Interface between gc and clients to control conservative scan

Fri Apr 21 17:46:00 GMT 2006

Here's what I've been using.
Is this OK?
Thanks,
Andrew.
2006年04月21日 Andrew Haley <aph@redhat.com>
	* include/gc.h (GC_register_has_static_roots_callback): Declare.
	* dyn_load.c (GC_has_static_roots): Declare.
	(GC_register_dynlib_callback): Call GC_has_static_roots.
Index: boehm-gc/include/gc.h
===================================================================

--- boehm-gc/include/gc.h	(revision 113114)
+++ boehm-gc/include/gc.h	(working copy)
@@ -925,6 +925,15 @@
 
 #endif /* THREADS && !SRC_M3 */
 
+/* Register a callback to control the scanning of dynamic libraries.
+ When the GC scans the static data of a dynamic library, it will
+ first call a user-supplied routine with filename of the library and
+ the address and length of the memory region. This routine should
+ return nonzero if that region should be scanned. */
+GC_API void GC_register_has_static_roots_callback 
+ (int (*callback)(const char *, void *, size_t));
+
+
 #if defined(GC_WIN32_THREADS) && !defined(__CYGWIN32__) && !defined(__CYGWIN__)
 # include <windows.h>
 
Index: boehm-gc/dyn_load.c
===================================================================
--- boehm-gc/dyn_load.c	(revision 113114)
+++ boehm-gc/dyn_load.c	(working copy)
@@ -119,6 +119,17 @@
 # endif
 # endif
 
+/* An user-supplied routine that is called to dtermine if a DSO must
+ be scanned by the gc. */
+static int (*GC_has_static_roots)(const char *, void *, size_t);
+/* Register the routine. */
+void
+GC_register_has_static_roots_callback 
+ (int (*callback)(const char *, void *, size_t))
+{
+ GC_has_static_roots = callback;
+}
+
 #if defined(SUNOS5DL) && !defined(USE_PROC_FOR_LIBRARIES)
 
 #ifdef LINT
@@ -371,7 +382,7 @@
 {
 return FALSE;
 }
- 
+
 # define HAVE_REGISTER_MAIN_STATIC_DATA
 
 #endif /* USE_PROC_FOR_LIBRARIES */
@@ -411,6 +422,11 @@
 	{
 	 if( !(p->p_flags & PF_W) ) break;
 	 start = ((char *)(p->p_vaddr)) + info->dlpi_addr;
+
+	 if (GC_has_static_roots 
+	 && !GC_has_static_roots(info->dlpi_name, start, p->p_memsz))
+	 break;
+
 	 GC_add_roots_inner(start, start + p->p_memsz, TRUE);
 	}
 break;
