phasta/phastaIO/phastaIO.cc

/*
 *
 * This is the SyncIO library that uses MPI-IO collective functions to
 * implement a flexible I/O checkpoint solution for a large number of
 * processors.
 *
 * Previous developer: Ning Liu         (liun2@cs.rpi.edu)
 *                     Jing Fu          (fuj@cs.rpi.edu)
 * Current developers: Michel Rasquin   (Michel.Rasquin@colorado.edu),
 *                     Ben Matthews     (benjamin.a.matthews@colorado.edu)
 *
 */

#include <map>
#include <vector>
#include <string>
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <sstream>
#include "phastaIO.h"
#include "mpi.h"
#include "phiotmrc.h"

#define VERSION_INFO_HEADER_SIZE 8192
#define DB_HEADER_SIZE 1024
#define ONE_MEGABYTE 1048576
#define TWO_MEGABYTE 2097152
#define ENDIAN_TEST_NUMBER 12180 // Troy's Zip Code!!
#define MAX_PHASTA_FILES 64
#define MAX_PHASTA_FILE_NAME_LENGTH 1024
#define MAX_FIELDS_NUMBER ((VERSION_INFO_HEADER_SIZE/MAX_FIELDS_NAME_LENGTH)-4) // The meta data include - MPI_IO_Tag, nFields, nFields*names of the fields, nppf
// -3 for MPI_IO_Tag, nFields and nppf, -4 for extra security (former nFiles)
#define MAX_FIELDS_NAME_LENGTH 128
#define DefaultMHSize (4*ONE_MEGABYTE)
//#define DefaultMHSize (8350) //For test
#define LATEST_WRITE_VERSION 1
#define inv1024sq 953.674316406e-9 // = 1/1024/1024
int MasterHeaderSize = -1;

bool PRINT_PERF = false; // default print no perf results
int irank = -1; // global rank, should never be manually manipulated
int mysize = -1;

// Static variables are bad but used here to store the subcommunicator and associated variables
// Prevent MPI_Comm_split to be called more than once, especially on BGQ with the V1R2M1 driver (leak detected in MPI_Comm_split - IBM working on it)
static int s_assign_local_comm = 0;
static MPI_Comm s_local_comm;
static int s_local_size = -1;
static int s_local_rank = -1;

//unsigned long long pool_align = 8;
//unsigned long long mem_address;

// the following defines are for debug printf
#define PHASTAIO_PREFIX "phastaIO debug: "
#define PHASTAIO_DEBUG 0 //default to not print any debugging info

#if PHASTAIO_DEBUG
#define phprintf( s, arg...) printf(PHASTAIO_PREFIX s "\n", ##arg)
#define phprintf_0( s, arg...) do{ \
	MPI_Comm_rank(MPI_COMM_WORLD, &irank); \
	if(irank == 0){ \
		printf(PHASTAIO_PREFIX "irank=0: " s "\n", ##arg); \
	} \
} while(0)
#else
#define phprintf( s, arg...)
#define phprintf_0( s, arg...)
#endif

enum PhastaIO_Errors
{
	MAX_PHASTA_FILES_EXCEEDED = -1,
	UNABLE_TO_OPEN_FILE = -2,
	NOT_A_MPI_FILE = -3,
	GPID_EXCEEDED = -4,
	DATA_TYPE_ILLEGAL = -5,
};

using namespace std;

namespace{

        typedef map<int, char*> mic;
	mic LastHeaderKey;
	vector< FILE* > fileArray;
	vector< bool > byte_order;
	vector< int > header_type;
	int DataSize=0;
	bool LastHeaderNotFound = false;
	bool Wrong_Endian = false ;
	bool Strict_Error = false ;
	bool binary_format = true;

	/***********************************************************************/
	/***************** NEW PHASTA IO CODE STARTS HERE **********************/
	/***********************************************************************/

	typedef struct
	{
		char filename[MAX_PHASTA_FILE_NAME_LENGTH];   /* defafults to 1024 */
		unsigned long long my_offset;
		unsigned long long next_start_address;
		unsigned long long **my_offset_table;
		unsigned long long **my_read_table;

		double * double_chunk;
		double * read_double_chunk;

		int field_count;
		int part_count;
		int read_field_count;
		int read_part_count;
		int GPid;
		int start_id;

		int mhsize;

		int myrank;
		int numprocs;
		int local_myrank;
		int local_numprocs;

		int nppp;
		int nPPF;
		int nFiles;
		int nFields;

		int * int_chunk;
		int * read_int_chunk;

		int Wrong_Endian;                            /* default to false */
		char * master_header;
		MPI_File file_handle;
		MPI_Comm local_comm;
	} phastaio_file_t;

	typedef struct
	{
		//unsigned long long my_offset;
		//unsigned long long **offset_table;
		//int fileID;
		int nppf, nfields;
		//int GPid;
		//int read_field_count;
		char * masterHeader;
	}serial_file;

	serial_file *SerialFile;
	phastaio_file_t *PhastaIOActiveFiles[MAX_PHASTA_FILES];
	int PhastaIONextActiveIndex = 0; /* indicates next index to allocate */

	// the caller has the responsibility to delete the returned string
	// TODO: StringStipper("nbc value? ") returns NULL?
	char*
		StringStripper( const char  istring[] ) {

			int length = strlen( istring );

			//char* dest = new char [ length + 1 ];
			char* dest = (char *)malloc( length + 1 );

			//char * dest;
			//dest = (char *)malloc( length + 1 + pool_align );
			//if (dest & 0x0F != 0) printf("not aligned!!!!\n");
			//mem_address = (long long )dest;
			//if( mem_address & (pool_align -1) )
			//  dest += pool_align - (mem_address & (pool_align -1));

			strcpy( dest, istring );
			dest[ length ] = '\0';

			if ( char* p = strpbrk( dest, " ") )
				*p = '\0';

			return dest;
		}

	inline int
		cscompare( const char teststring[],
				const char targetstring[] ) {

			char* s1 = const_cast<char*>(teststring);
			char* s2 = const_cast<char*>(targetstring);

			while( *s1 == ' ') s1++;
			while( *s2 == ' ') s2++;
			while( ( *s1 )
					&& ( *s2 )
					&& ( *s2 != '?')
					&& ( tolower( *s1 )==tolower( *s2 ) ) ) {
				s1++;
				s2++;
				while( *s1 == ' ') s1++;
				while( *s2 == ' ') s2++;
			}
			if ( !( *s1 ) || ( *s1 == '?') ) return 1;
			else return 0;
		}

	inline void
		isBinary( const char iotype[] ) {

			char* fname = StringStripper( iotype );
			if ( cscompare( fname, "binary" ) ) binary_format = true;
			else binary_format = false;
			free (fname);

		}

	inline size_t
		typeSize( const char typestring[] ) {

			char* ts1 = StringStripper( typestring );

			if ( cscompare( "integer", ts1 ) ) {
				free (ts1);
				return sizeof(int);
			} else if ( cscompare( "double", ts1 ) ) {
				free (ts1);
				return sizeof( double );
			} else {
				free (ts1);
				fprintf(stderr,"unknown type : %s\n",ts1);
				return 0;
			}
		}

	int
		readHeader( FILE*       fileObject,
				const char  phrase[],
				int*        params,
				int         expect ) {

			char* text_header;
			char* token;
			char Line[1024];
			char junk;
			bool FOUND = false ;
			int real_length;
			int skip_size, integer_value;
			int rewind_count=0;

			if( !fgets( Line, 1024, fileObject ) && feof( fileObject ) ) {
				rewind( fileObject );
				clearerr( fileObject );
				rewind_count++;
				fgets( Line, 1024, fileObject );
			}

			while( !FOUND  && ( rewind_count < 2 ) )  {
				if ( ( Line[0] != '\n' ) && ( real_length = strcspn( Line, "#" )) ){
					//text_header = new char [ real_length + 1 ];
					text_header = (char *)malloc( real_length + 1 );
					//text_header = (char *)malloc( real_length + 1 + pool_align );
					//mem_address = (long long )text_header;
					//if( mem_address & (pool_align -1) )
					//  text_header += pool_align - (mem_address & (pool_align -1));

					strncpy( text_header, Line, real_length );
					text_header[ real_length ] =static_cast<char>(NULL);
					token = strtok ( text_header, ":" );
					//if( cscompare( phrase , token ) ) {
                                        // Double comparison required because different fields can still start
                                        // with the same name for mixed meshes (nbc code, nbc values, etc).
                                        // Would be easy to fix cscompare instead but would it break sth else?
					if( cscompare( phrase , token ) && cscompare( token , phrase ) ) {
						FOUND = true ;
						token = strtok( NULL, " ,;<>" );
						skip_size = atoi( token );
						int i;
						for( i=0; i < expect && ( token = strtok( NULL," ,;<>") ); i++) {
							params[i] = atoi( token );
						}
						if ( i < expect ) {
							fprintf(stderr,"Aloha Expected # of ints not found for: %s\n",phrase );
						}
					} else if ( cscompare(token,"byteorder magic number") ) {
						if ( binary_format ) {
							fread((void*)&integer_value,sizeof(int),1,fileObject);
							fread( &junk, sizeof(char), 1 , fileObject );
							if ( 362436 != integer_value ) Wrong_Endian = true;
						} else{
							fscanf(fileObject, "%d\n", &integer_value );
						}
					} else {
						/* some other header, so just skip over */
						token = strtok( NULL, " ,;<>" );
						skip_size = atoi( token );
						if ( binary_format)
							fseek( fileObject, skip_size, SEEK_CUR );
						else
							for( int gama=0; gama < skip_size; gama++ )
								fgets( Line, 1024, fileObject );
					}
					free (text_header);
				} // end of if before while loop

				if ( !FOUND )
					if( !fgets( Line, 1024, fileObject ) && feof( fileObject ) ) {
						rewind( fileObject );
						clearerr( fileObject );
						rewind_count++;
						fgets( Line, 1024, fileObject );
					}
			}

			if ( !FOUND ) {
				//fprintf(stderr, "Error: Could not find: %s\n", phrase);
				if(irank == 0) printf("WARNING: Could not find: %s\n", phrase);
				return 1;
			}
			return 0;
		}

