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Guido van Rossuma3309961993-07-28 09:05:47 +00001#ifndef Py_CEVAL_H
2#define Py_CEVAL_H
3#ifdef __cplusplus
4extern "C" {
5#endif
6
Guido van Rossumf70e43a1991-02-19 12:39:46 +00007/***********************************************************
Guido van Rossum5799b521995-01-04 19:06:22 +00008Copyright 1991-1995 by Stichting Mathematisch Centrum, Amsterdam,
9The Netherlands.
Guido van Rossumf70e43a1991-02-19 12:39:46 +000010
11 All Rights Reserved
12
13Permission to use, copy, modify, and distribute this software and its
14documentation for any purpose and without fee is hereby granted,
15provided that the above copyright notice appear in all copies and that
16both that copyright notice and this permission notice appear in
17supporting documentation, and that the names of Stichting Mathematisch
18Centrum or CWI not be used in advertising or publicity pertaining to
19distribution of the software without specific, written prior permission.
20
21STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
22THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
23FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
24FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
25WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
26ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
27OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
28
29******************************************************************/
30
Guido van Rossumff4949e1992-08-05 19:58:53 +000031/* Interface to random parts in ceval.c */
Guido van Rossum3f5da241990-12-20 15:06:42 +000032
Guido van Rossumcaa63801995-01-12 11:45:45 +000033PyObject *PyEval_CallObject Py_PROTO((PyObject *, PyObject *));
Guido van Rossuma0490311991-07-27 21:33:03 +000034
Guido van Rossumcaa63801995-01-12 11:45:45 +000035PyObject *PyEval_GetBuiltins Py_PROTO((void));
36PyObject *PyEval_GetGlobals Py_PROTO((void));
37PyObject *PyEval_GetLocals Py_PROTO((void));
38PyObject *PyEval_GetOwner Py_PROTO((void));
39PyObject *PyEval_GetFrame Py_PROTO((void));
40int PyEval_GetRestricted Py_PROTO((void));
Guido van Rossum3f5da241990-12-20 15:06:42 +000041
Guido van Rossumcaa63801995-01-12 11:45:45 +000042void Py_FlushLine Py_PROTO((void));
Guido van Rossumff4949e1992-08-05 19:58:53 +000043
Guido van Rossumcaa63801995-01-12 11:45:45 +000044int Py_AddPendingCall Py_PROTO((int (*func) Py_PROTO((ANY *)), ANY *arg));
45int Py_MakePendingCalls Py_PROTO((void));
Guido van Rossum95664081994-09-14 13:23:36 +000046
Guido van Rossumff4949e1992-08-05 19:58:53 +000047
48/* Interface for threads.
49
50 A module that plans to do a blocking system call (or something else
51 that lasts a long time and doesn't touch Python data) can allow other
52 threads to run as follows:
53
54 ...preparations here...
Guido van Rossumcaa63801995-01-12 11:45:45 +000055 Py_BEGIN_ALLOW_THREADS
Guido van Rossumff4949e1992-08-05 19:58:53 +000056 ...blocking system call here...
Guido van Rossumcaa63801995-01-12 11:45:45 +000057 Py_END_ALLOW_THREADS
Guido van Rossum66cb3111994-12-30 15:33:50 +000058 ...interpret result here...
Guido van Rossumff4949e1992-08-05 19:58:53 +000059
Guido van Rossumcaa63801995-01-12 11:45:45 +000060 The Py_BEGIN_ALLOW_THREADS/Py_END_ALLOW_THREADS pair expands to a
61 {}-surrounded block.
Guido van Rossumff4949e1992-08-05 19:58:53 +000062 To leave the block in the middle (e.g., with return), you must insert
63 a line containing RET_SAVE before the return, e.g.
64
65 if (...premature_exit...) {
Guido van Rossumcaa63801995-01-12 11:45:45 +000066 Py_BLOCK_THREADS
67 PyErr_SetFromErrno(PyExc_IOError);
Guido van Rossumff4949e1992-08-05 19:58:53 +000068 return NULL;
69 }
70
71 An alternative is:
72
Guido van Rossumcaa63801995-01-12 11:45:45 +000073 Py_BLOCK_THREADS
Guido van Rossumff4949e1992-08-05 19:58:53 +000074 if (...premature_exit...) {
Guido van Rossumcaa63801995-01-12 11:45:45 +000075 PyErr_SetFromErrno(PyExc_IOError);
Guido van Rossumff4949e1992-08-05 19:58:53 +000076 return NULL;
77 }
Guido van Rossumcaa63801995-01-12 11:45:45 +000078 Py_UNBLOCK_THREADS
Guido van Rossumff4949e1992-08-05 19:58:53 +000079
80 For convenience, that the value of 'errno' is restored across
Guido van Rossumcaa63801995-01-12 11:45:45 +000081 Py_END_ALLOW_THREADS and RET_SAVE.
Guido van Rossumff4949e1992-08-05 19:58:53 +000082
Guido van Rossumcaa63801995-01-12 11:45:45 +000083 WARNING: NEVER NEST CALLS TO Py_BEGIN_ALLOW_THREADS AND
84 Py_END_ALLOW_THREADS!!!
Guido van Rossumff4949e1992-08-05 19:58:53 +000085
Guido van Rossumcaa63801995-01-12 11:45:45 +000086 The function PyEval_InitThreads() should be called only from
Guido van Rossumff4949e1992-08-05 19:58:53 +000087 initthread() in "threadmodule.c".
88
89 Note that not yet all candidates have been converted to use this
90 mechanism!
91*/
92
Guido van Rossumcaa63801995-01-12 11:45:45 +000093extern void PyEval_InitThreads Py_PROTO((void));
94extern PyObject *PyEval_SaveThread Py_PROTO((void));
95extern void PyEval_RestoreThread Py_PROTO((PyObject *));
Guido van Rossumff4949e1992-08-05 19:58:53 +000096
Guido van Rossumb6775db1994-08-01 11:34:53 +000097#ifdef WITH_THREAD
Guido van Rossumff4949e1992-08-05 19:58:53 +000098
Guido van Rossumcaa63801995-01-12 11:45:45 +000099#define Py_BEGIN_ALLOW_THREADS { \
100 PyObject *_save; \
101 _save = PyEval_SaveThread();
102#define Py_BLOCK_THREADS PyEval_RestoreThread(_save);
103#define Py_UNBLOCK_THREADS _save = PyEval_SaveThread();
104#define Py_END_ALLOW_THREADS PyEval_RestoreThread(_save); \
Guido van Rossumff4949e1992-08-05 19:58:53 +0000105 }
106
Guido van Rossumb6775db1994-08-01 11:34:53 +0000107#else /* !WITH_THREAD */
Guido van Rossumff4949e1992-08-05 19:58:53 +0000108
Guido van Rossumcaa63801995-01-12 11:45:45 +0000109#define Py_BEGIN_ALLOW_THREADS {
110#define Py_BLOCK_THREADS
111#define Py_UNBLOCK_THREADS
112#define Py_END_ALLOW_THREADS }
Guido van Rossumff4949e1992-08-05 19:58:53 +0000113
Guido van Rossumb6775db1994-08-01 11:34:53 +0000114#endif /* !WITH_THREAD */
Guido van Rossuma3309961993-07-28 09:05:47 +0000115
116#ifdef __cplusplus
117}
118#endif
119#endif /* !Py_CEVAL_H */