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/* /////////////////////////////////////////////////////////////////////////
* File: winstl/synch/semaphore.hpp
*
* Purpose: Semaphore class, based on Win32 kernel semaphore object.
*
* Created: 30th May 2006
* Updated: 11th September 2011
*
* Home: http://stlsoft.org/
*
* Copyright (c) 2006-2011, Matthew Wilson and Synesis Software
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name(s) of Matthew Wilson and Synesis Software nor the names of
* any contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* ////////////////////////////////////////////////////////////////////// */
/** \file winstl/synch/semaphore.hpp
*
* \brief [C++ only] Definition of winstl::semaphore class
* (\ref group__library__synch "Synchronisation" Library).
*/
#ifndef WINSTL_INCL_WINSTL_SYNCH_HPP_SEMAPHORE
#define WINSTL_INCL_WINSTL_SYNCH_HPP_SEMAPHORE
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
# define WINSTL_VER_WINSTL_SYNCH_HPP_SEMAPHORE_MAJOR 1
# define WINSTL_VER_WINSTL_SYNCH_HPP_SEMAPHORE_MINOR 3
# define WINSTL_VER_WINSTL_SYNCH_HPP_SEMAPHORE_REVISION 2
# define WINSTL_VER_WINSTL_SYNCH_HPP_SEMAPHORE_EDIT 23
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/* /////////////////////////////////////////////////////////////////////////
* Includes
*/
#ifndef WINSTL_INCL_WINSTL_H_WINSTL
# include <winstl/winstl.h>
#endif /* !WINSTL_INCL_WINSTL_H_WINSTL */
#ifndef STLSOFT_INCL_STLSOFT_SYNCH_HPP_CONCEPTS
# include <stlsoft/synch/concepts.hpp>
#endif /* !STLSOFT_INCL_STLSOFT_SYNCH_HPP_CONCEPTS */
#ifndef WINSTL_INCL_WINSTL_SYNCH_ERROR_HPP_EXCEPTIONS
# include <winstl/synch/error/exceptions.hpp>
#endif /* !WINSTL_INCL_WINSTL_SYNCH_ERROR_HPP_EXCEPTIONS */
/* /////////////////////////////////////////////////////////////////////////
* Namespace
*/
#ifndef _WINSTL_NO_NAMESPACE
# if defined(_STLSOFT_NO_NAMESPACE) || \
defined(STLSOFT_DOCUMENTATION_SKIP_SECTION)
/* There is no stlsoft namespace, so must define ::winstl */
namespace winstl
{
# else
/* Define stlsoft::winstl_project */
namespace stlsoft
{
namespace winstl_project
{
# endif /* _STLSOFT_NO_NAMESPACE */
#endif /* !_WINSTL_NO_NAMESPACE */
/* /////////////////////////////////////////////////////////////////////////
* Classes
*/
// class semaphore
/** This class acts as an semaphore based on the Win32
* kernel semaphore object
*
* \ingroup group__library__synch
*/
class semaphore
: public stlsoft_ns_qual(critical_section)< STLSOFT_CRITICAL_SECTION_ISNOT_RECURSIVE
, STLSOFT_CRITICAL_SECTION_IS_TRYABLE
>
, public stlsoft_ns_qual(synchronisable_object_tag)
{
public:
/// This type
typedef semaphore class_type;
/// The synchronisation handle type
typedef HANDLE synch_handle_type;
/// The Boolean type
typedef ws_bool_t bool_type;
/// The count type
typedef ws_size_t count_type;
/// The resource type
typedef HANDLE resource_type;
private:
#if 0
typedef LONG underlying_count_type_;
#else /* ? 0 */
typedef count_type underlying_count_type_;
#endif /* 0 */
public:
enum
{
maxCountValue = 0x7fffffff ///!< Borrowed from PThreads-win32
};
/// \name Construction
/// @{
public:
/// Conversion constructor
semaphore(synch_handle_type sem, bool_type bTakeOwnership)
