FS-10052: [libks] Add experimental ref counting to ks_pool #resolve

libs/libks/src/include/ks_pool.h

@@ -67,6 +67,8 @@ typedef enum {
 #define KS_POOL_FUNC_CALLOC 4	/* ks_pool_calloc function called */
 #define KS_POOL_FUNC_FREE  5	/* ks_pool_free function called */
 #define KS_POOL_FUNC_RESIZE 6	/* ks_pool_resize function called */
+#define KS_POOL_FUNC_INCREF 7	/* reference count incremented */
+#define KS_POOL_FUNC_DECREF 8	/* reference count decremented */
 
 /*
  * void ks_pool_log_func_t
@@ -293,6 +295,34 @@ KS_DECLARE(void *) ks_pool_calloc_ex(ks_pool_t *mp_p, const unsigned long ele_n,
 
 KS_DECLARE(ks_status_t) ks_pool_free_ex(ks_pool_t *mp_p, void **addrP);
 
+
+/*
+ * void *ks_pool_ref_ex
+ *
+ * DESCRIPTION:
+ *
+ * Ref count increment an address in a memoory pool.
+ *
+ * RETURNS:
+ *
+ * Success - The same pointer
+ *
+ * Failure - NULL
+ *
+ * ARGUMENTS:
+ *
+ * mp_p <-> Pointer to the memory pool.
+ *
+ * addr -> The addr to ref
+ *
+ * error_p <- Pointer to integer which, if not NULL, will be set with
+ * a ks_pool error code.
+ */
+
+KS_DECLARE(void *) ks_pool_ref_ex(ks_pool_t *mp_p, void *addr, ks_status_t *error_p);
+
+#define ks_pool_ref(_p, _x) ks_pool_ref_ex(_p, _x, NULL)
+
 /*
  * void *ks_pool_resize
  *

libs/libks/src/include/ks_types.h

@@ -85,6 +85,7 @@ KS_BEGIN_EXTERN_C
 		KS_STATUS_INACTIVE,
 		KS_STATUS_TIMEOUT,
 		/* Memory pool errors */
+		KS_STATUS_REFS_EXIST,      /* references exist */
 		KS_STATUS_ARG_NULL,        /* function argument is null */
 		KS_STATUS_ARG_INVALID,     /* function argument is invalid */
 		KS_STATUS_PNT,	           /* invalid ks_pool pointer */
@@ -105,6 +106,7 @@ KS_BEGIN_EXTERN_C
 		KS_STATUS_ALLOC,	       /* calloc,malloc,free,realloc failed */
 		KS_STATUS_PNT_OVER,	       /* pointer structure was overwritten */
 		KS_STATUS_INVALID_POINTER, /* address is not valid */
+		KS_STATUS_NOT_ALLOWED,     /* operation is not allowed */
 		/* Always insert new entries above this line*/
 		KS_STATUS_COUNT
 	} ks_status_t;

libs/libks/src/ks_pool.c

@@ -52,6 +52,7 @@ typedef struct alloc_prefix_s {
 	unsigned char m1;
 	unsigned long size;
 	unsigned char m2;
+	unsigned int refs;
 } alloc_prefix_t;
 
 #define PREFIX_SIZE sizeof(struct alloc_prefix_s)
@@ -949,6 +950,12 @@ static void *alloc_mem(ks_pool_t *mp_p, const unsigned long byte_size, ks_status
 	prefix->m1 = PRE_MAGIC1;
 	prefix->m2 = PRE_MAGIC2;
 	prefix->size = size;
+	prefix->refs++;
+
+	if (mp_p->mp_log_func != NULL) {
+		alloc_prefix_t *prefix = (alloc_prefix_t *) ((char *) addr - PREFIX_SIZE);
+		mp_p->mp_log_func(mp_p, KS_POOL_FUNC_INCREF, prefix->size, prefix->refs, NULL, addr, 0);
+	}
 
 	/* maintain our stats */
 	mp_p->mp_alloc_c++;
@@ -995,6 +1002,14 @@ static int free_mem(ks_pool_t *mp_p, void *addr)
 		return KS_STATUS_INVALID_POINTER;
 	}
 
+	if (prefix->refs > 0) {
+		prefix->refs--;
+	}
+
+	if (prefix->refs > 0) {
+		return KS_STATUS_REFS_EXIST;
+	}
+
 	size = prefix->size;
 
 	/*
@@ -1645,7 +1660,11 @@ KS_DECLARE(ks_status_t) ks_pool_free_ex(ks_pool_t *mp_p, void **addrP)
 
 	if (mp_p->mp_log_func != NULL) {
 		alloc_prefix_t *prefix = (alloc_prefix_t *) ((char *) addr - PREFIX_SIZE);
-		mp_p->mp_log_func(mp_p, KS_POOL_FUNC_FREE, prefix->size, 0, NULL, addr, 0);
+		if (prefix->refs == 1) {
+			mp_p->mp_log_func(mp_p, KS_POOL_FUNC_FREE, prefix->size, prefix->refs - 1, NULL, addr, 0);
+		} else {
+			mp_p->mp_log_func(mp_p, KS_POOL_FUNC_DECREF, prefix->size, prefix->refs - 1, NULL, addr, 0);
+		}
 	}
 
 	r = free_mem(mp_p, addr);
@@ -1662,13 +1681,68 @@ KS_DECLARE(ks_status_t) ks_pool_free_ex(ks_pool_t *mp_p, void **addrP)
 
