shift lmdb initialization to provider constructor which is called only once

src/collection/backend/lmdb.cc

@@ -501,43 +501,27 @@ end_txn:
 }
 
 
-MDBEnvProvider::MDBEnvProvider() :
+MDBEnvProvider::MDBEnvProvider() : m_env(NULL) {
-    m_env(NULL), initialized(false) {
-    pthread_mutex_init(&m_lock, NULL);
-}
-
-MDB_env* MDBEnvProvider::GetEnv() {
-    init();
-    return m_env;
-}
-
-MDB_dbi* MDBEnvProvider::GetDBI() {
-    init();
-    return &m_dbi;
-}
-
-void MDBEnvProvider::init() {
-    pthread_mutex_lock(&m_lock);
-    if (!initialized) {
     MDB_txn *txn;
-        initialized = true;
     mdb_env_create(&m_env);
     mdb_env_open(m_env, "./modsec-shared-collections",
         MDB_WRITEMAP | MDB_NOSUBDIR, 0664);
     mdb_txn_begin(m_env, NULL, 0, &txn);
     mdb_dbi_open(txn, NULL, MDB_CREATE | MDB_DUPSORT, &m_dbi);
     mdb_txn_commit(txn);
-    }
-    pthread_mutex_unlock(&m_lock);
 }
 
-void MDBEnvProvider::close() {
+MDB_env* MDBEnvProvider::GetEnv() {
-    pthread_mutex_lock(&m_lock);
+    return m_env;
-    if (initialized) {
+}
+
+MDB_dbi* MDBEnvProvider::GetDBI() {
+    return &m_dbi;
+}
+
+MDBEnvProvider::~MDBEnvProvider() {
     mdb_dbi_close(m_env, m_dbi);
     mdb_env_close(m_env);
-    }
-    pthread_mutex_unlock(&m_lock);
 }
 
 #endif

src/collection/backend/lmdb.h

@@ -83,16 +83,12 @@ class MDBEnvProvider {
     }
     MDB_env* GetEnv();
     MDB_dbi* GetDBI();
-
+    ~MDBEnvProvider();
  private:
     MDB_env *m_env;
     MDB_dbi m_dbi;
-    pthread_mutex_t m_lock;
 
     MDBEnvProvider();
-    bool initialized;
-    void init();
-    void close();
 };
 
 class LMDB :