- Boost - lists.boost.org

[mpl] has_xxx randomly broken in msvc
by shunsuke 12 Oct '07

12 Oct '07

Hi, For some reason, has_xxx fails to work in msvc-7.1 and 8.0 / Boost1.34 and HEAD. #include <boost/mpl/has_xxx.hpp> namespace my1 { BOOST_MPL_HAS_XXX_TRAIT_DEF(ppp) } #include <boost/mpl/apply.hpp> // does something bad for msvc. #include <boost/static_assert.hpp> namespace my2 { BOOST_MPL_HAS_XXX_TRAIT_DEF(ppp) } struct foo { typedef int ppp; }; BOOST_STATIC_ASSERT( my1::has_ppp< foo >::value ); // pass BOOST_STATIC_ASSERT( my2::has_ppp< foo >::value ); // failed int main() {} So Boost.Lambda and Boost.ResultOf randomly fail, because the both use has_result_type. The ticket: http://svn.boost.org/trac/boost/ticket/1317 Regards, -- Shunsuke Sogame

1 0

Re: [boost] Windows: Disable Static Libraries.
by Duft Markus 12 Oct '07

12 Oct '07

Vladimir Prus <> wrote: > Duft Markus wrote: > >> Hi all! >> >> I have a question regarding the boost build on Windows: I'm building >> boost with the following bjam command: >> >> cmd.exe /C ./tools/build/jam_src/${bindir}/bjam.exe -d2 >> -sTOOLS=${toolchain} "-sBUILD=release <threading>multi >> <cxxflags>-D_USE_32BIT_TIME_T <runtime-link>dynamic" >> "-s${vc_root}=${vcvars32}" > > You appears to be using Boost 1.33.*, with Boost.Build V1, right? Hi! Ah, yes, sorry, i forgot to mention the version. Of course it's 1.33.0... > >> Everything works fine so far, but: I want only the shared libraries >> (dlls), and am settings appropriate defines to use those versions in >> all other software i build. Thus the static libraries are completely >> useless for me (at least i think so, am i wrong?) >> >> Can i somehow disable static library builds? > > I'm not sure this is easily possible in the version you're using. In > Boost 1.34.*, using Boost.Build V2, you'd use: > > link=shared > > on the command like to build only shared libraries. Hm, ok, i tried that one allready without success as far as i remember. It's not really tragic, but building boost takes twice as long as it could, right now... Cheers, Markus > > - Volodya > > > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost -- 17.-19. Oktober 2007 Salomon Automation am 24. Deutschen Logistik-Kongress der BVL, Berlin; Stand W/09 14. November 2007 Salomon Automation an der LogIT Retail im Leopoldsmuseum in Wien Salomon Automation GmbH - Friesachstrasse 15 - A-8114 Friesach bei Graz Sitz der Gesellschaft: Friesach bei Graz UID-NR:ATU28654300 - Firmenbuchnummer: 49324 K Firmenbuchgericht: Landesgericht fur Zivilrechtssachen Graz

1 0

[math][Sunpro] Can anyone help porting to Sun's compiler?
by John Maddock 12 Oct '07

12 Oct '07

The new Math statistical distributions and special functions code currently fails with Sun's compiler http://beta.boost.org/development/tests/trunk/developer/output/Sandia-sun-b… with error messages such as: "../boost/math/concepts/real_concept.hpp", line 333: Error: Could not find a match for boost::math::tools::epsilon<boost::math::tools::T>(). "../boost/math/special_functions/detail/unchecked_factorial.hpp", line 268: Error: Could not find a match for boost::math::unchecked_factorial<boost::math::RT>(unsigned). "../boost/math/special_functions/detail/unchecked_factorial.hpp", line 269: Error: Could not find a match for boost::math::unchecked_factorial<boost::math::RT>(unsigned) needed in boost::math::unchecked_factorial<boost::math::RT>(unsigned). The gcc results on that platform are pretty good, so it seems a shame not to support Sun as well, anyone have ideas? Thanks, John Maddock.