} // end unnamed namespace


// begin of publicly visible functions

/**
 * This function takes a long long pointer and assign (start) phiotmrc value to it
 */
//void startTimer(unsigned long long* start) {
void startTimer(double* start) {

        if( !PRINT_PERF ) return;

	MPI_Barrier(MPI_COMM_WORLD);
	*start =  phiotmrc();
}

/**
 * This function takes a long long pointer and assign (end) phiotmrc value to it
 */
void endTimer(double* end) {

        if( !PRINT_PERF ) return;

	*end = phiotmrc();
	MPI_Barrier(MPI_COMM_WORLD);
}

/**
 * choose to print some performance results (or not) according to
 * the PRINT_PERF macro
 */
void printPerf(
		const char* func_name,
		double start,
		double end,
		unsigned long long datasize,
		int printdatainfo,
		const char* extra_msg) {

	if( !PRINT_PERF ) return;

	unsigned long long data_size = datasize;

	double time = end - start;

	unsigned long long isizemin,isizemax,isizetot;
	double sizemin,sizemax,sizeavg,sizetot,rate;
	double tmin, tmax, tavg, ttot;

	MPI_Allreduce(&time, &tmin,1, MPI_DOUBLE, MPI_MIN, MPI_COMM_WORLD);
	MPI_Allreduce(&time, &tmax,1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);
	MPI_Allreduce(&time, &ttot,1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
	tavg = ttot/mysize;

	if(irank == 0) {
		if ( PhastaIONextActiveIndex == 0 ) printf("** 1PFPP ");
		else  printf("** syncIO ");
		printf("%s(): Tmax = %f sec, Tmin = %f sec, Tavg = %f sec", func_name, tmax, tmin, tavg);
	}

	if(printdatainfo == 1) { // if printdatainfo ==1, compute I/O rate and block size
		MPI_Allreduce(&data_size,&isizemin,1,MPI_LONG_LONG_INT,MPI_MIN,MPI_COMM_WORLD);
		MPI_Allreduce(&data_size,&isizemax,1,MPI_LONG_LONG_INT,MPI_MAX,MPI_COMM_WORLD);
		MPI_Allreduce(&data_size,&isizetot,1,MPI_LONG_LONG_INT,MPI_SUM,MPI_COMM_WORLD);

		sizemin=(double)(isizemin*inv1024sq);
		sizemax=(double)(isizemax*inv1024sq);
		sizetot=(double)(isizetot*inv1024sq);
		sizeavg=(double)(1.0*sizetot/mysize);
		rate=(double)(1.0*sizetot/tmax);

		if( irank == 0) {
			printf(", Rate = %f MB/s [%s] \n \t\t\t block size: Min= %f MB; Max= %f MB; Avg= %f MB; Tot= %f MB\n", rate, extra_msg, sizemin,sizemax,sizeavg,sizetot);
		}
	}
	else {
		if(irank == 0) {
			printf(" \n");
			//printf(" (%s) \n", extra_msg);
		}
	}
}

/**
 * This function is normally called at the beginning of a read operation, before
 * init function.
 * This function (uses rank 0) reads out nfields, nppf, master header size,
 * endianess and allocates for masterHeader string.
 * These values are essential for following read operations. Rank 0 will bcast
 * these values to other ranks in the commm world
 *
 * If the file set is of old POSIX format, it would throw error and exit
 */
void queryphmpiio(const char filename[],int *nfields, int *nppf)
{
	MPI_Comm_rank(MPI_COMM_WORLD, &irank);
	MPI_Comm_size(MPI_COMM_WORLD, &mysize);

	if(irank == 0) {
		FILE * fileHandle;
		char* fname = StringStripper( filename );

		fileHandle = fopen (fname,"rb");
		if (fileHandle == NULL ) {
			printf("\nError: File %s doesn't exist! Please check!\n",fname);
		}
		else {
			SerialFile =(serial_file *)calloc( 1,  sizeof( serial_file) );
			//SerialFile = (serial_file *)malloc( sizeof( serial_file ) + pool_align );
			//mem_address = (long long )SerialFile;
			//if( mem_address & (pool_align -1) )
			//	SerialFile += pool_align - (mem_address & (pool_align -1));

			//SerialFile->masterHeader = (char *)malloc(MasterHeaderSize);
			//int meta_size_limit = 4*ONE_MEGABYTE;
			//int meta_size_limit = (4+ MAX_FIELDS_NUMBER ) * MAX_FIELDS_NAME_LENGTH;
			int meta_size_limit = VERSION_INFO_HEADER_SIZE;
			SerialFile->masterHeader = (char *)malloc( meta_size_limit );
			//SerialFile->masterHeader = (char *)malloc( meta_size_limit + pool_align );
			//mem_address = (long long )SerialFile;
			//if( mem_address & (pool_align -1) )
			//	SerialFile->masterHeader += pool_align - (mem_address & (pool_align -1));

			fread(SerialFile->masterHeader, 1, meta_size_limit, fileHandle);

			char read_out_tag[MAX_FIELDS_NAME_LENGTH];
			char version[MAX_FIELDS_NAME_LENGTH/4];
			int mhsize;
			char * token;
			int magic_number;

			memcpy( read_out_tag,
					SerialFile->masterHeader,
					MAX_FIELDS_NAME_LENGTH-1 );

			if ( cscompare ("MPI_IO_Tag",read_out_tag) ) {
				// Test endianess ...
				memcpy (&magic_number,
						SerialFile->masterHeader + sizeof("MPI_IO_Tag : ")-1, //-1 sizeof returns the size of the string+1 for "\0"
						sizeof(int) );                                        // masterheader should look like "MPI_IO_Tag : 12180 " with 12180 in binary format

				if ( magic_number != ENDIAN_TEST_NUMBER ) {
					printf("Endian is different!\n");
					// Will do swap later
				}

				// test version, old version, default masterheader size is 4M
				// newer version masterheader size is read from first line
				memcpy(version,
						SerialFile->masterHeader + MAX_FIELDS_NAME_LENGTH/2,
						MAX_FIELDS_NAME_LENGTH/4 - 1); //TODO: why -1?

				if( cscompare ("version",version) ) {
					// if there is "version" tag in the file, then it is newer format
					// read master header size from here, otherwise use default
					// Note: if version is "1", we know mhsize is at 3/4 place...

					token = strtok(version, ":");
					token = strtok(NULL, " ,;<>" );
					int iversion = atoi(token);

					if( iversion == 1) {
						memcpy( &mhsize,
								SerialFile->masterHeader + MAX_FIELDS_NAME_LENGTH/4*3 + sizeof("mhsize : ")-1,
								sizeof(int));
						if ( magic_number != ENDIAN_TEST_NUMBER )
							SwapArrayByteOrder(&mhsize, sizeof(int), 1);

						if( mhsize > DefaultMHSize ) {
							//if actual headersize is larger than default, let's re-read
							free(SerialFile->masterHeader);
							SerialFile->masterHeader = (char *)malloc(mhsize);
							fseek(fileHandle, 0, SEEK_SET); // reset the file stream position
							fread(SerialFile->masterHeader,1,mhsize,fileHandle);
						}
					}
					//TODO: check if this is a valid int??
					MasterHeaderSize = mhsize;
				}
				else { // else it's version 0's format w/o version tag, implicating MHSize=4M
					MasterHeaderSize = DefaultMHSize;
				}

				memcpy( read_out_tag,
						SerialFile->masterHeader+MAX_FIELDS_NAME_LENGTH+1,
						MAX_FIELDS_NAME_LENGTH ); //TODO: why +1

				// Read in # fields ...
				token = strtok( read_out_tag, ":" );
				token = strtok( NULL," ,;<>" );
				*nfields = atoi( token );
				if ( *nfields > MAX_FIELDS_NUMBER) {
					printf("Error queryphmpiio: nfields is larger than MAX_FIELDS_NUMBER!\n");
				}
				SerialFile->nfields=*nfields; //TODO: sanity check of this int?

				memcpy( read_out_tag,
						SerialFile->masterHeader + MAX_FIELDS_NAME_LENGTH * 2
						+ *nfields * MAX_FIELDS_NAME_LENGTH,
						MAX_FIELDS_NAME_LENGTH);

				token = strtok( read_out_tag, ":" );
				token = strtok( NULL," ,;<>" );
				*nppf = atoi( token );
				SerialFile->nppf=*nppf; //TODO: sanity check of int
			} // end of if("MPI_IO_TAG")
			else {
				printf("Error queryphmpiio: The file you opened is not of syncIO new format, please check! read_out_tag = %s\n",read_out_tag);
                                exit(1);
			}
			fclose(fileHandle);
                        free(SerialFile->masterHeader);
                        free(SerialFile);
		} //end of else
                free(fname);
	}

