/usr/include/ace/Barrier.h is in libace-dev 6.3.3+dfsg-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 | // -*- C++ -*-
//==========================================================================
/**
* @file Barrier.h
*
* Moved from Synch.h.
*
* @author Douglas C. Schmidt <schmidt@cs.wustl.edu>
*/
//==========================================================================
#ifndef ACE_BARRIER_H
#define ACE_BARRIER_H
#include /**/ "ace/pre.h"
#include /**/ "ace/ACE_export.h"
#if !defined (ACE_LACKS_PRAGMA_ONCE)
# pragma once
#endif /* ACE_LACKS_PRAGMA_ONCE */
#include /**/ "ace/config-all.h"
// ACE platform supports some form of threading.
#if !defined (ACE_HAS_THREADS)
#include "ace/OS_NS_errno.h"
ACE_BEGIN_VERSIONED_NAMESPACE_DECL
/**
* @class ACE_Barrier
*
* @brief This is a no-op to make ACE "syntactically consistent."
*/
class ACE_Export ACE_Barrier
{
public:
ACE_Barrier (unsigned int, const ACE_TCHAR * = 0, void * = 0) {}
~ACE_Barrier (void) {}
int wait (void) { ACE_NOTSUP_RETURN (-1); }
void dump (void) const {}
};
ACE_END_VERSIONED_NAMESPACE_DECL
#else /* ACE_HAS_THREADS */
#include "ace/Condition_Thread_Mutex.h"
ACE_BEGIN_VERSIONED_NAMESPACE_DECL
struct ACE_Export ACE_Sub_Barrier
{
// = Initialization.
ACE_Sub_Barrier (unsigned int count,
ACE_Thread_Mutex &lock,
const ACE_TCHAR *name = 0,
void *arg = 0);
~ACE_Sub_Barrier (void);
/// True if this generation of the barrier is done.
ACE_Condition_Thread_Mutex barrier_finished_;
/// Number of threads that are still running.
int running_threads_;
/// Dump the state of an object.
void dump (void) const;
/// Declare the dynamic allocation hooks.
ACE_ALLOC_HOOK_DECLARE;
};
/**
* @class ACE_Barrier
*
* @brief Implements "barrier synchronization".
*
* This class allows <count> number of threads to synchronize
* their completion of (one round of) a task, which is known as
* "barrier synchronization". After all the threads call <wait()>
* on the barrier they are all atomically released and can begin a new
* round.
*
* This implementation uses a "sub-barrier generation numbering"
* scheme to avoid overhead and to ensure that all threads wait to
* leave the barrier correct. This code is based on an article from
* SunOpsis Vol. 4, No. 1 by Richard Marejka
* (Richard.Marejka@canada.sun.com).
*/
class ACE_Export ACE_Barrier
{
public:
/// Initialize the barrier to synchronize @a count threads.
ACE_Barrier (unsigned int count,
const ACE_TCHAR *name = 0,
void *arg = 0);
/// Default destructor.
~ACE_Barrier (void);
/// Block the caller until all @c count threads have called @c wait and
/// then allow all the caller threads to continue in parallel.
///
/// @retval 0 after successfully waiting for all threads to wait.
/// @retval -1 if an error occurs or the barrier is shut
/// down (@sa shutdown ()).
int wait (void);
/// Shut the barrier down, aborting the wait of all waiting threads.
/// Any threads waiting on the barrier when it is shut down will return with
/// value -1, errno ESHUTDOWN.
///
/// @retval 0 for success, -1 if already shut down.
///
/// @since ACE beta 5.4.9.
int shutdown (void);
/// Dump the state of an object.
void dump (void) const;
/// Declare the dynamic allocation hooks.
ACE_ALLOC_HOOK_DECLARE;
protected:
/// Serialize access to the barrier state.
ACE_Thread_Mutex lock_;
/// Either 0 or 1, depending on whether we are the first generation
/// of waiters or the next generation of waiters.
int current_generation_;
/// Total number of threads that can be waiting at any one time.
int count_;
/**
* We keep two @c sub_barriers, one for the first "generation" of
* waiters, and one for the next "generation" of waiters. This
* efficiently solves the problem of what to do if all the first
* generation waiters don't leave the barrier before one of the
* threads calls wait() again (i.e., starts up the next generation
* barrier).
*/
ACE_Sub_Barrier sub_barrier_1_;
ACE_Sub_Barrier sub_barrier_2_;
ACE_Sub_Barrier *sub_barrier_[2];
private:
// = Prevent assignment and initialization.
void operator= (const ACE_Barrier &);
ACE_Barrier (const ACE_Barrier &);
};
/**
* @class ACE_Thread_Barrier
*
* @brief Implements "barrier synchronization" using ACE_Thread_Mutexes!
*
* This class is just a simple wrapper for ACE_Barrier that
* selects the USYNC_THREAD variant for the locks.
*/
class ACE_Export ACE_Thread_Barrier : public ACE_Barrier
{
public:
/// Create a Thread_Barrier, passing in the optional @a name.
ACE_Thread_Barrier (unsigned int count, const ACE_TCHAR *name = 0);
/// Default destructor.
~ACE_Thread_Barrier (void);
/// Dump the state of an object.
void dump (void) const;
/// Declare the dynamic allocation hooks.
ACE_ALLOC_HOOK_DECLARE;
};
ACE_END_VERSIONED_NAMESPACE_DECL
#if defined (__ACE_INLINE__)
#include "ace/Barrier.inl"
#endif /* __ACE_INLINE__ */
#endif /* !ACE_HAS_THREADS */
#include /**/ "ace/post.h"
#endif /* ACE_BARRIER_H */
|