Changeset 3155

Timestamp:

02/07/08 22:21:44 (10 months ago)

Author:

sean

Message:

Added GC.minimize(), which returns the memory used by empty pools back to the OS. This routine is also called within Gcx.bigAlloc() after a collection has failed to produce a sufficient block of memory for the allocation, and before a new pool is created. This closes #878

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/common/tango/core/Memory.d

@@ -18 +18 @@
-    extern (C) void gc_disable();
-    extern (C) void gc_collect();
+    extern (C) void gc_minimize();
-
-    extern (C) uint gc_getAttr( void* p );
@@ -88 +89 @@
-    {
-        gc_collect();
+    }
+
+    /**
+     * Indicates that the managed memory space be minimized by returning free
+     * physical memory to the operating system.  The amount of free memory
+     * returned depends on the allocator design and on program behavior.
+     */
+    static void minimize()
+    {
+        gc_minimize();
-    }
-

trunk/lib/gc/basic/gc.d

@@ -91 +91 @@
-}
-
+
+extern (C) void gc_minimize()
+{
+    _gc.minimize();
+}
+
-extern (C) uint gc_getAttr( void* p )
-{

trunk/lib/gc/basic/gcx.d

@@ -1259 +1259 @@
-
-    /**
+     * minimize free space usage
+     */
+    void minimize()
+    {
+        if (!thread_needLock())
+        {
+            gcx.minimize();
+        }
+        else synchronized (gcLock)
+        {
+            gcx.minimize();
+        }
+    }
+
+
+    /**
-     * Retrieve statistics about garbage collection.
-     * Useful for debugging and tuning.
@@ -1840 +1856 @@
-
-    /**
+     * Minimizes physical memory usage by returning free pools to the OS.
+     */
+    void minimize()
+    {
+        size_t n;
+        size_t pn;
+        Pool*  pool;
+        size_t ncommitted;
+
+        for (n = 0; n < npools; n++)
+        {
+            pool = pooltable[n];
+            ncommitted = pool.ncommitted;
+            for (pn = 0; pn < ncommitted; pn++)
+            {
+                if (cast(Bins)pool.pagetable[pn] != B_FREE)
+                    break;
+            }
+            if (pn < ncommitted)
+            {
+                n++;
+                continue;
+            }
+            pool.Dtor();
+            cstdlib.free(pool);
+            cstring.memmove(pooltable + n,
+                            pooltable + n + 1,
+                            (--npools - n) * (Pool*).sizeof);
+            minAddr = pooltable[0].baseAddr;
+            maxAddr = pooltable[npools - 1].topAddr;
+        }
+    }
+
+
+    /**
-     * Allocate a chunk of memory that is larger than a page.
-     * Return null if out of memory.
@@ -1882 +1933 @@
-                    continue;
-                }
+                // Release empty pools to prevent bloat
+                minimize();
-                // Allocate new pool
-                pool = newPool(npages);
@@ -1892 +1945 @@
-                goto L1;
-            case 1:
+                // Release empty pools to prevent bloat
+                minimize();
-                // Allocate new pool
-                pool = newPool(npages);