Use mutex lock to allow only 1 concurrent ETH tx send.

iguana/exchanges/LP_etomic.c

@@ -27,26 +27,7 @@
 
 int32_t LP_etomic_wait_for_confirmation(char *txId)
 {
-    EthTxReceipt receipt;
-    EthTxData txData;
-    do {
-        sleep(15);
-        printf("waiting for ETH txId to be confirmed: %s\n", txId);
-        receipt = getEthTxReceipt(txId);
-        if (receipt.confirmations < 1) {
-            txData = getEthTxData(txId);
-            if (txData.exists == 0) {
-                return(-1);
-            }
-        }
-    } while (receipt.confirmations < 1);
-
-    if (strcmp(receipt.status, "0x1") != 0) {
-        printf("ETH txid %s receipt status failed\n", txId);
-        return(-1);
-    }
-
-    return(receipt.confirmations);
+    return(waitForConfirmation(txId));
 }
 
 char *LP_etomicalice_send_fee(struct basilisk_swap *swap)

iguana/exchanges/etomicswap/CMakeLists.txt

@@ -1,11 +1,11 @@
-cmake_minimum_required(VERSION 2.8.9)
+cmake_minimum_required(VERSION 3.5.1)
 add_library(etomiclib-testnet etomiclib.cpp etomiccurl.c)
 add_library(etomiclib-mainnet etomiclib.cpp etomiccurl.c)
 target_compile_definitions(etomiclib-testnet PRIVATE ETOMIC_TESTNET)
 add_executable(alice alice.c)
 add_executable(bob bob.c)
 include_directories("${CMAKE_SOURCE_DIR}/cpp-ethereum")
-target_link_libraries(etomiclib-testnet PUBLIC curl libcrypto777 ethcore devcrypto devcore)
-target_link_libraries(etomiclib-mainnet PUBLIC curl libcrypto777 ethcore devcrypto devcore)
+target_link_libraries(etomiclib-testnet PUBLIC curl libcrypto777 ethcore devcrypto devcore pthread)
+target_link_libraries(etomiclib-mainnet PUBLIC curl libcrypto777 ethcore devcrypto devcore pthread)
 target_link_libraries(alice PUBLIC etomiclib-testnet)
-target_link_libraries(bob PUBLIC etomiclib-testnet)
+target_link_libraries(bob PUBLIC etomiclib-testnet)

iguana/exchanges/etomicswap/bob.c

@@ -14,6 +14,11 @@ char* aliceAddress = "0x485d2cc2d13a9e12E4b53D606DB1c8adc884fB8a";
 char* bobAddress = "0xbAB36286672fbdc7B250804bf6D14Be0dF69fa29";
 char* tokenAddress = "0xc0eb7AeD740E1796992A08962c15661bDEB58003";
 
+void *erc20ApproveThread(ApproveErc20Input *input) {
+    char *result = approveErc20(*input);
+    free(result);
+}
+
 int main(int argc, char** argv)
 {
     enum {
@@ -227,13 +232,32 @@ int main(int argc, char** argv)
             strcpy(input8.owner, bobAddress);
             strcpy(input8.tokenAddress, tokenAddress);
             strcpy(input8.secret, getenv("BOB_PK"));
-            result = approveErc20(input8);
+            ApproveErc20Input input123;
+            strcpy(input123.amount, "100");
+            strcpy(input123.spender, bobContractAddress);
+            strcpy(input123.owner, bobAddress);
+            strcpy(input123.tokenAddress, tokenAddress);
+            strcpy(input123.secret, getenv("BOB_PK"));
+            pthread_t t1, t2;
+            pthread_create(&t1, NULL, erc20ApproveThread, &input8);
+            pthread_create(&t2, NULL, erc20ApproveThread, &input123);
+            pthread_join(t1, NULL);
+            pthread_join(t2, NULL);
+            /*result = approveErc20(input8);
             if (result != NULL) {
                 printf("%s\n", result);
                 free(result);
             } else {
                 printf("Tx send result was NULL\n");
             }
+            result = approveErc20(&input8);
+            if (result != NULL) {
+                printf("%s\n", result);
+                free(result);
+            } else {
+                printf("Tx send result was NULL\n");
+            }
+             */
             break;
         case BOB_ETH_BALANCE:
             printf("%" PRIu64 "\n", getEthBalance(bobAddress));
@@ -263,6 +287,7 @@ int main(int argc, char** argv)
         default:
             return 1;
     }
+    /*
     char *pubkey = getPubKeyFromPriv(getenv("BOB_PK"));
     printf("pubkey: %s\n", pubkey);
     free(pubkey);
@@ -288,6 +313,6 @@ int main(int argc, char** argv)
 
     uint64_t gasPrice = getGasPriceFromStation();
     printf("gasPrice: %" PRIu64 "\n", gasPrice);
-
+    */
     return 0;
 }

