AllReduceSync Class Reference

#include <allreduce.h>

Public Member Functions
	AllReduceSync (const size_t total)
	~AllReduceSync ()
void	waitForSynchronization ()

Public Attributes
void **	buffers

Private Attributes
std::mutex *	m_mutex
std::condition_variable *	m_cv
size_t	m_total
uint32_t	m_count
bool	m_run

Detailed Description

Definition at line 98 of file allreduce.h.

Constructor & Destructor Documentation

AllReduceSync()

AllReduceSync::AllReduceSync

(

const size_t

total

)

Definition at line 12 of file allreduce_threads.cc.

References buffers, m_cv, and m_mutex.

                                               : m_total(total), m_count(0), m_run(true)
{
  m_mutex = new std::mutex;
  m_cv = new std::condition_variable;
  buffers = new void*[total];
}

~AllReduceSync()

AllReduceSync::~AllReduceSync

(

)

Definition at line 19 of file allreduce_threads.cc.

References buffers, m_cv, and m_mutex.

{
  delete m_mutex;
  delete m_cv;
  delete[] buffers;
}

Member Function Documentation

waitForSynchronization()

void AllReduceSync::waitForSynchronization

(

)

Definition at line 26 of file allreduce_threads.cc.

References m_count, m_cv, m_mutex, m_run, and m_total.

Referenced by AllReduceThreads::all_reduce().

{
  std::unique_lock<std::mutex> l(*m_mutex);
  m_count++;

  if (m_count >= m_total)
  {
    assert(m_count == m_total);

    m_cv->notify_all();

    // order of m_count before or after notify_all doesn't matter
    // since the lock is still hold at this point in time.
    m_count = 0;

    // flip for the next run
    m_run = !m_run;
  }
  else
  {
    bool current_run = m_run;
    // this predicate cannot depend on m_count, as somebody can race ahead and m_count++
    // FYI just wait can spuriously wake-up
    m_cv->wait(l, [this, current_run] { return m_run != current_run; });
  }
}

Member Data Documentation

buffers

void** AllReduceSync::buffers

Definition at line 120 of file allreduce.h.

Referenced by AllReduceThreads::all_reduce(), AllReduceSync(), and ~AllReduceSync().

m_count

uint32_t AllReduceSync::m_count

private

Definition at line 108 of file allreduce.h.

Referenced by waitForSynchronization().

m_cv

std::condition_variable* AllReduceSync::m_cv

private

Definition at line 102 of file allreduce.h.

Referenced by AllReduceSync(), waitForSynchronization(), and ~AllReduceSync().

m_mutex

std::mutex* AllReduceSync::m_mutex

private

Definition at line 101 of file allreduce.h.

Referenced by AllReduceSync(), waitForSynchronization(), and ~AllReduceSync().

m_run

bool AllReduceSync::m_run

private

Definition at line 111 of file allreduce.h.

Referenced by waitForSynchronization().

m_total

size_t AllReduceSync::m_total

private

Definition at line 105 of file allreduce.h.

Referenced by waitForSynchronization().

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The documentation for this class was generated from the following files:

• /mnt/c/w/linux/vowpal_wabbit/vowpalwabbit/allreduce.h
• /mnt/c/w/linux/vowpal_wabbit/vowpalwabbit/allreduce_threads.cc