add pool strcture and move src list to pool

src/pool.c

@@ -0,0 +1,91 @@
+
+#include <string.h>
+#include <stdlib.h>
+#include "pool.h"
+
+#define DEFAULT_START_SIZE 16
+
+pool *pool_new(void)
+{
+	pool *p;
+	p = malloc(sizeof(*p));
+	if (!p)
+		return NULL;
+	memset(p, 0, sizeof(*p));
+
+	p->array = calloc(DEFAULT_START_SIZE, sizeof(void *));
+	if (!p->array) {
+		free(p);
+		return NULL;
+	}
+
+	p->len = DEFAULT_START_SIZE;
+	p->num = 0;
+	lock_init(&p->lock);
+	return p;
+}
+
+void pool_free(pool *p)
+{
+	if (p->array)
+		free(p->array);
+	free(p);
+}
+
+int pool_push(pool *p, void *v)
+{
+	if (p->num == p->len) {
+		/* expand array */
+		size_t newlen = p->len * 2 * sizeof(void *);
+		void **new = realloc(p->array, newlen);
+		if (new == NULL)
+			return -1;
+		p->len = newlen;
+		p->array = new;
+	}
+	p->array[p->num] = v;
+	p->num++;
+	return 0;
+}
+
+int pool_push_lock(pool *p, void *v)
+{
+	int ret = -1;
+	pool_lock(p);
+	ret = pool_push(p, v);
+	pool_unlock(p);
+	return ret;
+}
+
+void *pool_pop(pool *p)
+{
+	return p->num == 0 ? NULL : p->array[--p->num];
+}
+
+void *pool_pop_lock(pool *p)
+{
+	void *v;
+	pool_lock(p);
+	v = pool_pop(p);
+	pool_unlock(p);
+	return v;
+}
+
+void *pool_iter_next(pool *p)
+{
+	if (p->num <= p->idx)
+		return NULL;
+
+	void *v = p->array[p->idx];
+	p->idx++;
+	return v;
+}
+
+void *pool_iter_next_lock(pool *p)
+{
+	void *v = NULL;
+	pool_lock(p);
+	v = pool_iter_next(p);
+	pool_unlock(p);
+	return v;
+}