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Diffstat (limited to 'coroutine.h')
| -rw-r--r-- | coroutine.h | 181 |
1 files changed, 0 insertions, 181 deletions
diff --git a/coroutine.h b/coroutine.h deleted file mode 100644 index d54a718..0000000 --- a/coroutine.h +++ /dev/null @@ -1,181 +0,0 @@ -/* coroutine.h
- *
- * Coroutine mechanics, implemented on top of standard ANSI C. See
- * http://www.chiark.greenend.org.uk/~sgtatham/coroutines.html for
- * a full discussion of the theory behind this.
- *
- * To use these macros to define a coroutine, you need to write a
- * function that looks something like this.
- *
- * [Simple version using static variables (scr macros)]
- * int ascending (void) {
- * static int i;
- *
- * scrBegin;
- * for (i=0; i<10; i++) {
- * scrReturn(i);
- * }
- * scrFinish(-1);
- * }
- *
- * [Re-entrant version using an explicit context structure (ccr macros)]
- * int ascending (ccrContParam) {
- * ccrBeginContext;
- * int i;
- * ccrEndContext(foo);
- *
- * ccrBegin(foo);
- * for (foo->i=0; foo->i<10; foo->i++) {
- * ccrReturn(foo->i);
- * }
- * ccrFinish(-1);
- * }
- *
- * In the static version, you need only surround the function body
- * with `scrBegin' and `scrFinish', and then you can do `scrReturn'
- * within the function and on the next call control will resume
- * just after the scrReturn statement. Any local variables you need
- * to be persistent across an `scrReturn' must be declared static.
- *
- * In the re-entrant version, you need to declare your persistent
- * variables between `ccrBeginContext' and `ccrEndContext'. These
- * will be members of a structure whose name you specify in the
- * parameter to `ccrEndContext'.
- *
- * The re-entrant macros will malloc() the state structure on first
- * call, and free() it when `ccrFinish' is reached. If you want to
- * abort in the middle, you can use `ccrStop' to free the state
- * structure immediately (equivalent to an explicit return() in a
- * caller-type routine).
- *
- * A coroutine returning void type may call `ccrReturnV',
- * `ccrFinishV' and `ccrStopV', or `scrReturnV', to avoid having to
- * specify an empty parameter to the ordinary return macros.
- *
- * Ground rules:
- * - never put `ccrReturn' or `scrReturn' within an explicit `switch'.
- * - never put two `ccrReturn' or `scrReturn' statements on the same
- * source line.
- *
- * The caller of a static coroutine calls it just as if it were an
- * ordinary function:
- *
- * void main(void) {
- * int i;
- * do {
- * i = ascending();
- * printf("got number %d\n", i);
- * } while (i != -1);
- * }
- *
- * The caller of a re-entrant coroutine must provide a context
- * variable:
- *
- * void main(void) {
- * ccrContext z = 0;
- * do {
- * printf("got number %d\n", ascending (&z));
- * } while (z);
- * }
- *
- * Note that the context variable is set back to zero when the
- * coroutine terminates (by crStop, or by control reaching
- * crFinish). This can make the re-entrant coroutines more useful
- * than the static ones, because you can tell when they have
- * finished.
- *
- * If you need to dispose of a crContext when it is non-zero (that
- * is, if you want to stop calling a coroutine without suffering a
- * memory leak), the caller should call `ccrAbort(ctx)' where `ctx'
- * is the context variable.
- *
- * This mechanism could have been better implemented using GNU C
- * and its ability to store pointers to labels, but sadly this is
- * not part of the ANSI C standard and so the mechanism is done by
- * case statements instead. That's why you can't put a crReturn()
- * inside a switch() statement.
- */
-
-/*
- * coroutine.h is copyright 1995,2000 Simon Tatham.
- *
- * Permission is hereby granted, free of charge, to any person
- * obtaining a copy of this software and associated documentation
- * files (the "Software"), to deal in the Software without
- * restriction, including without limitation the rights to use,
- * copy, modify, merge, publish, distribute, sublicense, and/or
- * sell copies of the Software, and to permit persons to whom the
- * Software is furnished to do so, subject to the following
- * conditions:
- *
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
- * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL SIMON TATHAM BE LIABLE FOR
- * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
- * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
- * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- *
- * $Id$
- */
-
-#ifndef COROUTINE_H
-#define COROUTINE_H
-
-#include <stdlib.h>
-
-/*
- * `scr' macros for static coroutines.
- */
-
-#define scrBegin static int scrLine = 0; switch(scrLine) { case 0:;
-#define scrFinish(z) } return (z)
-#define scrFinishV } return
-
-#define scrReturn(z) \
- do {\
- scrLine=__LINE__;\
- return (z); case __LINE__:;\
- } while (0)
-#define scrReturnV \
- do {\
- scrLine=__LINE__;\
- return; case __LINE__:;\
- } while (0)
-
-/*
- * `ccr' macros for re-entrant coroutines.
- */
-
-#define ccrContParam void **ccrParam
-
-#define ccrBeginContext struct ccrContextTag { int ccrLine
-#define ccrEndContext(x) } *x = (struct ccrContextTag *)*ccrParam
-
-#define ccrBegin(x) if(!x) {x= *ccrParam=malloc(sizeof(*x)); x->ccrLine=0;}\
- if (x) switch(x->ccrLine) { case 0:;
-#define ccrFinish(z) } free(*ccrParam); *ccrParam=0; return (z)
-#define ccrFinishV } free(*ccrParam); *ccrParam=0; return
-
-#define ccrReturn(z) \
- do {\
- ((struct ccrContextTag *)*ccrParam)->ccrLine=__LINE__;\
- return (z); case __LINE__:;\
- } while (0)
-#define ccrReturnV \
- do {\
- ((struct ccrContextTag *)*ccrParam)->ccrLine=__LINE__;\
- return; case __LINE__:;\
- } while (0)
-
-#define ccrStop(z) do{ free(*ccrParam); *ccrParam=0; return (z); }while(0)
-#define ccrStopV do{ free(*ccrParam); *ccrParam=0; return; }while(0)
-
-#define ccrContext void *
-#define ccrAbort(ctx) do { free (ctx); ctx = 0; } while (0)
-
-#endif /* COROUTINE_H */
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