[444] | 1 | /* This header file provides the reentrancy. */ |
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| 2 | |
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| 3 | /* The reentrant system calls here serve two purposes: |
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| 4 | |
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| 5 | 1) Provide reentrant versions of the system calls the ANSI C library |
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| 6 | requires. |
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| 7 | 2) Provide these system calls in a namespace clean way. |
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| 8 | |
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| 9 | It is intended that *all* system calls that the ANSI C library needs |
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| 10 | be declared here. It documents them all in one place. All library access |
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| 11 | to the system is via some form of these functions. |
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| 12 | |
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| 13 | The target may provide the needed syscalls by any of the following: |
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| 14 | |
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| 15 | 1) Define the reentrant versions of the syscalls directly. |
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| 16 | (eg: _open_r, _close_r, etc.). Please keep the namespace clean. |
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| 17 | When you do this, set "syscall_dir" to "syscalls" and add |
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| 18 | -DREENTRANT_SYSCALLS_PROVIDED to newlib_cflags in configure.host. |
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| 19 | |
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| 20 | 2) Define namespace clean versions of the system calls by prefixing |
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| 21 | them with '_' (eg: _open, _close, etc.). Technically, there won't be |
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| 22 | true reentrancy at the syscall level, but the library will be namespace |
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| 23 | clean. |
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| 24 | When you do this, set "syscall_dir" to "syscalls" in configure.host. |
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| 25 | |
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| 26 | 3) Define or otherwise provide the regular versions of the syscalls |
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| 27 | (eg: open, close, etc.). The library won't be reentrant nor namespace |
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| 28 | clean, but at least it will work. |
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| 29 | When you do this, add -DMISSING_SYSCALL_NAMES to newlib_cflags in |
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| 30 | configure.host. |
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| 31 | |
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| 32 | 4) Define or otherwise provide the regular versions of the syscalls, |
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| 33 | and do not supply functional interfaces for any of the reentrant |
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| 34 | calls. With this method, the reentrant syscalls are redefined to |
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| 35 | directly call the regular system call without the reentrancy argument. |
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| 36 | When you do this, specify both -DREENTRANT_SYSCALLS_PROVIDED and |
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| 37 | -DMISSING_SYSCALL_NAMES via newlib_cflags in configure.host and do |
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| 38 | not specify "syscall_dir". |
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| 39 | |
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| 40 | Stubs of the reentrant versions of the syscalls exist in the libc/reent |
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| 41 | source directory and are provided if REENTRANT_SYSCALLS_PROVIDED isn't |
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| 42 | defined. These stubs call the native system calls: _open, _close, etc. |
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| 43 | if MISSING_SYSCALL_NAMES is *not* defined, otherwise they call the |
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| 44 | non-underscored versions: open, close, etc. when MISSING_SYSCALL_NAMES |
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| 45 | *is* defined. |
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| 46 | |
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| 47 | By default, newlib functions call the reentrant syscalls internally, |
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| 48 | passing a reentrancy structure as an argument. This reentrancy structure |
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| 49 | contains data that is thread-specific. For example, the errno value is |
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| 50 | kept in the reentrancy structure. If multiple threads exist, each will |
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| 51 | keep a separate errno value which is intuitive since the application flow |
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| 52 | cannot check for failure reliably otherwise. |
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| 53 | |
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| 54 | The reentrant syscalls are either provided by the platform, by the |
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| 55 | libc/reent stubs, or in the case of both MISSING_SYSCALL_NAMES and |
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| 56 | REENTRANT_SYSCALLS_PROVIDED being defined, the calls are redefined to |
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| 57 | simply call the regular syscalls with no reentrancy struct argument. |
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| 58 | |
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| 59 | A single-threaded application does not need to worry about the reentrancy |
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| 60 | structure. It is used internally. |
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| 61 | |
