diff --git a/src/main/c/org_apache_activemq_artemis_nativo_jlibaio_LibaioContext.c b/src/main/c/org_apache_activemq_artemis_nativo_jlibaio_LibaioContext.c
index d495eb4..6a96b53 100644
--- a/src/main/c/org_apache_activemq_artemis_nativo_jlibaio_LibaioContext.c
+++ b/src/main/c/org_apache_activemq_artemis_nativo_jlibaio_LibaioContext.c
@@ -49,16 +49,15 @@ struct io_control {
 
     // This is used to make sure we don't return IOCB while something else is using them
     // this is to guarantee the submits could be done concurrently with polling
-    pthread_mutex_t iocbLock;
+    pthread_spinlock_t iocbLock;
 
     pthread_mutex_t pollLock;
 
     // a reusable pool of iocb
     struct iocb ** iocb;
     int queueSize;
-    int iocbPut;
-    int iocbGet;
-    int used;
+    //struct iocb* available_iocb = io_control->iocb[io_control->available-1] iff io_control->available > 0
+    int available;
 
 };
 
@@ -444,22 +443,18 @@ static inline struct io_control * getIOControl(JNIEnv* env, jobject pointer) {
 static inline struct iocb * getIOCB(struct io_control * control) {
     struct iocb * iocb = 0;
 
-    pthread_mutex_lock(&(control->iocbLock));
+    pthread_spin_lock(&(control->iocbLock));
 
     #ifdef DEBUG
-       fprintf (stdout, "getIOCB::used=%d, queueSize=%d, get=%d, put=%d\n", control->used, control->queueSize, control->iocbGet, control->iocbPut);
+       fprintf (stdout, "getIOCB::available=%d, queueSize=%d\n", control->available, control->queueSize);
     #endif
 
-    if (control->used < control->queueSize) {
-        control->used++;
-        iocb = control->iocb[control->iocbGet++];
-
-        if (control->iocbGet >= control->queueSize) {
-           control->iocbGet = 0;
-        }
+    if (control->available > 0) {
+        control->available--;
+        iocb = control->iocb[control->available];
     }
 
-    pthread_mutex_unlock(&(control->iocbLock));
+    pthread_spin_unlock(&(control->iocbLock));
     return iocb;
 }
 
@@ -467,18 +462,19 @@ static inline struct iocb * getIOCB(struct io_control * control) {
  * Put an iocb back on the pool of IOCBs
  */
 static inline void putIOCB(struct io_control * control, struct iocb * iocbBack) {
-    pthread_mutex_lock(&(control->iocbLock));
+    if (iocbBack == NULL) {
+        return;
+    }
+    pthread_spin_lock(&(control->iocbLock));
 
     #ifdef DEBUG
-       fprintf (stdout, "putIOCB::used=%d, queueSize=%d, get=%d, put=%d\n", control->used, control->queueSize, control->iocbGet, control->iocbPut);
+       fprintf (stdout, "putIOCB::available=%d, queueSize=%d\n", control->available, control->queueSize);
     #endif
-
-    control->used--;
-    control->iocb[control->iocbPut++] = iocbBack;
-    if (control->iocbPut >= control->queueSize) {
-       control->iocbPut = 0;
+    if (control->available < control->queueSize) {
+        control->iocb[control->available] = iocbBack;
+        control->available++;
     }
-    pthread_mutex_unlock(&(control->iocbLock));
+    pthread_spin_unlock(&(control->iocbLock));
 }
 
 static inline short submit(JNIEnv * env, struct io_control * theControl, struct iocb * iocb) {
@@ -537,7 +533,7 @@ static inline void iocb_destroy_bounded(struct io_control * theControl, int uppe
  * @param theControl
  */
 static inline void iocb_destroy(struct io_control * theControl) {
-    iocb_destroy_bounded(theControl, theControl->queueSize);
+    iocb_destroy_bounded(theControl, theControl->available);
 }
 
 /**
@@ -590,9 +586,10 @@ JNIEXPORT jobject JNICALL Java_org_apache_activemq_artemis_nativo_jlibaio_Libaio
        }
     }
     theControl->queueSize = queueSize;
+    //iocb pool is full
+    theControl->available = queueSize;
 
-
-    res = pthread_mutex_init(&(theControl->iocbLock), 0);
+    res = pthread_spin_init(&(theControl->iocbLock), 0);
     if (res) {
         iocb_destroy(theControl);
 
@@ -625,10 +622,6 @@ JNIEXPORT jobject JNICALL Java_org_apache_activemq_artemis_nativo_jlibaio_Libaio
         return NULL;
     }
 
-
-    theControl->iocbPut = 0;
-    theControl->iocbGet = 0;
-    theControl->used = 0;
     theControl->thisObject = (*env)->NewGlobalRef(env, thisObject);
 
     return (*env)->NewDirectByteBuffer(env, theControl, sizeof(struct io_control));
@@ -670,7 +663,9 @@ JNIEXPORT void JNICALL Java_org_apache_activemq_artemis_nativo_jlibaio_LibaioCon
     io_queue_release(theControl->ioContext);
 
     pthread_mutex_destroy(&(theControl->pollLock));
-    pthread_mutex_destroy(&(theControl->iocbLock));
+    pthread_spin_destroy(&(theControl->iocbLock));
+
+    const int leaked_iocbs = theControl->queueSize - theControl->available;
 
     iocb_destroy(theControl);
 
@@ -678,6 +673,11 @@ JNIEXPORT void JNICALL Java_org_apache_activemq_artemis_nativo_jlibaio_LibaioCon
 
     free(theControl->events);
     free(theControl);
+
+    if (leaked_iocbs > 0) {
+        throwIOException(env, "There are pending I/O operations");
+        return;
+    }
 }
 
 JNIEXPORT void JNICALL Java_org_apache_activemq_artemis_nativo_jlibaio_LibaioContext_close(JNIEnv* env, jclass clazz, jint fd) {