: m_sem(sem)
, m_maxCount(0)
, m_bOwnHandle(bTakeOwnership)
{
WINSTL_ASSERT(NULL != sem);
}
/// Creates an instance of the semaphore
ss_explicit_k semaphore(count_type initialCount, count_type maxCount = maxCountValue)
: m_sem(create_semaphore_(NULL, initialCount, maxCount, static_cast<ws_char_a_t const*>(NULL)))
, m_maxCount(maxCount)
, m_bOwnHandle(true)
{}
#ifndef STLSOFT_DOCUMENTATION_SKIP_SECTION
// This disambiguates cases where the initial count is 0
ss_explicit_k semaphore(int initialCount, count_type maxCount = maxCountValue)
: m_sem(create_semaphore_(NULL, static_cast<count_type>(initialCount), maxCount, static_cast<ws_char_a_t const*>(NULL)))
, m_maxCount(maxCount)
, m_bOwnHandle(true)
{}
#endif /* !STLSOFT_DOCUMENTATION_SKIP_SECTION */
/// Creates an instance of the semaphore
ss_explicit_k semaphore(ws_char_a_t const* name, count_type initialCount, count_type maxCount = maxCountValue)
: m_sem(create_semaphore_(NULL, initialCount, maxCount, name))
, m_maxCount(maxCount)
, m_bOwnHandle(true)
{}
/// Creates an instance of the semaphore
ss_explicit_k semaphore(ws_char_w_t const* name, count_type initialCount, count_type maxCount = maxCountValue)
: m_sem(create_semaphore_(NULL, initialCount, maxCount, name))
, m_maxCount(maxCount)
, m_bOwnHandle(true)
{}
/// Creates an instance of the semaphore
ss_explicit_k semaphore(ws_char_a_t const* name, LPSECURITY_ATTRIBUTES psa, count_type initialCount, count_type maxCount = maxCountValue)
: m_sem(create_semaphore_(psa, initialCount, maxCount, name))
, m_maxCount(maxCount)
, m_bOwnHandle(true)
{}
/// Creates an instance of the semaphore
ss_explicit_k semaphore(ws_char_w_t const* name, LPSECURITY_ATTRIBUTES psa, count_type initialCount, count_type maxCount = maxCountValue)
: m_sem(create_semaphore_(psa, initialCount, maxCount, name))
, m_maxCount(maxCount)
, m_bOwnHandle(true)
{}
/// Destroys an instance of the semaphore
~semaphore() stlsoft_throw_0()
{
if( NULL != m_sem &&
m_bOwnHandle)
{
::CloseHandle(m_sem);
}
}
/// @}
/// \name Operations
/// @{
public:
/// Acquires a lock on the semaphore, pending the thread until the lock is aquired
void lock()
{
WINSTL_ASSERT(NULL != m_sem);
DWORD dwRes = ::WaitForSingleObject(m_sem, INFINITE);
if(WAIT_OBJECT_0 != dwRes)
{
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
STLSOFT_THROW_X(synchronisation_exception("semaphore wait failed", ::GetLastError()));
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
}
}
/// Acquires a lock on the semaphore, pending the thread until the lock is aquired
bool_type lock(ws_dword_t wait)
{
WINSTL_ASSERT(NULL != m_sem);
DWORD dwRes = ::WaitForSingleObject(m_sem, wait);
if( WAIT_OBJECT_0 != dwRes &&
WAIT_TIMEOUT != dwRes)
{
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
STLSOFT_THROW_X(synchronisation_exception("semaphore wait failed", ::GetLastError()));
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
}
return (dwRes == WAIT_OBJECT_0);
}
/// Attempts to lock the semaphore
///
/// \return <b>true</b> if the semaphore was aquired, or <b>false</b> if not
bool_type try_lock()
{
return lock(0);
}
/// Releases an aquired lock on the semaphore, increasing the
/// semaphore's counter by one.
