diff options
| -rw-r--r-- | config.h | 5 | ||||
| -rw-r--r-- | integer.cpp | 79 | ||||
| -rw-r--r-- | integer.h | 13 |
3 files changed, 80 insertions, 17 deletions
@@ -596,13 +596,14 @@ NAMESPACE_END # define CRYPTOPP_USER_PRIORITY 350
#endif
-#if (CRYPTOPP_INIT_PRIORITY > 0) && !(defined(__APPLE__) || defined(__sun__))
+// Most platforms allow us to specify when to create C++ objects. Apple and Sun do not.
+#if (CRYPTOPP_INIT_PRIORITY > 0) && !(defined(NO_OS_DEPENDENCE) || defined(__APPLE__) || defined(__sun__))
# if (CRYPTOPP_GCC_VERSION >= 30000) || (CRYPTOPP_LLVM_CLANG_VERSION >= 20900) || (_INTEL_COMPILER >= 800)
# define HAVE_GCC_INIT_PRIORITY 1
# elif (CRYPTOPP_MSC_VERSION >= 1310)
# define HAVE_MSC_INIT_PRIORITY 1
# endif
-#endif // CRYPTOPP_INIT_PRIORITY, Sun, Darwin
+#endif // CRYPTOPP_INIT_PRIORITY, NO_OS_DEPENDENCE, Apple, Sun
// ***************** determine availability of OS features ********************
diff --git a/integer.cpp b/integer.cpp index 8df0b567..317ad89f 100644 --- a/integer.cpp +++ b/integer.cpp @@ -1,6 +1,37 @@ // integer.cpp - originally written and placed in the public domain by Wei Dai
// contains public domain code contributed by Alister Lee and Leonard Janke
+// Notes by JW: The Integer class needs to do two things. First, it needs to set function
+// pointers on some platforms, like X86 and X64. The function pointers select a fast multiply
+// and addition based on the cpu. Second, it wants to create Integer::Zero(), Integer::One()
+// and Integer::Two(). The function pointers are initialized in the class InitializeInteger.
+// Wei's original code was much simpler. It uses the Singleton pattern, but it always produced
+// memory findings. The Singleton generates memory findings because it used for a Create on
+// First Use pattern. Resource destruction effectivley requires running resource acquisition
+// with dependencies in reverse. For resources provided through the Singletons, there is no way
+// to express the dependency order to safely destroy resources.
+// The difference in the changes below is we use platform and language specific remediations
+// if they are available. If not available, then we fall back to Wei's original code. If
+// NO_OS_DEPENDENCE is defined, then the library uses Wei's original code.
+// Under all versions of C++ on Linux and Microsoft platforms, we can use GCC's init_priority
+// or MSVC's init_seg(lib) to initialize the function pointers and create the Integers 0, 1 and 2
+// after CRT startup. This avoids the Singletons and clears over half the reports of memory
+// leaks. However, it does not apply to Apple or Sun platforms.
+// C++11 allows us to use call_once to set the function pointers, and Integer does so when
+// init_priority and init_seg(lib) are not available. The class also uses the Singleton pattern
+// to ensure integers 0, 1 and 2 are available. The Singleton will produce memory findings, but
+// we don't have anything else to use in this case.
+// C++03 on platforms like Apple and Sun, we use a boolean flag to track when the function pointers
+// have been set based on the cpu. Its just a Nifty Counter in disguise, and its similar to using
+// the g_pAssignToInteger to track initialization. It has concurrency issues, but a race is not a
+// problem. It does not matter if two threads both set the same pointers. The Singleton pattern
+// is also used to ensure integers 0, 1 and 2 are available. The Singleton will produce memory
+// findings, but we don't have anything else to use in this case.
+// While not readily apparent, Integer does not need to inherit from InitializeInteger when
+// init_priority and init_seg(lib) are available. They just create an InitializePointers object
+// at the right time after CRT initialization. The additional class avoids the small runtime
+// overhead associated with checking the flags, and hides the detail from the interface.
+
#include "pch.h"
#include "config.h"
@@ -28,6 +59,7 @@ #include "smartptr.h"
#include "algparam.h"
#include "filters.h"
+#include "stdcpp.h"
#include "asn.h"
#include "oids.h"
#include "words.h"
@@ -73,11 +105,40 @@ NAMESPACE_BEGIN(CryptoPP)
static void SetFunctionPointers();
+#if defined(HAVE_GCC_INIT_PRIORITY) || defined(HAVE_MSC_INIT_PRIORITY)
+// Add InitializePointers to perform the work of setting pointers once.
+struct InitializePointers
+{
+ InitializePointers()
+ {
+ SetFunctionPointers();
+ }
+};
+// Leave InitializeInteger empty so no work is done.