iguana/exchanges/etomicswap/etomiccurl.c

@@ -2,7 +2,7 @@
 #include <curl/curl.h>
 
 static char *ethRpcUrl = ETOMIC_URL;
-static uint8_t gettingNonceFlag = 0;
+pthread_mutex_t sendTxMutex = PTHREAD_MUTEX_INITIALIZER;
 
 struct string {
     char *ptr;
@@ -115,20 +115,23 @@ char* sendRawTx(char* rawTx)
     char *txId = NULL;
     if (resultJson != NULL && is_cJSON_String(resultJson) && resultJson->valuestring != NULL) {
         char* tmp = resultJson->valuestring;
-        txId = (char*)malloc(strlen(tmp) + 1);
-        strcpy(txId, tmp);
+        if (waitForConfirmation(tmp) > 0) {
+            txId = (char *) malloc(strlen(tmp) + 1);
+            strcpy(txId, tmp);
+        }
     }
     cJSON_Delete(resultJson);
+    pthread_mutex_unlock(&sendTxMutex);
     return txId;
 }
 
 int64_t getNonce(char* address)
 {
-    while (gettingNonceFlag == 1) {
-        printf("Wait for other thread to get ETH nonce\n");
-        sleep(5);
-    }
-    gettingNonceFlag = 1;
+    // we should lock this mutex and unlock it only when transaction was already sent.
+    // make sure that sendRawTx is called after getting a nonce!
+    if (pthread_mutex_lock(&sendTxMutex) != 0) {
+        printf("Nonce mutex lock failed\n");
+    };
     cJSON *params = cJSON_CreateArray();
     cJSON_AddItemToArray(params, cJSON_CreateString(address));
     cJSON_AddItemToArray(params, cJSON_CreateString("pending"));
@@ -140,7 +143,6 @@ int64_t getNonce(char* address)
     }
     cJSON_Delete(nonceJson);
     printf("Got ETH nonce %d\n", (int)nonce);
-    gettingNonceFlag = 0;
     return nonce;
 }
 
@@ -273,7 +275,11 @@ uint64_t getGasPriceFromStation()
         }
 
         if (is_cJSON_Number(cJSON_GetObjectItem(resultJson, "average"))) {
+#ifdef ETOMIC_TESTNET
+            result = (uint64_t)(cJSON_GetObjectItem(resultJson, "average")->valuedouble / 10) + 10;
+#else
             result = (uint64_t)(cJSON_GetObjectItem(resultJson, "average")->valuedouble / 10) + 1;
+#endif
         }
         cJSON_Delete(resultJson);
         return result;
@@ -281,3 +287,27 @@ uint64_t getGasPriceFromStation()
         return DEFAULT_GAS_PRICE;
     }
 }
+
+int32_t waitForConfirmation(char *txId)
+{
+    EthTxReceipt receipt;
+    EthTxData txData;
+    do {
+        sleep(15);
+        printf("waiting for ETH txId to be confirmed: %s\n", txId);
+        receipt = getEthTxReceipt(txId);
+        if (receipt.confirmations < 1) {
+            txData = getEthTxData(txId);
+            if (txData.exists == 0) {
+                return(-1);
+            }
+        }
+    } while (receipt.confirmations < 1);
+
+    if (strcmp(receipt.status, "0x1") != 0) {
+        printf("ETH txid %s receipt status failed\n", txId);
+        return(-1);
+    }
+
+    return((int32_t)receipt.confirmations);
+}

iguana/exchanges/etomicswap/etomiccurl.h

@@ -3,11 +3,14 @@
 
 #include <stdint.h>
 #include <includes/cJSON.h>
+#ifdef _WIN32
+#include "../../../OSlibs/win/pthread.h"
+#endif
 
 #ifdef __cplusplus
 extern "C"{
 #endif
-    
+
 #ifdef ETOMIC_TESTNET
 #define ETOMIC_URL "https://ropsten.infura.io/y07GHxUyTgeN2mdfOonu"
 #define DEFAULT_GAS_PRICE 100
@@ -41,6 +44,7 @@ EthTxReceipt getEthTxReceipt(char *txId);
 EthTxData getEthTxData(char *txId);
 uint64_t getEthBlockNumber();
 uint64_t getGasPriceFromStation();
+int32_t waitForConfirmation(char *txId);
 
 #ifdef __cplusplus
 }

iguana/exchanges/etomicswap/etomiclib.cpp

@@ -52,7 +52,6 @@ char *approveErc20(ApproveErc20Input input)
     tx.gas = 300000;
     tx.gasPrice = getGasPriceFromStation() * boost::multiprecision::pow(u256(10), 9);
     tx.nonce = getNonce(input.owner);
-    uint8_t decimals = getErc20Decimals(input.tokenAddress);
     std::stringstream ss;
     ss << "0x095ea7b3"
        << "000000000000000000000000"