issm_threads.h File Reference

prototypes for issm_threads.h More...

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Data Structures
struct	pthread_handle

Functions
void	LaunchThread (void *function(void *), void *gate, int num_threads)
void	PartitionRange (int *pi0, int *pi1, int num_el, int num_threads, int my_thread)

Detailed Description

prototypes for issm_threads.h

Definition in file issm_threads.h.

Function Documentation

LaunchThread()

void LaunchThread	(	void *	functionvoid *,
		void *	gate,
		int	num_threads
	)

Definition at line 25 of file LaunchThread.cpp.

                                                                    {
 
   #ifdef _MULTITHREADING_
   int i;
   int            *status  = NULL;
   pthread_t      *threads = NULL;
   pthread_handle *handles = NULL;
 
   /*check number of threads*/
   if(num_threads<1)    _error_("number of threads must be at least 1");
   if(num_threads>2000) _error_("number of threads seems to be too high ("<<num_threads<<">2000)");
 
   /*dynamically allocate: */
   threads=xNew<pthread_t>(num_threads);
   handles=xNew<pthread_handle>(num_threads);
 
   for(i=0;i<num_threads;i++){
      handles[i].gate=gate;
      handles[i].id=i;
      handles[i].num=num_threads;
   }
   for(i=0;i<num_threads;i++){
 
      if(pthread_create(threads+i,NULL,function,(void*)(handles+i))){
         _error_("pthread_create error");
      }
   }
   for(i=0;i<num_threads;i++){
      if(pthread_join(threads[i],(void**)&status)){
         _error_("pthread_join error");
      }
   }
 
   /*Free ressources:*/
   xDelete<pthread_t>(threads);
   xDelete<pthread_handle>(handles);
 
   #else
   pthread_handle handle;
   handle.gate=gate;
   handle.id=0;
   handle.num=1;
 
   function((void*)&handle);
   #endif
}

PartitionRange()

void PartitionRange	(	int *	pi0,
		int *	pi1,
		int	num_el,
		int	num_threads,
		int	my_thread
	)

Definition at line 13 of file PartitionRange.cpp.

                                                                                {
 
   /*output: */
   int i0=-1;
   int i1=-1;
 
   int step;
   int i;
 
   /*distribute elements across threads :*/
   step=(int)floor((double)num_el/(double)num_threads);
   for(i=0;i<(my_thread+1);i++){
      i0=i*step;
      if(i==(num_threads-1))i1=num_el;
      else i1=i0+step;
   }
 
   /*Assign output pointers:*/
   *pi0=i0;
   *pi1=i1;
}