RandomX integration

Support RandomX PoW algorithm

18 files changed, 600 insertions, 45 deletions

diff --git a/src/crypto/CMakeLists.txt b/src/crypto/CMakeLists.txt
index 3a4d09fd8..80f1e5d7e 100644
--- a/src/crypto/CMakeLists.txt
+++ b/src/crypto/CMakeLists.txt
@@ -46,6 +46,7 @@ set(crypto_sources
   random.c
   skein.c
   slow-hash.c
+  rx-slow-hash.c
   CryptonightR_JIT.c
   tree-hash.c)
 
@@ -53,6 +54,8 @@ if(ARCH_ID STREQUAL "i386" OR ARCH_ID STREQUAL "x86_64" OR ARCH_ID STREQUAL "x86
 list(APPEND crypto_sources CryptonightR_template.S)
 endif()
 
+include_directories(${RANDOMX_INCLUDE})
+
 set(crypto_headers)
 
 set(crypto_private_headers
@@ -86,6 +89,7 @@ monero_add_library(cncrypto
 target_link_libraries(cncrypto
   PUBLIC
     epee
+    randomx
     ${Boost_SYSTEM_LIBRARY}
     ${SODIUM_LIBRARY}
   PRIVATE
diff --git a/src/crypto/c_threads.h b/src/crypto/c_threads.h
new file mode 100644
index 000000000..56d680ff8
--- /dev/null
+++ b/src/crypto/c_threads.h
@@ -0,0 +1,58 @@
+// Copyright (c) 2019, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+/* Brain-dead simple portability wrapper over thread APIs for C */
+#pragma once
+
+#ifdef _WIN32
+#include <windows.h>
+#define CTHR_MUTEX_TYPE	HANDLE
+#define CTHR_MUTEX_INIT	NULL
+#define CTHR_MUTEX_LOCK(x)	do { if (x == NULL) { \
+    HANDLE p = CreateMutex(NULL, FALSE, NULL); \
+    if (InterlockedCompareExchangePointer((PVOID*)&x, (PVOID)p, NULL) != NULL) \
+      CloseHandle(p); \
+  } WaitForSingleObject(x, INFINITE); } while(0)
+#define CTHR_MUTEX_UNLOCK(x)	ReleaseMutex(x)
+#define CTHR_THREAD_TYPE	HANDLE
+#define CTHR_THREAD_RTYPE	void
+#define CTHR_THREAD_RETURN	return
+#define CTHR_THREAD_CREATE(thr, func, arg)	thr = (HANDLE)_beginthread(func, 0, arg)
+#define CTHR_THREAD_JOIN(thr)			WaitForSingleObject(thr, INFINITE)
+#else
+#include <pthread.h>
+#define CTHR_MUTEX_TYPE pthread_mutex_t
+#define CTHR_MUTEX_INIT	PTHREAD_MUTEX_INITIALIZER
+#define CTHR_MUTEX_LOCK(x)	pthread_mutex_lock(&x)
+#define CTHR_MUTEX_UNLOCK(x)	pthread_mutex_unlock(&x)
+#define CTHR_THREAD_TYPE pthread_t
+#define CTHR_THREAD_RTYPE	void *
+#define CTHR_THREAD_RETURN	return NULL
+#define CTHR_THREAD_CREATE(thr, func, arg)	pthread_create(&thr, NULL, func, arg)
+#define CTHR_THREAD_JOIN(thr)			pthread_join(thr, NULL)
+#endif
diff --git a/src/crypto/hash-ops.h b/src/crypto/hash-ops.h
index 859c810bd..d117bb640 100644
--- a/src/crypto/hash-ops.h
+++ b/src/crypto/hash-ops.h
@@ -87,3 +87,11 @@ void hash_extra_jh(const void *data, size_t length, char *hash);
 void hash_extra_skein(const void *data, size_t length, char *hash);
 