///
/// \note Equivalent to \link winstl::semaphore::unlock(count_type) unlock()\endlink.
void unlock()
{
WINSTL_ASSERT(NULL != m_sem);
if(!::ReleaseSemaphore(m_sem, 1, NULL))
{
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
STLSOFT_THROW_X(synchronisation_exception("semaphore release failed", ::GetLastError()));
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
}
}
/// Releases a number of aquired "locks" on the semaphore,
/// increasing the semaphore's counter by the given value.
///
/// \param numLocksToRelease The number by which to increment the
/// semaphore's counter. If this is greater than the available
/// value, the function fails. (It will throw an exception, if
/// exception handling is enabled, or return -1 otherwise.)
///
/// \return Returns the value of the semaphore's counter prior to the
/// change effected by the call.
/// \retval -1 Indicates call failure (only if exception handling is not
/// enabled).
ws_long_t unlock(count_type numLocksToRelease)
{
WINSTL_ASSERT(NULL != m_sem);
WINSTL_ASSERT(numLocksToRelease > 0);
WINSTL_ASSERT(static_cast<LONG>(numLocksToRelease) > 0);
LONG previousCount = 0;
if(!::ReleaseSemaphore(m_sem, static_cast<LONG>(numLocksToRelease), &previousCount))
{
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
STLSOFT_THROW_X(synchronisation_exception("semaphore release failed", ::GetLastError()));
#else /* ? STLSOFT_CF_EXCEPTION_SUPPORT */
return -1;
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
}
return static_cast<ws_long_t>(previousCount);
}
/// @}
/// \name Accessors
/// @{
public:
/// The underlying kernel object handle
synch_handle_type handle()
{
return m_sem;
}
/// The underlying kernel object handle
synch_handle_type get()
{
return m_sem;
}
/// @}
// Implementation
private:
static HANDLE CreateSemaphore_A_arguments_adjusted_(
LPSECURITY_ATTRIBUTES psa
, underlying_count_type_ initialCount
, underlying_count_type_ maxCount
, ws_char_a_t const* name
)
{
return STLSOFT_NS_GLOBAL(CreateSemaphoreA)(psa, static_cast<LONG>(initialCount), static_cast<LONG>(maxCount), name);
}
static HANDLE CreateSemaphore_W_arguments_adjusted_(
LPSECURITY_ATTRIBUTES psa
, underlying_count_type_ initialCount
, underlying_count_type_ maxCount
, ws_char_w_t const* name
)
{
return STLSOFT_NS_GLOBAL(CreateSemaphoreW)(psa, static_cast<LONG>(initialCount), static_cast<LONG>(maxCount), name);
}
static synch_handle_type create_semaphore_(
LPSECURITY_ATTRIBUTES psa
, underlying_count_type_ initialCount
, underlying_count_type_ maxCount
, ws_char_a_t const* name
)
{
WINSTL_MESSAGE_ASSERT("Maximum semaphore count must be > 0", maxCount > 0);
WINSTL_ASSERT(initialCount <= maxCount);
synch_handle_type sem = CreateSemaphore_A_arguments_adjusted_(psa, initialCount, maxCount, name);
if(NULL == sem)
{
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
STLSOFT_THROW_X(synchronisation_exception("Failed to create kernel semaphore object", ::GetLastError()));
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
}
return sem;
}
static synch_handle_type create_semaphore_(
LPSECURITY_ATTRIBUTES psa
, underlying_count_type_ initialCount
, underlying_count_type_ maxCount
, ws_char_w_t const* name
)
{
WINSTL_MESSAGE_ASSERT("Maximum semaphore count must be > 0", maxCount > 0);
WINSTL_ASSERT(initialCount <= maxCount);
synch_handle_type sem = CreateSemaphore_W_arguments_adjusted_(psa, initialCount, maxCount, name);
if(NULL == sem)
{
#ifdef STLSOFT_CF_EXCEPTION_SUPPORT
STLSOFT_THROW_X(synchronisation_exception("Failed to create kernel semaphore object", ::GetLastError()));
#endif /* STLSOFT_CF_EXCEPTION_SUPPORT */
}
return sem;
}
// Members
private:
synch_handle_type m_sem; // The underlying semaphore object
const count_type m_maxCount; // Record of the maximum counter value
const bool_type m_bOwnHandle; // Does the instance own the handle?
