fix duplicated nonce usage

- avoid that a nonce which not fits to the current job is used (check jobId after start nonce is consumed)
- move jobId check into the if condition to get a new bunch of nonces
- CPU: add jobId validation after the start nonce is consumed

1 files changed, 7 insertions, 6 deletions

diff --git a/xmrstak/backend/globalStates.cpp b/xmrstak/backend/globalStates.cpp
index 9f41be2..3bd7d0e 100644
--- a/xmrstak/backend/globalStates.cpp
+++ b/xmrstak/backend/globalStates.cpp
@@ -47,20 +47,21 @@ void globalStates::switch_work(miner_work& pWork, pool_data& dat)
 {
 	jobLock.WriteLock();
 
+	/* This notifies all threads that the job has changed.
+	 * To avoid duplicated shared this must be done before the nonce is exchanged.
+	 */
+	iGlobalJobNo++;
+	
 	size_t xid = dat.pool_id;
 	dat.pool_id = pool_id;
 	pool_id = xid;
 
 	/* Maybe a worker thread is updating the nonce while we read it.
-	 * In that case GPUs check the job ID after a nonce update and in the
-	 * case that it is a CPU thread we have a small chance (max 6 nonces per CPU thread)
-	 * that we recalculate a nonce after we reconnect to the current pool
+	 * To avoid duplicated share calculations the job ID is checked in the worker thread
+	 * after the nonce is read.
 	 */
 	dat.iSavedNonce = iGlobalNonce.exchange(dat.iSavedNonce, std::memory_order_relaxed);
 	oGlobalWork = pWork;
-
-	// this notifies all threads that the job has changed
-	iGlobalJobNo++;
 	
 	jobLock.UnLock();
 }