Change mutex lock model to avoid dead lock and ensure locks are always released.

Additional cosmetic fixes:
 move 'name' as protected
 remove unnecessary local var
 Fix debug log

5 files changed, 202 insertions, 385 deletions

diff --git a/src/device/device.hpp b/src/device/device.hpp
index b47460472..dee191234 100644
--- a/src/device/device.hpp
+++ b/src/device/device.hpp
@@ -78,8 +78,10 @@ namespace hw {
            return false;
     }
 
-
     class device {
+    protected:
+        std::string  name;
+
     public:
 
         device()  {}
@@ -92,8 +94,6 @@ namespace hw {
         static const int SIGNATURE_FAKE = 1;
 
 
-        std::string  name;
-
         /* ======================================================================= */
         /*                              SETUP/TEARDOWN                             */
         /* ======================================================================= */
@@ -104,7 +104,15 @@ namespace hw {
         virtual bool release() = 0;
 
         virtual bool connect(void) = 0;
-        virtual bool disconnect() = 0;
+        virtual bool disconnect(void) = 0;
+
+        /* ======================================================================= */
+        /*  LOCKER                                                                 */
+        /* ======================================================================= */ 
+        virtual void lock(void) = 0;
+        virtual void unlock(void) = 0;
+        virtual bool try_lock(void) = 0;
+
 
         /* ======================================================================= */
         /*                             WALLET & ADDRESS                            */
diff --git a/src/device/device_default.cpp b/src/device/device_default.cpp
index d63dafe9e..fd6d1e5e2 100644
--- a/src/device/device_default.cpp
+++ b/src/device/device_default.cpp
@@ -81,6 +81,17 @@ namespace hw {
             dfns();
         }
 
+
+        /* ======================================================================= */
+        /*  LOCKER                                                                 */
+        /* ======================================================================= */ 
+    
+        void device_default::lock() { }
+
+        bool device_default::try_lock() { return true; }
+
+        void device_default::unlock() { }
+
         /* ======================================================================= */
         /*                             WALLET & ADDRESS                            */
         /* ======================================================================= */
diff --git a/src/device/device_default.hpp b/src/device/device_default.hpp
index 02faeba0c..f6a3261eb 100644
--- a/src/device/device_default.hpp
+++ b/src/device/device_default.hpp
@@ -60,6 +60,13 @@ namespace hw {
             bool disconnect() override;
 
             /* ======================================================================= */
+            /*  LOCKER                                                                 */
+            /* ======================================================================= */ 
+            void lock(void)  override;
+            void unlock(void) override;
+            bool try_lock(void) override;
+            
+            /* ======================================================================= */
             /*                             WALLET & ADDRESS                            */
             /* ======================================================================= */
             bool  get_public_address(cryptonote::account_public_address &pubkey) override;
diff --git a/src/device/device_ledger.cpp b/src/device/device_ledger.cpp
index b3c0035a1..30ecb67bb 100644
--- a/src/device/device_ledger.cpp
+++ b/src/device/device_ledger.cpp
@@ -33,7 +33,8 @@
 #include "cryptonote_basic/account.h"
 #include "cryptonote_basic/subaddress_index.h"
 
-
+#include <boost/thread/locks.hpp> 
+#include <boost/thread/lock_guard.hpp>
 
 namespace hw {
 
@@ -204,14 +205,51 @@ namespace hw {
       MDEBUG( "Device "<<this->id <<" Destroyed");
     }
 
+    /* ======================================================================= */
+    /*  LOCKER                                                                 */
+    /* ======================================================================= */ 
+    
+    //automatic lock one more level on device ensuring the current thread is allowed to use it
+    #define AUTO_LOCK_CMD() \
+      /* lock both mutexes without deadlock*/ \
+      boost::lock(device_locker, command_locker); \
+      /* make sure both already-locked mutexes are unlocked at the end of scope */ \
+      boost::lock_guard<boost::recursive_mutex> lock1(device_locker, boost::adopt_lock); \
+      boost::lock_guard<boost::mutex> lock2(command_locker, boost::adopt_lock)
+
+    //lock the device for a long sequence
+    void device_ledger::lock(void) {
+      MDEBUG( "Ask for LOCKING for device "<<this->name << " in thread ");
+      device_locker.lock();
+      MDEBUG( "Device "<<this->name << " LOCKed");
+    }
+
+    //lock the device for a long sequence
+    bool device_ledger::try_lock(void) {
+      MDEBUG( "Ask for LOCKING(try) for device "<<this->name << " in thread ");
+      bool r = device_locker.try_lock();
+      if (r) {
+        MDEBUG( "Device "<<this->name << " LOCKed(try)");
+      } else {
+        MDEBUG( "Device "<<this->name << " not LOCKed(try)");
+      }
+      return r;
+    }
+
+    //lock the device for a long sequence
+    void device_ledger::unlock(void) {
+      try {
+        MDEBUG( "Ask for UNLOCKING for device "<<this->name << " in thread ");
+      } catch (...) {
+      }
+      device_locker.unlock();
+      MDEBUG( "Device "<<this->name << " UNLOCKed");
+    }
 