InitializeInteger::InitializeInteger()
{
- SetFunctionPointers();
}
-
+#elif defined(CRYPTOPP_CXX11_SYNCHRONIZATION) && defined(CRYPTOPP_CXX11_DYNAMIC_INIT)
+std::once_flag s_flag;
+InitializeInteger::InitializeInteger()
+{
+ std::call_once(s_flag, []() {
+ SetFunctionPointers();
+ });
+}
+#else
+static bool s_flag;
+InitializeInteger::InitializeInteger()
+{
+ MEMORY_BARRIER();
+ if (s_flag == false)
+ {
+ SetFunctionPointers();
+ s_flag = true;
+ MEMORY_BARRIER();
+ }
+}
+#endif
template <long i>
struct NewInteger
{
@@ -89,15 +150,15 @@ struct NewInteger NAMESPACE_END
ANONYMOUS_NAMESPACE_BEGIN
-#if HAVE_GCC_INIT_PRIORITY
-const CryptoPP::InitializeInteger s_init __attribute__ ((init_priority (CRYPTOPP_INIT_PRIORITY + 30))) = CryptoPP::InitializeInteger();
+#if defined(HAVE_GCC_INIT_PRIORITY)
+const CryptoPP::InitializePointers s_init __attribute__ ((init_priority (CRYPTOPP_INIT_PRIORITY + 30))) = CryptoPP::InitializePointers();
const CryptoPP::Integer s_zero __attribute__ ((init_priority (CRYPTOPP_INIT_PRIORITY + 31))) = CryptoPP::Integer(0L);
const CryptoPP::Integer s_one __attribute__ ((init_priority (CRYPTOPP_INIT_PRIORITY + 32))) = CryptoPP::Integer(1L);
const CryptoPP::Integer s_two __attribute__ ((init_priority (CRYPTOPP_INIT_PRIORITY + 33))) = CryptoPP::Integer(2L);
-#elif HAVE_MSC_INIT_PRIORITY
+#elif defined(HAVE_MSC_INIT_PRIORITY)
#pragma warning(disable: 4075)
#pragma init_seg(".CRT$XCU-030")
-const CryptoPP::InitializeInteger s_init;
+const CryptoPP::InitializePointers s_init;
const CryptoPP::Integer s_zero(0L);
const CryptoPP::Integer s_one(1L);
const CryptoPP::Integer s_two(2L);
@@ -3025,7 +3086,7 @@ Integer Integer::Power2(size_t e) const Integer &Integer::Zero()
{
-#if HAVE_GCC_INIT_PRIORITY || HAVE_MSC_INIT_PRIORITY
+#if defined(HAVE_GCC_INIT_PRIORITY) || defined(HAVE_MSC_INIT_PRIORITY)
return s_zero;
#else
return Singleton<Integer, NewInteger<0L> >().Ref();
@@ -3034,7 +3095,7 @@ const Integer &Integer::Zero() const Integer &Integer::One()
{
-#if HAVE_GCC_INIT_PRIORITY || HAVE_MSC_INIT_PRIORITY
+#if defined(HAVE_GCC_INIT_PRIORITY) || defined(HAVE_MSC_INIT_PRIORITY)
return s_one;
#else
return Singleton<Integer, NewInteger<1L> >().Ref();
@@ -3043,7 +3104,7 @@ const Integer &Integer::One() const Integer &Integer::Two()
{
-#if HAVE_GCC_INIT_PRIORITY || HAVE_MSC_INIT_PRIORITY
+#if defined(HAVE_GCC_INIT_PRIORITY) || defined(HAVE_MSC_INIT_PRIORITY)
return s_two;
#else
return Singleton<Integer, NewInteger<2L> >().Ref();
@@ -8,6 +8,9 @@ //! has two data members. The first is a IntegerSecBlock (a SecBlock<word>) and it is
//! used to hold the representation. The second is a Sign (an enumeration), and it is
//! used to track the sign of the Integer.
+//! \details For details on how the Integer class initializes its function pointers using
+//! InitializeInteger and how it creates Integer::Zero(), Integer::One(), and
+//! Integer::Two(), then see the comments at the top of <tt>integer.cpp</tt>.
//! \since Crypto++ 1.0
#ifndef CRYPTOPP_INTEGER_H
@@ -38,14 +41,12 @@ typedef SecBlock<word, AllocatorWithCleanup<word, true> > IntegerSecBlock; //! has two data members. The first is a IntegerSecBlock (a SecBlock<word>) and it is
//! used to hold the representation. The second is a Sign (an enumeration), and it is
//! used to track the sign of the Integer.
+//! \details For details on how the Integer class initializes its function pointers using
+//! InitializeInteger and how it creates Integer::Zero(), Integer::One(), and
+//! Integer::Two(), then see the comments at the top of <tt>integer.cpp</tt>.
//! \since Crypto++ 1.0
//! \nosubgrouping
-class CRYPTOPP_DLL Integer
-#if HAVE_GCC_INIT_PRIORITY || HAVE_MSC_INIT_PRIORITY
- : private InitializeInteger, public ASN1Object
-#else
- : public ASN1Object
-#endif
+class CRYPTOPP_DLL Integer : private InitializeInteger, public ASN1Object
{
public:
//! \name ENUMS, EXCEPTIONS, and TYPEDEFS
|