\(\newcommand{\W}[1]{ \; #1 \; }\) \(\newcommand{\R}[1]{ {\rm #1} }\) \(\newcommand{\B}[1]{ {\bf #1} }\) \(\newcommand{\D}[2]{ \frac{\partial #1}{\partial #2} }\) \(\newcommand{\DD}[3]{ \frac{\partial^2 #1}{\partial #2 \partial #3} }\) \(\newcommand{\Dpow}[2]{ \frac{\partial^{#1}}{\partial {#2}^{#1}} }\) \(\newcommand{\dpow}[2]{ \frac{ {\rm d}^{#1}}{{\rm d}\, {#2}^{#1}} }\)

multi_atomic_two_takedown

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Multi-Threaded atomic_two Take Down

Syntax

ok = multi_atomic_two_takedown ( square_root )

Purpose

This routine gathers up the results for each thread and frees memory that was allocated by multi_atomic_two_setup .

Thread

It is assumed that this function is called by thread zero and all the other threads are blocked (waiting).

square_root

This argument has prototype

vector<double>& square_root

The input value of square_root does not matter. Upon return, it has the same size and is the element by element square root of y_squared .

ok

This return value has prototype

bool ok

If it is false, multi_atomic_two_takedown detected an error.

Source

namespace {
bool multi_atomic_two_takedown(vector<double>& square_root)
{  bool ok            = true;
   ok                &= thread_alloc::thread_num() == 0;
   size_t num_threads = std::max(num_threads_, size_t(1));
   //
   // extract square roots in original order
   square_root.resize(0);
   for(size_t thread_num = 0; thread_num < num_threads; thread_num++)
   {  // results for this thread
      size_t n = work_all_[thread_num]->square_root->size();
      for(size_t i = 0; i < n; i++)
         square_root.push_back((* work_all_[thread_num]->square_root )[i]);
   }
   //
   // go down so that free memory for other threads before memory for master
   size_t thread_num = num_threads;
   while(thread_num--)
   {  // check that this tread was ok with the work it did
      ok  &= work_all_[thread_num]->ok;
      //
      // run destructor on vector object for this thread
      delete work_all_[thread_num]->y_squared;
      delete work_all_[thread_num]->square_root;
      //
      // run destructor on function object for this thread
      delete work_all_[thread_num]->fun;
      //
      // delete problem specific information
      void* v_ptr = static_cast<void*>( work_all_[thread_num] );
      thread_alloc::return_memory( v_ptr );
      //
      // check that there is no longer any memory inuse by this thread
      if( thread_num > 0 )
      {  ok &= 0 == thread_alloc::inuse(thread_num);
         //
         // return all memory being held for future use by this thread
         thread_alloc::free_available(thread_num);
      }
   }
   return ok;
}
}