 void tree_hash(const char (*hashes)[HASH_SIZE], size_t count, char *root_hash);
+
+#define RX_BLOCK_VERSION	12
+void rx_slow_hash_allocate_state(void);
+void rx_slow_hash_free_state(void);
+uint64_t rx_seedheight(const uint64_t height);
+void rx_seedheights(const uint64_t height, uint64_t *seed_height, uint64_t *next_height);
+void rx_slow_hash(const uint64_t mainheight, const uint64_t seedheight, const char *seedhash, const void *data, size_t length, char *hash, int miners, int is_alt);
+void rx_reorg(const uint64_t split_height);
diff --git a/src/crypto/rx-slow-hash.c b/src/crypto/rx-slow-hash.c
new file mode 100644
index 000000000..ada372864
--- /dev/null
+++ b/src/crypto/rx-slow-hash.c
@@ -0,0 +1,357 @@
+// Copyright (c) 2019, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <assert.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "randomx.h"
+#include "c_threads.h"
+#include "hash-ops.h"
+#include "misc_log_ex.h"
+
+#define RX_LOGCAT	"randomx"
+
+#if defined(_MSC_VER)
+#define THREADV __declspec(thread)
+#else
+#define THREADV __thread
+#endif
+
+typedef struct rx_state {
+  CTHR_MUTEX_TYPE rs_mutex;
+  char rs_hash[32];
+  uint64_t  rs_height;
+  randomx_cache *rs_cache;
+} rx_state;
+
+static CTHR_MUTEX_TYPE rx_mutex = CTHR_MUTEX_INIT;
+static CTHR_MUTEX_TYPE rx_dataset_mutex = CTHR_MUTEX_INIT;
+
+static rx_state rx_s[2] = {{CTHR_MUTEX_INIT,{0},0,0},{CTHR_MUTEX_INIT,{0},0,0}};
+
+static randomx_dataset *rx_dataset;
+static uint64_t rx_dataset_height;
+static THREADV randomx_vm *rx_vm = NULL;
+static THREADV int rx_toggle;
+
+static void local_abort(const char *msg)
+{
+  fprintf(stderr, "%s\n", msg);
+#ifdef NDEBUG
+  _exit(1);
+#else
+  abort();
+#endif
+}
+
+/**
+ * @brief uses cpuid to determine if the CPU supports the AES instructions
+ * @return true if the CPU supports AES, false otherwise
+ */
+
+static inline int force_software_aes(void)
+{
+  static int use = -1;
+
+  if (use != -1)
+    return use;
+
+  const char *env = getenv("MONERO_USE_SOFTWARE_AES");
+  if (!env) {
+    use = 0;
+  }
+  else if (!strcmp(env, "0") || !strcmp(env, "no")) {
+    use = 0;
+  }
+  else {
+    use = 1;
+  }
+  return use;
+}
+
+static void cpuid(int CPUInfo[4], int InfoType)
+{
+#if defined(__x86_64__)
+    __asm __volatile__
+    (
+    "cpuid":
+        "=a" (CPUInfo[0]),
+        "=b" (CPUInfo[1]),
+        "=c" (CPUInfo[2]),
+        "=d" (CPUInfo[3]) :
+            "a" (InfoType), "c" (0)
+        );
+#endif
+}
+static inline int check_aes_hw(void)
+{
+#if defined(__x86_64__)
+    int cpuid_results[4];
+    static int supported = -1;
+
+    if(supported >= 0)
+        return supported;
+
+    cpuid(cpuid_results,1);
+    return supported = cpuid_results[2] & (1 << 25);
+#else
+    return 0;
+#endif
+}
+
+static volatile int use_rx_jit_flag = -1;
+
+static inline int use_rx_jit(void)
+{
+#if defined(__x86_64__)
+
+  if (use_rx_jit_flag != -1)
+    return use_rx_jit_flag;
+
+  const char *env = getenv("MONERO_USE_RX_JIT");
+  if (!env) {
+    use_rx_jit_flag = 1;
+  }
+  else if (!strcmp(env, "0") || !strcmp(env, "no")) {
+    use_rx_jit_flag = 0;
+  }
+  else {
+    use_rx_jit_flag = 1;
+  }
+  return use_rx_jit_flag;
+#else
+  return 0;
+#endif
+}
+
+#define SEEDHASH_EPOCH_BLOCKS	2048	/* Must be same as BLOCKS_SYNCHRONIZING_MAX_COUNT in cryptonote_config.h */
+#define SEEDHASH_EPOCH_LAG		64
+
+void rx_reorg(const uint64_t split_height) {
+  int i;
+  CTHR_MUTEX_LOCK(rx_mutex);
+  for (i=0; i<2; i++) {
+    if (split_height < rx_s[i].rs_height)
+      rx_s[i].rs_height = 1;	/* set to an invalid seed height */
+  }
+  CTHR_MUTEX_UNLOCK(rx_mutex);
+}
+
+uint64_t rx_seedheight(const uint64_t height) {
+  uint64_t s_height =  (height <= SEEDHASH_EPOCH_BLOCKS+SEEDHASH_EPOCH_LAG) ? 0 :
+                       (height - SEEDHASH_EPOCH_LAG - 1) & ~(SEEDHASH_EPOCH_BLOCKS-1);
+  return s_height;
+}
+
+void rx_seedheights(const uint64_t height, uint64_t *seedheight, uint64_t *nextheight) {
+  *seedheight = rx_seedheight(height);
+  *nextheight = rx_seedheight(height + SEEDHASH_EPOCH_LAG);
+}
+
+typedef struct seedinfo {
+  randomx_cache *si_cache;
+  unsigned long si_start;
+  unsigned long si_count;
+} seedinfo;
+
+static CTHR_THREAD_RTYPE rx_seedthread(void *arg) {
+  seedinfo *si = arg;
+  randomx_init_dataset(rx_dataset, si->si_cache, si->si_start, si->si_count);
+  CTHR_THREAD_RETURN;
+}
+
+static void rx_initdata(randomx_cache *rs_cache, const int miners, const uint64_t seedheight) {
+  if (miners > 1) {
+    unsigned long delta = randomx_dataset_item_count() / miners;
+    unsigned long start = 0;
+    int i;
+    seedinfo *si;
+    CTHR_THREAD_TYPE *st;
+    si = malloc(miners * sizeof(seedinfo));
+    if (si == NULL)
+      local_abort("Couldn't allocate RandomX mining threadinfo");
+    st = malloc(miners * sizeof(CTHR_THREAD_TYPE));
+    if (st == NULL) {
+      free(si);
+      local_abort("Couldn't allocate RandomX mining threadlist");
+    }
+    for (i=0; i<miners-1; i++) {
+      si[i].si_cache = rs_cache;
+      si[i].si_start = start;
+      si[i].si_count = delta;
+      start += delta;
+    }
