Replace the spinlock on ProxySQL_Admin::wrlock with a pthread mutex or wrlock

include/proxy_defines.h

@@ -0,0 +1,4 @@
+
+// If defined then active pthread mutex in ProxySQL_Admin else use the wrlock
+#define PA_PTHREAD_MUTEX
+

include/proxysql_admin.h

@@ -1,5 +1,7 @@
 #ifndef __CLASS_PROXYSQL_ADMIN_H
 #define __CLASS_PROXYSQL_ADMIN_H
+
+#include "proxy_defines.h"
 #include "proxysql.h"
 #include "cpp.h"
 #include <vector>
@@ -58,8 +60,19 @@ class ProxySQL_Admin {
 	int main_poll_nfds;
 	struct pollfd *main_poll_fds;
 	int *main_callback_func;
+
+
 	rwlock_t rwlock;
+
+#ifdef PA_PTHREAD_MUTEX
+	pthread_mutex_t mysql_servers_lock;
+#else
 	rwlock_t mysql_servers_rwlock;
+#endif
+
+	
+
+
 	void wrlock();
 	void wrunlock();
 

lib/ProxySQL_Admin.cpp

@@ -2450,8 +2450,18 @@ ProxySQL_Admin::ProxySQL_Admin() {
 		}
 
 	SPA=this;
+
+	//Initialize locker
 	spinlock_rwlock_init(&rwlock);
+
+#ifdef PA_PTHREAD_MUTEX
+	pthread_mutex_init(&mysql_servers_lock, NULL);
+#else
 	spinlock_rwlock_init(&mysql_servers_rwlock);
+#endif
+
+
+
 	variables.admin_credentials=strdup("admin:admin");
 	variables.stats_credentials=strdup("stats:stats");
 	if (GloVars.__cmd_proxysql_admin_socket) {
@@ -2493,11 +2503,19 @@ void ProxySQL_Admin::wrunlock() {
 };
 
 void ProxySQL_Admin::mysql_servers_wrlock() {
-	spin_wrlock(&mysql_servers_rwlock);
+	#ifdef PA_PTHREAD_MUTEX
+		pthread_mutex_lock(&mysql_servers_lock);
+	#else
+		spin_wrlock(&mysql_servers_rwlock);
+	#endif
 };
 
 void ProxySQL_Admin::mysql_servers_wrunlock() {
-	spin_wrunlock(&mysql_servers_rwlock);
+	#ifdef PA_PTHREAD_MUTEX
+		pthread_mutex_unlock(&mysql_servers_lock);
+	#else
+		spin_wrunlock(&mysql_servers_rwlock);
+	#endif
 };
 
 void ProxySQL_Admin::print_version() {