     /* ======================================================================= */
     /*                                   MISC                                  */
     /* ======================================================================= */
     bool device_ledger::reset() {
-
-      lock_device();
-      try {
         int offset;
         reset_buffer();
 
@@ -227,12 +265,7 @@ namespace hw {
         this->buffer_send[4] = offset-5;
         this->length_send = offset;
         this->exchange();
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
      
     unsigned int device_ledger::exchange(unsigned int ok, unsigned int mask) {
@@ -261,30 +294,6 @@ namespace hw {
       memset(this->buffer_recv, 0, BUFFER_RECV_SIZE);
     }
 
-    void device_ledger::lock_device()   {
-      MDEBUG( "Ask for LOCKING for device "<<this->id);
-      device_locker.lock();
-      MDEBUG( "Device "<<this->id << " LOCKed");
-    }
-    void device_ledger::unlock_device() {
-      try {
-        MDEBUG( "Ask for UNLOCKING for device "<<this->id);
-      } catch (...) {
-      }
-      device_locker.unlock();
-      MDEBUG( "Device "<<this->id << " UNLOCKed");
-    }
-    void device_ledger::lock_tx()       {
-      MDEBUG( "Ask for LOCKING for TX "<<this->id);
-      //tx_locker.lock();
-      MDEBUG( "TX "<<this->id << " LOCKed");
-    }
-    void device_ledger::unlock_tx()     {
-      MDEBUG( "Ask for UNLOCKING for TX "<<this->id);
-      //tx_locker.unlock();
-      MDEBUG( "TX "<<this->id << " UNLOCKed");
-    }
-
     /* ======================================================================= */
     /*                              SETUP/TEARDOWN                             */
     /* ======================================================================= */
@@ -416,11 +425,9 @@ namespace hw {
     /*                             WALLET & ADDRESS                            */
     /* ======================================================================= */
 
-    /* Application API */
      bool device_ledger::get_public_address(cryptonote::account_public_address &pubkey){
+        AUTO_LOCK_CMD();
 
-      lock_device();
-      try {
         int offset;
         reset_buffer();
 
@@ -440,21 +447,16 @@ namespace hw {
 
         memmove(pubkey.m_view_public_key.data, this->buffer_recv, 32);
         memmove(pubkey.m_spend_public_key.data, this->buffer_recv+32, 32);
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+ 
+        return true;
     }
 
     bool  device_ledger::get_secret_keys(crypto::secret_key &viewkey , crypto::secret_key &spendkey) {
+        AUTO_LOCK_CMD();
       memset(viewkey.data, 0x00, 32);
       memset(spendkey.data, 0xFF, 32);
 
       #ifdef DEBUG_HWDEVICE
-      lock_device();
-      try {
         //spcialkey, normal conf handled in decrypt
         int offset;
         reset_buffer();
@@ -476,18 +478,13 @@ namespace hw {
         //clear key
         memmove(ledger::viewkey.data,  this->buffer_recv+64, 32);
         memmove(ledger::spendkey.data, this->buffer_recv+96, 32);
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
+
       #endif
       return true;
     }
 
     bool  device_ledger::generate_chacha_key(const cryptonote::account_keys &keys, crypto::chacha_key &key) {
-      lock_device();
-      try {
+        AUTO_LOCK_CMD();
         int offset;
 
         #ifdef DEBUG_HWDEVICE
@@ -519,11 +516,6 @@ namespace hw {
         hw::ledger::check32("generate_chacha_key_prehashed", "key", (char*)key_x.data(), (char*)key.data());
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
       return true;
     }
 