+    si[i].si_cache = rs_cache;
+    si[i].si_start = start;
+    si[i].si_count = randomx_dataset_item_count() - start;
+    for (i=1; i<miners; i++) {
+      CTHR_THREAD_CREATE(st[i], rx_seedthread, &si[i]);
+    }
+    randomx_init_dataset(rx_dataset, rs_cache, 0, si[0].si_count);
+    for (i=1; i<miners; i++) {
+      CTHR_THREAD_JOIN(st[i]);
+    }
+    free(st);
+    free(si);
+  } else {
+    randomx_init_dataset(rx_dataset, rs_cache, 0, randomx_dataset_item_count());
+  }
+  rx_dataset_height = seedheight;
+}
+
+void rx_slow_hash(const uint64_t mainheight, const uint64_t seedheight, const char *seedhash, const void *data, size_t length,
+  char *hash, int miners, int is_alt) {
+  uint64_t s_height = rx_seedheight(mainheight);
+  int changed = 0;
+  int toggle = is_alt ? s_height : seedheight;
+  randomx_flags flags = RANDOMX_FLAG_DEFAULT;
+  rx_state *rx_sp;
+  randomx_cache *cache;
+
+  toggle = (toggle & SEEDHASH_EPOCH_BLOCKS) != 0;
+  CTHR_MUTEX_LOCK(rx_mutex);
+
+  /* if alt block but with same seed as mainchain, no need for alt cache */
+  if (is_alt && s_height == seedheight && !memcmp(rx_s[toggle].rs_hash, seedhash, sizeof(rx_s[toggle].rs_hash)))
+    is_alt = 0;
+
+  /* RPC could request an earlier block on mainchain */
+  if (!is_alt && s_height > seedheight)
+    is_alt = 1;
+
+  toggle ^= (is_alt != 0);
+  if (toggle != rx_toggle)
+    changed = 1;
+  rx_toggle = toggle;
+
+  rx_sp = &rx_s[toggle];
+  CTHR_MUTEX_LOCK(rx_sp->rs_mutex);
+  CTHR_MUTEX_UNLOCK(rx_mutex);
+
+  cache = rx_sp->rs_cache;
+  if (cache == NULL) {
+    if (use_rx_jit())
+      flags |= RANDOMX_FLAG_JIT;
+    if (cache == NULL) {
+      cache = randomx_alloc_cache(flags | RANDOMX_FLAG_LARGE_PAGES);
+      if (cache == NULL) {
+        mdebug(RX_LOGCAT, "Couldn't use largePages for RandomX cache");
+        cache = randomx_alloc_cache(flags);
+      }
+      if (cache == NULL)
+        local_abort("Couldn't allocate RandomX cache");
+    }
+  }
+  if (rx_sp->rs_height != seedheight || rx_sp->rs_cache == NULL || memcmp(seedhash, rx_sp->rs_hash, sizeof(rx_sp->rs_hash))) {
+    randomx_init_cache(cache, seedhash, 32);
+    rx_sp->rs_cache = cache;
+    rx_sp->rs_height = seedheight;
+    memcpy(rx_sp->rs_hash, seedhash, sizeof(rx_sp->rs_hash));
+    changed = 1;
+  }
+  if (rx_vm == NULL) {
+    randomx_flags flags = RANDOMX_FLAG_DEFAULT;
+    if (use_rx_jit()) {
+      flags |= RANDOMX_FLAG_JIT;
+      if (!miners)
+          flags |= RANDOMX_FLAG_SECURE;
+    }
+    if(!force_software_aes() && check_aes_hw())
+      flags |= RANDOMX_FLAG_HARD_AES;
+    if (miners) {
+      CTHR_MUTEX_LOCK(rx_dataset_mutex);
+      if (rx_dataset == NULL) {
+        rx_dataset = randomx_alloc_dataset(RANDOMX_FLAG_LARGE_PAGES);
+        if (rx_dataset == NULL) {
+          mdebug(RX_LOGCAT, "Couldn't use largePages for RandomX dataset");
+          rx_dataset = randomx_alloc_dataset(RANDOMX_FLAG_DEFAULT);
+        }
+        if (rx_dataset != NULL)
+          rx_initdata(rx_sp->rs_cache, miners, seedheight);
+      }
+      if (rx_dataset != NULL)
+        flags |= RANDOMX_FLAG_FULL_MEM;
+      else {
+        miners = 0;
+        mwarning(RX_LOGCAT, "Couldn't allocate RandomX dataset for miner");
+      }
+      CTHR_MUTEX_UNLOCK(rx_dataset_mutex);
+    }
+    rx_vm = randomx_create_vm(flags | RANDOMX_FLAG_LARGE_PAGES, rx_sp->rs_cache, rx_dataset);
+    if(rx_vm == NULL) { //large pages failed
+      mdebug(RX_LOGCAT, "Couldn't use largePages for RandomX VM");
+      rx_vm = randomx_create_vm(flags, rx_sp->rs_cache, rx_dataset);
+    }
+    if(rx_vm == NULL) {//fallback if everything fails
+      flags = RANDOMX_FLAG_DEFAULT | (miners ? RANDOMX_FLAG_FULL_MEM : 0);
+      rx_vm = randomx_create_vm(flags, rx_sp->rs_cache, rx_dataset);
+    }
+    if (rx_vm == NULL)
+      local_abort("Couldn't allocate RandomX VM");
+  } else if (miners) {
+    CTHR_MUTEX_LOCK(rx_dataset_mutex);
+    if (rx_dataset != NULL && rx_dataset_height != seedheight)
+      rx_initdata(cache, miners, seedheight);
+    CTHR_MUTEX_UNLOCK(rx_dataset_mutex);
+  } else if (changed) {
+    randomx_vm_set_cache(rx_vm, rx_sp->rs_cache);
+  }
+  /* mainchain users can run in parallel */
+  if (!is_alt)
+    CTHR_MUTEX_UNLOCK(rx_sp->rs_mutex);
+  randomx_calculate_hash(rx_vm, data, length, hash);
+  /* altchain slot users always get fully serialized */
+  if (is_alt)
+    CTHR_MUTEX_UNLOCK(rx_sp->rs_mutex);
+}
+
+void rx_slow_hash_allocate_state(void) {
+}
+
+void rx_slow_hash_free_state(void) {
+  if (rx_vm != NULL) {
+    randomx_destroy_vm(rx_vm);
+    rx_vm = NULL;
+  }
+}
+
+void rx_stop_mining(void) {
+  CTHR_MUTEX_LOCK(rx_dataset_mutex);
+  if (rx_dataset != NULL) {
+    randomx_dataset *rd = rx_dataset;
+    rx_dataset = NULL;
+    randomx_release_dataset(rd);
+  }
+  CTHR_MUTEX_UNLOCK(rx_dataset_mutex);
+}
diff --git a/src/crypto/slow-hash.c b/src/crypto/slow-hash.c
index 647471513..88eb751a6 100644
--- a/src/crypto/slow-hash.c
+++ b/src/crypto/slow-hash.c
@@ -742,7 +742,7 @@ BOOL SetLockPagesPrivilege(HANDLE hProcess, BOOL bEnable)
  * the allocated buffer.
  */
 
