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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 //////////////////////////// */
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