2 5

Runtime Dynamic Dispatch Library (0.2)
by Dean Michael Berris 12 Oct '07

12 Oct '07

Hi Everyone, This version of the Dispatcher uses Boost.Fusion and Boost.Function. It also contains the strategized_map template (and test) which is basically an associative container which allows you to strategize the index validation and routing of the index. The strategized_map though is currently undocumented, though the unit tests already provide hints on how to use it. This release has been tested on Linux with GCC version 4.1.2 and Windows with MSVC 8.0 (Visual C++ 2005) against Boost's Subversion trunk. Comments and suggestions would be most appreciated. Please feel free to download the package(s) from Sourceforge: http://tinyurl.com/2cbzyl Or from the Boost Vault: http://tinyurl.com/24m2y2 This still does not implement the multiple-signature feature which I'm still contemplating on putting in, but this is already useful by itself. Please let me know if you would like to see some more compelling features you'd like to see in this library so that I can put them in before I formally submit it for review. Those who want to help cleaning up the code (and maybe doing some funky pre-processor programming) and implementing more features are welcome -- please let me know so that I can grant you write access to the subversion repository at Sourceforge. Have a great weekend everyone! -- Dean Michael C. Berris Software Engineer, Friendster, Inc. [http://cplusplus-soup.blogspot.com/] [mikhailberis(a)gmail.com] [+63 928 7291459] [+1 408 4049523]

14 85

Access to unaligned (packed) structs
by Roland Schwarz 12 Oct '07

12 Oct '07

I am searching for a library / component / pattern that will help me with the following problem: I have a memory structure in raw memory (received from a measurement instrument), that is unaligned in its data members. Now I want to have an access interface to this data that comes as close as possible to access of a struct. E.g. struct foo { char a; int b; } Altough my raw data "char* pdata" has an 8bit followed by a 32bit I want to be able to do something like: foo data(pdata); and then char ch = data.a; int n = data.b; Does anyone know about such a library? (This should work compiler/platform independent of course.) Thank you, Roland aka speedsnail

5 15

Windows: Disable Static Libraries.
by Duft Markus 12 Oct '07

12 Oct '07

Hi all! I have a question regarding the boost build on Windows: I'm building boost with the following bjam command: cmd.exe /C ./tools/build/jam_src/${bindir}/bjam.exe -d2 -sTOOLS=${toolchain} "-sBUILD=release <threading>multi <cxxflags>-D_USE_32BIT_TIME_T <runtime-link>dynamic" "-s${vc_root}=${vcvars32}" Everything works fine so far, but: I want only the shared libraries (dlls), and am settings appropriate defines to use those versions in all other software i build. Thus the static libraries are completely useless for me (at least i think so, am i wrong?) Can i somehow disable static library builds? Cheers, Markus -- 17.-19. Oktober 2007 Salomon Automation am 24. Deutschen Logistik-Kongress der BVL, Berlin; Stand W/09 14. November 2007 Salomon Automation an der LogIT Retail im Leopoldsmuseum in Wien Salomon Automation GmbH - Friesachstrasse 15 - A-8114 Friesach bei Graz Sitz der Gesellschaft: Friesach bei Graz UID-NR:ATU28654300 - Firmenbuchnummer: 49324 K Firmenbuchgericht: Landesgericht fur Zivilrechtssachen Graz

2 1

Smoke tests
by Beman Dawes 11 Oct '07

11 Oct '07

I'm calling the rapid turnaround tests "Smoke Tests". A section has been added to the testing doc page explaining them, with links to results; see: http://beta.boost.org/development/testing.html The Win32 and Ubuntu tests are currently checking for svn updates every 15 minutes. These tests are run on fast modern machines, so the tests usually take less than 5 minutes. Of course it will take longer if a header changes that lots of libraries depend on. I've also going to try to add Mac OS-X to the mix, but that machine is old and slow so cycle times are likely to be much longer. It will get added to the web page as soon as it is cycling regularly. Enjoy, --Beman

1 0

Access to unaligned (packed) structs - ONE FINAL TRY - Formatting problems
by Sid Sacek 11 Oct '07