-void slow_hash_allocate_state(void)
+void cn_slow_hash_allocate_state(void)
 {
     if(hp_state != NULL)
         return;
@@ -804,7 +804,7 @@ void slow_hash_allocate_state(void)
  *@brief frees the state allocated by slow_hash_allocate_state
  */
 
-void slow_hash_free_state(void)
+void cn_slow_hash_free_state(void)
 {
     if(hp_state == NULL)
         return;
@@ -892,7 +892,7 @@ void cn_slow_hash(const void *data, size_t length, char *hash, int variant, int
 
     // this isn't supposed to happen, but guard against it for now.
     if(hp_state == NULL)
-        slow_hash_allocate_state();
+        cn_slow_hash_allocate_state();
 
     // locals to avoid constant TLS dereferencing
     uint8_t *local_hp_state = hp_state;
@@ -1009,13 +1009,13 @@ void cn_slow_hash(const void *data, size_t length, char *hash, int variant, int
 }
 
 #elif !defined NO_AES && (defined(__arm__) || defined(__aarch64__))
-void slow_hash_allocate_state(void)
+void cn_slow_hash_allocate_state(void)
 {
   // Do nothing, this is just to maintain compatibility with the upgraded slow-hash.c
   return;
 }
 
-void slow_hash_free_state(void)
+void cn_slow_hash_free_state(void)
 {
   // As above
   return;
@@ -1582,13 +1582,13 @@ void cn_slow_hash(const void *data, size_t length, char *hash, int variant, int
 
 #define hp_jitfunc ((v4_random_math_JIT_func)NULL)
 
-void slow_hash_allocate_state(void)
+void cn_slow_hash_allocate_state(void)
 {
   // Do nothing, this is just to maintain compatibility with the upgraded slow-hash.c
   return;
 }
 
-void slow_hash_free_state(void)
+void cn_slow_hash_free_state(void)
 {
   // As above
   return;
@@ -1765,3 +1765,15 @@ void cn_slow_hash(const void *data, size_t length, char *hash, int variant, int
 }
 
 #endif
+
+void slow_hash_allocate_state(void)
+{
+  cn_slow_hash_allocate_state();
+  rx_slow_hash_allocate_state();
+}
+
+void slow_hash_free_state(void)
+{
+  cn_slow_hash_free_state();
+  rx_slow_hash_free_state();
+}
diff --git a/src/cryptonote_basic/cryptonote_format_utils.cpp b/src/cryptonote_basic/cryptonote_format_utils.cpp
index 7d7de416d..8bf3574db 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.cpp
+++ b/src/cryptonote_basic/cryptonote_format_utils.cpp
@@ -1218,21 +1218,6 @@ namespace cryptonote
     return p;
   }
   //---------------------------------------------------------------
-  bool get_block_longhash(const block& b, crypto::hash& res, uint64_t height)
-  {
-    // block 202612 bug workaround
-    if (height == 202612)
-    {
-      static const std::string longhash_202612 = "84f64766475d51837ac9efbef1926486e58563c95a19fef4aec3254f03000000";
-      string_tools::hex_to_pod(longhash_202612, res);
-      return true;
-    }
-    blobdata bd = get_block_hashing_blob(b);
-    const int cn_variant = b.major_version >= 7 ? b.major_version - 6 : 0;
-    crypto::cn_slow_hash(bd.data(), bd.size(), res, cn_variant, height);
-    return true;
-  }
-  //---------------------------------------------------------------
   std::vector<uint64_t> relative_output_offsets_to_absolute(const std::vector<uint64_t>& off)
   {
     std::vector<uint64_t> res = off;
@@ -1253,13 +1238,6 @@ namespace cryptonote
     return res;
   }
   //---------------------------------------------------------------
-  crypto::hash get_block_longhash(const block& b, uint64_t height)
-  {
-    crypto::hash p = null_hash;
-    get_block_longhash(b, p, height);
-    return p;
-  }
-  //---------------------------------------------------------------
   bool parse_and_validate_block_from_blob(const blobdata& b_blob, block& b, crypto::hash *block_hash)
   {
     std::stringstream ss;
diff --git a/src/cryptonote_basic/cryptonote_format_utils.h b/src/cryptonote_basic/cryptonote_format_utils.h
index c9de2a56e..284494299 100644
--- a/src/cryptonote_basic/cryptonote_format_utils.h
+++ b/src/cryptonote_basic/cryptonote_format_utils.h
@@ -117,8 +117,6 @@ namespace cryptonote
   bool calculate_block_hash(const block& b, crypto::hash& res, const blobdata *blob = NULL);
   bool get_block_hash(const block& b, crypto::hash& res);
   crypto::hash get_block_hash(const block& b);
-  bool get_block_longhash(const block& b, crypto::hash& res, uint64_t height);
-  crypto::hash get_block_longhash(const block& b, uint64_t height);
   bool parse_and_validate_block_from_blob(const blobdata& b_blob, block& b, crypto::hash *block_hash);
   bool parse_and_validate_block_from_blob(const blobdata& b_blob, block& b);
   bool parse_and_validate_block_from_blob(const blobdata& b_blob, block& b, crypto::hash &block_hash);
diff --git a/src/cryptonote_basic/miner.cpp b/src/cryptonote_basic/miner.cpp
index 856cccdeb..0188bf114 100644
--- a/src/cryptonote_basic/miner.cpp
+++ b/src/cryptonote_basic/miner.cpp
@@ -36,8 +36,10 @@
 #include "syncobj.h"
 #include "cryptonote_basic_impl.h"
 #include "cryptonote_format_utils.h"
+#include "cryptonote_core/cryptonote_tx_utils.h"
 #include "file_io_utils.h"
 #include "common/command_line.h"
+#include "common/util.h"
 #include "string_coding.h"
 #include "string_tools.h"
 #include "storages/portable_storage_template_helper.h"
@@ -98,12 +100,13 @@ namespace cryptonote
   }
 