@@ -532,11 +524,8 @@ namespace hw {
     /* ======================================================================= */
 
     bool device_ledger::derive_subaddress_public_key(const crypto::public_key &pub, const crypto::key_derivation &derivation, const std::size_t output_index, crypto::public_key &derived_pub){
-
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::public_key pub_x = pub;
@@ -552,8 +541,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_DERIVE_SUBADDRESS_PUBLIC_KEY;
         this->buffer_send[2] = 0x00;
@@ -561,7 +548,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //pub
         memmove(this->buffer_send+offset, pub.data, 32);
@@ -587,29 +574,22 @@ namespace hw {
         hw::ledger::check32("derive_subaddress_public_key", "derived_pub", derived_pub_x.data, derived_pub.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
       return true;
     }
 
     crypto::public_key device_ledger::get_subaddress_spend_public_key(const cryptonote::account_keys& keys, const cryptonote::subaddress_index &index) {
-      crypto::public_key D;
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        crypto::public_key D;
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const cryptonote::account_keys     keys_x =  hw::ledger::decrypt(keys);
         const cryptonote::subaddress_index index_x = index;
         crypto::public_key                 D_x;
-        hw::ledger::log_hexbuffer("derive_subaddress_public_key: [[IN]]  keys.m_view_secret_key ", keys_x.m_view_secret_key.data,32);
-        hw::ledger::log_hexbuffer("derive_subaddress_public_key: [[IN]]  keys.m_spend_secret_key", keys_x.m_spend_secret_key.data,32);
+        hw::ledger::log_hexbuffer("get_subaddress_spend_public_key: [[IN]]  keys.m_view_secret_key ", keys_x.m_view_secret_key.data,32);
+        hw::ledger::log_hexbuffer("get_subaddress_spend_public_key: [[IN]]  keys.m_spend_secret_key", keys_x.m_spend_secret_key.data,32);
         hw::ledger::log_message  ("get_subaddress_spend_public_key: [[IN]]  index               ", std::to_string(index_x.major)+"."+std::to_string(index_x.minor));
-        this->controle_device->get_subaddress_spend_public_key(keys_x, index_x, D_x);
+        D_x = this->controle_device->get_subaddress_spend_public_key(keys_x, index_x);
         hw::ledger::log_hexbuffer("get_subaddress_spend_public_key: [[OUT]] derivation          ", D_x.data, 32);
         #endif
 
@@ -644,12 +624,7 @@ namespace hw {
         hw::ledger::check32("get_subaddress_spend_public_key", "D", D_x.data, D.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return D;
+        return D;
     }
 
     std::vector<crypto::public_key>  device_ledger::get_subaddress_spend_public_keys(const cryptonote::account_keys &keys, uint32_t account, uint32_t begin, uint32_t end) {
@@ -665,24 +640,22 @@ namespace hw {
     }
 
     cryptonote::account_public_address device_ledger::get_subaddress(const cryptonote::account_keys& keys, const cryptonote::subaddress_index &index) {
-      cryptonote::account_public_address address;
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        cryptonote::account_public_address address;
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const cryptonote::account_keys            keys_x =  hw::ledger::decrypt(keys);
         const cryptonote::subaddress_index        index_x = index;
         cryptonote::account_public_address  address_x;
-        hw::ledger::log_hexbuffer("derive_subaddress_public_key: [[IN]]  keys.m_view_secret_key ", keys_x.m_view_secret_key.data, 32);
-        hw::ledger::log_hexbuffer("derive_subaddress_public_key: [[IN]]  keys.m_view_public_key",  keys_x.m_account_address.m_view_public_key.data, 32);
-        hw::ledger::log_hexbuffer("derive_subaddress_public_key: [[IN]]  keys.m_view_secret_key ", keys_x.m_view_secret_key.data, 32);
-        hw::ledger::log_hexbuffer("derive_subaddress_public_key: [[IN]]  keys.m_spend_public_key", keys_x.m_account_address.m_spend_public_key.data, 32);
+        hw::ledger::log_hexbuffer("get_subaddress: [[IN]]  keys.m_view_secret_key ", keys_x.m_view_secret_key.data, 32);
+        hw::ledger::log_hexbuffer("get_subaddress: [[IN]]  keys.m_view_public_key",  keys_x.m_account_address.m_view_public_key.data, 32);
+        hw::ledger::log_hexbuffer("get_subaddress: [[IN]]  keys.m_view_secret_key ", keys_x.m_view_secret_key.data, 32);
+        hw::ledger::log_hexbuffer("get_subaddress: [[IN]]  keys.m_spend_public_key", keys_x.m_account_address.m_spend_public_key.data, 32);
         hw::ledger::log_message  ("get_subaddress: [[IN]]  index                                ", std::to_string(index_x.major)+"."+std::to_string(index_x.minor));
-        this->controle_device->get_subaddress(keys_x, index_x, address_x);
-        hw::ledger::log_hexbuffer("derive_subaddress_public_key: [[IN]]  keys.m_view_public_key ", address_x.m_view_public_key.data, 32);
-        hw::ledger::log_hexbuffer("derive_subaddress_public_key: [[IN]]  keys.m_spend_public_key", address_x.m_spend_public_key.data, 32);
+        address_x = this->controle_device->get_subaddress(keys_x, index_x);
+        hw::ledger::log_hexbuffer("get_subaddress: [[OUT]]  keys.m_view_public_key ", address_x.m_view_public_key.data, 32);
+        hw::ledger::log_hexbuffer("get_subaddress: [[OUT]]  keys.m_spend_public_key", address_x.m_spend_public_key.data, 32);
         #endif
 
