/** This header file provides the reentrancy. */
  

  /** The reentrant system calls here serve two purposes:
  

  

  1) Provide reentrant versions of the system calls the ANSI C library
  

  requires.
  

  

  2) Provide these system calls in a namespace clean way.
  

  

  It is intended that all system calls that the ANSI C library needs
  

  be declared here. It documents them all in one place. All library access
  

  to the system is via some form of these functions.
  

  

  The target may provide the needed syscalls by any of the following:
  

  

  1) Define the reentrant versions of the syscalls directly.
  

  (eg: _open_r, _close_r, etc.). Please keep the namespace clean.
  

  When you do this, set "syscall_dir" to "syscalls" and add
  

  -DREENTRANT_SYSCALLS_PROVIDED to newlib_cflags in configure.host.
  

  

  2) Define namespace clean versions of the system calls by prefixing
  

  them with '_' (eg: _open, _close, etc.). Technically, there won't be
  

  true reentrancy at the syscall level, but the library will be namespace
  

  clean.
  

  When you do this, set "syscall_dir" to "syscalls" in configure.host.
  

  

  3) Define or otherwise provide the regular versions of the syscalls
  

  (eg: open, close, etc.). The library won't be reentrant nor namespace
  

  clean, but at least it will work.
  

  When you do this, add -DMISSING_SYSCALL_NAMES to newlib_cflags in
  

  configure.host.
  

  

  4) Define or otherwise provide the regular versions of the syscalls,
  

  and do not supply functional interfaces for any of the reentrant
  

  calls. With this method, the reentrant syscalls are redefined to
  

  directly call the regular system call without the reentrancy argument.
  

  When you do this, specify both -DREENTRANT_SYSCALLS_PROVIDED and
  

  -DMISSING_SYSCALL_NAMES via newlib_cflags in configure.host and do
  

  not specify "syscall_dir".
  

  

  Stubs of the reentrant versions of the syscalls exist in the libc/reent
  

  source directory and are provided if REENTRANT_SYSCALLS_PROVIDED isn't
  

  defined. These stubs call the native system calls: _open, _close, etc.
  

  if MISSING_SYSCALL_NAMES is not defined, otherwise they call the
  

  non-underscored versions: open, close, etc. when MISSING_SYSCALL_NAMES
  

  is defined.
  

  

  By default, newlib functions call the reentrant syscalls internally,
  

  passing a reentrancy structure as an argument. This reentrancy structure
  

  contains data that is thread-specific. For example, the errno value is
  

  kept in the reentrancy structure. If multiple threads exist, each will
  

  keep a separate errno value which is intuitive since the application flow
  

  cannot check for failure reliably otherwise.
  

  

  The reentrant syscalls are either provided by the platform, by the
  

  libc/reent stubs, or in the case of both MISSING_SYSCALL_NAMES and
  

  REENTRANT_SYSCALLS_PROVIDED being defined, the calls are redefined to
  

  simply call the regular syscalls with no reentrancy struct argument.
  

  

  A single-threaded application does not need to worry about the reentrancy
  

  structure. It is used internally.
  

  

  A multi-threaded application needs either to manually manage reentrancy
  

  structures or use dynamic reentrancy.
  

  

  Manually managing reentrancy structures entails calling special reentrant
  

  versions of newlib functions that have an additional reentrancy argument.
  

  For example, _printf_r. By convention, the first argument is the
  

  reentrancy structure. By default, the normal version of the function
  

  uses the default reentrancy structure: _REENT. The reentrancy structure
  

  is passed internally, eventually to the reentrant syscalls themselves.
  

  How the structures are stored and accessed in this model is up to the
  

  application.
  

  

  Dynamic reentrancy is specified by the __DYNAMIC_REENT__ flag. This
  

  flag denotes setting up a macro to replace _REENT with a function call
  

  to __getreent(). This function needs to be implemented by the platform
  

  and it is meant to return the reentrancy structure for the current
  

  thread. When the regular C functions (e.g. printf) go to call internal
  

  routines with the default _REENT structure, they end up calling with
  

  the reentrancy structure for the thread. Thus, application code does not
  

  need to call the _r routines nor worry about reentrancy structures. */
  

  

  /** WARNING: All identifiers here must begin with an underscore. This file is
  

  included by stdio.h and others and we therefore must only use identifiers
  

  in the namespace allotted to us. */
  

  

  #ifndef _REENT_H_
  

  #ifdef __cplusplus
  

  extern "C" {
  

  #endif
  

  #define _REENT_H_
  

  

  #include <sys/reent.h>
  

  #include <sys/_types.h>
  

  #include <machine/types.h>
  

  

  #define __need_size_t
  

  #define __need_ptrdiff_t
  

  #include <stddef.h>
  

  

  /** FIXME: not namespace clean */
  

  struct stat;
  

  struct tms;
  

  struct timeval;
  

  struct timezone;
  

  

  #if defined(REENTRANT_SYSCALLS_PROVIDED) && defined(MISSING_SYSCALL_NAMES)
  