 
-  miner::miner(i_miner_handler* phandler):m_stop(1),
+  miner::miner(i_miner_handler* phandler, Blockchain* pbc):m_stop(1),
     m_template{},
     m_template_no(0),
     m_diffic(0),
     m_thread_index(0),
     m_phandler(phandler),
+    m_pbc(pbc),
     m_height(0),
     m_threads_active(0),
     m_pausers_count(0),
@@ -429,6 +432,7 @@ namespace cryptonote
   {
     boost::interprocess::ipcdetail::atomic_write32(&m_stop, 1);
   }
+  extern "C" void rx_stop_mining(void);
   //-----------------------------------------------------------------------------------------------------
   bool miner::stop()
   {
@@ -461,15 +465,16 @@ namespace cryptonote
     MINFO("Mining has been stopped, " << m_threads.size() << " finished" );
     m_threads.clear();
     m_threads_autodetect.clear();
+    rx_stop_mining();
     return true;
   }
   //-----------------------------------------------------------------------------------------------------
-  bool miner::find_nonce_for_given_block(block& bl, const difficulty_type& diffic, uint64_t height)
+  bool miner::find_nonce_for_given_block(const Blockchain *pbc, block& bl, const difficulty_type& diffic, uint64_t height)
   {
     for(; bl.nonce != std::numeric_limits<uint32_t>::max(); bl.nonce++)
     {
       crypto::hash h;
-      get_block_longhash(bl, h, height);
+      get_block_longhash(pbc, bl, h, height, tools::get_max_concurrency());
 
       if(check_hash(h, diffic))
       {
@@ -565,7 +570,7 @@ namespace cryptonote
 
       b.nonce = nonce;
       crypto::hash h;
-      get_block_longhash(b, h, height);
+      get_block_longhash(m_pbc, b, h, height, tools::get_max_concurrency());
 
       if(check_hash(h, local_diff))
       {
diff --git a/src/cryptonote_basic/miner.h b/src/cryptonote_basic/miner.h
index ac7a0381c..4efbcbec3 100644
--- a/src/cryptonote_basic/miner.h
+++ b/src/cryptonote_basic/miner.h
@@ -52,13 +52,15 @@ namespace cryptonote
     ~i_miner_handler(){};
   };
 
+  class Blockchain;
+
   /************************************************************************/
   /*                                                                      */
   /************************************************************************/
   class miner
   {
   public: 
-    miner(i_miner_handler* phandler);
+    miner(i_miner_handler* phandler, Blockchain* pbc);
     ~miner();
     bool init(const boost::program_options::variables_map& vm, network_type nettype);
     static void init_options(boost::program_options::options_description& desc);
@@ -74,7 +76,7 @@ namespace cryptonote
     bool on_idle();
     void on_synchronized();
     //synchronous analog (for fast calls)
-    static bool find_nonce_for_given_block(block& bl, const difficulty_type& diffic, uint64_t height);
+    static bool find_nonce_for_given_block(const Blockchain *pbc, block& bl, const difficulty_type& diffic, uint64_t height);
     void pause();
     void resume();
     void do_print_hashrate(bool do_hr);
@@ -133,6 +135,7 @@ namespace cryptonote
     std::list<boost::thread> m_threads;
     epee::critical_section m_threads_lock;
     i_miner_handler* m_phandler;
+    Blockchain* m_pbc;
     account_public_address m_mine_address;
     epee::math_helper::once_a_time_seconds<5> m_update_block_template_interval;
     epee::math_helper::once_a_time_seconds<2> m_update_merge_hr_interval;
diff --git a/src/cryptonote_config.h b/src/cryptonote_config.h
index 53c487d02..6b1c2a546 100644
--- a/src/cryptonote_config.h
+++ b/src/cryptonote_config.h
@@ -96,6 +96,7 @@
 #define BLOCKS_IDS_SYNCHRONIZING_DEFAULT_COUNT          10000  //by default, blocks ids count in synchronizing
 #define BLOCKS_SYNCHRONIZING_DEFAULT_COUNT_PRE_V4       100    //by default, blocks count in blocks downloading
 #define BLOCKS_SYNCHRONIZING_DEFAULT_COUNT              20     //by default, blocks count in blocks downloading
+#define BLOCKS_SYNCHRONIZING_MAX_COUNT                  2048   //must be a power of 2, greater than 128, equal to SEEDHASH_EPOCH_BLOCKS
 