         if (index.is_zero()) {
@@ -717,20 +690,13 @@ namespace hw {
         hw::ledger::check32("get_subaddress", "address.m_spend_public_key.data", address_x.m_spend_public_key.data, address.m_spend_public_key.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return address;
+        return address;
     }
 
     crypto::secret_key  device_ledger::get_subaddress_secret_key(const crypto::secret_key &sec, const cryptonote::subaddress_index &index) {
-      crypto::secret_key sub_sec;
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        crypto::secret_key sub_sec;
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::secret_key            sec_x =  hw::ledger::decrypt(sec);
@@ -738,7 +704,7 @@ namespace hw {
         crypto::secret_key            sub_sec_x;
         hw::ledger::log_message  ("get_subaddress_secret_key: [[IN]]  index  ", std::to_string(index.major)+"."+std::to_string(index.minor));
         hw::ledger::log_hexbuffer("get_subaddress_secret_key: [[IN]]  sec    ", sec_x.data, 32);
-        this->controle_device->get_subaddress_secret_key(sec_x, index_x, sub_sec_x);
+        sub_sec_x = this->controle_device->get_subaddress_secret_key(sec_x, index_x);
         hw::ledger::log_hexbuffer("get_subaddress_secret_key: [[OUT]] sub_sec", sub_sec_x.data, 32);
         #endif
 
@@ -751,7 +717,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //sec
         memmove(this->buffer_send+offset, sec.data, 32);
@@ -772,12 +738,7 @@ namespace hw {
         hw::ledger::check32("get_subaddress_secret_key", "sub_sec", sub_sec_x.data, sub_sec_clear.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return sub_sec;
+        return sub_sec;
     }
 
     /* ======================================================================= */
@@ -785,10 +746,9 @@ namespace hw {
     /* ======================================================================= */
 
     bool  device_ledger::verify_keys(const crypto::secret_key &secret_key, const crypto::public_key &public_key) {
-      lock_device();
-      try {
-        int offset =0,sw;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset, sw;
+
         reset_buffer();
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_VERIFY_KEY;
@@ -816,20 +776,12 @@ namespace hw {
           this->buffer_recv[2] << 8  |
           this->buffer_recv[3] << 0  ;
 
-        unlock_device();
         return verified == 1;
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return false;
     }
 
