EOF on failure (e.g., if the flush fails, or it is not a
+// valid file or the file is not open, etc.).
+static int __cdecl _fclose_nolock_internal(FILE* const public_stream, __crt_cached_ptd_host& ptd)
+{
+    __crt_stdio_stream const stream(public_stream);
+
+    _UCRT_VALIDATE_RETURN(ptd, stream.valid(), EINVAL, EOF);
+
+    int result = EOF;
+
+    if (stream.is_in_use())
+    {
+        result = __acrt_stdio_flush_nolock(stream.public_stream(), ptd);
+        __acrt_stdio_free_buffer_nolock(stream.public_stream());
+
+        if (_close_internal(_fileno(stream.public_stream()), ptd) < 0)
+        {
+            result = EOF;
+        }
+        else if (stream->_tmpfname != nullptr)
+        {
+            _free_crt(stream->_tmpfname);
+            stream->_tmpfname = nullptr;
+        }
+    }
+
+    __acrt_stdio_free_stream(stream);
+
+    return result;
+}
+
+extern "C" int __cdecl _fclose_nolock(FILE* const public_stream)
+{
+    __crt_cached_ptd_host ptd;
+    return _fclose_nolock_internal(public_stream, ptd);
+}
+
+static int __cdecl _fclose_internal(FILE* const public_stream, __crt_cached_ptd_host& ptd)
+{
+    __crt_stdio_stream const stream(public_stream);
+
+    _UCRT_VALIDATE_RETURN(ptd, stream.valid(), EINVAL, EOF);
+
+    // If the stream is backed by a string, it requires no synchronization,
+    // flushing, etc., so we can simply free it, which resets all of its
+    // data to the defaults.
+    if (stream.is_string_backed())
+    {
+        __acrt_stdio_free_stream(stream);
+        return EOF;
+    }
+
+    int return_value = 0;
+
+    _lock_file(stream.public_stream());
+    __try
+    {
+        return_value = _fclose_nolock_internal(stream.public_stream(), ptd);
+    }
+    __finally
+    {
+        _unlock_file(stream.public_stream());
+    }
+
+    return return_value;
+}
+
+extern "C" int __cdecl fclose(FILE* const public_stream)
+{
+    __crt_cached_ptd_host ptd;
+    return _fclose_internal(public_stream, ptd);
+}