1 files changed, 46 insertions, 62 deletions

diff --git a/src/allocators.h b/src/allocators.h
index 85af8fe376..7012ef7e2a 100644
--- a/src/allocators.h
+++ b/src/allocators.h
@@ -1,36 +1,19 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2012 The Bitcoin developers
+// Copyright (c) 2009-2013 The Bitcoin developers
 // Distributed under the MIT/X11 software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
 #ifndef BITCOIN_ALLOCATORS_H
 #define BITCOIN_ALLOCATORS_H
 
-#include <string.h>
+#include <map>
 #include <string>
+#include <string.h>
+
 #include <boost/thread/mutex.hpp>
-#include <map>
+#include <boost/thread/once.hpp>
 #include <openssl/crypto.h> // for OPENSSL_cleanse()
 
-#ifdef WIN32
-#ifdef _WIN32_WINNT
-#undef _WIN32_WINNT
-#endif
-#define _WIN32_WINNT 0x0501
-#define WIN32_LEAN_AND_MEAN 1
-#ifndef NOMINMAX
-#define NOMINMAX
-#endif
-#include <windows.h>
-// This is used to attempt to keep keying material out of swap
-// Note that VirtualLock does not provide this as a guarantee on Windows,
-// but, in practice, memory that has been VirtualLock'd almost never gets written to
-// the pagefile except in rare circumstances where memory is extremely low.
-#else
-#include <sys/mman.h>
-#include <limits.h> // for PAGESIZE
-#include <unistd.h> // for sysconf
-#endif
-
 /**
  * Thread-safe class to keep track of locked (ie, non-swappable) memory pages.
  *
@@ -53,6 +36,12 @@ public:
         page_mask = ~(page_size - 1);
     }
 
+    ~LockedPageManagerBase()
+    {
+        assert(this->GetLockedPageCount() == 0);
+    }
+
+
     // For all pages in affected range, increase lock count
     void LockRange(void *p, size_t size)
     {
@@ -115,21 +104,6 @@ private:
     Histogram histogram;
 };
 
-/** Determine system page size in bytes */
-static inline size_t GetSystemPageSize()
-{
-    size_t page_size;
-#if defined(WIN32)
-    SYSTEM_INFO sSysInfo;
-    GetSystemInfo(&sSysInfo);
-    page_size = sSysInfo.dwPageSize;
-#elif defined(PAGESIZE) // defined in limits.h
-    page_size = PAGESIZE;
-#else // assume some POSIX OS
-    page_size = sysconf(_SC_PAGESIZE);
-#endif
-    return page_size;
-}
 
 /**
  * OS-dependent memory page locking/unlocking.
@@ -141,39 +115,49 @@ public:
     /** Lock memory pages.
      * addr and len must be a multiple of the system page size
      */
-    bool Lock(const void *addr, size_t len)
-    {
-#ifdef WIN32
-        return VirtualLock(const_cast<void*>(addr), len);
-#else
-        return mlock(addr, len) == 0;
-#endif
-    }
+    bool Lock(const void *addr, size_t len);
     /** Unlock memory pages.
      * addr and len must be a multiple of the system page size
      */
-    bool Unlock(const void *addr, size_t len)
-    {
-#ifdef WIN32
-        return VirtualUnlock(const_cast<void*>(addr), len);
-#else
-        return munlock(addr, len) == 0;
-#endif
-    }
+    bool Unlock(const void *addr, size_t len);
 };
 
 /**
  * Singleton class to keep track of locked (ie, non-swappable) memory pages, for use in
  * std::allocator templates.
+ *
+ * Some implementations of the STL allocate memory in some constructors (i.e., see
+ * MSVC's vector<T> implementation where it allocates 1 byte of memory in the allocator.)
+ * Due to the unpredictable order of static initializers, we have to make sure the
+ * LockedPageManager instance exists before any other STL-based objects that use
+ * secure_allocator are created. So instead of having LockedPageManager also be
+ * static-intialized, it is created on demand.
  */
 class LockedPageManager: public LockedPageManagerBase<MemoryPageLocker>
 {
 public:
-    static LockedPageManager instance; // instantiated in util.cpp
+    static LockedPageManager& Instance() 
+    {
+        boost::call_once(LockedPageManager::CreateInstance, LockedPageManager::init_flag);
+        return *LockedPageManager::_instance;
+    }
+
 private:
-    LockedPageManager():
-        LockedPageManagerBase<MemoryPageLocker>(GetSystemPageSize())
-    {}
+    LockedPageManager();
+
+    static void CreateInstance()
+    {
+        // Using a local static instance guarantees that the object is initialized
+        // when it's first needed and also deinitialized after all objects that use
+        // it are done with it.  I can think of one unlikely scenario where we may
+        // have a static deinitialization order/problem, but the check in
+        // LockedPageManagerBase's destructor helps us detect if that ever happens.
+        static LockedPageManager instance;
+        LockedPageManager::_instance = &instance;
+    }
+
+    static LockedPageManager* _instance;
+    static boost::once_flag init_flag;
 };
 
 //
@@ -181,12 +165,12 @@ private:
 // Intended for non-dynamically allocated structures.
 //
 template<typename T> void LockObject(const T &t) {
-    LockedPageManager::instance.LockRange((void*)(&t), sizeof(T));
+    LockedPageManager::Instance().LockRange((void*)(&t), sizeof(T));
 }
 
 template<typename T> void UnlockObject(const T &t) {
     OPENSSL_cleanse((void*)(&t), sizeof(T));
-    LockedPageManager::instance.UnlockRange((void*)(&t), sizeof(T));
+    LockedPageManager::Instance().UnlockRange((void*)(&t), sizeof(T));
 }
 
 //
@@ -218,7 +202,7 @@ struct secure_allocator : public std::allocator<T>
         T *p;
         p = std::allocator<T>::allocate(n, hint);
         if (p != NULL)
-            LockedPageManager::instance.LockRange(p, sizeof(T) * n);
+            LockedPageManager::Instance().LockRange(p, sizeof(T) * n);
         return p;
     }
 
@@ -227,7 +211,7 @@ struct secure_allocator : public std::allocator<T>
         if (p != NULL)
         {
             OPENSSL_cleanse(p, sizeof(T) * n);
-            LockedPageManager::instance.UnlockRange(p, sizeof(T) * n);
+            LockedPageManager::Instance().UnlockRange(p, sizeof(T) * n);
         }
         std::allocator<T>::deallocate(p, n);
     }