From: Sami Kiminki <skiminki@users.noreply.github.com>
Date: Thu, 14 May 2020 09:00:35 +0000 (+0300)
Subject: Fix a Windows-only crash on exit without 'quit'
X-Git-Url: https://git.sesse.net/?p=stockfish;a=commitdiff_plain;h=beb327f910ed782f358d69201643ccd99b982a48

Fix a Windows-only crash on exit without 'quit'

There was a bug in commit d4763424d2728fe2dfd0a6fe747666feb6a2fdbb
(Add support for Windows large pages) that could result in trying to
free memory allocated with VirtualAlloc incorrectly with free().

Fix this by reverting the TT.resize(0) logic in the previous commit,
and instead, just call aligned_ttmem_free() in
TranspositionTable::~TranspositionTable().

fixes https://github.com/official-stockfish/Stockfish/issues/2677

closes https://github.com/official-stockfish/Stockfish/pull/2679

No functional change
---

diff --git a/src/main.cpp b/src/main.cpp
index c7cf2c6f..6eeda66d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -49,7 +49,6 @@ int main(int argc, char* argv[]) {
 
   UCI::loop(argc, argv);
 
-  TT.resize(0);
   Threads.set(0);
   return 0;
 }
diff --git a/src/misc.cpp b/src/misc.cpp
index b1c0feeb..e0cc6ed5 100644
--- a/src/misc.cpp
+++ b/src/misc.cpp
@@ -390,7 +390,7 @@ void* aligned_ttmem_alloc(size_t allocSize, void*& mem) {
 
 void aligned_ttmem_free(void* mem) {
 
-  if (!VirtualFree(mem, 0, MEM_RELEASE))
+  if (mem && !VirtualFree(mem, 0, MEM_RELEASE))
   {
       DWORD err = GetLastError();
       std::cerr << "Failed to free transposition table. Error code: 0x" <<
diff --git a/src/misc.h b/src/misc.h
index 9d53c2da..05bfc7de 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -34,7 +34,7 @@ const std::string compiler_info();
 void prefetch(void* addr);
 void start_logger(const std::string& fname);
 void* aligned_ttmem_alloc(size_t size, void*& mem);
-void aligned_ttmem_free(void* mem);
+void aligned_ttmem_free(void* mem); // nop if mem == nullptr
 
 void dbg_hit_on(bool b);
 void dbg_hit_on(bool c, bool b);
diff --git a/src/tt.cpp b/src/tt.cpp
index 6ee63138..4e06bed9 100644
--- a/src/tt.cpp
+++ b/src/tt.cpp
@@ -63,14 +63,7 @@ void TranspositionTable::resize(size_t mbSize) {
 
   Threads.main()->wait_for_search_finished();
 
-  if (mem)
-      aligned_ttmem_free(mem);
-
-  if (!mbSize)
-  {
-      mem = nullptr;
-      return;
-  }
+  aligned_ttmem_free(mem);
 
   clusterCount = mbSize * 1024 * 1024 / sizeof(Cluster);
   table = static_cast<Cluster*>(aligned_ttmem_alloc(clusterCount * sizeof(Cluster), mem));
diff --git a/src/tt.h b/src/tt.h
index 8b70f797..bd723a86 100644
--- a/src/tt.h
+++ b/src/tt.h
@@ -75,7 +75,7 @@ class TranspositionTable {
   static_assert(sizeof(Cluster) == 32, "Unexpected Cluster size");
 
 public:
- ~TranspositionTable() { free(mem); }
+ ~TranspositionTable() { aligned_ttmem_free(mem); }
   void new_search() { generation8 += 8; } // Lower 3 bits are used by PV flag and Bound
   TTEntry* probe(const Key key, bool& found) const;
   int hashfull() const;