 #define CRYPTONOTE_MEMPOOL_TX_LIVETIME                    (86400*3) //seconds, three days
 #define CRYPTONOTE_MEMPOOL_TX_FROM_ALT_BLOCK_LIVETIME     604800 //seconds, one week
diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 5cf4952ae..bcf99bbed 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -95,7 +95,8 @@ Blockchain::Blockchain(tx_memory_pool& tx_pool) :
   m_difficulty_for_next_block_top_hash(crypto::null_hash),
   m_difficulty_for_next_block(1),
   m_btc_valid(false),
-  m_batch_success(true)
+  m_batch_success(true),
+  m_prepare_height(0)
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
 }
@@ -754,6 +755,13 @@ crypto::hash Blockchain::get_block_id_by_height(uint64_t height) const
   return null_hash;
 }
 //------------------------------------------------------------------
+crypto::hash Blockchain::get_pending_block_id_by_height(uint64_t height) const
+{
+  if (m_prepare_height && height >= m_prepare_height && height - m_prepare_height < m_prepare_nblocks)
+    return (*m_prepare_blocks)[height - m_prepare_height].hash;
+  return get_block_id_by_height(height);
+}
+//------------------------------------------------------------------
 bool Blockchain::get_block_by_hash(const crypto::hash &h, block &blk, bool *orphan) const
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
@@ -1029,6 +1037,7 @@ bool Blockchain::switch_to_alternative_blockchain(std::list<block_extended_info>
   }
 
   m_hardfork->reorganize_from_chain_height(split_height);
+  get_block_longhash_reorg(split_height);
 
   std::shared_ptr<tools::Notify> reorg_notify = m_reorg_notify;
   if (reorg_notify)
@@ -1684,7 +1693,30 @@ bool Blockchain::handle_alternative_block(const block& b, const crypto::hash& id
     difficulty_type current_diff = get_next_difficulty_for_alternative_chain(alt_chain, bei);
     CHECK_AND_ASSERT_MES(current_diff, false, "!!!!!!! DIFFICULTY OVERHEAD !!!!!!!");
     crypto::hash proof_of_work = null_hash;
-    get_block_longhash(bei.bl, proof_of_work, bei.height);
+    if (b.major_version >= RX_BLOCK_VERSION)
+    {
+      crypto::hash seedhash = null_hash;
+      uint64_t seedheight = rx_seedheight(bei.height);
+      // seedblock is on the alt chain somewhere
+      if (alt_chain.size() && alt_chain.front().height <= seedheight)
+      {
+        for (auto it=alt_chain.begin(); it != alt_chain.end(); it++)
+        {
+          if (it->height == seedheight+1)
+          {
+            seedhash = it->bl.prev_id;
+            break;
+          }
+        }
+      } else
+      {
+        seedhash = get_block_id_by_height(seedheight);
+      }
+      get_altblock_longhash(bei.bl, proof_of_work, get_current_blockchain_height(), bei.height, seedheight, seedhash);
+    } else
+    {
+      get_block_longhash(this, bei.bl, proof_of_work, bei.height, 0);
+    }
     if(!check_hash(proof_of_work, current_diff))
     {
       MERROR_VER("Block with id: " << id << std::endl << " for alternative chain, does not have enough proof of work: " << proof_of_work << std::endl << " expected difficulty: " << current_diff);
@@ -3613,7 +3645,7 @@ leave:
       proof_of_work = it->second;
     }
     else
-      proof_of_work = get_block_longhash(bl, blockchain_height);
+      proof_of_work = get_block_longhash(this, bl, blockchain_height, 0);
 
     // validate proof_of_work versus difficulty target
     if(!check_hash(proof_of_work, current_diffic))
@@ -4114,7 +4146,7 @@ void Blockchain::block_longhash_worker(uint64_t height, const epee::span<const b
     if (m_cancel)
        break;
     crypto::hash id = get_block_hash(block);
-    crypto::hash pow = get_block_longhash(block, height++);
+    crypto::hash pow = get_block_longhash(this, block, height++, 0);
     map.emplace(id, pow);
   }
 
@@ -4430,6 +4462,9 @@ bool Blockchain::prepare_handle_incoming_blocks(const std::vector<block_complete
       m_blocks_longhash_table.clear();
       uint64_t thread_height = height;
       tools::threadpool::waiter waiter;
+      m_prepare_height = height;
+      m_prepare_nblocks = blocks_entry.size();
+      m_prepare_blocks = &blocks;
       for (unsigned int i = 0; i < threads; i++)
       {
         unsigned nblocks = batches;
@@ -4440,6 +4475,7 @@ bool Blockchain::prepare_handle_incoming_blocks(const std::vector<block_complete
       }
 
       waiter.wait(&tpool);
+      m_prepare_height = 0;
 
       if (m_cancel)
          return false;
diff --git a/src/cryptonote_core/blockchain.h b/src/cryptonote_core/blockchain.h
index 178b2cb24..552a53e89 100644
--- a/src/cryptonote_core/blockchain.h
+++ b/src/cryptonote_core/blockchain.h
@@ -206,6 +206,18 @@ namespace cryptonote
     crypto::hash get_block_id_by_height(uint64_t height) const;
 
