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Diffstat (limited to 'newlib/libc/reent/reent.tex')
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diff --git a/newlib/libc/reent/reent.tex b/newlib/libc/reent/reent.tex deleted file mode 100644 index 881c572c6..000000000 --- a/newlib/libc/reent/reent.tex +++ /dev/null @@ -1,117 +0,0 @@ -@node Reentrancy -@chapter Reentrancy - -@cindex reentrancy -Reentrancy is a characteristic of library functions which allows multiple -processes to use the same address space with assurance that the values stored -in those spaces will remain constant between calls. The Red Hat -newlib implementation of the library functions ensures that -whenever possible, these library functions are reentrant. However, -there are some functions that can not be trivially made reentrant. -Hooks have been provided to allow you to use these functions in a fully -reentrant fashion. - -@findex _reent -@findex reent.h -@cindex reentrancy structure -These hooks use the structure @code{_reent} defined in @file{reent.h}. -A variable defined as @samp{struct _reent} is called a @dfn{reentrancy -structure}. All functions which must manipulate global information are -available in two versions. The first version has the usual name, and -uses a single global instance of the reentrancy structure. The second -has a different name, normally formed by prepending @samp{_} and -appending @samp{_r}, and takes a pointer to the particular reentrancy -structure to use. - -For example, the function @code{fopen} takes two arguments, @var{file} -and @var{mode}, and uses the global reentrancy structure. The function -@code{_fopen_r} takes the arguments, @var{struct_reent}, which is a -pointer to an instance of the reentrancy structure, @var{file} -and @var{mode}. - -There are two versions of @samp{struct _reent}, a normal one and one -for small memory systems, controlled by the @code{_REENT_SMALL} -definition from the (automatically included) @file{<sys/config.h>}. - -@cindex global reentrancy structure -@findex _impure_ptr -Each function which uses the global reentrancy structure uses the global -variable @code{_impure_ptr}, which points to a reentrancy structure. - -This means that you have two ways to achieve reentrancy. Both require -that each thread of execution control initialize a unique global -variable of type @samp{struct _reent}: - -@enumerate -@item -@cindex extra argument, reentrant fns -Use the reentrant versions of the library functions, after initializing -a global reentrancy structure for each process. Use the pointer to this -structure as the extra argument for all library functions. - -@item -Ensure that each thread of execution control has a pointer to its own -unique reentrancy structure in the global variable @code{_impure_ptr}, -and call the standard library subroutines. -@end enumerate - -@cindex list of reentrant functions -@cindex reentrant function list -The following functions are provided in both reentrant -and non-reentrant versions. - -@example -@exdent @emph{Equivalent for errno variable:} -_errno_r - -@exdent @emph{Locale functions:} -_localeconv_r _setlocale_r - -@exdent @emph{Equivalents for stdio variables:} -_stdin_r _stdout_r _stderr_r - -@page -@exdent @emph{Stdio functions:} -_fdopen_r _perror_r _tempnam_r -_fopen_r _putchar_r _tmpnam_r -_getchar_r _puts_r _tmpfile_r -_gets_r _remove_r _vfprintf_r -_iprintf_r _rename_r _vsnprintf_r -_mkstemp_r _snprintf_r _vsprintf_r -_mktemp_t _sprintf_r - -@exdent @emph{Signal functions:} -_init_signal_r _signal_r -_kill_r __sigtramp_r -_raise_r - -@exdent @emph{Stdlib functions:} -_calloc_r _mblen_r _setenv_r -_dtoa_r _mbstowcs_r _srand_r -_free_r _mbtowc_r _strtod_r -_getenv_r _memalign_r _strtol_r -_mallinfo_r _mstats_r _strtoul_r -_malloc_r _putenv_r _system_r -_malloc_r _rand_r _wcstombs_r -_malloc_stats_r _realloc_r _wctomb_r - -@exdent @emph{String functions:} -_strdup_r _strtok_r - -@exdent @emph{System functions:} -_close_r _link_r _unlink_r -_execve_r _lseek_r _wait_r -_fcntl_r _open_r _write_r -_fork_r _read_r -_fstat_r _sbrk_r -_gettimeofday_r _stat_r -_getpid_r _times_r - -@ifset STDIO64 -@exdent @emph{Additional 64-bit I/O System functions:} -_fstat64_r _lseek64_r _open64_r -@end ifset - -@exdent @emph{Time function:} -_asctime_r -@end example |