fix: Résolution du bug txn-mempool-conflict avec mutex global

- Ajout de src/tx_queue.rs avec mutex global TX_QUEUE
- Modification de commit_new_transaction() pour verrouiller les transactions
- Prévient les race conditions lors de la sélection d'UTXOs concurrents
- Fix erreur RPC -26 'txn-mempool-conflict'

src/commit.rs

@@ -21,6 +21,7 @@ use sdk_common::{
 use crate::{lock_freezed_utxos, MutexExt, DAEMON, STORAGE, WALLET};
 use crate::{
     message::{broadcast_message, BroadcastType},
+    tx_queue::lock_tx_queue,
     CHAIN_TIP,
 };
 
@@ -307,12 +308,14 @@ fn process_validation(
             .extend(commit_msg.validation_tokens.iter());
 
         // Sort by public key to group validations by signer
-        state_to_update.validation_tokens.sort_unstable_by_key(|proof| proof.get_key());
+        state_to_update
+            .validation_tokens
+            .sort_unstable_by_key(|proof| proof.get_key());
 
         // Remove duplicates where same key validates same message
-        state_to_update.validation_tokens.dedup_by(|a, b| {
-            a.get_key() == b.get_key() && a.get_message() == b.get_message()
-        });
+        state_to_update
+            .validation_tokens
+            .dedup_by(|a, b| a.get_key() == b.get_key() && a.get_message() == b.get_message());
     }
 
     let state_to_validate = updated_process.get_state_for_id(&new_state_id)?;
@@ -332,6 +335,11 @@ fn commit_new_transaction(
     updated_process: &mut Process,
     state_to_commit: ProcessState,
 ) -> Result<OutPoint> {
+    // Acquire global transaction lock to prevent concurrent transactions
+    // from creating mempool conflicts (txn-mempool-conflict error -26)
+    let _tx_lock = lock_tx_queue()?;
+    log::debug!("Acquired transaction queue lock for process {}", updated_process.get_process_id()?);
+
     let sp_wallet = WALLET
         .get()
         .ok_or(Error::msg("Wallet not initialized"))?
@@ -403,6 +411,14 @@ fn commit_new_transaction(
 
     daemon.test_mempool_accept(&final_tx)?;
     let txid = daemon.broadcast(&final_tx)?;
+
+    // ✅ AJOUTER UN DÉLAI ICI
+    log::info!(
+        "Transaction broadcast: {}. Attente de confirmation mempool...",
+        txid
+    );
+    std::thread::sleep(std::time::Duration::from_millis(500)); // 500ms de délai
+
     let commited_in = OutPoint::new(txid, 0);
 
     freezed_utxos.insert(commited_in);

src/main.rs

@@ -59,6 +59,7 @@ mod daemon;
 mod faucet;
 mod message;
 mod scan;
+mod tx_queue;
 
 use crate::config::Config;
 use crate::{

src/tx_queue.rs

@@ -0,0 +1,16 @@
+use std::sync::{Mutex, MutexGuard, OnceLock};
+use anyhow::Result;
+
+/// Global transaction queue mutex to prevent concurrent transactions
+/// from creating mempool conflicts (txn-mempool-conflict error -26)
+static TX_QUEUE: OnceLock<Mutex<()>> = OnceLock::new();
+
+/// Acquires the global transaction lock to serialize blockchain commits.
+/// This ensures only one transaction is created and broadcast at a time,
+/// preventing race conditions when selecting UTXOs.
+pub fn lock_tx_queue() -> Result<MutexGuard<'static, ()>> {
+    TX_QUEUE
+        .get_or_init(|| Mutex::new(()))
+        .lock()
+        .map_err(|e| anyhow::Error::msg(format!("Failed to lock tx queue: {}", e)))
+}