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authorJohn Newbery <john@johnnewbery.com>2019-07-23 11:49:53 -0400
committerAntoine Riard <ariard@student.42.fr>2019-08-01 13:43:29 -0400
commitfb62f128bbfd8c6cd72ea8e23331a4bae23883ab (patch)
tree55008efc4536f40f59177f33e5faa6d886a40a27 /src
parentb8eecf8e79dad92ff07b851b1b29c2a66546bbc1 (diff)
Tidy up BroadcastTransaction()
Diffstat (limited to 'src')
-rw-r--r--src/node/transaction.cpp37
-rw-r--r--src/node/transaction.h9
2 files changed, 30 insertions, 16 deletions
diff --git a/src/node/transaction.cpp b/src/node/transaction.cpp
index 0cbf645984..8e56496358 100644
--- a/src/node/transaction.cpp
+++ b/src/node/transaction.cpp
@@ -23,15 +23,17 @@ TransactionError BroadcastTransaction(const CTransactionRef tx, std::string& err
{ // cs_main scope
LOCK(cs_main);
+ // If the transaction is already confirmed in the chain, don't do anything
+ // and return early.
CCoinsViewCache &view = *pcoinsTip;
- bool fHaveChain = false;
- for (size_t o = 0; !fHaveChain && o < tx->vout.size(); o++) {
+ for (size_t o = 0; o < tx->vout.size(); o++) {
const Coin& existingCoin = view.AccessCoin(COutPoint(hashTx, o));
- fHaveChain = !existingCoin.IsSpent();
+ // IsSpent doesnt mean the coin is spent, it means the output doesnt' exist.
+ // So if the output does exist, then this transaction exists in the chain.
+ if (!existingCoin.IsSpent()) return TransactionError::ALREADY_IN_CHAIN;
}
- bool fHaveMempool = mempool.exists(hashTx);
- if (!fHaveMempool && !fHaveChain) {
- // push to local node and sync with wallets
+ if (!mempool.exists(hashTx)) {
+ // Transaction is not already in the mempool. Submit it.
CValidationState state;
bool fMissingInputs;
if (!AcceptToMemoryPool(mempool, state, std::move(tx), &fMissingInputs,
@@ -46,24 +48,31 @@ TransactionError BroadcastTransaction(const CTransactionRef tx, std::string& err
err_string = FormatStateMessage(state);
return TransactionError::MEMPOOL_ERROR;
}
- } else if (wait_callback) {
- // If wallet is enabled, ensure that the wallet has been made aware
- // of the new transaction prior to returning. This prevents a race
- // where a user might call sendrawtransaction with a transaction
- // to/from their wallet, immediately call some wallet RPC, and get
- // a stale result because callbacks have not yet been processed.
+ }
+
+ // Transaction was accepted to the mempool.
+
+ if (wait_callback) {
+ // For transactions broadcast from outside the wallet, make sure
+ // that the wallet has been notified of the transaction before
+ // continuing.
+ //
+ // This prevents a race where a user might call sendrawtransaction
+ // with a transaction to/from their wallet, immediately call some
+ // wallet RPC, and get a stale result because callbacks have not
+ // yet been processed.
CallFunctionInValidationInterfaceQueue([&promise] {
promise.set_value();
});
callback_set = true;
}
- } else if (fHaveChain) {
- return TransactionError::ALREADY_IN_CHAIN;
}
} // cs_main
if (callback_set) {
+ // Wait until Validation Interface clients have been notified of the
+ // transaction entering the mempool.
promise.get_future().wait();
}
diff --git a/src/node/transaction.h b/src/node/transaction.h
index 08ceace7f8..cf64fc28d9 100644
--- a/src/node/transaction.h
+++ b/src/node/transaction.h
@@ -11,14 +11,19 @@
#include <util/error.h>
/**
- * Broadcast a transaction
+ * Submit a transaction to the mempool and (optionally) relay it to all P2P peers.
+ *
+ * Mempool submission can be synchronous (will await mempool entry notification
+ * over the CValidationInterface) or asynchronous (will submit and not wait for
+ * notification), depending on the value of wait_callback. wait_callback MUST
+ * NOT be set while cs_main, cs_mempool or cs_wallet are held to avoid
+ * deadlock.
*
* @param[in] tx the transaction to broadcast
* @param[out] &err_string reference to std::string to fill with error string if available
* @param[in] max_tx_fee reject txs with fees higher than this (if 0, accept any fee)
* @param[in] relay flag if both mempool insertion and p2p relay are requested
* @param[in] wait_callback, wait until callbacks have been processed to avoid stale result due to a sequentially RPC.
- * It MUST NOT be set while cs_main, cs_mempool or cs_wallet are held to avoid deadlock
* return error
*/
NODISCARD TransactionError BroadcastTransaction(CTransactionRef tx, std::string& err_string, const CAmount& max_tx_fee, bool relay, bool wait_callback);