 }
 
+/*
+ * void *ks_pool_ref_ex
+ *
+ * DESCRIPTION:
+ *
+ * Ref count increment an address in a memoory pool.
+ *
+ * RETURNS:
+ *
+ * Success - The same pointer
+ *
+ * Failure - NULL
+ *
+ * ARGUMENTS:
+ *
+ * mp_p <-> Pointer to the memory pool.
+ *
+ * addr -> The addr to ref
+ *
+ * error_p <- Pointer to integer which, if not NULL, will be set with
+ * a ks_pool error code.
+ */
+KS_DECLARE(void *) ks_pool_ref_ex(ks_pool_t *mp_p, void *addr, ks_status_t *error_p)
+{
+	alloc_prefix_t *prefix;
+
+	if (mp_p->mp_magic != KS_POOL_MAGIC) {
+		SET_POINTER(error_p, KS_STATUS_PNT);
+		return NULL;
+	}
+
+	if (mp_p->mp_magic2 != KS_POOL_MAGIC) {
+		SET_POINTER(error_p, KS_STATUS_POOL_OVER);
+		return NULL;
+	}
+
+	ks_mutex_lock(mp_p->mutex);
+	prefix = (alloc_prefix_t *) ((char *) addr - PREFIX_SIZE);
+
+	if (!(prefix->m1 == PRE_MAGIC1 && prefix->m2 == PRE_MAGIC2)) {
+		SET_POINTER(error_p, KS_STATUS_INVALID_POINTER);
+		return NULL;
+	}
+
+	prefix->refs++;
+
+	if (mp_p->mp_log_func != NULL) {
+		alloc_prefix_t *prefix = (alloc_prefix_t *) ((char *) addr - PREFIX_SIZE);
+		mp_p->mp_log_func(mp_p, KS_POOL_FUNC_INCREF, prefix->size, prefix->refs, NULL, addr, 0);
+	}
+
+	ks_mutex_unlock(mp_p->mutex);
+
+	return addr;
+}
+
 /*
  * void *ks_pool_resize_ex
  *
  * DESCRIPTION:
  *
- * Reallocate an address in a mmeory pool to a new size.  This is
- * different from realloc in that it needs the old address' size.  
+ * Reallocate an address in a memory pool to a new size.  This is
  *
  * RETURNS:
  *
@@ -1722,6 +1796,12 @@ KS_DECLARE(void *) ks_pool_resize_ex(ks_pool_t *mp_p, void *old_addr, const unsi
 
 
 	ks_mutex_lock(mp_p->mutex);
+
+	if (prefix->refs > 1) {
+		SET_POINTER(error_p,KS_STATUS_NOT_ALLOWED);
+		return NULL;
+	}
+
 	old_byte_size = prefix->size;
 
 	/*

libs/libks/test/testpools.c

@@ -4,6 +4,7 @@
 #include <stdio.h>
 #include <string.h>
 #include "tap.h"
+#define STR "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 
 static void fill(char *str, int bytes, char c)
 {
@@ -48,7 +49,7 @@ int main(int argc, char **argv)
 
 	ks_init();
 
-	plan(11);
+	plan(14);
 
 	if (argc > 1) {
 		int tmp = atoi(argv[1]);
@@ -100,10 +101,38 @@ int main(int argc, char **argv)
 		exit(255);
 	}
 
-	fill(str, bytes, '-');
+
+	ks_snprintf(str, bytes, "%s", STR);
 	printf("%s\n", str);
 
 
+	printf("ALLOC3 (refs):\n");
+
+	str = ks_pool_ref(pool, str);
+
+	printf("STR [%s]\n", str);
+
+	ks_pool_free(pool, &str);
+
+	ok(str != NULL && !strcmp(str, STR));
+
+	printf("STR [%s]\n", str);
+
+	ks_pool_free(pool, &str);
+
+	ok(str == NULL);
+
+	str = ks_pool_alloc(pool, bytes);
+
+	ok(str != NULL);
+	if (!str) {
+		fprintf(stderr, "ALLOC2 ERR: [FAILED]\n");
+		exit(255);
+	}
+
+	fill(str, bytes, '-');
+	printf("%s\n", str);
+
 	printf("ALLOC OBJ:\n");
 
 	foo = ks_pool_alloc(pool, sizeof(struct foo));
@@ -168,13 +197,13 @@ int main(int argc, char **argv)
 	printf("RESIZE:\n");
 
 
-	ks_snprintf(str, bytes, "%s", "ABCDEFGHIJKLM");
+	ks_snprintf(str, bytes, "%s", STR);
 	printf("1 STR [%s]\n", str);
 	bytes *= 2;
 	str = ks_pool_resize(pool, str, bytes);
 	printf("2 STR [%s]\n", str);
 
-	ok(!strcmp(str, "ABCDEFGHIJKLM"));
+	ok(!strcmp(str, STR));
 
 	if (!str) {
 		fprintf(stderr, "RESIZE ERR: [FAILED]\n");