	// Bcast value to every one
	MPI_Bcast( nfields, 1, MPI_INT, 0, MPI_COMM_WORLD );
	MPI_Bcast( nppf, 1, MPI_INT, 0, MPI_COMM_WORLD );
	MPI_Bcast( &MasterHeaderSize, 1, MPI_INT, 0, MPI_COMM_WORLD );
	phprintf("Info queryphmpiio: myrank = %d, MasterHeaderSize = %d", irank, MasterHeaderSize);
}

/**
 * This function computes the right master header size (round to size of 2^n).
 * This is only needed for file format version 1 in "write" mode.
 */
int computeMHSize(int nfields, int nppf, int version) {
	int mhsize;
	if(version == 1) {
		//int meta_info_size = (2+nfields+1) * MAX_FIELDS_NAME_LENGTH; // 2 is MPI_IO_TAG and nFields, the others 1 is nppf
		int meta_info_size = VERSION_INFO_HEADER_SIZE;
		int actual_size =  nfields * nppf * sizeof(long long) + meta_info_size;
		//printf("actual_size = %d, offset table size = %d\n", actual_size,  nfields * nppf * sizeof(long long));
		if (actual_size > DefaultMHSize) {
			mhsize = (int) ceil( (double) actual_size/DefaultMHSize); // it's rounded to ceiling of this value
			mhsize *= DefaultMHSize;
		}
		else {
			mhsize = DefaultMHSize;
		}
	}
	return mhsize;
}

/**
 * Computes correct color of a rank according to number of files.
 */
extern "C" int computeColor( int myrank, int numprocs, int nfiles) {
	int color =
		(int)(myrank / (numprocs / nfiles));
	return color;
}


/**
 * Check the file descriptor.
 */
void checkFileDescriptor(const char fctname[],
                         int*  fileDescriptor ) {
	if ( *fileDescriptor < 0 ) {
		printf("Error: File descriptor = %d in %s\n",*fileDescriptor,fctname);
		exit(1);
	}
}

/**
 * Initialize the file struct members and allocate space for file struct
 * buffers.
 *
 * Note: this function is only called when we are using new format. Old POSIX
 * format should skip this routine and call openfile() directly instead.
 */
int initphmpiio( int *nfields, int *nppf, int *nfiles, int *filehandle, const char mode[])
{
	// we init irank again in case query not called (e.g. syncIO write case)
	MPI_Comm_rank(MPI_COMM_WORLD, &irank);
	MPI_Comm_size(MPI_COMM_WORLD, &mysize);

	phprintf("Info initphmpiio: entering function, myrank = %d, MasterHeaderSize = %d", irank, MasterHeaderSize);

	double timer_start, timer_end;
	startTimer(&timer_start);

	char* imode = StringStripper( mode );

	// Note: if it's read, we presume query was called prior to init and
	// MasterHeaderSize is already set to correct value from parsing header
	// otherwise it's write then it needs some computation to be set
	if ( cscompare( "read", imode ) ) {
		// do nothing
	}
	else if( cscompare( "write", imode ) ) {
		MasterHeaderSize =  computeMHSize(*nfields, *nppf, LATEST_WRITE_VERSION);
	}
	else {
		printf("Error initphmpiio: can't recognize the mode %s", imode);
                exit(1);
	}
        free ( imode );

	phprintf("Info initphmpiio: myrank = %d, MasterHeaderSize = %d", irank, MasterHeaderSize);

	int i, j;

	if( PhastaIONextActiveIndex == MAX_PHASTA_FILES ) {
		printf("Error initphmpiio: PhastaIONextActiveIndex = MAX_PHASTA_FILES");
                endTimer(&timer_end);
	        printPerf("initphmpiio", timer_start, timer_end, 0, 0, "");
		return MAX_PHASTA_FILES_EXCEEDED;
	}
	//		else if( PhastaIONextActiveIndex == 0 )  //Hang in debug mode on Intrepid
	//		{
	//			for( i = 0; i < MAX_PHASTA_FILES; i++ );
	//			{
	//				PhastaIOActiveFiles[i] = NULL;
	//			}
	//		}


	PhastaIOActiveFiles[PhastaIONextActiveIndex] = (phastaio_file_t *)calloc( 1,  sizeof( phastaio_file_t) );
	//PhastaIOActiveFiles[PhastaIONextActiveIndex] = ( phastaio_file_t *)calloc( 1 + 1, sizeof( phastaio_file_t ) );
	//mem_address = (long long )PhastaIOActiveFiles[PhastaIONextActiveIndex];
	//if( mem_address & (pool_align -1) )
	//	PhastaIOActiveFiles[PhastaIONextActiveIndex] += pool_align - (mem_address & (pool_align -1));

	i = PhastaIONextActiveIndex;
	PhastaIONextActiveIndex++;

	//PhastaIOActiveFiles[i]->next_start_address = 2*TWO_MEGABYTE;

	PhastaIOActiveFiles[i]->next_start_address = MasterHeaderSize;  // what does this mean??? TODO

	PhastaIOActiveFiles[i]->Wrong_Endian = false;

	PhastaIOActiveFiles[i]->nFields = *nfields;
	PhastaIOActiveFiles[i]->nPPF = *nppf;
	PhastaIOActiveFiles[i]->nFiles = *nfiles;
	MPI_Comm_rank(MPI_COMM_WORLD, &(PhastaIOActiveFiles[i]->myrank));
	MPI_Comm_size(MPI_COMM_WORLD, &(PhastaIOActiveFiles[i]->numprocs));


	if( *nfiles > 1 ) { // split the ranks according to each mpiio file

		if ( s_assign_local_comm == 0) { // call mpi_comm_split for the first (and only) time

			if (PhastaIOActiveFiles[i]->myrank == 0) printf("Building subcommunicator\n");

			int color = computeColor(PhastaIOActiveFiles[i]->myrank, PhastaIOActiveFiles[i]->numprocs, PhastaIOActiveFiles[i]->nFiles);
			MPI_Comm_split(MPI_COMM_WORLD,
					color,
					PhastaIOActiveFiles[i]->myrank,
					&(PhastaIOActiveFiles[i]->local_comm));
			MPI_Comm_size(PhastaIOActiveFiles[i]->local_comm,
					&(PhastaIOActiveFiles[i]->local_numprocs));
			MPI_Comm_rank(PhastaIOActiveFiles[i]->local_comm,
					&(PhastaIOActiveFiles[i]->local_myrank));

			// back up now these variables so that we do not need to call comm_split again
			s_local_comm = PhastaIOActiveFiles[i]->local_comm;
			s_local_size = PhastaIOActiveFiles[i]->local_numprocs;
			s_local_rank = PhastaIOActiveFiles[i]->local_myrank;
			s_assign_local_comm = 1;
		}
		else { // recycle the subcommunicator
			if (PhastaIOActiveFiles[i]->myrank == 0) printf("Recycling subcommunicator\n");
			PhastaIOActiveFiles[i]->local_comm = s_local_comm;
			PhastaIOActiveFiles[i]->local_numprocs = s_local_size;
			PhastaIOActiveFiles[i]->local_myrank = s_local_rank;
		}
	}
	else { // *nfiles == 1 here - no need to call mpi_comm_split here

		if (PhastaIOActiveFiles[i]->myrank == 0) printf("Bypassing subcommunicator\n");
		PhastaIOActiveFiles[i]->local_comm = MPI_COMM_WORLD;
		PhastaIOActiveFiles[i]->local_numprocs = PhastaIOActiveFiles[i]->numprocs;
		PhastaIOActiveFiles[i]->local_myrank = PhastaIOActiveFiles[i]->myrank;

	}

	PhastaIOActiveFiles[i]->nppp =
		PhastaIOActiveFiles[i]->nPPF/PhastaIOActiveFiles[i]->local_numprocs;

	PhastaIOActiveFiles[i]->start_id = PhastaIOActiveFiles[i]->nPPF *
		(int)(PhastaIOActiveFiles[i]->myrank/PhastaIOActiveFiles[i]->local_numprocs) +
		(PhastaIOActiveFiles[i]->local_myrank * PhastaIOActiveFiles[i]->nppp);

	PhastaIOActiveFiles[i]->my_offset_table =
		( unsigned long long ** ) calloc( MAX_FIELDS_NUMBER , sizeof( unsigned long long *) );
	//( unsigned long long **)calloc( MAX_FIELDS_NUMBER + pool_align, sizeof(unsigned long long *) );
	//mem_address = (long long )PhastaIOActiveFiles[i]->my_offset_table;
	//if( mem_address & (pool_align -1) )
	//	PhastaIOActiveFiles[i]->my_offset_table += pool_align - (mem_address & (pool_align -1));