11 Oct '07

#include <stdio.h> #define CPU_SPARC ( defined( __sparc ) || defined( sparc ) ) #include "safe_access.h" #pragma pack( 1 ) struct foo { unsigned char a; // doesn't need safe access SA( unsigned int ) b; // unaligned int needs safe access }; #pragma pack() int main( int, char ** ) { foo foo = { 0xAA, 0xBBBBBBBB }; unsigned char a = foo.a; unsigned int b = foo.b; printf( " &a = %p a = %x \n", &foo.a, a ); printf( " &b = %p b = %x \n", &foo.b, b ); foo.a = 0x12; foo.b = 0x34567890; printf( " a = %x \n", int( foo.a ) ); printf( " b = %x \n", int( foo.b ) ); } //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //--------------------------------------------------------------------------------------- // Safe Access // // These routines are used to access memory addresses that would cause bus-errors on the // SPARC platform if accessed in the normal C++ way, due to misaligned memory addresses. //--------------------------------------------------------------------------------------- #ifndef __SAFE_ACCESS_H__ #define __SAFE_ACCESS_H__ #pragma once //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //--------------------------------------------------------------------------------------- // Safe Variable Copy // // These routines behave like memcpy function calls, but are specialized for data type // sizes 2, 4, and 8 bytes. It is designed to execute in the fewest number of assembly // instructions without calling memcpy. Under the SUN platform using SPARC processors, // crashes occur with bus-alignment errors when data is located at random addresses. //--------------------------------------------------------------------------------------- template< int Sizeof_Variable > void safe_variable_copy( void *, const void * ); //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //--------------------------------------------------------------------------------------- // Specialization for sizeof( short ) // // safe_variable_copy< 2 >( &left, &right ) //--------------------------------------------------------------------------------------- template<> inline void safe_variable_copy< 2 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; } //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //--------------------------------------------------------------------------------------- // Specialization for sizeof( int ) // // safe_variable_copy< 4 >( &left, &right ) //--------------------------------------------------------------------------------------- template<> inline void safe_variable_copy< 4 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; static_cast< char * >( left )[ 2 ] = static_cast< const char * >( right )[ 2 ]; static_cast< char * >( left )[ 3 ] = static_cast< const char * >( right )[ 3 ]; } //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //--------------------------------------------------------------------------------------- // Specialization for sizeof( long long ) // // safe_variable_copy< 8 >( &left, &right ) //--------------------------------------------------------------------------------------- template<> inline void safe_variable_copy< 8 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; static_cast< char * >( left )[ 2 ] = static_cast< const char * >( right )[ 2 ]; static_cast< char * >( left )[ 3 ] = static_cast< const char * >( right )[ 3 ]; static_cast< char * >( left )[ 4 ] = static_cast< const char * >( right )[ 4 ]; static_cast< char * >( left )[ 5 ] = static_cast< const char * >( right )[ 5 ]; static_cast< char * >( left )[ 6 ] = static_cast< const char * >( right )[ 6 ]; static_cast< char * >( left )[ 7 ] = static_cast< const char * >( right )[ 7 ]; } //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //--------------------------------------------------------------------------------------- // Safe Access // // This templated function is used to prevent a bus errors under the SUN SPARC systems. // We wrap the misaligned variables with a function call to this routine. //--------------------------------------------------------------------------------------- template< typename Ty > inline Ty safe_access( const Ty & value ) { Ty result; // access memory using a memory-aligned variable safe_variable_copy< sizeof( Ty ) >( &result, &value ); return result; // pass back the value from misaligned variable } //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //--------------------------------------------------------------------------------------- // Safe Access Data Wrapper // // This wrapper class is used to wrap data defined in structures that are possibly // misaligned for the computer's bus architecture. It is typically meant to be used // inside data structures that are packed using the #pragma pack(n). // // Example of usage: // #if 0 #pragma pack(1) struct Packed_Structure { u8 status; // this is aligned at offset 0 SA( u32 ) value; // this is aligned at offset 1 ( can cause a bus error ) }; #pragma pack() void foo( Packed_Structure * pk ) { u8 var1 = pk->status; u32 var2 = pk->value; // this can no longer cause a bus error } #endif // // The data type 'SA( u32 )' in the above structure uses the 'safe_access' method to // ensure that bus errors don't occur when the data is being accessed on the fragile // platform. Since the network structures are typically packed, and possibly aligned // on addresses that can cause bus errors, the structure's data elements should use // versions of data elements that are 'access safe'. //--------------------------------------------------------------------------------------- template< typename Ty > struct safe_access_wrapper { Ty m_data; // contains the data that is possibly misaligned operator Ty() const { return safe_access( m_data ); } const Ty & operator = ( const Ty & value ) { safe_variable_copy< sizeof( Ty ) >( &m_data, &value ); return m_data; } }; //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ //--------------------------------------------------------------------------------------- // SAFE() Macro ( Safe Access ) // SA() Macro ( Safe Access Type Wrapper ) // // The SA() macro is used to wrap structure elements inside packed structures that may // cause bus errors when accessed, like on the SPARC processors. // Example of usage: // // #pragma pack(1) // struct Packed_Structure // { // u8 byte_aligned; // accessing this never causes a bus error // SA( u32 ) mis_aligned; // accessing this can no longer cause a bus error // }; // // The SAFE() macro is used to wrap access to basic data types that cause bus errors. // Example of usage: // // void foo( Packed_Structure * pk ) // { // u32 var1 = pk->variable; // this may cause a bus error on the SPARC chip // u32 var2 = SAFE( pk->variable ); // this can no longer cause a bus error // } //--------------------------------------------------------------------------------------- #if CPU_SPARC #define SA( type ) safe_access_wrapper< type > #define SAFE( argument ) safe_access( argument ) #else #define SA( type ) type #define SAFE( argument ) ( argument ) #endif #endif // #ifndef __SAFE_ACCESS_H__ // //--------------------------------------------------------------------------------------- //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 0

