minor CTable refactoring

src/cmem.c

@@ -10,6 +10,17 @@
 // realloc wrapper
 void *cosmoM_reallocate(CState *state, void *buf, size_t oldSize, size_t newSize)
 {
+#ifdef GC_DEBUG
+    if (buf) {
+        if (newSize == 0) {
+            printf("freeing %p, reclaiming %ld bytes...\n", buf, oldSize);
+        } else {
+            printf("realloc %p, byte difference: %ld\n", buf, newSize - oldSize);
+        }
+    } else {
+        printf("allocating new buffer of size %ld\n", newSize - oldSize);
+    }
+#endif
     state->allocatedBytes += newSize - oldSize;
 
     if (newSize == 0) { // it needs to be freed
@@ -59,7 +70,7 @@ static void markTable(CState *state, CTable *tbl)
     if (tbl->table == NULL) // table is still being initialized
         return;
 
-    int cap = tbl->capacityMask + 1;
+    int cap = cosmoT_getCapacity(tbl);
     for (int i = 0; i < cap; i++) {
         CTableEntry *entry = &tbl->table[i];
         markValue(state, entry->key);
@@ -67,13 +78,18 @@ static void markTable(CState *state, CTable *tbl)
     }
 }
 
-// frees white members from the table
+// removes white members from the table
 static void tableRemoveWhite(CState *state, CTable *tbl)
 {
     if (tbl->table == NULL) // table is still being initialized
         return;
 
-    int cap = tbl->capacityMask + 1;
+    int cap = cosmoT_getCapacity(tbl);
+
+#ifdef GC_DEBUG
+    printf("tableRemoveWhite: %p, cap: %d\n", tbl, cap);
+#endif
+
     for (int i = 0; i < cap; i++) {
         CTableEntry *entry = &tbl->table[i];
         if (IS_REF(entry->key) &&
@@ -295,7 +311,6 @@ COSMO_API void cosmoM_collectGarbage(CState *state)
     printf("-- GC end, reclaimed %ld bytes (started at %ld, ended at %ld), next garbage collection "
            "scheduled at %ld bytes\n",
            start - state->allocatedBytes, start, state->allocatedBytes, state->nextGC);
-    getchar(); // pauses execution
 #endif
 }
 

src/cmem.h

@@ -73,10 +73,13 @@ COSMO_API void cosmoM_addRoot(CState *state, CObj *newRoot);
 // lets the VM know this root is no longer held in a reference and is able to be freed
 COSMO_API void cosmoM_removeRoot(CState *state, CObj *oldRoot);
 
-// wrapper for cosmoM_reallocate so we can track our memory usage (it's also safer :P)
+// wrapper for cosmoM_reallocate so we can track our memory usage
 static inline void *cosmoM_xmalloc(CState *state, size_t sz)
 {
     return cosmoM_reallocate(state, NULL, 0, sz);
 }
 
+// #define cosmoM_xmalloc(state, sz) \
+//         (printf("allocating new buffer at %s:%d of size %ld\n", __FILE__, __LINE__, sz), cosmoM_reallocate(state, NULL, 0, sz))
+
 #endif

src/ctable.c

@@ -34,6 +34,7 @@ void cosmoT_initTable(CState *state, CTable *tbl, int startCap)
     tbl->capacityMask = startCap - 1;
     tbl->count = 0;
     tbl->tombstones = 0;
+    tbl->tombThreshold = 32;
     tbl->table = NULL; // to let out GC know we're initalizing
     tbl->table = cosmoM_xmalloc(state, sizeof(CTableEntry) * startCap);
 
@@ -47,7 +48,7 @@ void cosmoT_initTable(CState *state, CTable *tbl, int startCap)
 void cosmoT_addTable(CState *state, CTable *from, CTable *to)
 {
     CTableEntry *entry;
-    int cap = from->capacityMask + 1;
+    int cap = cosmoT_getCapacity(from);
 
     for (int i = 0; i < cap; i++) {
         entry = &from->table[i];
@@ -60,7 +61,7 @@ void cosmoT_addTable(CState *state, CTable *from, CTable *to)
 
 void cosmoT_clearTable(CState *state, CTable *tbl)
 {
-    cosmoM_freearray(state, CTableEntry, tbl->table, (tbl->capacityMask + 1));
+    cosmoM_freearray(state, CTableEntry, tbl->table, cosmoT_getCapacity(tbl));
 }
 
 static uint32_t getObjectHash(CObj *obj)
@@ -113,10 +114,10 @@ static CTableEntry *findEntry(CState *state, CTableEntry *entries, int mask, CVa
             if (IS_NIL(entry->val)) {
                 // it's empty! if we found a tombstone, return that so it'll be reused
                 return tomb != NULL ? tomb : entry;
-            } else {
+            }
+
             // its a tombstone!
             tomb = entry;
-            }
         } else if (cosmoV_equal(state, entry->key, key)) {
             return entry;
         }
@@ -141,7 +142,7 @@ static void resizeTbl(CState *state, CTable *tbl, int newCapacity, bool canShrin
         return;
 
