X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=src%2Fsyzygy%2Ftbprobe.cpp;h=57c7d872e1b496a104774582de1a07838b4587af;hb=7accf07c0b9cb3e2b932da5dd11b7d321745895e;hp=235fe1953bf97505a8be256b617ef124d9647278;hpb=166bf90e4172b77aa0c420ed271fa55e92301a70;p=stockfish

diff --git a/src/syzygy/tbprobe.cpp b/src/syzygy/tbprobe.cpp
index 235fe195..57c7d872 100644
--- a/src/syzygy/tbprobe.cpp
+++ b/src/syzygy/tbprobe.cpp
@@ -216,6 +216,7 @@ public:
         fstat(fd, &statbuf);
         *mapping = statbuf.st_size;
         *baseAddress = mmap(nullptr, statbuf.st_size, PROT_READ, MAP_SHARED, fd, 0);
+        madvise(*baseAddress, statbuf.st_size, MADV_RANDOM);
         ::close(fd);
 
         if (*baseAddress == MAP_FAILED) {
@@ -223,8 +224,9 @@ public:
             exit(1);
         }
 #else
+        // Note FILE_FLAG_RANDOM_ACCESS is only a hint to Windows and as such may get ignored.
         HANDLE fd = CreateFile(fname.c_str(), GENERIC_READ, FILE_SHARE_READ, nullptr,
-                               OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
+                               OPEN_EXISTING, FILE_FLAG_RANDOM_ACCESS, nullptr);
 
         if (fd == INVALID_HANDLE_VALUE)
             return *baseAddress = nullptr, nullptr;
@@ -1106,10 +1108,10 @@ void* mapped(TBTable<Type>& e, const Position& pos) {
 
     static Mutex mutex;
 
-    // Use 'aquire' to avoid a thread reads 'ready' == true while another is
-    // still working, this could happen due to compiler reordering.
+    // Use 'acquire' to avoid a thread reading 'ready' == true while
+    // another is still working. (compiler reordering may cause this).
     if (e.ready.load(std::memory_order_acquire))
-        return e.baseAddress; // Could be nullptr if file does not exsist
+        return e.baseAddress; // Could be nullptr if file does not exist
 
     std::unique_lock<Mutex> lk(mutex);
 
@@ -1276,7 +1278,7 @@ void Tablebases::init(const std::string& paths) {
                         continue; // First on diagonal, second above
 
                     else if (!off_A1H8(s1) && !off_A1H8(s2))
-                        bothOnDiagonal.push_back(std::make_pair(idx, s2));
+                        bothOnDiagonal.emplace_back(idx, s2);
 
                     else
                         MapKK[idx][s2] = code++;