Changeset 3073

Timestamp:

01/07/08 14:34:49 (11 months ago)

Author:

sean

Message:

Added GC.reserve(size_t) as a means of telling the GC to obtain a specific amount of memory from the OS and mark it as free. This is an optimization feature intended to allow programmers to tune the performance of applications which are expected to use a specific or minimum amount of memory. Calling this routine ensures that the specified amount of memory is immediately available and no collections should occur until more than the requested number of bytes are allocated during the program run. This closes #817.

Files:

• trunk/lib/common/tango/core/Memory.d (modified) (2 diffs)
• trunk/lib/gc/basic/gc.d (modified) (3 diffs)
• trunk/lib/gc/basic/gcx.d (modified) (2 diffs)

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

@@ -27 +27 @@
-    extern (C) void*  gc_realloc( void* p, size_t sz, uint ba = 0 );
-    extern (C) size_t gc_extend( void* p, size_t mx, size_t sz );
+    extern (C) size_t gc_reserve( size_t sz );
-    extern (C) void   gc_free( void* p );
-
@@ -282 +283 @@
-
-    /**
+     * Requests that at least sz bytes of memory be obtained from the operating
+     * system and marked as free.
+     *
+     * Params:
+     *  sz = The desired size in bytes.
+     *
+     * Returns:
+     *  The actual number of bytes reserved or zero on error.
+     */
+    static size_t reserve( size_t sz )
+    {
+        return gc_reserve( sz );
+    }
+
+
+    /**
-     * Deallocates the memory referenced by p.  If p is null, no action
-     * occurs.  If p references memory not originally allocated by this

trunk/lib/gc/basic/gc.d

@@ -26 +26 @@
-
-private import gcx;
+private import gcstats;
-private import tango.stdc.stdlib;
-
@@ -125 +126 @@
-}
-
+extern (C) size_t gc_reserve( size_t sz )
+{
+    return _gc.reserve( sz );
+}
+
-extern (C) void gc_free( void* p )
-{
@@ -143 +149 @@
-{
-    return _gc.query( p );
+}
+
+// NOTE: This routine is experimental.  The stats or function name may change
+//       before it is made officially available.
+extern (C) GCStats gc_stats()
+{
+    GCStats stats;
+    _gc.getStats(stats);
+    return stats;
-}
-

trunk/lib/gc/basic/gcx.d

@@ -792 +792 @@
-     *
-     */
+    size_t reserve(size_t size)
+    {
+        if (!size)
+        {
+            return 0;
+        }
+
+        if (!thread_needLock())
+        {
+            return reserveNoSync(size);
+        }
+        else synchronized (gcLock)
+        {
+            return reserveNoSync(size);
+        }
+    }
+
+
+    //
+    //
+    //
+    private size_t reserveNoSync(size_t size)
+    {
+        assert(size != 0);
+        assert(gcx);
+
+        return gcx.reserve(size);
+    }
+
+
+    /**
+     *
+     */
-    void free(void *p)
-    {
@@ -1781 +1814 @@
-        }
-        return bin;
+    }
+
+
+    /**
+     * Allocate a new pool of at least size bytes.
+     * Sort it into pooltable[].
+     * Mark all memory in the pool as B_FREE.
+     * Return the actual number of bytes reserved or 0 on error.
+     */
+    size_t reserve(size_t size)
+    {
+        uint npages = (size + PAGESIZE - 1) / PAGESIZE;
+        Pool *pool = newPool(npages);
+
+        if (!pool || pool.extendPages(npages) == ~0u)
+            return 0;
+        return pool.ncommitted * PAGESIZE;
-    }
-