Import guile-1.8 as multiple upstream tarball component

[lilypond.git] / guile18 / libguile / continuations.h

diff --git a/guile18/libguile/continuations.h b/guile18/libguile/continuations.h
new file mode 100644 (file)
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+++ b/guile18/libguile/continuations.h
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+/* classes: h_files */
+
+#ifndef SCM_CONTINUATIONS_H
+#define SCM_CONTINUATIONS_H
+
+/* Copyright (C) 1995,1996,2000,2001, 2006 Free Software Foundation, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+\f
+
+#include "libguile/__scm.h"
+
+#ifdef __ia64__
+#include <signal.h>
+#include <ucontext.h>
+#endif /* __ia64__ */
+\f
+
+/* a continuation SCM is a non-immediate pointing to a heap cell with:
+   word 0: bits 0-15: smob type tag: scm_tc16_continuation.
+           bits 16-31: unused.
+   word 1: malloc block containing an scm_t_contregs structure with a
+           tail array of SCM_STACKITEM.  the size of the array is stored
+          in the num_stack_items field of the structure.
+*/
+
+SCM_API scm_t_bits scm_tc16_continuation;
+
+typedef struct 
+{
+  SCM throw_value;
+  scm_i_jmp_buf jmpbuf;
+  SCM dynenv;
+#ifdef __ia64__
+  void *backing_store;
+  unsigned long backing_store_size;
+#endif /* __ia64__ */
+  size_t num_stack_items;   /* size of the saved stack.  */
+  SCM root;                 /* continuation root identifier.  */
+
+  /* The offset from the live stack location to this copy.  This is
+     used to adjust pointers from within the copied stack to the stack
+     itself.
+
+     Thus, when you read a pointer from the copied stack that points
+     into the live stack, you need to add OFFSET so that it points
+     into the copy.
+  */
+  scm_t_ptrdiff offset;
+
+  /* The most recently created debug frame on the live stack, before
+     it was saved.  This needs to be adjusted with OFFSET, above.
+  */
+  struct scm_t_debug_frame *dframe;
+
+  SCM_STACKITEM stack[1];    /* copied stack of size num_stack_items.  */ 
+} scm_t_contregs;
+
+#define SCM_CONTINUATIONP(x)   SCM_TYP16_PREDICATE (scm_tc16_continuation, x)
+
+#define SCM_CONTREGS(x)                ((scm_t_contregs *) SCM_CELL_WORD_1 (x))
+
+#define SCM_CONTINUATION_LENGTH(x) (SCM_CONTREGS (x)->num_stack_items)
+#define SCM_SET_CONTINUATION_LENGTH(x, n)\
+   (SCM_CONTREGS (x)->num_stack_items = (n))
+#define SCM_JMPBUF(x)           ((SCM_CONTREGS (x))->jmpbuf)
+#define SCM_DYNENV(x)           ((SCM_CONTREGS (x))->dynenv)
+#define SCM_THROW_VALUE(x)      ((SCM_CONTREGS (x))->throw_value)
+#define SCM_CONTINUATION_ROOT(x) ((SCM_CONTREGS (x))->root)   
+#define SCM_DFRAME(x)           ((SCM_CONTREGS (x))->dframe)
+
+\f
+
+SCM_API SCM scm_make_continuation (int *first);
+
+SCM_API void *scm_c_with_continuation_barrier (void *(*func)(void*), void *);
+SCM_API SCM scm_with_continuation_barrier (SCM proc);
+
+SCM_API SCM scm_i_with_continuation_barrier (scm_t_catch_body body,
+                                            void *body_data,
+                                            scm_t_catch_handler handler,
+                                            void *handler_data,
+                                            scm_t_catch_handler pre_unwind_handler,
+                                            void *pre_unwind_handler_data);
+
+SCM_API void scm_init_continuations (void);
+
+#endif  /* SCM_CONTINUATIONS_H */
+
+/*
+  Local Variables:
+  c-file-style: "gnu"
+  End:
+*/