Merge pull request #1827 from cohcho/nonce_iteration_without_tests

nonce iteration optimization

src/backend/common/WorkerJob.h

@@ -66,14 +66,12 @@ public:
 
     inline bool nextRound(uint32_t rounds, uint32_t roundSize)
     {
-        bool ok = true;
         m_rounds[index()]++;
 
         if ((m_rounds[index()] % rounds) == 0) {
             for (size_t i = 0; i < N; ++i) {
-                *nonce(i) = Nonce::next(index(), *nonce(i), rounds * roundSize, currentJob().isNicehash(), &ok);
+                if (!Nonce::next(index(), nonce(i), rounds * roundSize, nonceMask())) {
-                if (!ok) {
+                    return false;
-                    break;
                 }
             }
         }
@@ -83,13 +81,14 @@ public:
             }
         }
 
-        return ok;
+        return true;
     }
 
 
 private:
     inline int32_t nonceOffset() const  { return currentJob().nonceOffset(); }
     inline size_t nonceSize() const     { return currentJob().nonceSize(); }
+    inline uint64_t nonceMask() const     { return m_nonce_mask[index()]; }
 
     inline void save(const Job &job, uint32_t reserveCount, Nonce::Backend backend)
     {
@@ -97,12 +96,13 @@ private:
         const size_t size = job.size();
         m_jobs[index()]   = job;
         m_rounds[index()] = 0;
+        m_nonce_mask[index()] = job.isNicehash() ? 0xFFFFFFULL : (nonceSize() == sizeof(uint64_t) ? (-1ull  >> (job.extraNonce().size() * 4 + 1)): 0xFFFFFFFFULL);
 
         m_jobs[index()].setBackend(backend);
 
         for (size_t i = 0; i < N; ++i) {
             memcpy(m_blobs[index()] + (i * size), job.blob(), size);
-            *nonce(i) = Nonce::next(index(), *nonce(i), reserveCount, job.isNicehash());
+            Nonce::next(index(), nonce(i), reserveCount, nonceMask());
         }
     }
 
@@ -110,6 +110,7 @@ private:
     alignas(16) uint8_t m_blobs[2][Job::kMaxBlobSize * N]{};
     Job m_jobs[2];
     uint32_t m_rounds[2] = { 0, 0 };
+    uint64_t m_nonce_mask[2];
     uint64_t m_sequence  = 0;
     uint8_t m_index      = 0;
 };
@@ -125,41 +126,23 @@ inline uint32_t *xmrig::WorkerJob<1>::nonce(size_t)
 template<>
 inline bool xmrig::WorkerJob<1>::nextRound(uint32_t rounds, uint32_t roundSize)
 {
-    bool ok = true;
     m_rounds[index()]++;
 
     uint32_t* n = nonce();
-    const uint32_t prev_nonce = *n;
 
     if ((m_rounds[index()] % rounds) == 0) {
-        *n = Nonce::next(index(), *n, rounds * roundSize, currentJob().isNicehash(), &ok);
+        if (!Nonce::next(index(), n, rounds * roundSize, nonceMask())) {
+            return false;
+        }
+        if (nonceSize() == sizeof(uint64_t)) {
+            m_jobs[index()].nonce()[1] = n[1];
+        }
     }
     else {
         *n += roundSize;
     }
 
-    // Increment higher 32 bits of a 64-bit nonce when lower 32 bits overflow
+    return true;
-    if (!currentJob().isNicehash() && (nonceSize() == sizeof(uint64_t))) {
-        const bool wrapped = (*n < prev_nonce);
-        const bool wraps_this_round = (static_cast<uint64_t>(*n) + roundSize > (1ULL << 32));
-
-        // Account for the case when starting nonce hasn't wrapped yet, but some nonces in the current round will wrap
-        if (wrapped || wraps_this_round) {
-            // Set lower 32 bits to 0 when higher 32 bits change
-            Nonce::reset(index());
-
-            // Sets *n to 0 and Nonce::m_nonce[index] to the correct next value
-            *n = 0;
-            Nonce::next(index(), *n, rounds * roundSize, currentJob().isNicehash(), &ok);
-
-            ++n[1];
-
-            Job& job = m_jobs[index()];
-            memcpy(job.blob(), blob(), job.size());
-        }
-    }
-
-    return ok;
 }
 