     CTableEntry *entries = cosmoM_xmalloc(state, size);
-    oldCap = tbl->capacityMask + 1;
+    oldCap = cosmoT_getCapacity(tbl);
     newCount = 0;
 
     // set all nodes as NIL : NIL
@@ -176,10 +177,10 @@ bool cosmoT_checkShrink(CState *state, CTable *tbl)
 {
     // if count > 8 and active entries < tombstones
     if (tbl->count > MIN_TABLE_CAPACITY &&
-        (tbl->count - tbl->tombstones < tbl->tombstones ||
+        (tbl->count - tbl->tombstones < tbl->tombstones || tbl->tombstones > tbl->tombThreshold)) {
-         tbl->tombstones > 50)) { // TODO: 50 should be a threshhold
+        // shrink based on active entries to the next pow of 2
-        resizeTbl(state, tbl, nextPow2(tbl->count - tbl->tombstones) * GROW_FACTOR,
+        resizeTbl(state, tbl, nextPow2(tbl->count - tbl->tombstones) * GROW_FACTOR, false);
-                  false); // shrink based on active entries to the next pow of 2
+        tbl->tombThreshold = tbl->count / 4;
         return true;
     }
 
@@ -190,7 +191,7 @@ bool cosmoT_checkShrink(CState *state, CTable *tbl)
 COSMO_API CValue *cosmoT_insert(CState *state, CTable *tbl, CValue key)
 {
     // make sure we have enough space allocated
-    int cap = tbl->capacityMask + 1;
+    int cap = cosmoT_getCapacity(tbl);
     if (tbl->count + 1 > (int)(cap * MAX_TABLE_FILL)) {
         // grow table
         int newCap = cap * GROW_FACTOR;
@@ -198,8 +199,7 @@ COSMO_API CValue *cosmoT_insert(CState *state, CTable *tbl, CValue key)
     }
 
     // insert into the table
-    CTableEntry *entry =
+    CTableEntry *entry = findEntry(state, tbl->table, tbl->capacityMask, key);
-        findEntry(state, tbl->table, tbl->capacityMask, key); // -1 for our capacity mask
 
     if (IS_NIL(entry->key)) {
         if (IS_NIL(entry->val)) // is it empty?
@@ -255,9 +255,10 @@ CObjString *cosmoT_lookupString(CTable *tbl, const char *str, int length, uint32
 {
     if (tbl->count == 0)
         return 0; // sanity check
-    uint32_t indx =
+
-        hash & tbl->capacityMask; // since we know the capacity will *always* be a power of 2, we
+    // since we know the capacity will *always* be a power of 2, we
     // can use bitwise & to perform a MUCH faster mod operation
+    uint32_t indx = hash & tbl->capacityMask;
 
     // keep looking for an open slot in the entries array
     while (true) {
@@ -280,7 +281,7 @@ CObjString *cosmoT_lookupString(CTable *tbl, const char *str, int length, uint32
 void cosmoT_printTable(CTable *tbl, const char *name)
 {
     printf("==== [[%s]] ====\n", name);
-    int cap = tbl->capacityMask + 1;
+    int cap = cosmoT_getCapacity(tbl);
     for (int i = 0; i < cap; i++) {
         CTableEntry *entry = &tbl->table[i];
         if (!(IS_NIL(entry->key))) {

src/ctable.h

@@ -18,9 +18,12 @@ typedef struct CTable
     int count;
     int capacityMask; // +1 to get the capacity
     int tombstones;
+    int tombThreshold;
     CTableEntry *table;
 } CTable;
 
+#define cosmoT_getCapacity(tbl) ((tbl)->capacityMask + 1)
+
 COSMO_API void cosmoT_initTable(CState *state, CTable *tbl, int startCap);
 COSMO_API void cosmoT_clearTable(CState *state, CTable *tbl);
 COSMO_API int cosmoT_count(CTable *tbl);

src/cvm.c

@@ -640,7 +640,7 @@ int _tbl__next(CState *state, int nargs, CValue *args)
     CObjTable *table = (CObjTable *)cosmoV_readRef(val);
 
     // while the entry is invalid, go to the next entry
-    int cap = table->tbl.capacityMask + 1;
+    int cap = cosmoT_getCapacity(&table->tbl);
     CTableEntry *entry;
     do {
         entry = &table->tbl.table[index++];
@@ -1037,7 +1037,9 @@ int cosmoV_execute(CState *state)
                         cosmoV_pop(state); // pop the object from the stack
                         cosmoV_pushValue(state, val);
                         cosmoV_pushRef(state, (CObj *)obj);
-                        if (!cosmoV_call(state, 1, 1)) // we expect 1 return value on the stack, the iterable object
+                        if (!cosmoV_call(
+                                state, 1,
+                                1)) // we expect 1 return value on the stack, the iterable object
                             return -1;
 
                         StkPtr iObj = cosmoV_getTop(state, 0);