diff options
Diffstat (limited to 'newlib/libc/include/reent.h')
| -rw-r--r-- | newlib/libc/include/reent.h | 87 |
1 files changed, 5 insertions, 82 deletions
diff --git a/newlib/libc/include/reent.h b/newlib/libc/include/reent.h index dfd0c9a36..639789e71 100644 --- a/newlib/libc/include/reent.h +++ b/newlib/libc/include/reent.h @@ -10,7 +10,7 @@ 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: + There are three ways a target may provide the needed syscalls. 1) Define the reentrant versions of the syscalls directly. (eg: _open_r, _close_r, etc.). Please keep the namespace clean. @@ -29,56 +29,11 @@ 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. */ + source directory and are used if REENTRANT_SYSCALLS_PROVIDED isn't defined. + They use the native system calls: _open, _close, etc. if they're available + (MISSING_SYSCALL_NAMES is *not* defined), otherwise open, close, etc. + (MISSING_SYSCALL_NAMES *is* defined). */ /* 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 @@ -104,35 +59,6 @@ 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 _open_r(__reent, __path, __flag, __m) open(__path, __flag, __m) -#define _read_r(__reent, __fd, __buff, __cnt) read(__fd, __buff, __cnt) -#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)); @@ -141,7 +67,6 @@ 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)); @@ -170,8 +95,6 @@ extern int _fstat64_r _PARAMS ((struct _reent *, int, struct stat64 *)); extern int _open64_r _PARAMS ((struct _reent *, const char *, int, int)); #endif -#endif - #ifdef __cplusplus } #endif |