Merge pull request #254 from fireice-uk/topic-race-fix

Race condition fix

minethd.cpp

@@ -161,6 +161,7 @@ minethd::minethd(miner_work& pWork, size_t iNo, bool double_work, bool no_prefet
 	bNoPrefetch = no_prefetch;
 	this->affinity = affinity;
 
+	std::lock_guard<std::mutex> lock(work_thd_mtx);
 	if(double_work)
 		oWorkThd = std::thread(&minethd::double_work_main, this);
 	else
@@ -363,6 +364,9 @@ minethd::cn_hash_fun minethd::func_selector(bool bHaveAes, bool bNoPrefetch)
 
 void minethd::pin_thd_affinity()
 {
+	//Lock is needed because we need to use oWorkThd
+	std::lock_guard<std::mutex> lock(work_thd_mtx);
+
 	// pin memory to NUMA node
 	bindMemoryToNUMANode(affinity);
 

minethd.h

 #pragma once
 #include <thread>
 #include <atomic>
+#include <mutex>
 #include "crypto/cryptonight.h"
 
 class telemetry
@@ -130,6 +131,8 @@ private:
 	miner_work oWork;
 
 	void pin_thd_affinity();
+	// Held by the creating context to prevent a race cond with oWorkThd = std::thread(...)
+	std::mutex work_thd_mtx;
 
 	std::thread oWorkThd;
 	uint8_t iThreadNo;