	PhastaIOActiveFiles[i]->my_read_table =
		( unsigned long long ** ) calloc( MAX_FIELDS_NUMBER , sizeof( unsigned long long *) );
	//( unsigned long long **)calloc( MAX_FIELDS_NUMBER + pool_align, sizeof( unsigned long long *) );
	//mem_address = (long long )PhastaIOActiveFiles[i]->my_read_table;
	//if( mem_address & (pool_align -1) )
	//	PhastaIOActiveFiles[i]->my_read_table += pool_align - (mem_address & (pool_align -1));

	for (j=0; j<*nfields; j++)
	{
		PhastaIOActiveFiles[i]->my_offset_table[j] =
			( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nppp , sizeof( unsigned long long) );
		//( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nppp + pool_align, sizeof( unsigned long long)  );
		//mem_address = (long long )PhastaIOActiveFiles[i]->my_offset_table[j];
		//if( mem_address & (pool_align -1) )
		//	PhastaIOActiveFiles[i]->my_offset_table[j] += pool_align - (mem_address & (pool_align -1));

		PhastaIOActiveFiles[i]->my_read_table[j] =
			( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nppp , sizeof( unsigned long long) );
		//( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nppp , sizeof( unsigned long long) + pool_align );
		//mem_address = (long long )PhastaIOActiveFiles[i]->my_read_table[j];
		//if( mem_address & (pool_align -1) )
		//	PhastaIOActiveFiles[i]->my_read_table[j] += pool_align - (mem_address & (pool_align -1));
	}
	*filehandle = i;

	PhastaIOActiveFiles[i]->master_header = (char *)calloc(MasterHeaderSize,sizeof( char ));
	PhastaIOActiveFiles[i]->double_chunk = (double *)calloc(1,sizeof( double ));
	PhastaIOActiveFiles[i]->int_chunk = (int *)calloc(1,sizeof( int ));
	PhastaIOActiveFiles[i]->read_double_chunk = (double *)calloc(1,sizeof( double ));
	PhastaIOActiveFiles[i]->read_int_chunk = (int *)calloc(1,sizeof( int ));

	/*
		 PhastaIOActiveFiles[i]->master_header =
		 ( char * ) calloc( MasterHeaderSize + pool_align, sizeof( char )  );
		 mem_address = (long long )PhastaIOActiveFiles[i]->master_header;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->master_header += pool_align - (mem_address & (pool_align -1));

		 PhastaIOActiveFiles[i]->double_chunk =
		 ( double * ) calloc( 1 + pool_align , sizeof( double ) );
		 mem_address = (long long )PhastaIOActiveFiles[i]->double_chunk;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->double_chunk += pool_align - (mem_address & (pool_align -1));

		 PhastaIOActiveFiles[i]->int_chunk =
		 ( int * ) calloc( 1 + pool_align , sizeof( int ) );
		 mem_address = (long long )PhastaIOActiveFiles[i]->int_chunk;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->int_chunk += pool_align - (mem_address & (pool_align -1));

		 PhastaIOActiveFiles[i]->read_double_chunk =
		 ( double * ) calloc( 1 + pool_align , sizeof( double ) );
		 mem_address = (long long )PhastaIOActiveFiles[i]->read_double_chunk;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->read_double_chunk += pool_align - (mem_address & (pool_align -1));

		 PhastaIOActiveFiles[i]->read_int_chunk =
		 ( int * ) calloc( 1 + pool_align , sizeof( int ) );
		 mem_address = (long long )PhastaIOActiveFiles[i]->read_int_chunk;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->read_int_chunk += pool_align - (mem_address & (pool_align -1));
		 */

	// Time monitoring
	endTimer(&timer_end);
	printPerf("initphmpiio", timer_start, timer_end, 0, 0, "");

	phprintf_0("Info initphmpiio: quiting function");

	return i;
}

/**
 * Destruct the file struct and free buffers allocated in init function.
 */
void finalizephmpiio( int *fileDescriptor )
{
	double timer_start, timer_end;
	startTimer(&timer_start);

	int i, j;
	i = *fileDescriptor;
	//PhastaIONextActiveIndex--;

	/* //free the offset table for this phasta file */
	//for(j=0; j<MAX_FIELDS_NUMBER; j++) //Danger: undefined behavior for my_*_table.[j] not allocated or not initialized to NULL
	for(j=0; j<PhastaIOActiveFiles[i]->nFields; j++)
	{
		free( PhastaIOActiveFiles[i]->my_offset_table[j]);
		free( PhastaIOActiveFiles[i]->my_read_table[j]);
	}
	free ( PhastaIOActiveFiles[i]->my_offset_table );
	free ( PhastaIOActiveFiles[i]->my_read_table );
	free ( PhastaIOActiveFiles[i]->master_header );
	free ( PhastaIOActiveFiles[i]->double_chunk );
	free ( PhastaIOActiveFiles[i]->int_chunk );
	free ( PhastaIOActiveFiles[i]->read_double_chunk );
	free ( PhastaIOActiveFiles[i]->read_int_chunk );

	free( PhastaIOActiveFiles[i]);

	endTimer(&timer_end);
	printPerf("finalizempiio", timer_start, timer_end, 0, 0, "");

	PhastaIONextActiveIndex--;
}


/**
 * Special init for M2N in order to create a subcommunicator for the reduced solution (requires PRINT_PERF to be false for now)
 * Initialize the file struct members and allocate space for file struct buffers.
 *
 * Note: this function is only called when we are using new format. Old POSIX
 * format should skip this routine and call openfile() directly instead.
 */
int initphmpiiosub( int *nfields, int *nppf, int *nfiles, int *filehandle, const char mode[],MPI_Comm my_local_comm)
{
	// we init irank again in case query not called (e.g. syncIO write case)

	MPI_Comm_rank(my_local_comm, &irank);
	MPI_Comm_size(my_local_comm, &mysize);

	phprintf("Info initphmpiio: entering function, myrank = %d, MasterHeaderSize = %d", irank, MasterHeaderSize);

	double timer_start, timer_end;
	startTimer(&timer_start);

	char* imode = StringStripper( mode );

	// Note: if it's read, we presume query was called prior to init and
	// MasterHeaderSize is already set to correct value from parsing header
	// otherwise it's write then it needs some computation to be set
	if ( cscompare( "read", imode ) ) {
		// do nothing
	}
	else if( cscompare( "write", imode ) ) {
		MasterHeaderSize =  computeMHSize(*nfields, *nppf, LATEST_WRITE_VERSION);
	}
	else {
		printf("Error initphmpiio: can't recognize the mode %s", imode);
                exit(1);
	}
        free ( imode );

	phprintf("Info initphmpiio: myrank = %d, MasterHeaderSize = %d", irank, MasterHeaderSize);

	int i, j;

	if( PhastaIONextActiveIndex == MAX_PHASTA_FILES ) {
		printf("Error initphmpiio: PhastaIONextActiveIndex = MAX_PHASTA_FILES");
                endTimer(&timer_end);
	        printPerf("initphmpiio", timer_start, timer_end, 0, 0, "");
		return MAX_PHASTA_FILES_EXCEEDED;
	}
	//		else if( PhastaIONextActiveIndex == 0 )  //Hang in debug mode on Intrepid
	//		{
	//			for( i = 0; i < MAX_PHASTA_FILES; i++ );
	//			{
	//				PhastaIOActiveFiles[i] = NULL;
	//			}
	//		}


	PhastaIOActiveFiles[PhastaIONextActiveIndex] = (phastaio_file_t *)calloc( 1,  sizeof( phastaio_file_t) );
	//PhastaIOActiveFiles[PhastaIONextActiveIndex] = ( phastaio_file_t *)calloc( 1 + 1, sizeof( phastaio_file_t ) );
	//mem_address = (long long )PhastaIOActiveFiles[PhastaIONextActiveIndex];
	//if( mem_address & (pool_align -1) )
	//	PhastaIOActiveFiles[PhastaIONextActiveIndex] += pool_align - (mem_address & (pool_align -1));

	i = PhastaIONextActiveIndex;
	PhastaIONextActiveIndex++;

	//PhastaIOActiveFiles[i]->next_start_address = 2*TWO_MEGABYTE;

	PhastaIOActiveFiles[i]->next_start_address = MasterHeaderSize;  // what does this mean??? TODO

	PhastaIOActiveFiles[i]->Wrong_Endian = false;

	PhastaIOActiveFiles[i]->nFields = *nfields;
	PhastaIOActiveFiles[i]->nPPF = *nppf;
	PhastaIOActiveFiles[i]->nFiles = *nfiles;
	MPI_Comm_rank(my_local_comm, &(PhastaIOActiveFiles[i]->myrank));
	MPI_Comm_size(my_local_comm, &(PhastaIOActiveFiles[i]->numprocs));

	int color = computeColor(PhastaIOActiveFiles[i]->myrank, PhastaIOActiveFiles[i]->numprocs, PhastaIOActiveFiles[i]->nFiles);
	MPI_Comm_split(my_local_comm,
			color,
			PhastaIOActiveFiles[i]->myrank,
			&(PhastaIOActiveFiles[i]->local_comm));
	MPI_Comm_size(PhastaIOActiveFiles[i]->local_comm,
			&(PhastaIOActiveFiles[i]->local_numprocs));
	MPI_Comm_rank(PhastaIOActiveFiles[i]->local_comm,
			&(PhastaIOActiveFiles[i]->local_myrank));
	PhastaIOActiveFiles[i]->nppp =
		PhastaIOActiveFiles[i]->nPPF/PhastaIOActiveFiles[i]->local_numprocs;

	PhastaIOActiveFiles[i]->start_id = PhastaIOActiveFiles[i]->nPPF *
		(int)(PhastaIOActiveFiles[i]->myrank/PhastaIOActiveFiles[i]->local_numprocs) +
		(PhastaIOActiveFiles[i]->local_myrank * PhastaIOActiveFiles[i]->nppp);