     /**
+     * @brief gets a block's hash given a height
+     *
+     * Used only by prepare_handle_incoming_blocks. Will look in the list of incoming blocks
+     * if the height is contained there.
+     *
+     * @param height the height of the block
+     *
+     * @return the hash of the block at the requested height, or a zeroed hash if there is no such block
+     */
+    crypto::hash get_pending_block_id_by_height(uint64_t height) const;
+
+    /**
      * @brief gets the block with a given hash
      *
      * @param h the hash to look for
@@ -1077,6 +1089,11 @@ namespace cryptonote
     std::shared_ptr<tools::Notify> m_block_notify;
     std::shared_ptr<tools::Notify> m_reorg_notify;
 
+    // for prepare_handle_incoming_blocks
+    uint64_t m_prepare_height;
+    uint64_t m_prepare_nblocks;
+    std::vector<block> *m_prepare_blocks;
+
     /**
      * @brief collects the keys for all outputs being "spent" as an input
      *
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index e34ab8fbd..245be5778 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -219,7 +219,7 @@ namespace cryptonote
   core::core(i_cryptonote_protocol* pprotocol):
               m_mempool(m_blockchain_storage),
               m_blockchain_storage(m_mempool),
-              m_miner(this),
+              m_miner(this, &m_blockchain_storage),
               m_starter_message_showed(false),
               m_target_blockchain_height(0),
               m_checkpoints_path(""),
@@ -655,6 +655,8 @@ namespace cryptonote
     CHECK_AND_ASSERT_MES(r, false, "Failed to initialize blockchain storage");
 
     block_sync_size = command_line::get_arg(vm, arg_block_sync_size);
+    if (block_sync_size > BLOCKS_SYNCHRONIZING_MAX_COUNT)
+      MERROR("Error --block-sync-size cannot be greater than " << BLOCKS_SYNCHRONIZING_MAX_COUNT);
 
     MGINFO("Loading checkpoints");
 
diff --git a/src/cryptonote_core/cryptonote_tx_utils.cpp b/src/cryptonote_core/cryptonote_tx_utils.cpp
index 955d6a4b0..d2e022347 100644
--- a/src/cryptonote_core/cryptonote_tx_utils.cpp
+++ b/src/cryptonote_core/cryptonote_tx_utils.cpp
@@ -37,6 +37,7 @@ using namespace epee;
 #include "common/apply_permutation.h"
 #include "cryptonote_tx_utils.h"
 #include "cryptonote_config.h"
+#include "blockchain.h"
 #include "cryptonote_basic/miner.h"
 #include "cryptonote_basic/tx_extra.h"
 #include "crypto/crypto.h"
@@ -658,9 +659,59 @@ namespace cryptonote
     bl.minor_version = CURRENT_BLOCK_MINOR_VERSION;
     bl.timestamp = 0;
     bl.nonce = nonce;
-    miner::find_nonce_for_given_block(bl, 1, 0);
+    miner::find_nonce_for_given_block(NULL, bl, 1, 0);
     bl.invalidate_hashes();
     return true;
   }
   //---------------------------------------------------------------
+  void get_altblock_longhash(const block& b, crypto::hash& res, const uint64_t main_height, const uint64_t height, const uint64_t seed_height, const crypto::hash& seed_hash)
+  {
+    blobdata bd = get_block_hashing_blob(b);
+    rx_slow_hash(main_height, seed_height, seed_hash.data, bd.data(), bd.size(), res.data, 0, 1);
+  }
+
+  bool get_block_longhash(const Blockchain *pbc, const block& b, crypto::hash& res, const uint64_t height, const int miners)
+  {
+    // block 202612 bug workaround
+    if (height == 202612)
+    {
+      static const std::string longhash_202612 = "84f64766475d51837ac9efbef1926486e58563c95a19fef4aec3254f03000000";
+      epee::string_tools::hex_to_pod(longhash_202612, res);
+      return true;
+    }
+    blobdata bd = get_block_hashing_blob(b);
+    if (b.major_version >= RX_BLOCK_VERSION)
+    {
+      uint64_t seed_height, main_height;
+      crypto::hash hash;
+      if (pbc != NULL)
+      {
+        seed_height = rx_seedheight(height);
+        hash = pbc->get_pending_block_id_by_height(seed_height);
+        main_height = pbc->get_current_blockchain_height();
+      } else
+      {
+        memset(&hash, 0, sizeof(hash));  // only happens when generating genesis block
+        seed_height = 0;
+        main_height = 0;
+      }
+      rx_slow_hash(main_height, seed_height, hash.data, bd.data(), bd.size(), res.data, miners, 0);
+    } else {
+      const int pow_variant = b.major_version >= 7 ? b.major_version - 6 : 0;
+      crypto::cn_slow_hash(bd.data(), bd.size(), res, pow_variant, height);
+    }
+    return true;
+  }
+
+  crypto::hash get_block_longhash(const Blockchain *pbc, const block& b, const uint64_t height, const int miners)
+  {
+    crypto::hash p = crypto::null_hash;
+    get_block_longhash(pbc, b, p, height, miners);
+    return p;
+  }
+
+  void get_block_longhash_reorg(const uint64_t split_height)
+  {
+    rx_reorg(split_height);
+  }
 }
diff --git a/src/cryptonote_core/cryptonote_tx_utils.h b/src/cryptonote_core/cryptonote_tx_utils.h
index b03eb6e70..309e4177f 100644
--- a/src/cryptonote_core/cryptonote_tx_utils.h
+++ b/src/cryptonote_core/cryptonote_tx_utils.h
@@ -132,6 +132,13 @@ namespace cryptonote
     , uint32_t nonce
     );
 
