Use locks instead of semaphores in ledger subprovider

2 files changed, 15 insertions, 27 deletions

diff --git a/packages/subproviders/src/globals.d.ts b/packages/subproviders/src/globals.d.ts
index e59f4ad8a..25f7f4483 100644
--- a/packages/subproviders/src/globals.d.ts
+++ b/packages/subproviders/src/globals.d.ts
@@ -67,16 +67,6 @@ declare module '@ledgerhq/hw-transport-node-hid' {
     }
 }
 
-// Semaphore-async-await declarations
-declare module 'semaphore-async-await' {
-    class Semaphore {
-        constructor(permits: number);
-        public wait(): Promise<void>;
-        public signal(): void;
-    }
-    export default Semaphore;
-}
-
 // web3-provider-engine declarations
 declare module 'web3-provider-engine/subproviders/subprovider' {
     class Subprovider {}
diff --git a/packages/subproviders/src/subproviders/ledger.ts b/packages/subproviders/src/subproviders/ledger.ts
index 03f7ef493..b67b49bee 100644
--- a/packages/subproviders/src/subproviders/ledger.ts
+++ b/packages/subproviders/src/subproviders/ledger.ts
@@ -4,7 +4,7 @@ import EthereumTx = require('ethereumjs-tx');
 import ethUtil = require('ethereumjs-util');
 import HDNode = require('hdkey');
 import * as _ from 'lodash';
-import Semaphore from 'semaphore-async-await';
+import { Lock } from 'semaphore-async-await';
 import * as Web3 from 'web3';
 
 import {
@@ -24,8 +24,8 @@ const ASK_FOR_ON_DEVICE_CONFIRMATION = false;
 const SHOULD_GET_CHAIN_CODE = true;
 
 export class LedgerSubprovider extends Subprovider {
-    private _nonceLock: Semaphore;
-    private _connectionLock: Semaphore;
+    private _nonceLock = new Lock();
+    private _connectionLock = new Lock();
     private _networkId: number;
     private _derivationPath: string;
     private _derivationPathIndex: number;
@@ -39,8 +39,6 @@ export class LedgerSubprovider extends Subprovider {
     }
     constructor(config: LedgerSubproviderConfigs) {
         super();
-        this._nonceLock = new Semaphore(1);
-        this._connectionLock = new Semaphore(1);
         this._networkId = config.networkId;
         this._ledgerEthereumClientFactoryAsync = config.ledgerEthereumClientFactoryAsync;
         this._derivationPath = config.derivationPath || DEFAULT_DERIVATION_PATH;
@@ -221,27 +219,27 @@ export class LedgerSubprovider extends Subprovider {
         return derivationPath;
     }
     private async _createLedgerClientAsync(): Promise<LedgerEthereumClient> {
-        await this._connectionLock.wait();
+        await this._connectionLock.acquire();
         if (!_.isUndefined(this._ledgerClientIfExists)) {
-            this._connectionLock.signal();
+            this._connectionLock.release();
             throw new Error(LedgerSubproviderErrors.MultipleOpenConnectionsDisallowed);
         }
         const ledgerEthereumClient = await this._ledgerEthereumClientFactoryAsync();
-        this._connectionLock.signal();
+        this._connectionLock.release();
         return ledgerEthereumClient;
     }
     private async _destroyLedgerClientAsync() {
-        await this._connectionLock.wait();
+        await this._connectionLock.acquire();
         if (_.isUndefined(this._ledgerClientIfExists)) {
-            this._connectionLock.signal();
+            this._connectionLock.release();
             return;
         }
         await this._ledgerClientIfExists.transport.close();
         this._ledgerClientIfExists = undefined;
-        this._connectionLock.signal();
+        this._connectionLock.release();
     }
     private async _sendTransactionAsync(txParams: PartialTxParams): Promise<string> {
-        await this._nonceLock.wait();
+        await this._nonceLock.acquire();
         try {
             // fill in the extras
             const filledParams = await this._populateMissingTxParamsAsync(txParams);
@@ -253,29 +251,29 @@ export class LedgerSubprovider extends Subprovider {
                 params: [signedTx],
             };
             const result = await this.emitPayloadAsync(payload);
-            this._nonceLock.signal();
+            this._nonceLock.release();
             return result.result;
         } catch (err) {
-            this._nonceLock.signal();
+            this._nonceLock.release();
             throw err;
         }
     }
     private async _signTransactionWithoutSendingAsync(txParams: PartialTxParams): Promise<ResponseWithTxParams> {
-        await this._nonceLock.wait();
+        await this._nonceLock.acquire();
         try {
             // fill in the extras
             const filledParams = await this._populateMissingTxParamsAsync(txParams);
             // sign it
             const signedTx = await this.signTransactionAsync(filledParams);
 
-            this._nonceLock.signal();
+            this._nonceLock.release();
             const result = {
                 raw: signedTx,
                 tx: txParams,
             };
             return result;
         } catch (err) {
-            this._nonceLock.signal();
+            this._nonceLock.release();
             throw err;
         }
     }