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| 62 | A multi-threaded application needs either to manually manage reentrancy |
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| 63 | structures or use dynamic reentrancy. |
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| 64 | |
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| 65 | Manually managing reentrancy structures entails calling special reentrant |
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| 66 | versions of newlib functions that have an additional reentrancy argument. |
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| 67 | For example, _printf_r. By convention, the first argument is the |
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| 68 | reentrancy structure. By default, the normal version of the function |
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| 69 | uses the default reentrancy structure: _REENT. The reentrancy structure |
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| 70 | is passed internally, eventually to the reentrant syscalls themselves. |
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| 71 | How the structures are stored and accessed in this model is up to the |
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| 72 | application. |
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| 73 | |
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| 74 | Dynamic reentrancy is specified by the __DYNAMIC_REENT__ flag. This |
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| 75 | flag denotes setting up a macro to replace _REENT with a function call |
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| 76 | to __getreent(). This function needs to be implemented by the platform |
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| 77 | and it is meant to return the reentrancy structure for the current |
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| 78 | thread. When the regular C functions (e.g. printf) go to call internal |
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| 79 | routines with the default _REENT structure, they end up calling with |
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| 80 | the reentrancy structure for the thread. Thus, application code does not |
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| 81 | need to call the _r routines nor worry about reentrancy structures. */ |
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| 82 | |
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| 83 | /* WARNING: All identifiers here must begin with an underscore. This file is |
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| 84 | included by stdio.h and others and we therefore must only use identifiers |
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| 85 | in the namespace allotted to us. */ |
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| 86 | |
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| 87 | #ifndef _REENT_H_ |
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| 88 | #ifdef __cplusplus |
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| 89 | extern "C" { |
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| 90 | #endif |
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| 91 | #define _REENT_H_ |
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| 92 | |
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| 93 | #include <sys/reent.h> |
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| 94 | #include <sys/_types.h> |
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| 95 | |
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| 96 | #define __need_size_t |
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| 97 | #define __need_ptrdiff_t |
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| 98 | #include <stddef.h> |
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| 99 | |
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| 100 | /* FIXME: not namespace clean */ |
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| 101 | struct stat; |
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| 102 | struct tms; |
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| 103 | struct timeval; |
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| 104 | struct timezone; |
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| 105 | |
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| 106 | #if defined(REENTRANT_SYSCALLS_PROVIDED) && defined(MISSING_SYSCALL_NAMES) |
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| 107 | |
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| 108 | #define _close_r(__reent, __fd) close(__fd) |
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| 109 | #define _execve_r(__reent, __f, __arg, __env) execve(__f, __arg, __env) |
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| 110 | #define _fcntl_r(__reent, __fd, __cmd, __arg) fcntl(__fd, __cmd, __arg) |
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| 111 | #define _fork_r(__reent) fork() |
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| 112 | #define _fstat_r(__reent, __fdes, __stat) fstat(__fdes, __stat) |
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| 113 | #define _getpid_r(__reent) getpid() |
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| 114 | #define _isatty_r(__reent, __desc) isatty(__desc) |
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| 115 | #define _kill_r(__reent, __pid, __signal) kill(__pid, __signal) |
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| 116 | #define _link_r(__reent, __oldpath, __newpath) link(__oldpath, __newpath) |
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| 117 | #define _lseek_r(__reent, __fdes, __off, __w) lseek(__fdes, __off, __w) |
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| 118 | #define _mkdir_r(__reent, __path, __m) mkdir(__path, __m) |
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| 119 | #define _open_r(__reent, __path, __flag, __m) open(__path, __flag, __m) |
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| 120 | #define _read_r(__reent, __fd, __buff, __cnt) read(__fd, __buff, __cnt) |
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| 121 | #define _rename_r(__reent, __old, __new) rename(__old, __new) |
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| 122 | #define _sbrk_r(__reent, __incr) sbrk(__incr) |
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| 123 | #define _stat_r(__reent, __path, __buff) stat(__path, __buff) |