	PhastaIOActiveFiles[i]->my_offset_table =
		( unsigned long long ** ) calloc( MAX_FIELDS_NUMBER , sizeof( unsigned long long *) );
	//( unsigned long long **)calloc( MAX_FIELDS_NUMBER + pool_align, sizeof(unsigned long long *) );
	//mem_address = (long long )PhastaIOActiveFiles[i]->my_offset_table;
	//if( mem_address & (pool_align -1) )
	//	PhastaIOActiveFiles[i]->my_offset_table += pool_align - (mem_address & (pool_align -1));

	PhastaIOActiveFiles[i]->my_read_table =
		( unsigned long long ** ) calloc( MAX_FIELDS_NUMBER , sizeof( unsigned long long *) );
	//( unsigned long long **)calloc( MAX_FIELDS_NUMBER + pool_align, sizeof( unsigned long long *) );
	//mem_address = (long long )PhastaIOActiveFiles[i]->my_read_table;
	//if( mem_address & (pool_align -1) )
	//	PhastaIOActiveFiles[i]->my_read_table += pool_align - (mem_address & (pool_align -1));

	for (j=0; j<*nfields; j++)
	{
		PhastaIOActiveFiles[i]->my_offset_table[j] =
			( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nppp , sizeof( unsigned long long) );
		//( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nppp + pool_align, sizeof( unsigned long long)  );
		//mem_address = (long long )PhastaIOActiveFiles[i]->my_offset_table[j];
		//if( mem_address & (pool_align -1) )
		//	PhastaIOActiveFiles[i]->my_offset_table[j] += pool_align - (mem_address & (pool_align -1));

		PhastaIOActiveFiles[i]->my_read_table[j] =
			( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nppp , sizeof( unsigned long long) );
		//( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nppp , sizeof( unsigned long long) + pool_align );
		//mem_address = (long long )PhastaIOActiveFiles[i]->my_read_table[j];
		//if( mem_address & (pool_align -1) )
		//	PhastaIOActiveFiles[i]->my_read_table[j] += pool_align - (mem_address & (pool_align -1));
	}
	*filehandle = i;

	PhastaIOActiveFiles[i]->master_header = (char *)calloc(MasterHeaderSize,sizeof( char ));
	PhastaIOActiveFiles[i]->double_chunk = (double *)calloc(1,sizeof( double ));
	PhastaIOActiveFiles[i]->int_chunk = (int *)calloc(1,sizeof( int ));
	PhastaIOActiveFiles[i]->read_double_chunk = (double *)calloc(1,sizeof( double ));
	PhastaIOActiveFiles[i]->read_int_chunk = (int *)calloc(1,sizeof( int ));

	/*
		 PhastaIOActiveFiles[i]->master_header =
		 ( char * ) calloc( MasterHeaderSize + pool_align, sizeof( char )  );
		 mem_address = (long long )PhastaIOActiveFiles[i]->master_header;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->master_header += pool_align - (mem_address & (pool_align -1));

		 PhastaIOActiveFiles[i]->double_chunk =
		 ( double * ) calloc( 1 + pool_align , sizeof( double ) );
		 mem_address = (long long )PhastaIOActiveFiles[i]->double_chunk;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->double_chunk += pool_align - (mem_address & (pool_align -1));

		 PhastaIOActiveFiles[i]->int_chunk =
		 ( int * ) calloc( 1 + pool_align , sizeof( int ) );
		 mem_address = (long long )PhastaIOActiveFiles[i]->int_chunk;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->int_chunk += pool_align - (mem_address & (pool_align -1));

		 PhastaIOActiveFiles[i]->read_double_chunk =
		 ( double * ) calloc( 1 + pool_align , sizeof( double ) );
		 mem_address = (long long )PhastaIOActiveFiles[i]->read_double_chunk;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->read_double_chunk += pool_align - (mem_address & (pool_align -1));

		 PhastaIOActiveFiles[i]->read_int_chunk =
		 ( int * ) calloc( 1 + pool_align , sizeof( int ) );
		 mem_address = (long long )PhastaIOActiveFiles[i]->read_int_chunk;
		 if( mem_address & (pool_align -1) )
		 PhastaIOActiveFiles[i]->read_int_chunk += pool_align - (mem_address & (pool_align -1));
		 */

	// Time monitoring
	endTimer(&timer_end);
	printPerf("initphmpiiosub", timer_start, timer_end, 0, 0, "");

	phprintf_0("Info initphmpiiosub: quiting function");

	return i;
}


/** open file for both POSIX and MPI-IO syncIO format.
 *
 * If it's old POSIX format, simply call posix fopen().
 *
 * If it's MPI-IO foramt:
 * in "read" mode, it builds the header table that points to the offset of
 * fields for parts;
 * in "write" mode, it opens the file with MPI-IO open routine.
 */
void openfile(const char filename[],
               const char mode[],
               int*  fileDescriptor )
{
	phprintf_0("Info: entering openfile");

	double timer_start, timer_end;
	startTimer(&timer_start);

	if ( PhastaIONextActiveIndex == 0 )
	{
		FILE* file=NULL ;
		*fileDescriptor = 0;
		char* fname = StringStripper( filename );
		char* imode = StringStripper( mode );

		if ( cscompare( "read", imode ) ) file = fopen(fname, "rb" );
		else if( cscompare( "write", imode ) ) file = fopen(fname, "wb" );
		else if( cscompare( "append", imode ) ) file = fopen(fname, "ab" );

		if ( !file ){
			fprintf(stderr,"Error openfile: unable to open file %s",fname ) ;
		} else {
			fileArray.push_back( file );
			byte_order.push_back( false );
			header_type.push_back( sizeof(int) );
			*fileDescriptor = fileArray.size();
		}
		free (fname);
		free (imode);
	}
	else // else it would be parallel I/O, opposed to posix io
	{
		char* fname = StringStripper( filename );
		char* imode = StringStripper( mode );
		int rc;
                int i = *fileDescriptor;
		checkFileDescriptor("openfile",&i);
		char* token;

		if ( cscompare( "read", imode ) )
		{
			//	      if (PhastaIOActiveFiles[i]->myrank == 0)
			//                printf("\n **********\nRead open ... ... regular version\n");

			rc = MPI_File_open( PhastaIOActiveFiles[i]->local_comm,
					fname,
					MPI_MODE_RDONLY,
					MPI_INFO_NULL,
					&(PhastaIOActiveFiles[i]->file_handle) );

			if(rc)
			{
				*fileDescriptor = UNABLE_TO_OPEN_FILE;
				printf("Error openfile: Unable to open file %s! File descriptor = %d\n",fname,*fileDescriptor);
                                endTimer(&timer_end);
                                printPerf("openfile", timer_start, timer_end, 0, 0, "");
				return;
			}

			MPI_Status read_tag_status;
			char read_out_tag[MAX_FIELDS_NAME_LENGTH];
			int j;
			int magic_number;

			if ( PhastaIOActiveFiles[i]->local_myrank == 0 ) {
				MPI_File_read_at( PhastaIOActiveFiles[i]->file_handle,
						0,
						PhastaIOActiveFiles[i]->master_header,
						MasterHeaderSize,
						MPI_CHAR,
						&read_tag_status );
			}

			MPI_Bcast( PhastaIOActiveFiles[i]->master_header,
					MasterHeaderSize,
					MPI_CHAR,
					0,
					PhastaIOActiveFiles[i]->local_comm );

			memcpy( read_out_tag,
					PhastaIOActiveFiles[i]->master_header,
					MAX_FIELDS_NAME_LENGTH-1 );

			if ( cscompare ("MPI_IO_Tag",read_out_tag) )
			{
				// Test endianess ...
				memcpy ( &magic_number,
						PhastaIOActiveFiles[i]->master_header+sizeof("MPI_IO_Tag : ")-1, //-1 sizeof returns the size of the string+1 for "\0"
						sizeof(int) );                                                   // masterheader should look like "MPI_IO_Tag : 12180 " with 12180 in binary format

				if ( magic_number != ENDIAN_TEST_NUMBER )
				{
					PhastaIOActiveFiles[i]->Wrong_Endian = true;
				}

				memcpy( read_out_tag,
						PhastaIOActiveFiles[i]->master_header+MAX_FIELDS_NAME_LENGTH+1, // TODO: WHY +1???
						MAX_FIELDS_NAME_LENGTH );

				// Read in # fields ...
				token = strtok ( read_out_tag, ":" );
				token = strtok( NULL," ,;<>" );
				PhastaIOActiveFiles[i]->nFields = atoi( token );

				unsigned long long **header_table;
				header_table = ( unsigned long long ** )calloc(PhastaIOActiveFiles[i]->nFields, sizeof(unsigned long long *));
				//header_table = ( unsigned long long ** ) calloc( PhastaIOActiveFiles[i]->nFields  + pool_align, sizeof(unsigned long long *));
				//mem_address = (long long )header_table;
				//if( mem_address & (pool_align -1) )
				//	header_table += pool_align - (mem_address & (pool_align -1));

				for ( j = 0; j < PhastaIOActiveFiles[i]->nFields; j++ )
				{
					header_table[j]=( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nPPF , sizeof( unsigned long long));
					//header_table[j]=( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nPPF + pool_align, sizeof(unsigned long long *));
					//mem_address = (long long )header_table[j];
					//if( mem_address & (pool_align -1) )
					//	header_table[j] += pool_align - (mem_address & (pool_align -1));
				}

