X-Git-Url: http://wien.tomnetworks.com/gitweb/?p=hs-boehmgc.git;a=blobdiff_plain;f=gc-7.2%2Finclude%2Fgc_backptr.h;fp=gc-7.2%2Finclude%2Fgc_backptr.h;h=6256f41668944307622c1d8aaf802215ed4c2a71;hp=0000000000000000000000000000000000000000;hb=324587ba93dc77f37406d41fd2a20d0e0d94fb1d;hpb=2a4ea609491b225a1ceb06da70396e93916f137a

diff --git a/gc-7.2/include/gc_backptr.h b/gc-7.2/include/gc_backptr.h
new file mode 100644
index 0000000..6256f41
--- /dev/null
+++ b/gc-7.2/include/gc_backptr.h
@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 1994 by Xerox Corporation.  All rights reserved.
+ * Copyright (c) 1996 by Silicon Graphics.  All rights reserved.
+ * Copyright (c) 1998 by Fergus Henderson.  All rights reserved.
+ * Copyright (c) 2000-2009 by Hewlett-Packard Development Company.
+ * All rights reserved.
+ *
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
+ *
+ * Permission is hereby granted to use or copy this program
+ * for any purpose,  provided the above notices are retained on all copies.
+ * Permission to modify the code and to distribute modified code is granted,
+ * provided the above notices are retained, and a notice that the code was
+ * modified is included with the above copyright notice.
+ */
+
+/*
+ * This is a simple API to implement pointer back tracing, i.e.
+ * to answer questions such as "who is pointing to this" or
+ * "why is this object being retained by the collector"
+ *
+ * This API assumes that we have an ANSI C compiler.
+ *
+ * Most of these calls yield useful information on only after
+ * a garbage collection.  Usually the client will first force
+ * a full collection and then gather information, preferably
+ * before much intervening allocation.
+ *
+ * The implementation of the interface is only about 99.9999%
+ * correct.  It is intended to be good enough for profiling,
+ * but is not intended to be used with production code.
+ *
+ * Results are likely to be much more useful if all allocation is
+ * accomplished through the debugging allocators.
+ *
+ * The implementation idea is due to A. Demers.
+ */
+
+#ifndef GC_BACKPTR_H
+#define GC_BACKPTR_H
+
+#ifndef GC_H
+# include "gc.h"
+#endif
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/* Store information about the object referencing dest in *base_p     */
+/* and *offset_p.                                                     */
+/* If multiple objects or roots point to dest, the one reported       */
+/* will be the last on used by the garbage collector to trace the     */
+/* object.                                                            */
+/*   source is root ==> *base_p = address, *offset_p = 0              */
+/*   source is heap object ==> *base_p != 0, *offset_p = offset       */
+/*   Returns 1 on success, 0 if source couldn't be determined.        */
+/* Dest can be any address within a heap object.                      */
+typedef enum {
+    GC_UNREFERENCED,    /* No reference info available.         */
+    GC_NO_SPACE,        /* Dest not allocated with debug alloc. */
+    GC_REFD_FROM_ROOT,  /* Referenced directly by root *base_p. */
+    GC_REFD_FROM_REG,   /* Referenced from a register, i.e.     */
+                        /* a root without an address.           */
+    GC_REFD_FROM_HEAP,  /* Referenced from another heap obj.    */
+    GC_FINALIZER_REFD   /* Finalizable and hence accessible.    */
+} GC_ref_kind;
+
+GC_API GC_ref_kind GC_CALL GC_get_back_ptr_info(void * /* dest */,
+                                                void ** /* base_p */,
+                                                size_t * /* offset_p */);
+
+/* Generate a random heap address.            */
+/* The resulting address is in the heap, but  */
+/* not necessarily inside a valid object.     */
+GC_API void * GC_CALL GC_generate_random_heap_address(void);
+
+/* Generate a random address inside a valid marked heap object. */
+GC_API void * GC_CALL GC_generate_random_valid_address(void);
+
+/* Force a garbage collection and generate a backtrace from a   */
+/* random heap address.                                         */
+/* This uses the GC logging mechanism (GC_printf) to produce    */
+/* output.  It can often be called from a debugger.  The        */
+/* source in dbg_mlc.c also serves as a sample client.          */
+GC_API void GC_CALL GC_generate_random_backtrace(void);
+
+/* Print a backtrace from a specific address.  Used by the      */
+/* above.  The client should call GC_gcollect() immediately     */
+/* before invocation.                                           */
+GC_API void GC_CALL GC_print_backtrace(void *);
+
+#ifdef __cplusplus
+  } /* end of extern "C" */
+#endif
+
+#endif /* GC_BACKPTR_H */