Changeset 390 for soft/giet_vm/giet_libs/malloc.c

Timestamp:

Aug 7, 2014, 4:57:07 PM (10 years ago)

Author:

alain

Message:

1) Introducing the new system call giet_get_xy() in stdio.h,

required for the free() funcyion in malloc.h

2) Fixing bugs in malloc.c

File:

• soft/giet_vm/giet_libs/malloc.c (modified) (5 diffs)

soft/giet_vm/giet_libs/malloc.c

@@ -78 +78 @@
     }
 
-    // compute alloc[] minimal array size
+    // compute size of block containin alloc[] array 
     alloc_size = heap_size / MIN_BLOCK_SIZE;
+    if ( alloc_size < MIN_BLOCK_SIZE) alloc_size = MIN_BLOCK_SIZE;
 
     // get index for the corresponding block
@@ -98 +99 @@
     unsigned int   base = heap_base;
     unsigned int*  ptr;
-    for ( index = heap_index-1 ; index > alloc_index ; index-- )
+    for ( index = heap_index-1 ; index >= alloc_index ; index-- )
     {
         heap[x][y].free[index] = base;
@@ -247 +248 @@
     }
 
+    // normalize size
+    if ( size < MIN_BLOCK_SIZE ) size = MIN_BLOCK_SIZE;
+
     // compute requested_index for the free[] array
     unsigned int requested_index = GET_SIZE_INDEX( size );
@@ -258 +262 @@
                                    requested_index );
 
-    // update the alloc[] array
-    unsigned offset = (base - heap[x][y].heap_base) / MIN_BLOCK_SIZE;
-    unsigned char* ptr = (unsigned char*)(heap[x][y].alloc_base + offset);
-    *ptr = requested_index;
+    // update the alloc[] array if block found
+    if ( base != 0 )
+    {
+        unsigned offset = (base - heap[x][y].heap_base) / MIN_BLOCK_SIZE;
+        unsigned char* ptr = (unsigned char*)(heap[x][y].alloc_base + offset);
+        *ptr = requested_index;
+    }
 
     // release the lock
@@ -286 +293 @@
 void free( void* ptr )
 {
-    // To be done
-    // - first : to compute the cluster coordinate
-    // - second : retrieve the block length from the
-    // - third : try to concatenate with another free block of same size
-    // - fourth : update the free[] array
+    unsigned int vaddr = (unsigned int)ptr;
+
+    // get the cluster coordinate
+    unsigned int x;
+    unsigned int y;
+    giet_get_xy( ptr, &x, &y );
+
+    // compute index in alloc[] array
+    unsigned index = ( (unsigned int)ptr - heap[x][y].heap_base ) / MAX_BLOCK_SIZE;
+ 
+    // get the freed block size_index
+    unsigned char* p i        = (unsigned char*)(heap[x][y].alloc_base + index);
+    unsigned int   size_index = (unsigned int)*p;
+
+    // update the free[] array and NEXT pointer
+    *(unsigned int*)ptr         = heap[x][y].free[size_index];
+    heap[x][y].free[size_index] = (unsigned int)ptr;
+    
+    // TODO try to concatenate with another free block of same size
+    // this require probably to replace this simple push by a recursive function
 }