     bool device_ledger::scalarmultKey(rct::key & aP, const rct::key &P, const rct::key &a) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const rct::key P_x    =  P;
@@ -843,8 +795,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_SECRET_SCAL_MUL_KEY;
         this->buffer_send[2] = 0x00;
@@ -852,7 +802,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //pub
         memmove(this->buffer_send+offset, P.bytes, 32);
@@ -873,19 +823,12 @@ namespace hw {
         hw::ledger::check32("scalarmultKey", "mulkey", (char*)aP_x.bytes, (char*)aP.bytes);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::scalarmultBase(rct::key &aG, const rct::key &a) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const rct::key a_x    =  hw::ledger::decrypt(a);
@@ -897,8 +840,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_SECRET_SCAL_MUL_BASE;
         this->buffer_send[2] = 0x00;
@@ -906,7 +847,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //sec
         memmove(this->buffer_send+offset, a.bytes, 32);
@@ -923,20 +864,12 @@ namespace hw {
         hw::ledger::check32("scalarmultBase", "mulkey", (char*)aG_x.bytes, (char*)aG.bytes);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::sc_secret_add( crypto::secret_key &r, const crypto::secret_key &a, const crypto::secret_key &b) {
-
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::secret_key a_x = hw::ledger::decrypt(a);
@@ -947,8 +880,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_SECRET_KEY_ADD;
         this->buffer_send[2] = 0x00;
@@ -956,7 +887,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //sec key
         memmove(this->buffer_send+offset, a.data, 32);
@@ -977,23 +908,16 @@ namespace hw {
         hw::ledger::check32("sc_secret_add", "r", r_x.data, r_clear.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     crypto::secret_key  device_ledger::generate_keys(crypto::public_key &pub, crypto::secret_key &sec, const crypto::secret_key& recovery_key, bool recover) {
-      if (recover) {
-        throw std::runtime_error("device generate key does not support recover");
-      }
+        AUTO_LOCK_CMD();
+        if (recover) {
+           throw std::runtime_error("device generate key does not support recover");
+        }
 
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         bool recover_x = recover;
@@ -1004,8 +928,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_GENERATE_KEYPAIR;
         this->buffer_send[2] = 0x00;
@@ -1013,7 +935,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
 
         this->buffer_send[4] = offset-5;
@@ -1031,20 +953,13 @@ namespace hw {
         hw::ledger::check32("generate_keys", "pub", pub_x.data, pub.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return sec;
+        return sec;
 
     }
 
     bool device_ledger::generate_key_derivation(const crypto::public_key &pub, const crypto::secret_key &sec, crypto::key_derivation &derivation) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::public_key pub_x = pub;
@@ -1065,7 +980,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //pub
         memmove(this->buffer_send+offset, pub.data, 32);
@@ -1086,19 +1001,13 @@ namespace hw {
         hw::ledger::check32("generate_key_derivation", "derivation", derivation_x.data, derivation_clear.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
+
       return true;
     }
 
     bool device_ledger::derivation_to_scalar(const crypto::key_derivation &derivation, const size_t output_index, crypto::ec_scalar &res) {
-      lock_device();
-      try {
+        AUTO_LOCK_CMD();
         int offset;
-        unsigned char options;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::key_derivation derivation_x = hw::ledger::decrypt(derivation);
@@ -1112,8 +1021,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_DERIVATION_TO_SCALAR;
         this->buffer_send[2] = 0x00;
@@ -1121,7 +1028,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //derivattion
         memmove(this->buffer_send+offset, derivation.data, 32);
@@ -1145,19 +1052,12 @@ namespace hw {
         hw::ledger::check32("derivation_to_scalar", "res", res_x.data, res_clear.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::derive_secret_key(const crypto::key_derivation &derivation, const std::size_t output_index, const crypto::secret_key &sec, crypto::secret_key &derived_sec) {
-      lock_device();
-      try {
+        AUTO_LOCK_CMD();
         int offset;
-        unsigned char options;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::key_derivation derivation_x   = hw::ledger::decrypt(derivation);
@@ -1173,8 +1073,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_DERIVE_SECRET_KEY;
         this->buffer_send[2] = 0x00;
@@ -1182,7 +1080,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //derivation
         memmove(this->buffer_send+offset, derivation.data, 32);
@@ -1209,20 +1107,13 @@ namespace hw {
         hw::ledger::check32("derive_secret_key", "derived_sec", derived_sec_x.data, derived_sec_clear.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::derive_public_key(const crypto::key_derivation &derivation, const std::size_t output_index, const crypto::public_key &pub, crypto::public_key &derived_pub){
-      lock_device();
-      try {
+        AUTO_LOCK_CMD();
         int offset;
-        unsigned char options;
-
+      
         #ifdef DEBUG_HWDEVICE
         const crypto::key_derivation derivation_x   = hw::ledger::decrypt(derivation);
         const std::size_t            output_index_x = output_index;
@@ -1237,8 +1128,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_DERIVE_PUBLIC_KEY;
         this->buffer_send[2] = 0x00;
@@ -1246,7 +1135,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //derivation
         memmove(this->buffer_send+offset, derivation.data, 32);
@@ -1272,19 +1161,12 @@ namespace hw {
         hw::ledger::check32("derive_public_key", "derived_pub", derived_pub_x.data, derived_pub.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::secret_key_to_public_key(const crypto::secret_key &sec, crypto::public_key &pub) {
-      lock_device();
-      try {
+        AUTO_LOCK_CMD();
         int offset;
-        unsigned char options;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::secret_key sec_x = hw::ledger::decrypt(sec);
@@ -1299,8 +1181,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_SECRET_KEY_TO_PUBLIC_KEY;
         this->buffer_send[2] = 0x00;
@@ -1308,7 +1188,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //sec key
         memmove(this->buffer_send+offset, sec.data, 32);
@@ -1325,19 +1205,12 @@ namespace hw {
         hw::ledger::check32("secret_key_to_public_key", "pub", pub_x.data, pub.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::generate_key_image(const crypto::public_key &pub, const crypto::secret_key &sec, crypto::key_image &image){
-      lock_device();
-      try {
+        AUTO_LOCK_CMD();
         int offset;
-        unsigned char options;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::public_key pub_x = pub;
@@ -1351,8 +1224,6 @@ namespace hw {
 