+  class Blockchain;
+  bool get_block_longhash(const Blockchain *pb, const block& b, crypto::hash& res, const uint64_t height, const int miners);
+  void get_altblock_longhash(const block& b, crypto::hash& res, const uint64_t main_height, const uint64_t height,
+    const uint64_t seed_height, const crypto::hash& seed_hash);
+  crypto::hash get_block_longhash(const Blockchain *pb, const block& b, const uint64_t height, const int miners);
+  void get_block_longhash_reorg(const uint64_t split_height);
+
 }
 
 BOOST_CLASS_VERSION(cryptonote::tx_source_entry, 1)
diff --git a/src/hardforks/hardforks.cpp b/src/hardforks/hardforks.cpp
index 3cb148c60..41aa3e9cb 100644
--- a/src/hardforks/hardforks.cpp
+++ b/src/hardforks/hardforks.cpp
@@ -86,6 +86,7 @@ const hardfork_t testnet_hard_forks[] = {
   { 9, 1057778, 0, 1533297600 },
   { 10, 1154318, 0, 1550153694 },
   { 11, 1155038, 0, 1550225678 },
+  { 12, 1308737, 0, 1569582000 },
 };
 const size_t num_testnet_hard_forks = sizeof(testnet_hard_forks) / sizeof(testnet_hard_forks[0]);
 const uint64_t testnet_hard_fork_version_1_till = 624633;
diff --git a/src/rpc/core_rpc_server.cpp b/src/rpc/core_rpc_server.cpp
index 3f53d59cf..66af4a364 100644
--- a/src/rpc/core_rpc_server.cpp
+++ b/src/rpc/core_rpc_server.cpp
@@ -1060,6 +1060,7 @@ namespace cryptonote
       case 1: res.pow_algorithm = "CNv1 (Cryptonight variant 1)"; break;
       case 2: case 3: res.pow_algorithm = "CNv2 (Cryptonight variant 2)"; break;
       case 4: case 5: res.pow_algorithm = "CNv4 (Cryptonight variant 4)"; break;
+      case 6: res.pow_algorithm = "RandomX"; break;
       default: res.pow_algorithm = "I'm not sure actually"; break;
     }
     if (res.is_background_mining_enabled)
@@ -1440,6 +1441,18 @@ namespace cryptonote
       LOG_ERROR("Failed to create block template");
       return false;
     }
+    if (b.major_version >= RX_BLOCK_VERSION)
+    {
+      uint64_t seed_height, next_height;
+      crypto::hash seed_hash;
+      crypto::rx_seedheights(res.height, &seed_height, &next_height);
+      seed_hash = m_core.get_block_id_by_height(seed_height);
+      res.seed_hash = string_tools::pod_to_hex(seed_hash);
+      if (next_height != seed_height) {
+        seed_hash = m_core.get_block_id_by_height(next_height);
+        res.next_seed_hash = string_tools::pod_to_hex(seed_hash);
+      }
+    }
     store_difficulty(wdiff, res.difficulty, res.wide_difficulty, res.difficulty_top64);
     blobdata block_blob = t_serializable_object_to_blob(b);
     crypto::public_key tx_pub_key = cryptonote::get_tx_pub_key_from_extra(b.miner_tx);
@@ -1582,7 +1595,7 @@ namespace cryptonote
         return false;
       }
       b.nonce = req.starting_nonce;
-      miner::find_nonce_for_given_block(b, template_res.difficulty, template_res.height);
+      miner::find_nonce_for_given_block(&(m_core.get_blockchain_storage()), b, template_res.difficulty, template_res.height);
 
       submit_req.front() = string_tools::buff_to_hex_nodelimer(block_to_blob(b));
       r = on_submitblock(submit_req, submit_res, error_resp, ctx);
@@ -1627,7 +1640,7 @@ namespace cryptonote
     response.reward = get_block_reward(blk);
     response.block_size = response.block_weight = m_core.get_blockchain_storage().get_db().get_block_weight(height);
     response.num_txes = blk.tx_hashes.size();
-    response.pow_hash = fill_pow_hash ? string_tools::pod_to_hex(get_block_longhash(blk, height)) : "";
+    response.pow_hash = fill_pow_hash ? string_tools::pod_to_hex(get_block_longhash(&(m_core.get_blockchain_storage()), blk, height, 0)) : "";
     response.long_term_weight = m_core.get_blockchain_storage().get_db().get_block_long_term_weight(height);
     response.miner_tx_hash = string_tools::pod_to_hex(cryptonote::get_transaction_hash(blk.miner_tx));
     return true;
diff --git a/src/rpc/core_rpc_server_commands_defs.h b/src/rpc/core_rpc_server_commands_defs.h
index 39995c206..2760260f6 100644
--- a/src/rpc/core_rpc_server_commands_defs.h
+++ b/src/rpc/core_rpc_server_commands_defs.h
@@ -894,6 +894,8 @@ namespace cryptonote
       uint64_t reserved_offset;
       uint64_t expected_reward;
       std::string prev_hash;
+      std::string seed_hash;
+      std::string next_seed_hash;
       blobdata blocktemplate_blob;
       blobdata blockhashing_blob;
       std::string status;
@@ -911,6 +913,8 @@ namespace cryptonote
         KV_SERIALIZE(blockhashing_blob)
         KV_SERIALIZE(status)
         KV_SERIALIZE(untrusted)
+        KV_SERIALIZE(seed_hash)
+        KV_SERIALIZE(next_seed_hash)
       END_KV_SERIALIZE_MAP()
     };
     typedef epee::misc_utils::struct_init<response_t> response;