				// Read in the offset table ...
				for ( j = 0; j < PhastaIOActiveFiles[i]->nFields; j++ )
				{
                                        if ( PhastaIOActiveFiles[i]->local_myrank == 0 ) {
						memcpy( header_table[j],
							PhastaIOActiveFiles[i]->master_header +
							VERSION_INFO_HEADER_SIZE +
							j * PhastaIOActiveFiles[i]->nPPF * sizeof(unsigned long long),
							PhastaIOActiveFiles[i]->nPPF * sizeof(unsigned long long) );
                                        }

					MPI_Scatter( header_table[j],
							PhastaIOActiveFiles[i]->nppp,
							MPI_LONG_LONG_INT,
							PhastaIOActiveFiles[i]->my_read_table[j],
							PhastaIOActiveFiles[i]->nppp,
							MPI_LONG_LONG_INT,
							0,
							PhastaIOActiveFiles[i]->local_comm );

					// Swap byte order if endianess is different ...
					if ( PhastaIOActiveFiles[i]->Wrong_Endian ) {
						SwapArrayByteOrder( PhastaIOActiveFiles[i]->my_read_table[j],
								sizeof(long long int),
								PhastaIOActiveFiles[i]->nppp );
					}
				}

                                for ( j = 0; j < PhastaIOActiveFiles[i]->nFields; j++ ) {
                                	free ( header_table[j] );
                                }
                                free (header_table);

			} // end of if MPI_IO_TAG
			else //else not valid MPI file
			{
				*fileDescriptor = NOT_A_MPI_FILE;
				printf("Error openfile: The file %s you opened is not in syncIO new format, please check again! File descriptor = %d, MasterHeaderSize = %d, read_out_tag = %s\n",fname,*fileDescriptor,MasterHeaderSize,read_out_tag);
				//Printing MasterHeaderSize is useful to test a compiler bug on Intrepid BGP
                                endTimer(&timer_end);
                                printPerf("openfile", timer_start, timer_end, 0, 0, "");
				return;
			}
		} // end of if "read"
		else if( cscompare( "write", imode ) )
		{
			rc = MPI_File_open( PhastaIOActiveFiles[i]->local_comm,
					fname,
					MPI_MODE_WRONLY | MPI_MODE_CREATE,
					MPI_INFO_NULL,
					&(PhastaIOActiveFiles[i]->file_handle) );
			if(rc)
			{
				*fileDescriptor = UNABLE_TO_OPEN_FILE;
				return;
			}
		} // end of if "write"
		free (fname);
		free (imode);
	} // end of if FileIndex != 0

	endTimer(&timer_end);
	printPerf("openfile", timer_start, timer_end, 0, 0, "");
}

/** close file for both POSIX and MPI-IO syncIO format.
 *
 * If it's old POSIX format, simply call posix fclose().
 *
 * If it's MPI-IO foramt:
 * in "read" mode, it simply close file with MPI-IO close routine.
 * in "write" mode, rank 0 in each group will re-assemble the master header and
 * offset table and write to the beginning of file, then close the file.
 */
void closefile( int* fileDescriptor,
                 const char mode[] )
{
	double timer_start, timer_end;
	startTimer(&timer_start);

	int i = *fileDescriptor;
	checkFileDescriptor("closefile",&i);

	if ( PhastaIONextActiveIndex == 0 ) {
		char* imode = StringStripper( mode );

		if( cscompare( "write", imode )
				|| cscompare( "append", imode ) ) {
			fflush( fileArray[ *fileDescriptor - 1 ] );
		}

		fclose( fileArray[ *fileDescriptor - 1 ] );
		free (imode);
     	}
	else {
		char* imode = StringStripper( mode );

		//write master header here:
		if ( cscompare( "write", imode ) ) {
			//	      if ( PhastaIOActiveFiles[i]->nPPF * PhastaIOActiveFiles[i]->nFields < 2*ONE_MEGABYTE/8 )  //SHOULD BE CHECKED
			//		MasterHeaderSize = 4*ONE_MEGABYTE;
			//	      else
			//		MasterHeaderSize = 4*ONE_MEGABYTE + PhastaIOActiveFiles[i]->nPPF * PhastaIOActiveFiles[i]->nFields * 8 - 2*ONE_MEGABYTE;

			MasterHeaderSize = computeMHSize( PhastaIOActiveFiles[i]->nFields, PhastaIOActiveFiles[i]->nPPF, LATEST_WRITE_VERSION);
			phprintf_0("Info closefile: myrank = %d, MasterHeaderSize = %d\n", PhastaIOActiveFiles[i]->myrank, MasterHeaderSize);

			MPI_Status write_header_status;
			char mpi_tag[MAX_FIELDS_NAME_LENGTH];
			char version[MAX_FIELDS_NAME_LENGTH/4];
			char mhsize[MAX_FIELDS_NAME_LENGTH/4];
			int magic_number = ENDIAN_TEST_NUMBER;

			if ( PhastaIOActiveFiles[i]->local_myrank == 0 )
			{
				bzero((void*)mpi_tag,MAX_FIELDS_NAME_LENGTH);
				sprintf(mpi_tag, "MPI_IO_Tag : ");
				memcpy(PhastaIOActiveFiles[i]->master_header,
						mpi_tag,
						MAX_FIELDS_NAME_LENGTH);

				bzero((void*)version,MAX_FIELDS_NAME_LENGTH/4);
				// this version is "1", print version in ASCII
				sprintf(version, "version : %d",1);
				memcpy(PhastaIOActiveFiles[i]->master_header + MAX_FIELDS_NAME_LENGTH/2,
						version,
						MAX_FIELDS_NAME_LENGTH/4);

				// master header size is computed using the formula above
				bzero((void*)mhsize,MAX_FIELDS_NAME_LENGTH/4);
				sprintf(mhsize, "mhsize : ");
				memcpy(PhastaIOActiveFiles[i]->master_header + MAX_FIELDS_NAME_LENGTH/4*3,
						mhsize,
						MAX_FIELDS_NAME_LENGTH/4);

				bzero((void*)mpi_tag,MAX_FIELDS_NAME_LENGTH);
				sprintf(mpi_tag,
						"\nnFields : %d\n",
						PhastaIOActiveFiles[i]->nFields);
				memcpy(PhastaIOActiveFiles[i]->master_header+MAX_FIELDS_NAME_LENGTH,
						mpi_tag,
						MAX_FIELDS_NAME_LENGTH);

				bzero((void*)mpi_tag,MAX_FIELDS_NAME_LENGTH);
				sprintf(mpi_tag, "\nnPPF : %d\n", PhastaIOActiveFiles[i]->nPPF);
				memcpy( PhastaIOActiveFiles[i]->master_header+
						PhastaIOActiveFiles[i]->nFields *
						MAX_FIELDS_NAME_LENGTH +
						MAX_FIELDS_NAME_LENGTH * 2,
						mpi_tag,
						MAX_FIELDS_NAME_LENGTH);

				memcpy( PhastaIOActiveFiles[i]->master_header+sizeof("MPI_IO_Tag : ")-1, //-1 sizeof returns the size of the string+1 for "\0"
						&magic_number,
						sizeof(int));

				memcpy( PhastaIOActiveFiles[i]->master_header+sizeof("mhsize : ") -1 + MAX_FIELDS_NAME_LENGTH/4*3,
						&MasterHeaderSize,
						sizeof(int));
			}

			int j = 0;
			unsigned long long **header_table;
			header_table = ( unsigned long long ** )calloc(PhastaIOActiveFiles[i]->nFields, sizeof(unsigned long long *));
			//header_table = ( unsigned long long ** ) calloc( PhastaIOActiveFiles[i]->nFields  + pool_align, sizeof(unsigned long long *));
			//mem_address = (long long )header_table;
			//if( mem_address & (pool_align -1) )
			//	header_table += pool_align - (mem_address & (pool_align -1));

			for ( j = 0; j < PhastaIOActiveFiles[i]->nFields; j++ ) {
				header_table[j]=( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nPPF , sizeof( unsigned long long));
				//header_table[j]=( unsigned long long * ) calloc( PhastaIOActiveFiles[i]->nPPF + pool_align, sizeof (unsigned long long *));
				//mem_address = (long long )header_table[j];
				//if( mem_address & (pool_align -1) )
				//	header_table[j] += pool_align - (mem_address & (pool_align - 1));
			}

			//if( irank == 0 ) printf("gonna mpi_gather, myrank = %d\n", irank);
			for ( j = 0; j < PhastaIOActiveFiles[i]->nFields; j++ ) {
				MPI_Gather( PhastaIOActiveFiles[i]->my_offset_table[j],
						PhastaIOActiveFiles[i]->nppp,
						MPI_LONG_LONG_INT,
						header_table[j],
						PhastaIOActiveFiles[i]->nppp,
						MPI_LONG_LONG_INT,
						0,
						PhastaIOActiveFiles[i]->local_comm );
			}

			if ( PhastaIOActiveFiles[i]->local_myrank == 0 ) {

			        //if( irank == 0 ) printf("gonna memcpy for every procs, myrank = %d\n", irank);
				for ( j = 0; j < PhastaIOActiveFiles[i]->nFields; j++ ) {
					memcpy ( PhastaIOActiveFiles[i]->master_header +
						VERSION_INFO_HEADER_SIZE +
						j * PhastaIOActiveFiles[i]->nPPF * sizeof(unsigned long long),
						header_table[j],
						PhastaIOActiveFiles[i]->nPPF * sizeof(unsigned long long) );
				}

