sdm: Add Sys::* types for system call wrappers.

- Add Sys class which encapsulates all system calls.
- Fix crash if display initialization failed.

Change-Id: I622aa7f415bf10a6c65a730cbe0dcf2426bae963
diff --git a/sdm/include/utils/sys.h b/sdm/include/utils/sys.h
new file mode 100644
index 0000000..1c7e415
--- /dev/null
+++ b/sdm/include/utils/sys.h
@@ -0,0 +1,60 @@
+/*
+* Copyright (c) 2015, The Linux Foundation. All rights reserved.
+*
+* Redistribution and use in source and binary forms, with or without modification, are permitted
+* provided that the following conditions are met:
+*    * Redistributions of source code must retain the above copyright notice, this list of
+*      conditions and the following disclaimer.
+*    * Redistributions in binary form must reproduce the above copyright notice, this list of
+*      conditions and the following disclaimer in the documentation and/or other materials provided
+*      with the distribution.
+*    * Neither the name of The Linux Foundation nor the names of its contributors may be used to
+*      endorse or promote products derived from this software without specific prior written
+*      permission.
+*
+* THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+* NON-INFRINGEMENT ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef __SYS_H__
+#define __SYS_H__
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <poll.h>
+
+namespace sdm {
+
+class Sys {
+ public:
+  // Pointers to system calls which are either mapped to actual system call or virtual driver.
+  typedef int (*ioctl)(int, int, ...);
+  typedef int (*open)(const char *, int, ...);
+  typedef int (*close)(int);
+  typedef int (*poll)(struct pollfd *, nfds_t, int);
+  typedef ssize_t (*pread)(int, void *, size_t, off_t);
+  typedef ssize_t (*pwrite)(int, const void *, size_t, off_t);
+  typedef FILE* (*fopen)( const char *fname, const char *mode);
+  typedef int (*fclose)(FILE* fileptr);
+  typedef ssize_t (*getline)(char **lineptr, size_t *linelen, FILE *stream);
+
+  static ioctl ioctl_;
+  static open open_;
+  static close close_;
+  static poll poll_;
+  static pread pread_;
+  static pwrite pwrite_;
+  static fopen fopen_;
+  static fclose fclose_;
+  static getline getline_;
+};
+
+}  // namespace sdm
+
+#endif  // __SYS_H__