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| 124 | #define _times_r(__reent, __time) times(__time) |
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| 125 | #define _unlink_r(__reent, __path) unlink(__path) |
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| 126 | #define _wait_r(__reent, __status) wait(__status) |
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| 127 | #define _write_r(__reent, __fd, __buff, __cnt) write(__fd, __buff, __cnt) |
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| 128 | #define _gettimeofday_r(__reent, __tp, __tzp) gettimeofday(__tp, __tzp) |
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| 129 | |
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| 130 | #ifdef __LARGE64_FILES |
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| 131 | #define _lseek64_r(__reent, __fd, __off, __w) lseek64(__fd, __off, __w) |
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| 132 | #define _fstat64_r(__reent, __fd, __buff) fstat64(__fd, __buff) |
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| 133 | #define _open64_r(__reent, __path, __flag, __m) open64(__path, __flag, __m) |
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| 134 | #endif |
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| 135 | |
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| 136 | #else |
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| 137 | /* Reentrant versions of system calls. */ |
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| 138 | |
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| 139 | extern int _close_r (struct _reent *, int); |
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| 140 | extern int _execve_r (struct _reent *, const char *, char *const *, char *const *); |
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| 141 | extern int _fcntl_r (struct _reent *, int, int, int); |
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| 142 | extern int _fork_r (struct _reent *); |
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| 143 | extern int _fstat_r (struct _reent *, int, struct stat *); |
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| 144 | extern int _getpid_r (struct _reent *); |
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| 145 | extern int _isatty_r (struct _reent *, int); |
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| 146 | extern int _kill_r (struct _reent *, int, int); |
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| 147 | extern int _link_r (struct _reent *, const char *, const char *); |
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| 148 | extern _off_t _lseek_r (struct _reent *, int, _off_t, int); |
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| 149 | extern int _mkdir_r (struct _reent *, const char *, int); |
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| 150 | extern int _open_r (struct _reent *, const char *, int, int); |
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| 151 | extern _ssize_t _read_r (struct _reent *, int, void *, size_t); |
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| 152 | extern int _rename_r (struct _reent *, const char *, const char *); |
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| 153 | extern void *_sbrk_r (struct _reent *, ptrdiff_t); |
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| 154 | extern int _stat_r (struct _reent *, const char *, struct stat *); |
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| 155 | extern _CLOCK_T_ _times_r (struct _reent *, struct tms *); |
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| 156 | extern int _unlink_r (struct _reent *, const char *); |
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| 157 | extern int _wait_r (struct _reent *, int *); |
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| 158 | extern _ssize_t _write_r (struct _reent *, int, const void *, size_t); |
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| 159 | |
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| 160 | /* This one is not guaranteed to be available on all targets. */ |
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| 161 | extern int _gettimeofday_r (struct _reent *, struct timeval *__tp, void *__tzp); |
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| 162 | |
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| 163 | #ifdef __LARGE64_FILES |
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| 164 | |
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| 165 | |
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| 166 | #if defined(__CYGWIN__) |
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| 167 | #define stat64 stat |
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| 168 | #endif |
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| 169 | struct stat64; |
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| 170 | |
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| 171 | extern _off64_t _lseek64_r (struct _reent *, int, _off64_t, int); |
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| 172 | extern int _fstat64_r (struct _reent *, int, struct stat64 *); |
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| 173 | extern int _open64_r (struct _reent *, const char *, int, int); |
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| 174 | extern int _stat64_r (struct _reent *, const char *, struct stat64 *); |
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| 175 | |
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| 176 | /* Don't pollute namespace if not building newlib. */ |
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| 177 | #if defined (__CYGWIN__) && !defined (_COMPILING_NEWLIB) |
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| 178 | #undef stat64 |
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| 179 | #endif |
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| 180 | |
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| 181 | #endif |
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| 182 | |
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| 183 | #endif |
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| 184 | |
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| 185 | #ifdef __cplusplus |
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| 186 | } |
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| 187 | #endif |
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| 188 | #endif /* _REENT_H_ */ |
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