				//if( irank == 0 ) printf("gonna file_write_at(), myrank = %d\n", irank);
				MPI_File_write_at( PhastaIOActiveFiles[i]->file_handle,
						0,
						PhastaIOActiveFiles[i]->master_header,
						MasterHeaderSize,
						MPI_CHAR,
						&write_header_status );
			}

			////free(PhastaIOActiveFiles[i]->master_header);

			for ( j = 0; j < PhastaIOActiveFiles[i]->nFields; j++ ) {
				free ( header_table[j] );
			}
			free (header_table);
		}

		//if( irank == 0 ) printf("gonna file_close(), myrank = %d\n", irank);
		MPI_File_close( &( PhastaIOActiveFiles[i]->file_handle ) );
		free ( imode );
	}

	endTimer(&timer_end);
	printPerf("closefile_", timer_start, timer_end, 0, 0, "");
}

void readheader( int* fileDescriptor,
                  const  char keyphrase[],
                  void* valueArray,
                  int*  nItems,
                  const char  datatype[],
                  const char  iotype[] )
{
     	double timer_start, timer_end;

	startTimer(&timer_start);

	int i = *fileDescriptor;
	checkFileDescriptor("readheader",&i);

	if ( PhastaIONextActiveIndex == 0 ) {
		int filePtr = *fileDescriptor - 1;
		FILE* fileObject;
		int* valueListInt;

		if ( *fileDescriptor < 1 || *fileDescriptor > (int)fileArray.size() ) {
			fprintf(stderr,"No file associated with Descriptor %d\n",*fileDescriptor);
			fprintf(stderr,"openfile_ function has to be called before \n") ;
			fprintf(stderr,"acessing the file\n ") ;
			fprintf(stderr,"fatal error: cannot continue, returning out of call\n");
                        endTimer(&timer_end);
                        printPerf("readheader", timer_start, timer_end, 0, 0, "");
			return;
		}

                if( LastHeaderKey.count(filePtr) )
                  free(LastHeaderKey[filePtr]);
                const int l = strlen(keyphrase)+1;
                LastHeaderKey[filePtr] = (char*) malloc(l*sizeof(char));
                strcpy(LastHeaderKey[filePtr], keyphrase);
		LastHeaderNotFound = false;

		fileObject = fileArray[ filePtr ] ;
		Wrong_Endian = byte_order[ filePtr ];

		isBinary( iotype );
		typeSize( datatype );   //redundant call, just avoid a compiler warning.

		// right now we are making the assumption that we will only write integers
		// on the header line.

		valueListInt = static_cast< int* >( valueArray );
		int ierr = readHeader( fileObject ,
				keyphrase,
				valueListInt,
				*nItems ) ;

		byte_order[ filePtr ] = Wrong_Endian ;

		if ( ierr ) LastHeaderNotFound = true;

		//return ; // don't return, go to the end to print perf
	}
	else {
		unsigned int skip_size;
		int* valueListInt;
		valueListInt = static_cast <int*>(valueArray);
		char* token = NULL;
		bool FOUND = false ;
		isBinary( iotype );

		MPI_Status read_offset_status;
		char read_out_tag[MAX_FIELDS_NAME_LENGTH];
                memset(read_out_tag, '\0', MAX_FIELDS_NAME_LENGTH);
		char readouttag[MAX_FIELDS_NUMBER][MAX_FIELDS_NAME_LENGTH];
		int j;

		int string_length = strlen( keyphrase );
		char* buffer = (char*) malloc ( string_length+1 );
		//char* buffer = ( char * ) malloc( string_length + 1 + pool_align );
		//mem_address = (long long )buffer;
		//if( mem_address & (pool_align -1) )
		//  buffer += pool_align - (mem_address & (pool_align -1));

		strcpy ( buffer, keyphrase );
		buffer[ string_length ] = '\0';

		char* st2 = strtok ( buffer, "@" );
		st2 = strtok (NULL, "@");
		PhastaIOActiveFiles[i]->GPid = atoi(st2);
		if ( char* p = strpbrk(buffer, "@") )
			*p = '\0';

		// Check if the user has input the right GPid
		if ( ( PhastaIOActiveFiles[i]->GPid <=
					PhastaIOActiveFiles[i]->myrank *
					PhastaIOActiveFiles[i]->nppp )||
				( PhastaIOActiveFiles[i]->GPid >
					( PhastaIOActiveFiles[i]->myrank + 1 ) *
					PhastaIOActiveFiles[i]->nppp ) )
		{
			*fileDescriptor = NOT_A_MPI_FILE;
			printf("Error readheader: The file is not in syncIO new format, please check! myrank = %d, GPid = %d, nppp = %d, keyphrase = %s\n", PhastaIOActiveFiles[i]->myrank, PhastaIOActiveFiles[i]->GPid, PhastaIOActiveFiles[i]->nppp, keyphrase);
                        // It is possible atoi could not generate a clear integer from st2 because of additional garbage character in keyphrase
                        endTimer(&timer_end);
                        printPerf("readheader", timer_start, timer_end, 0, 0, "");
			return;
		}

		// Find the field we want ...
		//for ( j = 0; j<MAX_FIELDS_NUMBER; j++ )
		for ( j = 0; j<PhastaIOActiveFiles[i]->nFields; j++ )
		{
			memcpy( readouttag[j],
					PhastaIOActiveFiles[i]->master_header + j*MAX_FIELDS_NAME_LENGTH+MAX_FIELDS_NAME_LENGTH*2+1,
					MAX_FIELDS_NAME_LENGTH-1 );
		}

		for ( j = 0; j<PhastaIOActiveFiles[i]->nFields; j++ )
		{
			token = strtok ( readouttag[j], ":" );

			//if ( cscompare( buffer, token ) )
			if ( cscompare( token , buffer ) && cscompare( buffer, token ) )
                        // This double comparison is required for the field "number of nodes" and all the other fields that start with "number of nodes" (i.g. number of nodes in the mesh").
                        // Would be safer to rename "number of nodes" by "number of nodes in the part" so that the name are completely unique. But much more work to do that (Nspre, phParAdapt, etc).
                        // Since the field name are unique in SyncIO (as it includes part ID), this should be safe and there should be no issue with the "?" trailing character.
			{
				PhastaIOActiveFiles[i]->read_field_count = j;
				FOUND = true;
                                //printf("buffer: %s | token: %s | j: %d\n",buffer,token,j);
				break;
			}
		}
                free(buffer);

		if (!FOUND)
		{
			//if(irank==0) printf("Warning readheader: Not found %s \n",keyphrase); //PhastaIOActiveFiles[i]->myrank is certainly initialized here.
			if(PhastaIOActiveFiles[i]->myrank == 0) printf("WARNING readheader: Not found %s\n",keyphrase);
                        endTimer(&timer_end);
                        printPerf("readheader", timer_start, timer_end, 0, 0, "");
			return;
		}

		// Find the part we want ...
		PhastaIOActiveFiles[i]->read_part_count = PhastaIOActiveFiles[i]->GPid -
			PhastaIOActiveFiles[i]->myrank * PhastaIOActiveFiles[i]->nppp - 1;

		PhastaIOActiveFiles[i]->my_offset =
			PhastaIOActiveFiles[i]->my_read_table[PhastaIOActiveFiles[i]->read_field_count][PhastaIOActiveFiles[i]->read_part_count];

		// 	  printf("****Rank %d offset is %d\n",PhastaIOActiveFiles[i]->myrank,PhastaIOActiveFiles[i]->my_offset);

		// Read each datablock header here ...

		MPI_File_read_at_all( PhastaIOActiveFiles[i]->file_handle,
				PhastaIOActiveFiles[i]->my_offset+1,
				read_out_tag,
				MAX_FIELDS_NAME_LENGTH-1,
				MPI_CHAR,
				&read_offset_status );
		token = strtok ( read_out_tag, ":" );

		// 	  printf("&&&&Rank %d read_out_tag is %s\n",PhastaIOActiveFiles[i]->myrank,read_out_tag);

		if( cscompare( keyphrase , token ) ) //No need to compare also token with keyphrase like above. We should already have the right one. Otherwise there is a problem.
		{
			FOUND = true ;
			token = strtok( NULL, " ,;<>" );
			skip_size = atoi( token );
			for( j=0; j < *nItems && ( token = strtok( NULL," ,;<>") ); j++ )
				valueListInt[j] = atoi( token );

			if ( j < *nItems )
			{
				fprintf( stderr, "Expected # of ints not found for: %s\n", keyphrase );
			}
		}
                else {
                  //if(irank==0)
		  if(PhastaIOActiveFiles[i]->myrank == 0)
                  // If we enter this if, there is a problem with the name of some fields
                  {
                    printf("Error readheader: Unexpected mismatch between keyphrase = %s and token = %s\n",keyphrase,token);
                  }
                }
	}

	endTimer(&timer_end);
	printPerf("readheader", timer_start, timer_end, 0, 0, "");

