| /* 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__) |
| #define stat64 stat |
| #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 *)); |
| |
| /* Don't pollute namespace if not building newlib. */ |
| #if defined (__CYGWIN__) && !defined (_COMPILING_NEWLIB) |
| #undef stat64 |
| #endif |
| |
| #endif |
| |
| #endif |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| #endif /* _REENT_H_ */ |