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Fix for issue #4225 to allow static initialization of boost::once_flag

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[SVN r63795]
This commit is contained in:
Anthony Williams
2010-07-09 21:15:57 +00:00
parent 68012dd92c
commit 784494274b
2 changed files with 86 additions and 48 deletions
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126
include/boost/thread/win32/once.hpp
View File

@@ -35,41 +35,85 @@ namespace boost
long status;
long count;
long throw_count;
void* event_handle;
~once_flag()
{
if(count)
{
BOOST_ASSERT(count==throw_count);
}
void* const old_event=BOOST_INTERLOCKED_EXCHANGE_POINTER(&event_handle,0);
if(old_event)
{
::boost::detail::win32::CloseHandle(old_event);
}
}
};
#define BOOST_ONCE_INIT {0,0,0,0}
#define BOOST_ONCE_INIT {0,0,0}
namespace detail
{
inline void* allocate_event_handle(void*& handle)
#ifdef BOOST_NO_ANSI_APIS
typedef wchar_t once_char_type;
#else
typedef char once_char_type;
#endif
unsigned const once_mutex_name_fixed_length=54;
unsigned const once_mutex_name_length=once_mutex_name_fixed_length+
sizeof(void*)*2+sizeof(unsigned long)*2+1;
template <class I>
void int_to_string(I p, once_char_type* buf)
{
void* const new_handle=::boost::detail::win32::create_anonymous_event(
::boost::detail::win32::manual_reset_event,
::boost::detail::win32::event_initially_reset);
void* event_handle=BOOST_INTERLOCKED_COMPARE_EXCHANGE_POINTER(&handle,
new_handle,0);
if(event_handle)
for(unsigned i=0; i < sizeof(I)*2; ++i,++buf)
{
::boost::detail::win32::CloseHandle(new_handle);
return event_handle;
#ifdef BOOST_NO_ANSI_APIS
once_char_type const a=L'A';
#else
once_char_type const a='A';
#endif
*buf = a + static_cast<once_char_type>((p >> (i*4)) & 0x0f);
}
return new_handle;
*buf = 0;
}
inline void name_once_mutex(once_char_type* mutex_name,void* flag_address)
{
#ifdef BOOST_NO_ANSI_APIS
static const once_char_type fixed_mutex_name[]=L"Local\\{C15730E2-145C-4c5e-B005-3BC753F42475}-once-flag";
#else
static const once_char_type fixed_mutex_name[]="Local\\{C15730E2-145C-4c5e-B005-3BC753F42475}-once-flag";
#endif
BOOST_STATIC_ASSERT(sizeof(fixed_mutex_name) ==
(sizeof(once_char_type)*(once_mutex_name_fixed_length+1)));
std::memcpy(mutex_name,fixed_mutex_name,sizeof(fixed_mutex_name));
detail::int_to_string(reinterpret_cast<std::ptrdiff_t>(flag_address),
mutex_name + once_mutex_name_fixed_length);
detail::int_to_string(win32::GetCurrentProcessId(),
mutex_name + once_mutex_name_fixed_length + sizeof(void*)*2);
}
inline void* open_once_event(once_char_type* mutex_name,void* flag_address)
{
if(!*mutex_name)
{
name_once_mutex(mutex_name,flag_address);
}
#ifdef BOOST_NO_ANSI_APIS
return ::boost::detail::win32::OpenEventW(
#else
return ::boost::detail::win32::OpenEventA(
#endif
::boost::detail::win32::synchronize |
::boost::detail::win32::event_modify_state,
false,
mutex_name);
}
inline void* create_once_event(once_char_type* mutex_name,void* flag_address)
{
if(!*mutex_name)
{
name_once_mutex(mutex_name,flag_address);
}
#ifdef BOOST_NO_ANSI_APIS
return ::boost::detail::win32::CreateEventW(
#else
return ::boost::detail::win32::CreateEventA(
#endif
0,::boost::detail::win32::manual_reset_event,
::boost::detail::win32::event_initially_reset,
mutex_name);
}
}
@@ -83,8 +127,10 @@ namespace boost
long const running_value=0x7f0725e3;
long status;
bool counted=false;
void* event_handle=0;
detail::win32::handle_manager event_handle;
long throw_count=0;
detail::once_char_type mutex_name[detail::once_mutex_name_length];
mutex_name[0]=0;
while((status=::boost::detail::interlocked_read_acquire(&flag.status))
!=function_complete_flag_value)
@@ -96,7 +142,7 @@ namespace boost
{
if(!event_handle)
{
event_handle=::boost::detail::interlocked_read_acquire(&flag.event_handle);
event_handle=detail::open_once_event(mutex_name,&flag);
}
if(event_handle)
{
@@ -112,7 +158,7 @@ namespace boost
if(!event_handle &&
(::boost::detail::interlocked_read_acquire(&flag.count)>1))
{
event_handle=::boost::detail::allocate_event_handle(flag.event_handle);
event_handle=detail::create_once_event(mutex_name,&flag);
}
if(event_handle)
{
@@ -130,7 +176,7 @@ namespace boost
BOOST_INTERLOCKED_EXCHANGE(&flag.status,0);
if(!event_handle)
{
event_handle=::boost::detail::interlocked_read_acquire(&flag.event_handle);
event_handle=detail::open_once_event(mutex_name,&flag);
}
if(event_handle)
{
@@ -149,31 +195,15 @@ namespace boost
{
break;
}
event_handle=::boost::detail::interlocked_read_acquire(&flag.event_handle);
if(!event_handle)
{
event_handle=::boost::detail::allocate_event_handle(flag.event_handle);
event_handle=detail::create_once_event(mutex_name,&flag);
continue;
}
}
BOOST_VERIFY(!::boost::detail::win32::WaitForSingleObject(
event_handle,::boost::detail::win32::infinite));
}
if(counted || throw_count)
{
if(!BOOST_INTERLOCKED_EXCHANGE_ADD(&flag.count,(counted?-1:0)-throw_count))
{
if(!event_handle)
{
event_handle=::boost::detail::interlocked_read_acquire(&flag.event_handle);
}
if(event_handle)
{
BOOST_INTERLOCKED_EXCHANGE_POINTER(&flag.event_handle,0);
::boost::detail::win32::CloseHandle(event_handle);
}
}
}
}
}