// Not to be implemented
private:
semaphore(class_type const& rhs);
semaphore& operator =(class_type const& rhs);
};
/* /////////////////////////////////////////////////////////////////////////
* Shims
*/
/** Overload of the form of the winstl::get_synch_handle() shim for
* the winstl::semaphore type.
*
* \param sem The winstl::semaphore instance
*
* \retval The synchronisation handle of \c sem
*/
inline HANDLE get_synch_handle(semaphore &sem)
{
return sem.get();
}
/** Overload of the form of the winstl::get_kernel_handle() shim for
* the winstl::semaphore type.
*
* \ingroup group__library__shims__kernel_handle_attribute
*
* \param sem The winstl::semaphore instance
*
* \retval The synchronisation handle of \c sem
*/
inline HANDLE get_kernel_handle(semaphore &sem)
{
return sem.get();
}
#ifndef _WINSTL_NO_NAMESPACE
# if defined(_STLSOFT_NO_NAMESPACE) || \
defined(STLSOFT_DOCUMENTATION_SKIP_SECTION)
} // namespace winstl
# else
} // namespace winstl_project
# endif /* _STLSOFT_NO_NAMESPACE */
#endif /* !_WINSTL_NO_NAMESPACE */
/** This \ref group__concept__shims "control shim" aquires a lock on the given semaphore
*
* \ingroup group__concept__shim__synchronisation_control
*
* \param sem The semaphore on which to aquire the lock.
*/
inline void lock_instance(winstl_ns_qual(semaphore) &sem)
{
sem.lock();
}
/** This \ref group__concept__shims "control shim" releases a lock on the given semaphore
*
* \ingroup group__concept__shim__synchronisation_control
*
* \param sem The semaphore on which to release the lock
*/
inline void unlock_instance(winstl_ns_qual(semaphore) &sem)
{
sem.unlock();
}
#ifndef _WINSTL_NO_NAMESPACE
# if defined(_STLSOFT_NO_NAMESPACE) || \
defined(STLSOFT_DOCUMENTATION_SKIP_SECTION)
namespace winstl {
# else
namespace winstl_project {
# if defined(STLSOFT_COMPILER_IS_BORLAND)
using ::stlsoft::lock_instance;
using ::stlsoft::unlock_instance;
# endif /* compiler */
# endif /* _STLSOFT_NO_NAMESPACE */
#endif /* !_WINSTL_NO_NAMESPACE */
/* /////////////////////////////////////////////////////////////////////////
* lock_traits
*/
// class lock_traits
/** Traits for the semaphore class
*
* \ingroup group__library__synch
*/
struct semaphore_lock_traits
{
public:
/// The lockable type
typedef semaphore lock_type;
/// This type
typedef semaphore_lock_traits class_type;
// Operations
public:
/// Lock the given semaphore instance
static void lock(semaphore &c)
{
lock_instance(c);
}
/// Unlock the given semaphore instance
static void unlock(semaphore &c)
{
unlock_instance(c);
}
};
////////////////////////////////////////////////////////////////////////////
// Unit-testing
#ifdef STLSOFT_UNITTEST
# include "./unittest/semaphore_unittest_.h"
#endif /* STLSOFT_UNITTEST */
/* ////////////////////////////////////////////////////////////////////// */
#ifndef _WINSTL_NO_NAMESPACE
# if defined(_STLSOFT_NO_NAMESPACE) || \
defined(STLSOFT_DOCUMENTATION_SKIP_SECTION)
} // namespace winstl
# else
} // namespace winstl_project
} // namespace stlsoft
# endif /* _STLSOFT_NO_NAMESPACE */
#endif /* !_WINSTL_NO_NAMESPACE */
/* ////////////////////////////////////////////////////////////////////// */
#endif /* !WINSTL_INCL_WINSTL_SYNCH_HPP_SEMAPHORE */
/* ///////////////////////////// end of file //////////////////////////// */