  #define _close_r(__reent, __fd) close(__fd)
  

  

  #define _execve_r(__reent, __f, __arg, __env) execve(__f, __arg, __env)
  

  #define _fcntl_r(__reent, __fd, __cmd, __arg) fcntl(__fd, __cmd, __arg)
  

  #define _fork_r(__reent) fork()
  

  #define _fstat_r(__reent, __fdes, __stat) fstat(__fdes, __stat)
  

  #define _getpid_r(__reent) getpid()
  

  #define _isatty_r(__reent, __desc) isatty(__desc)
  

  #define _kill_r(__reent, __pid, __signal) kill(__pid, __signal)
  

  #define _link_r(__reent, __oldpath, __newpath) link(__oldpath, __newpath)
  

  #define _lseek_r(__reent, __fdes, __off, __w) lseek(__fdes, __off, __w)
  

  #define _mkdir_r(__reent, __path, __m) mkdir(__path, __m)
  

  #define _open_r(__reent, __path, __flag, __m) open(__path, __flag, __m)
  

  #define _read_r(__reent, __fd, __buff, __cnt) read(__fd, __buff, __cnt)
  

  #define _rename_r(__reent, __old, __new) rename(__old, __new)
  

  #define _sbrk_r(__reent, __incr) sbrk(__incr)
  

  #define _stat_r(__reent, __path, __buff) stat(__path, __buff)
  

  #define _times_r(__reent, __time) times(__time)
  

  #define _unlink_r(__reent, __path) unlink(__path)
  

  #define _wait_r(__reent, __status) wait(__status)
  

  #define _write_r(__reent, __fd, __buff, __cnt) write(__fd, __buff, __cnt)
  

  #define _gettimeofday_r(__reent, __tp, __tzp) gettimeofday(__tp, __tzp)
  

  

  #ifdef __LARGE64_FILES
  

  #define _lseek64_r(__reent, __fd, __off, __w) lseek64(__fd, __off, __w)
  

  #define _fstat64_r(__reent, __fd, __buff) fstat64(__fd, __buff)
  

  #define _open64_r(__reent, __path, __flag, __m) open64(__path, __flag, __m)
  

  #endif
  

  

  #else
  

  /** Reentrant versions of system calls. */
  

  

  extern int _close_r _PARAMS ((struct _reent *, int));
  

  extern int _execve_r _PARAMS ((struct _reent *, const char *, char *const *, char *const *));
  

  extern int _fcntl_r _PARAMS ((struct _reent *, int, int, int));
  

  extern int _fork_r _PARAMS ((struct _reent *));
  

  extern int _fstat_r _PARAMS ((struct _reent *, int, struct stat *));
  

  extern int _getpid_r _PARAMS ((struct _reent *));
  

  extern int _isatty_r _PARAMS ((struct _reent *, int));
  

  extern int _kill_r _PARAMS ((struct _reent *, int, int));
  

  extern int _link_r _PARAMS ((struct _reent *, const char *, const char *));
  

  extern _off_t _lseek_r _PARAMS ((struct _reent *, int, _off_t, int));
  

  extern int _mkdir_r _PARAMS ((struct _reent *, const char *, int));
  

  extern int _open_r _PARAMS ((struct _reent *, const char *, int, int));
  

  extern _ssize_t _read_r _PARAMS ((struct _reent *, int, void *, size_t));
  

  extern int _rename_r _PARAMS ((struct _reent *, const char *, const char *));
  

  extern void *_sbrk_r _PARAMS ((struct _reent *, ptrdiff_t));
  

  extern int _stat_r _PARAMS ((struct _reent *, const char *, struct stat *));
  

  extern _CLOCK_T_ _times_r _PARAMS ((struct _reent *, struct tms *));
  

  extern int _unlink_r _PARAMS ((struct _reent *, const char *));
  

  extern int _wait_r _PARAMS ((struct _reent *, int *));
  

  extern _ssize_t _write_r _PARAMS ((struct _reent *, int, const void *, size_t));
  

  

  /** This one is not guaranteed to be available on all targets. */
  

  extern int _gettimeofday_r _PARAMS ((struct _reent *, struct timeval *__tp, void *__tzp));
  

  

  #ifdef __LARGE64_FILES
  

  

  #if defined(__CYGWIN__) && defined(_COMPILING_NEWLIB)
  

  #define stat64 __stat64
  

  #endif
  

  

  struct stat64;
  

  

  extern _off64_t _lseek64_r _PARAMS ((struct _reent *, int, _off64_t, int));
  

  extern int _fstat64_r _PARAMS ((struct _reent *, int, struct stat64 *));
  

  extern int _open64_r _PARAMS ((struct _reent *, const char *, int, int));
  

  extern int _stat64_r _PARAMS ((struct _reent *, const char *, struct stat64 *));
  

  #endif
  

  

  #endif
  

  

  #ifdef __cplusplus
  

  }
  

  

  #endif
  

  #endif /** _REENT_H_ */