8
include/boost/thread/win32/thread_primitives.hpp
View File

@@ -31,14 +31,18 @@ namespace boost
unsigned const infinite=INFINITE;
unsigned const timeout=WAIT_TIMEOUT;
handle const invalid_handle_value=INVALID_HANDLE_VALUE;
unsigned const event_modify_state=EVENT_MODIFY_STATE;
unsigned const synchronize=SYNCHRONIZE;
# ifdef BOOST_NO_ANSI_APIS
using ::CreateMutexW;
using ::CreateEventW;
using ::OpenEventW;
using ::CreateSemaphoreW;
# else
using ::CreateMutexA;
using ::CreateEventA;
using ::OpenEventA;
using ::CreateSemaphoreA;
# endif
using ::CloseHandle;
@@ -100,6 +104,8 @@ namespace boost
unsigned const infinite=~0U;
unsigned const timeout=258U;
handle const invalid_handle_value=(handle)(-1);
unsigned const event_modify_state=2;
unsigned const synchronize=0x100000u;
extern "C"
{
@@ -108,10 +114,12 @@ namespace boost
__declspec(dllimport) void* __stdcall CreateMutexW(_SECURITY_ATTRIBUTES*,int,wchar_t const*);
__declspec(dllimport) void* __stdcall CreateSemaphoreW(_SECURITY_ATTRIBUTES*,long,long,wchar_t const*);
__declspec(dllimport) void* __stdcall CreateEventW(_SECURITY_ATTRIBUTES*,int,int,wchar_t const*);
__declspec(dllimport) void* __stdcall OpenEventW(unsigned long,int,wchar_t const*);
# else
__declspec(dllimport) void* __stdcall CreateMutexA(_SECURITY_ATTRIBUTES*,int,char const*);
__declspec(dllimport) void* __stdcall CreateSemaphoreA(_SECURITY_ATTRIBUTES*,long,long,char const*);
__declspec(dllimport) void* __stdcall CreateEventA(_SECURITY_ATTRIBUTES*,int,int,char const*);
__declspec(dllimport) void* __stdcall OpenEventA(unsigned long,int,char const*);
# endif
__declspec(dllimport) int __stdcall CloseHandle(void*);
__declspec(dllimport) int __stdcall ReleaseMutex(void*);