Changeset 2647

Timestamp:

10/12/07 15:59:51 (1 year ago)

Author:

sean

Message:

Added gc_addrOf(p) to find the base address of the block containing p. Related to ticket #557.

Files:

• trunk/lib/common/tango/core/Memory.d (modified) (2 diffs)
• trunk/lib/gc/basic/gc.d (modified) (1 diff)
• trunk/lib/gc/basic/gcx.d (modified) (4 diffs)
• trunk/lib/gc/stub/gc.d (modified) (1 diff)

trunk/lib/common/tango/core/Memory.d

@@ -29 +29 @@
-    extern (C) void   gc_free( void* p );
-
+    extern (C) void*  gc_addrOf( void* p );
-    extern (C) size_t gc_sizeOf( void* p );
-
@@ -277 +278 @@
-
-    /**
+     * Returns the base address of the memory block containing p.  This value
+     * is useful to determine whether p is an interior pointer, and the result
+     * may be passed to routines such as sizeOf which may otherwise fail.  If p
+     * references memory not originally allocated by this garbage collector, if
+     * p is null, or if the garbage collector does not support this operation,
+     * null will be returned.
+     *
+     * Params:
+     *  p = A pointer to the root or the interior of a valid memory block or to
+     *      null.
+     *
+     * Returns:
+     *  The base address of the memory block referenced by p or null on error.
+     */
+    static void* addrOf( void* p )
+    {
+        return gc_addrOf( p );
+    }
+
+
+    /**
-     * Returns the true size of the memory block referenced by p.  This value
-     * represents the maximum number of bytes for which a call to realloc may

trunk/lib/gc/basic/gc.d

@@ -127 +127 @@
-}
-
+extern (C) void* gc_addrOf( void* p )
+{
+    return _gc.addrOf( p );
+}
+
-extern (C) size_t gc_sizeOf( void* p )
-{

trunk/lib/gc/basic/gcx.d

@@ -866 +866 @@
-
-    /**
+     * Determine the base address of the block containing p.  If p is not a gc
+     * allocated pointer, return null.
+     */
+    void* addrOf(void *p)
+    {
+        if (!p)
+        {
+            return null;
+        }
+
+        if (!thread_needLock())
+        {
+            return addrOfNoSync(p);
+        }
+        else synchronized (gcLock)
+        {
+            return addrOfNoSync(p);
+        }
+    }
+
+
+    //
+    //
+    //
+    void* addrOfNoSync(void *p)
+    {
+        if (!p)
+        {
+            return null;
+        }
+
+        return gcx.findBase(p);
+    }
+
+
+    /**
-     * Determine the allocated size of pointer p.  If p is an interior pointer
-     * or not a gc allocated pointer, return 0.
@@ -1527 +1563 @@
-                    break;
-                }
+            }
+        }
+        return null;
+    }
+
+
+    /**
+     * Find base address of block containing pointer p.
+     * Returns null if not a gc'd pointer
+     */
+    void* findBase(void *p)
+    {
+        Pool *pool;
+
+        pool = findPool(p);
+        if (pool)
+        {
+            size_t offset = cast(size_t)(p - pool.baseAddr);
+            uint pn = offset / PAGESIZE;
+            Bins bin = cast(Bins)pool.pagetable[pn];
+
+            // Adjust bit to be at start of allocated memory block
+            if (bin <= B_PAGE)
+            {
+                return pool.baseAddr + (offset & notbinsize[bin]);
+            }
+            else if (bin == B_PAGEPLUS)
+            {
+                do
+                {   --pn, offset -= PAGESIZE;
+                } while (cast(Bins)pool.pagetable[pn] == B_PAGEPLUS);
+
+                return pool.baseAddr + (offset & (offset.max ^ (PAGESIZE-1)));
+            }
+            else
+            {
+                // we are in a B_FREE or B_UNCOMMITTED page
+                return null;
-            }
-        }
@@ -1836 +1910 @@
-                if (pool)
-                {
-uin
+size_
-                    uint biti;
-                    uint pn = offset / PAGESIZE;
@@ -2405 +2479 @@
-                pool = findPool(p);
-                assert(pool);
-uin
+size_
-                uint biti;
-                uint pn = offset / PAGESIZE;

trunk/lib/gc/stub/gc.d

@@ -114 +114 @@
-}
-
+extern (C) void* gc_addrOf( void* p )
+{
+    return null;
+}
+
-extern (C) size_t gc_sizeOf( void* p )
-{