         reset_buffer();
 
-        options = 0;
-
         this->buffer_send[0] = 0x00;
         this->buffer_send[1] = INS_GEN_KEY_IMAGE;
         this->buffer_send[2] = 0x00;
@@ -1360,7 +1231,7 @@ namespace hw {
         this->buffer_send[4] = 0x00;
         offset = 5;
         //options
-        this->buffer_send[offset] = options;
+        this->buffer_send[offset] = 0;
         offset += 1;
         //pub
         memmove(this->buffer_send+offset, pub.data, 32);
@@ -1380,12 +1251,7 @@ namespace hw {
         hw::ledger::check32("generate_key_image", "image", image_x.data, image.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     /* ======================================================================= */
@@ -1393,12 +1259,9 @@ namespace hw {
     /* ======================================================================= */
 
     bool device_ledger::open_tx(crypto::secret_key &tx_key) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
-        lock_tx();
         reset_buffer();
         key_map.clear();
 
@@ -1423,19 +1286,13 @@ namespace hw {
         this->exchange();
 
         memmove(tx_key.data, &this->buffer_recv[32], 32);
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+  
+        return true;
     }
 
     bool  device_ledger::set_signature_mode(unsigned int sig_mode) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset ;
 
         reset_buffer();
 
@@ -1455,25 +1312,19 @@ namespace hw {
         this->buffer_send[4] = offset-5;
         this->length_send = offset;
         this->exchange();
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
+        
       return true;
     }
 
     bool device_ledger::encrypt_payment_id(crypto::hash8 &payment_id, const crypto::public_key &public_key, const crypto::secret_key &secret_key) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const crypto::public_key public_key_x = public_key;
         const crypto::secret_key secret_key_x = hw::ledger::decrypt(secret_key);
         crypto::hash8 payment_id_x = payment_id;
-        this->controle_device->encrypt_payment_id(public_key_x, secret_key_x, payment_id_x);
+        this->controle_device->encrypt_payment_id(payment_id_x, public_key_x, secret_key_x);
         #endif
 
         reset_buffer();
@@ -1506,32 +1357,19 @@ namespace hw {
         hw::ledger::check8("stealth", "payment_id", payment_id_x.data, payment_id.data);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::add_output_key_mapping(const crypto::public_key &Aout, const crypto::public_key &Bout, const bool is_subaddress, const size_t real_output_index,
                                                const rct::key &amount_key,  const crypto::public_key &out_eph_public_key)  {
-      lock_device();
-      try {
+        AUTO_LOCK_CMD();
         key_map.add(ABPkeys(rct::pk2rct(Aout),rct::pk2rct(Bout), is_subaddress, real_output_index, rct::pk2rct(out_eph_public_key), amount_key));
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool  device_ledger::ecdhEncode(rct::ecdhTuple & unmasked, const rct::key & AKout) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const rct::key AKout_x =   hw::ledger::decrypt(AKout);
@@ -1574,19 +1412,12 @@ namespace hw {
         hw::ledger::log_hexbuffer("Blind AKV input", (char*)&this->buffer_recv[64], 3*32);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool  device_ledger::ecdhDecode(rct::ecdhTuple & masked, const rct::key & AKout) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         #ifdef DEBUG_HWDEVICE
         const rct::key AKout_x =   hw::ledger::decrypt(AKout);
@@ -1627,21 +1458,13 @@ namespace hw {
         hw::ledger::check32("ecdhDecode", "mask", (char*)masked_x.mask.bytes,(char*) masked.mask.bytes);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::mlsag_prehash(const std::string &blob, size_t inputs_size, size_t outputs_size,
                                      const rct::keyV &hashes, const rct::ctkeyV &outPk,
                                      rct::key &prehash) {
-
-      lock_device();
-      try {
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
         unsigned int  data_offset, C_offset, kv_offset, i;
         const char *data;
 