Access to unaligned (packed) structs - TRYING AGAIN
by Sid Sacek 11 Oct '07

11 Oct '07

#include <stdio.h> #define CPU_SPARC ( defined( __sparc ) || defined( sparc ) ) #include "safe_access.h" #pragma pack( 1 ) struct foo { unsigned char a; // doesn't need safe access SA( unsigned int ) b; // unaligned int needs safe access }; #pragma pack() int main( int, char ** ) { foo foo = { 0xAA, 0xBBBBBBBB }; unsigned char a = foo.a; unsigned int b = foo.b; printf( " &a = %p a = %x \n", &foo.a, a ); printf( " &b = %p b = %x \n", &foo.b, b ); foo.a = 0x12; foo.b = 0x34567890; printf( " a = %x \n", int( foo.a ) ); printf( " b = %x \n", int( foo.b ) ); } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Safe Access // // These routines are used to access memory addresses that would cause bus-errors on the // SPARC platform if accessed in the normal C++ way, due to misaligned memory addresses. //-------------------------------------------------------------------------- ------------- #ifndef __SAFE_ACCESS_H__ #define __SAFE_ACCESS_H__ #pragma once //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Safe Variable Copy // // These routines behave like memcpy function calls, but are specialized for data type // sizes 2, 4, and 8 bytes. It is designed to execute in the fewest number of assembly // instructions without calling memcpy. Under the SUN platform using SPARC processors, // crashes occur with bus-alignment errors when data is located at random addresses. //-------------------------------------------------------------------------- ------------- template< int Sizeof_Variable > void safe_variable_copy( void *, const void * ); //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Specialization for sizeof( short ) // // safe_variable_copy< 2 >( &left, &right ) //-------------------------------------------------------------------------- ------------- template<> inline void safe_variable_copy< 2 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Specialization for sizeof( int ) // // safe_variable_copy< 4 >( &left, &right ) //-------------------------------------------------------------------------- ------------- template<> inline void safe_variable_copy< 4 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; static_cast< char * >( left )[ 2 ] = static_cast< const char * >( right )[ 2 ]; static_cast< char * >( left )[ 3 ] = static_cast< const char * >( right )[ 3 ]; } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Specialization for sizeof( long long ) // // safe_variable_copy< 8 >( &left, &right ) //-------------------------------------------------------------------------- ------------- template<> inline void safe_variable_copy< 8 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; static_cast< char * >( left )[ 2 ] = static_cast< const char * >( right )[ 2 ]; static_cast< char * >( left )[ 3 ] = static_cast< const char * >( right )[ 3 ]; static_cast< char * >( left )[ 4 ] = static_cast< const char * >( right )[ 4 ]; static_cast< char * >( left )[ 5 ] = static_cast< const char * >( right )[ 5 ]; static_cast< char * >( left )[ 6 ] = static_cast< const char * >( right )[ 6 ]; static_cast< char * >( left )[ 7 ] = static_cast< const char * >( right )[ 7 ]; } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Safe Access // // This templated function is used to prevent a bus errors under the SUN SPARC systems. // We wrap the misaligned variables with a function call to this routine. //-------------------------------------------------------------------------- ------------- template< typename Ty > inline Ty safe_access( const Ty & value ) { Ty result; // access memory using a memory-aligned variable safe_variable_copy< sizeof( Ty ) >( &result, &value ); return result; // pass back the value from misaligned variable } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Safe Access Data Wrapper // // This wrapper class is used to wrap data defined in structures that are possibly // misaligned for the computer's bus architecture. It is typically meant to be used // inside data structures that are packed using the #pragma pack(n). // // Example of usage: // #if 0 #pragma pack(1) struct Packed_Structure { u8 status; // this is aligned at offset 0 SA( u32 ) value; // this is aligned at offset 1 ( can cause a bus error ) }; #pragma pack() void foo( Packed_Structure * pk ) { u8 var1 = pk->status; u32 var2 = pk->value; // this can no longer cause a bus error } #endif // // The data type 'SA( u32 )' in the above structure uses the 'safe_access' method to // ensure that bus errors don't occur when the data is being accessed on the fragile // platform. Since the network structures are typically packed, and possibly aligned // on addresses that can cause bus errors, the structure's data elements should use // versions of data elements that are 'access safe'. //-------------------------------------------------------------------------- ------------- template< typename Ty > struct safe_access_wrapper { Ty m_data; // contains the data that is possibly misaligned operator Ty() const { return safe_access( m_data ); } const Ty & operator = ( const Ty & value ) { safe_variable_copy< sizeof( Ty ) >( &m_data, &value ); return m_data; } }; //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // SAFE() Macro ( Safe Access ) // SA() Macro ( Safe Access Type Wrapper ) // // The SA() macro is used to wrap structure elements inside packed structures that may // cause bus errors when accessed, like on the SPARC processors. // Example of usage: // // #pragma pack(1) // struct Packed_Structure // { // u8 byte_aligned; // accessing this never causes a bus error // SA( u32 ) mis_aligned; // accessing this can no longer cause a bus error // }; // // The SAFE() macro is used to wrap access to basic data types that cause bus errors. // Example of usage: // // void foo( Packed_Structure * pk ) // { // u32 var1 = pk->variable; // this may cause a bus error on the SPARC chip // u32 var2 = SAFE( pk->variable ); // this can no longer cause a bus error // } //-------------------------------------------------------------------------- ------------- #if CPU_SPARC #define SA( type ) safe_access_wrapper< type > #define SAFE( argument ) safe_access( argument ) #else #define SA( type ) type #define SAFE( argument ) ( argument ) #endif #endif // #ifndef __SAFE_ACCESS_H__ // //-------------------------------------------------------------------------- ------------- //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++

