libc: io: implement file io buffering and internal locking for concurrency

2026-04-01 18:51:13 +01:00
parent f2e650d368
commit 548387c43a
23 changed files with 948 additions and 73 deletions
@@ -0,0 +1,29 @@
+#include "file.h"
+
+#include <unistd.h>
+
+size_t fwrite(
+	const void *buf,
+	size_t size,
+	size_t count,
+	struct __opaque_file *stream)
+{
+	__libc_file_lock(stream);
+	size_t total = size * count;
+	if (total == 0) {
+		return 0;
+	}
+
+	long ret = __libc_file_write(stream, buf, total);
+	if (ret == 0) {
+		stream->f_flags |= FILE_EOF;
+	}
+
+	if (ret < 0) {
+		stream->f_flags |= FILE_ERR;
+		ret = 0;
+	}
+
+	__libc_file_unlock(stream);
+	return ret;
+}