@@ -1834,21 +1657,15 @@ namespace hw {
         hw::ledger::check32("mlsag_prehash", "prehash", (char*)prehash_x.bytes, (char*)prehash.bytes);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
 
     bool device_ledger::mlsag_prepare(const rct::key &H, const rct::key &xx,
                                      rct::key &a, rct::key &aG, rct::key &aHP, rct::key &II) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
+        unsigned char options;
 
         #ifdef DEBUG_HWDEVICE
         const rct::key H_x = H;
@@ -1897,19 +1714,13 @@ namespace hw {
         hw::ledger::check32("mlsag_prepare", "II", (char*)II_x.bytes, (char*)II.bytes);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::mlsag_prepare(rct::key &a, rct::key &aG) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
+        unsigned char options;
 
         #ifdef DEBUG_HWDEVICE
         rct::key a_x;
@@ -1941,19 +1752,13 @@ namespace hw {
         hw::ledger::check32("mlsag_prepare", "AG", (char*)aG_x.bytes, (char*)aG.bytes);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::mlsag_hash(const rct::keyV &long_message, rct::key &c) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
+        unsigned char options;
         size_t cnt;
 
         #ifdef DEBUG_HWDEVICE
@@ -1991,20 +1796,12 @@ namespace hw {
         hw::ledger::check32("mlsag_hash", "c", (char*)c_x.bytes, (char*)c.bytes);
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
-
+        return true;
     }
 
     bool device_ledger::mlsag_sign(const rct::key &c, const rct::keyV &xx, const rct::keyV &alpha, const size_t rows, const size_t dsRows, rct::keyV &ss) {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         CHECK_AND_ASSERT_THROW_MES(dsRows<=rows, "dsRows greater than rows");
         CHECK_AND_ASSERT_THROW_MES(xx.size() == rows, "xx size does not match rows");
@@ -2061,19 +1858,12 @@ namespace hw {
         }
         #endif
 
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     bool device_ledger::close_tx() {
-      lock_device();
-      try {
-        int offset =0;
-        unsigned char options = 0;
+        AUTO_LOCK_CMD();
+        int offset;
 
         reset_buffer();
 
@@ -2091,13 +1881,7 @@ namespace hw {
         this->length_send = offset;
         this->exchange();
 
-        unlock_tx();
-        unlock_device();
-      }catch (...)  {
-        unlock_device();
-        throw;
-      }
-      return true;
+        return true;
     }
 
     /* ---------------------------------------------------------- */
diff --git a/src/device/device_ledger.hpp b/src/device/device_ledger.hpp
index e06c5f72c..2053067bd 100644
--- a/src/device/device_ledger.hpp
+++ b/src/device/device_ledger.hpp
@@ -36,7 +36,8 @@
 #include "device.hpp"
 #include <PCSC/winscard.h>
 #include <PCSC/wintypes.h>
-
+#include <boost/thread/mutex.hpp>
+#include <boost/thread/recursive_mutex.hpp>
 
 namespace hw {
 
@@ -80,13 +81,11 @@ namespace hw {
 
     class device_ledger : public hw::device {
     private:
-        mutable std::mutex   device_locker;
-        mutable std::mutex   tx_locker;
-        void lock_device() ;
-        void unlock_device() ;
-        void lock_tx() ;
-        void unlock_tx() ;
- 
+        // Locker for concurrent access
+        mutable boost::recursive_mutex   device_locker;
+        mutable boost::mutex   command_locker;
+
+        //PCSC management 
         std::string  full_name;
         SCARDCONTEXT hContext;
         SCARDHANDLE  hCard;
@@ -130,6 +129,14 @@ namespace hw {
         bool connect(void) override;
         bool disconnect() override;
 
+
+        /* ======================================================================= */
+        /*  LOCKER                                                                 */
+        /* ======================================================================= */ 
+        void lock(void)  override;
+        void unlock(void) override;
+        bool try_lock(void) override;
+
         /* ======================================================================= */
         /*                             WALLET & ADDRESS                            */
         /* ======================================================================= */