1 0

Access to unaligned (packed) structs
by Sid Sacek 11 Oct '07

11 Oct '07

#include <stdio.h> #define CPU_SPARC ( defined( __sparc ) || defined( sparc ) ) #include "safe_access.h" #pragma pack( 1 ) struct foo { unsigned char a; // doesn't need safe access SA( unsigned int ) b; // unaligned int needs safe access }; #pragma pack() int main( int, char ** ) { foo foo = { 0xAA, 0xBBBBBBBB }; unsigned char a = foo.a; unsigned int b = foo.b; printf( " &a = %p a = %x \n", &foo.a, a ); printf( " &b = %p b = %x \n", &foo.b, b ); foo.a = 0x12; foo.b = 0x34567890; printf( " a = %x \n", int( foo.a ) ); printf( " b = %x \n", int( foo.b ) ); } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Safe Access // // These routines are used to access memory addresses that would cause bus-errors on the // SPARC platform if accessed in the normal C++ way, due to misaligned memory addresses. //-------------------------------------------------------------------------- ------------- #ifndef __SAFE_ACCESS_H__ #define __SAFE_ACCESS_H__ #pragma once //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Safe Variable Copy // // These routines behave like memcpy function calls, but are specialized for data type // sizes 2, 4, and 8 bytes. It is designed to execute in the fewest number of assembly // instructions without calling memcpy. Under the SUN platform using SPARC processors, // crashes occur with bus-alignment errors when data is located at random addresses. //-------------------------------------------------------------------------- ------------- template< int Sizeof_Variable > void safe_variable_copy( void *, const void * ); //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Specialization for sizeof( short ) // // safe_variable_copy< 2 >( &left, &right ) //-------------------------------------------------------------------------- ------------- template<> inline void safe_variable_copy< 2 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Specialization for sizeof( int ) // // safe_variable_copy< 4 >( &left, &right ) //-------------------------------------------------------------------------- ------------- template<> inline void safe_variable_copy< 4 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; static_cast< char * >( left )[ 2 ] = static_cast< const char * >( right )[ 2 ]; static_cast< char * >( left )[ 3 ] = static_cast< const char * >( right )[ 3 ]; } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Specialization for sizeof( long long ) // // safe_variable_copy< 8 >( &left, &right ) //-------------------------------------------------------------------------- ------------- template<> inline void safe_variable_copy< 8 >( void * left, const void * right ) { static_cast< char * >( left )[ 0 ] = static_cast< const char * >( right )[ 0 ]; static_cast< char * >( left )[ 1 ] = static_cast< const char * >( right )[ 1 ]; static_cast< char * >( left )[ 2 ] = static_cast< const char * >( right )[ 2 ]; static_cast< char * >( left )[ 3 ] = static_cast< const char * >( right )[ 3 ]; static_cast< char * >( left )[ 4 ] = static_cast< const char * >( right )[ 4 ]; static_cast< char * >( left )[ 5 ] = static_cast< const char * >( right )[ 5 ]; static_cast< char * >( left )[ 6 ] = static_cast< const char * >( right )[ 6 ]; static_cast< char * >( left )[ 7 ] = static_cast< const char * >( right )[ 7 ]; } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Safe Access // // This templated function is used to prevent a bus errors under the SUN SPARC systems. // We wrap the misaligned variables with a function call to this routine. //-------------------------------------------------------------------------- ------------- template< typename Ty > inline Ty safe_access( const Ty & value ) { Ty result; // access memory using a memory-aligned variable safe_variable_copy< sizeof( Ty ) >( &result, &value ); return result; // pass back the value from misaligned variable } //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // Safe Access Data Wrapper // // This wrapper class is used to wrap data defined in structures that are possibly // misaligned for the computer's bus architecture. It is typically meant to be used // inside data structures that are packed using the #pragma pack(n). // // Example of usage: // #if 0 #pragma pack(1) struct Packed_Structure { u8 status; // this is aligned at offset 0 SA( u32 ) value; // this is aligned at offset 1 ( can cause a bus error ) }; #pragma pack() void foo( Packed_Structure * pk ) { u8 var1 = pk->status; u32 var2 = pk->value; // this can no longer cause a bus error } #endif // // The data type 'SA( u32 )' in the above structure uses the 'safe_access' method to // ensure that bus errors don't occur when the data is being accessed on the fragile // platform. Since the network structures are typically packed, and possibly aligned // on addresses that can cause bus errors, the structure's data elements should use // versions of data elements that are 'access safe'. //-------------------------------------------------------------------------- ------------- template< typename Ty > struct safe_access_wrapper { Ty m_data; // contains the data that is possibly misaligned operator Ty() const { return safe_access( m_data ); } const Ty & operator = ( const Ty & value ) { safe_variable_copy< sizeof( Ty ) >( &m_data, &value ); return m_data; } }; //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++ //-------------------------------------------------------------------------- ------------- // SAFE() Macro ( Safe Access ) // SA() Macro ( Safe Access Type Wrapper ) // // The SA() macro is used to wrap structure elements inside packed structures that may // cause bus errors when accessed, like on the SPARC processors. // Example of usage: // // #pragma pack(1) // struct Packed_Structure // { // u8 byte_aligned; // accessing this never causes a bus error // SA( u32 ) mis_aligned; // accessing this can no longer cause a bus error // }; // // The SAFE() macro is used to wrap access to basic data types that cause bus errors. // Example of usage: // // void foo( Packed_Structure * pk ) // { // u32 var1 = pk->variable; // this may cause a bus error on the SPARC chip // u32 var2 = SAFE( pk->variable ); // this can no longer cause a bus error // } //-------------------------------------------------------------------------- ------------- #if CPU_SPARC #define SA( type ) safe_access_wrapper< type > #define SAFE( argument ) safe_access( argument ) #else #define SA( type ) type #define SAFE( argument ) ( argument ) #endif #endif // #ifndef __SAFE_ACCESS_H__ // //-------------------------------------------------------------------------- ------------- //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ +++++++++++++

1 0