tighten up the mempool assertions

git-svn-id: file:///svn/tokudb@469 c7de825b-a66e-492c-adef-691d508d4ae1

newbrt/mempool.c

@@ -4,7 +4,7 @@
 
 void mempool_init(struct mempool *mp, void *base, int size) {
     // printf("mempool_init %p %p %d\n", mp, base, size);
-    assert(base != 0 && size > 0);
+    assert(base != 0 && size >= 0);
     mp->base = base;
     mp->size = size;
     mp->free_offset = 0;
@@ -39,7 +39,7 @@ int mempool_get_frag_size(struct mempool *mp) {
 }
 
 void *mempool_malloc(struct mempool *mp, int size, int alignment) {
-    assert(mp->free_offset < mp->size);
+    assert(mp->free_offset <= mp->size);
     void *vp;
     int offset = (mp->free_offset + (alignment-1)) & ~(alignment-1);
     if (offset + size > mp->size) {
@@ -48,14 +48,14 @@ void *mempool_malloc(struct mempool *mp, int size, int alignment) {
         vp = mp->base + offset;
         mp->free_offset = offset + size;
     }
-    assert(mp->free_offset < mp->size);
+    assert(mp->free_offset <= mp->size);
     assert(((long)vp & (alignment-1)) == 0);
-    assert(vp == 0 || (mp->base <= vp && vp + size  < mp->base + mp->size)); 
+    assert(vp == 0 || (mp->base <= vp && vp + size <= mp->base + mp->size)); 
     return vp;
 }
 
 void mempool_mfree(struct mempool *mp, void *vp, int size) {
-    assert(size > 0 && mp->base <= vp && vp + size  < mp->base + mp->size); 
+    assert(size >= 0 && mp->base <= vp && vp + size <= mp->base + mp->size); 
     mp->frag_size += size;
     assert(mp->frag_size <= mp->size);
 }

newbrt/memtest.c

+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "memory.h"
+#include "mempool.h"
+
+void test_mempool_limits(int size) {
+    void *base = malloc(size);
+    struct mempool mempool;
+    mempool_init(&mempool, base, size);
+
+    int i;
+    for (i=0;; i++) {
+        void *vp = mempool_malloc(&mempool, 1, 1);
+        if (vp == 0) 
+            break;
+    }
+    assert(i == size);
+
+    mempool_fini(&mempool);
+    free(base);
+}
+
+void test_mempool_malloc_mfree(int size) {
+    void *base = malloc(size);
+    struct mempool mempool;
+    mempool_init(&mempool, base, size);
+
+    void *vp[size];
+    int i;
+    for (i=0;; i++) {
+        vp[i] = mempool_malloc(&mempool, 1, 1);
+        if (vp[i] == 0) 
+            break;
+    }
+    assert(i == size);
+
+    for (i=0; i<size; i++) 
+        mempool_mfree(&mempool, vp[i], 1);
+    assert(mempool_get_frag_size(&mempool) == size);
+
+    mempool_fini(&mempool);
+    free(base);
+}
+
+int main() {
+    test_mempool_limits(0);
+    test_mempool_limits(256);
+    test_mempool_malloc_mfree(0);
+    test_mempool_malloc_mfree(256);
+    return 0;
+}