 
@@ -169,11 +152,12 @@ inline void xmrig::WorkerJob<1>::save(const Job &job, uint32_t reserveCount, Non
     m_index           = job.index();
     m_jobs[index()]   = job;
     m_rounds[index()] = 0;
+    m_nonce_mask[index()] = job.isNicehash() ? 0xFFFFFFULL : (nonceSize() == sizeof(uint64_t) ? (-1ull  >> (job.extraNonce().size() * 4 + 1)): 0xFFFFFFFFULL);
 
     m_jobs[index()].setBackend(backend);
 
     memcpy(blob(), job.blob(), job.size());
-    *nonce() = Nonce::next(index(), *nonce(), reserveCount, currentJob().isNicehash());
+    Nonce::next(index(), nonce(), reserveCount, nonceMask());
 }
 
 

src/crypto/common/Nonce.cpp

@@ -26,18 +26,14 @@
 #include "crypto/common/Nonce.h"
 
 
-#include <mutex>
-
-
 namespace xmrig {
 
 
 std::atomic<bool> Nonce::m_paused;
 std::atomic<uint64_t> Nonce::m_sequence[Nonce::MAX];
-uint32_t Nonce::m_nonces[2] = { 0, 0 };
+std::atomic<uint64_t> Nonce::m_nonces[2] = { {0}, {0} };
 
 
-static std::mutex mutex;
 static Nonce nonce;
 
 
@@ -54,40 +50,32 @@ xmrig::Nonce::Nonce()
 }
 
 
-uint32_t xmrig::Nonce::next(uint8_t index, uint32_t nonce, uint32_t reserveCount, bool nicehash, bool *ok)
+bool xmrig::Nonce::next(uint8_t index, uint32_t *nonce, uint32_t reserveCount, uint64_t mask)
 {
-    uint32_t next;
+    if (reserveCount == 0 || mask < reserveCount - 1) {
-
+        return false;
-    std::lock_guard<std::mutex> lock(mutex);
+    }
-
-    if (nicehash) {
-        if ((m_nonces[index] + reserveCount) > 0x1000000) {
-            if (ok) {
-                *ok = false;
-            }
 
+    uint64_t counter = m_nonces[index].fetch_add(reserveCount, std::memory_order_relaxed);
+    while (true) {
+        if (mask < counter) {
+            return false;
+        } else if (mask - counter <= reserveCount - 1) {
             pause(true);
-
+            if (mask - counter < reserveCount - 1) {
-            return 0;
+                return false;
+            }
         }
-
+        else if (0xFFFFFFFFUL - (uint32_t)counter < reserveCount - 1) {
-        next = (nonce & 0xFF000000) | m_nonces[index];
+            counter = m_nonces[index].fetch_add(reserveCount, std::memory_order_relaxed);
+            continue;
+        }
+        *nonce = (nonce[0] & ~mask) | counter;
+        if (mask > 0xFFFFFFFFULL) {
+            nonce[1] = (nonce[1] & (~mask >> 32)) | (counter  >> 32);
+        }
+        return true;
     }
-    else {
-        next = m_nonces[index];
-    }
-
-    m_nonces[index] += reserveCount;
-
-    return next;
-}
-
-
-void xmrig::Nonce::reset(uint8_t index)
-{
-    std::lock_guard<std::mutex> lock(mutex);
-
-    m_nonces[index] = 0;
 }
 
 

src/crypto/common/Nonce.h

@@ -49,18 +49,18 @@ public:
     static inline bool isPaused()                                       { return m_paused.load(std::memory_order_relaxed); }
     static inline uint64_t sequence(Backend backend)                    { return m_sequence[backend].load(std::memory_order_relaxed); }
     static inline void pause(bool paused)                               { m_paused = paused; }
+    static inline void reset(uint8_t index)                             { m_nonces[index] = 0; }
     static inline void stop(Backend backend)                            { m_sequence[backend] = 0; }
     static inline void touch(Backend backend)                           { m_sequence[backend]++; }
 
-    static uint32_t next(uint8_t index, uint32_t nonce, uint32_t reserveCount, bool nicehash, bool *ok = nullptr);
+    static bool next(uint8_t index, uint32_t *nonce, uint32_t reserveCount, uint64_t mask);
-    static void reset(uint8_t index);
     static void stop();
     static void touch();
 
 private:
     static std::atomic<bool> m_paused;
     static std::atomic<uint64_t> m_sequence[MAX];
-    static uint32_t m_nonces[2];
+    static std::atomic<uint64_t> m_nonces[2];
 };