Move repositories to 'repos/' subdirectory

This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.

Issue #1082

repos/libports/include/libc-plugin/fd_alloc.h

@@ -0,0 +1,97 @@
+/*
+ * \brief  file descriptor allocator interface
+ * \author Christian Prochaska 
+ * \date   2010-01-21
+ *
+ */
+
+/*
+ * Copyright (C) 2010-2013 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU General Public License version 2.
+ */
+
+#ifndef _LIBC_PLUGIN__FD_ALLOC_H_
+#define _LIBC_PLUGIN__FD_ALLOC_H_
+
+#include <base/allocator_avl.h>
+#include <base/lock.h>
+#include <base/printf.h>
+#include <os/path.h>
+
+/* libc includes */
+#include <stdlib.h>
+#include <string.h>
+
+#include <libc-plugin/plugin.h>
+
+enum { MAX_NUM_FDS = 1024 };
+
+namespace Libc {
+
+	/**
+	 * Plugin-specific file-descriptor context
+	 */
+	class Plugin_context { };
+
+	enum { ANY_FD = -1 };
+
+	struct File_descriptor
+	{
+		int             libc_fd = -1;
+		char     const *fd_path = 0;  /* for 'fchdir', 'fstat' */
+		Plugin         *plugin  = 0;
+		Plugin_context *context = 0;
+		unsigned        flags   = 0;  /* for 'fcntl' */
+		unsigned        status  = 0;  /* for 'fcntl' */
+		Genode::Lock    lock;
+
+		void path(char const *newpath)
+		{
+			if (newpath) {
+				size_t const path_size = ::strlen(newpath) + 1;
+				char *buf = (char*)malloc(path_size);
+				if (!buf) {
+					PERR("could not allocate path buffer for libc_fd %d%s",
+					     libc_fd, libc_fd == ANY_FD ? " (any)" : "");
+					return;
+				}
+				::memcpy(buf, newpath, path_size);
+				fd_path = buf;
+			} else
+				fd_path = 0;
+		}
+	};
+
+
+	class File_descriptor_allocator : Allocator_avl_tpl<File_descriptor>
+	{
+		public:
+
+			/**
+			 * Constructor
+			 */
+			File_descriptor_allocator();
+
+			/**
+			 * Allocate file descriptor
+			 */
+			File_descriptor *alloc(Plugin *plugin, Plugin_context *context, int libc_fd = -1);
+
+			/**
+			 * Release file descriptor
+			 */
+			void free(File_descriptor *fdo);
+
+			File_descriptor *find_by_libc_fd(int libc_fd);
+	};
+
+
+	/**
+	 * Return singleton instance of file-descriptor allocator
+	 */
+	extern File_descriptor_allocator *file_descriptor_allocator();
+}
+
+#endif /* _LIBC_PLUGIN__FD_ALLOC_H_ */