}

void readdatablock( int*  fileDescriptor,
                     const char keyphrase[],
                     void* valueArray,
                     int*  nItems,
                     const char  datatype[],
                     const char  iotype[] )
{
	//if(irank == 0) printf("entering readdatablock()\n");
	unsigned long long data_size = 0;
	double timer_start, timer_end;
	startTimer(&timer_start);

	int i = *fileDescriptor;
	checkFileDescriptor("readdatablock",&i);

	if ( PhastaIONextActiveIndex == 0 ) {
		int filePtr = *fileDescriptor - 1;
		FILE* fileObject;
		char junk;

		if ( *fileDescriptor < 1 || *fileDescriptor > (int)fileArray.size() ) {
			fprintf(stderr,"No file associated with Descriptor %d\n",*fileDescriptor);
			fprintf(stderr,"openfile_ function has to be called before\n") ;
			fprintf(stderr,"acessing the file\n ") ;
			fprintf(stderr,"fatal error: cannot continue, returning out of call\n");
                        endTimer(&timer_end);
                        printPerf("readdatablock", timer_start, timer_end, 0, 0, "");
			return;
		}

		// error check..
		// since we require that a consistant header always preceed the data block
		// let us check to see that it is actually the case.

		if ( ! cscompare( LastHeaderKey[ filePtr ], keyphrase ) ) {
			fprintf(stderr, "Header not consistant with data block\n");
			fprintf(stderr, "Header: %s\n", LastHeaderKey[ filePtr ] );
			fprintf(stderr, "DataBlock: %s\n ", keyphrase );
			fprintf(stderr, "Please recheck read sequence \n");
			if( Strict_Error ) {
				fprintf(stderr, "fatal error: cannot continue, returning out of call\n");
                                endTimer(&timer_end);
                                printPerf("readdatablock", timer_start, timer_end, 0, 0, "");
				return;
			}
		}

		if ( LastHeaderNotFound ) {
                        endTimer(&timer_end);
                        printPerf("readdatablock", timer_start, timer_end, 0, 0, "");
                        return;
                }
		fileObject = fileArray[ filePtr ];
		Wrong_Endian = byte_order[ filePtr ];

		size_t type_size = typeSize( datatype );
		int nUnits = *nItems;
		isBinary( iotype );

                free(LastHeaderKey[filePtr]);
                LastHeaderKey.erase(filePtr);

		if ( binary_format ) {
			fread( valueArray, type_size, nUnits, fileObject );
			fread( &junk, sizeof(char), 1 , fileObject );
			if ( Wrong_Endian ) SwapArrayByteOrder( valueArray, type_size, nUnits );
		} else {

			char* ts1 = StringStripper( datatype );
			if ( cscompare( "integer", ts1 ) ) {
				for( int n=0; n < nUnits ; n++ )
					fscanf(fileObject, "%d\n",(int*)((int*)valueArray+n) );
			} else if ( cscompare( "double", ts1 ) ) {
				for( int n=0; n < nUnits ; n++ )
					fscanf(fileObject, "%lf\n",(double*)((double*)valueArray+n) );
			}
			free (ts1);
		}

		//return;
	}
	else {
		// 	  printf("read data block\n");
		MPI_Status read_data_status;
		size_t type_size = typeSize( datatype );
		int nUnits = *nItems;
		isBinary( iotype );

		// read datablock then
		//MR CHANGE
		//             if ( cscompare ( datatype, "double"))
		char* ts2 = StringStripper( datatype );
		if ( cscompare ( "double" , ts2))
			//MR CHANGE END
		{

			MPI_File_read_at_all_begin( PhastaIOActiveFiles[i]->file_handle,
					PhastaIOActiveFiles[i]->my_offset + DB_HEADER_SIZE,
					valueArray,
					nUnits,
					MPI_DOUBLE );
			MPI_File_read_at_all_end( PhastaIOActiveFiles[i]->file_handle,
					valueArray,
					&read_data_status );
			data_size=8*nUnits;

		}
		//MR CHANGE
		//             else if ( cscompare ( datatype, "integer"))
		else if ( cscompare ( "integer" , ts2))
			//MR CHANGE END
		{
			MPI_File_read_at_all_begin(PhastaIOActiveFiles[i]->file_handle,
					PhastaIOActiveFiles[i]->my_offset + DB_HEADER_SIZE,
					valueArray,
					nUnits,
					MPI_INT );
			MPI_File_read_at_all_end( PhastaIOActiveFiles[i]->file_handle,
					valueArray,
					&read_data_status );
			data_size=4*nUnits;
		}
		else
		{
			*fileDescriptor = DATA_TYPE_ILLEGAL;
			printf("readdatablock - DATA_TYPE_ILLEGAL - %s\n",datatype);
                        endTimer(&timer_end);
                        printPerf("readdatablock", timer_start, timer_end, 0, 0, "");
			return;
		}
                free(ts2);


		// 	  printf("%d Read finishe\n",PhastaIOActiveFiles[i]->myrank);

		// Swap data byte order if endianess is different ...
		if ( PhastaIOActiveFiles[i]->Wrong_Endian )
		{
			SwapArrayByteOrder( valueArray, type_size, nUnits );
		}
	}

	endTimer(&timer_end);
	char extra_msg[1024];
	memset(extra_msg, '\0', 1024);
	char* key = StringStripper(keyphrase);
	sprintf(extra_msg, " field is %s ", key);
	printPerf("readdatablock", timer_start, timer_end, data_size, 1, extra_msg);
        free(key);

}

void writeheader(  const int* fileDescriptor,
                    const char keyphrase[],
                    const void* valueArray,
                    const int* nItems,
                    const int* ndataItems,
                    const char datatype[],
                    const char iotype[])
{

	//if(irank == 0) printf("entering writeheader()\n");

	double timer_start, timer_end;
	startTimer(&timer_start);

	int i = *fileDescriptor;
	checkFileDescriptor("writeheader",&i);

	if ( PhastaIONextActiveIndex == 0 ) {
		int filePtr = *fileDescriptor - 1;
		FILE* fileObject;

		if ( *fileDescriptor < 1 || *fileDescriptor > (int)fileArray.size() ) {
			fprintf(stderr,"No file associated with Descriptor %d\n",*fileDescriptor);
			fprintf(stderr,"openfile_ function has to be called before \n") ;
			fprintf(stderr,"acessing the file\n ") ;
			fprintf(stderr,"fatal error: cannot continue, returning out of call\n");
                        endTimer(&timer_end);
                        printPerf("writeheader", timer_start, timer_end, 0, 0, "");
			return;
		}

                if( LastHeaderKey.count(filePtr) )
                  free(LastHeaderKey[filePtr]);
                const int l = strlen(keyphrase)+1;
                LastHeaderKey[filePtr] = (char*) malloc(l*sizeof(char));
                strcpy(LastHeaderKey[filePtr], keyphrase);
		DataSize = *ndataItems;
		fileObject = fileArray[ filePtr ] ;
		size_t type_size = typeSize( datatype );
		isBinary( iotype );
		header_type[ filePtr ] = type_size;

		int _newline = ( *ndataItems > 0 ) ? sizeof( char ) : 0;
		int size_of_nextblock =
			( binary_format ) ? type_size*( *ndataItems )+ _newline : *ndataItems ;

		fprintf( fileObject, "%s : < %d > ", keyphrase, size_of_nextblock );
		for( int i = 0; i < *nItems; i++ )
			fprintf(fileObject, "%d ", *((int*)((int*)valueArray+i)));
		fprintf(fileObject, "\n");

		//return ;
	}
	else { // else it's parallel I/O
		DataSize = *ndataItems;
		size_t type_size = typeSize( datatype );
		isBinary( iotype );
		char mpi_tag[MAX_FIELDS_NAME_LENGTH];

		int string_length = strlen( keyphrase );
		char* buffer = (char*) malloc ( string_length+1 );
		//char* buffer = ( char * ) malloc( string_length + 1 + pool_align );
		//mem_address = (long long )buffer;
		//if( mem_address & (pool_align -1) )
		// buffer += pool_align - (mem_address & (pool_align -1));

		strcpy ( buffer, keyphrase);
		buffer[ string_length ] = '\0';

		char* st2 = strtok ( buffer, "@" );
		st2 = strtok (NULL, "@");
		PhastaIOActiveFiles[i]->GPid = atoi(st2);

		if ( char* p = strpbrk(buffer, "@") )
			*p = '\0';

	        bzero((void*)mpi_tag,MAX_FIELDS_NAME_LENGTH);
		sprintf(mpi_tag, "\n%s : %d\n", buffer, PhastaIOActiveFiles[i]->field_count);
		unsigned long long offset_value;

		int temp = *ndataItems;
		unsigned long long number_of_items = (unsigned long long)temp;
		MPI_Barrier(PhastaIOActiveFiles[i]->local_comm);

		MPI_Scan( &number_of_items,
				&offset_value,
				1,
				MPI_LONG_LONG_INT,
				MPI_SUM,
				PhastaIOActiveFiles[i]->local_comm );

		offset_value = (offset_value - number_of_items) * type_size;

		offset_value += PhastaIOActiveFiles[i]->local_myrank *
			DB_HEADER_SIZE +
			PhastaIOActiveFiles[i]->next_start_address;
		// This offset is the starting address of each datablock header...
		PhastaIOActiveFiles[i]->my_offset = offset_value;

		// Write in my offset table ...
		PhastaIOActiveFiles[i]->my_offset_table[PhastaIOActiveFiles[i]->field_count][PhastaIOActiveFiles[i]->part_count] =
			PhastaIOActiveFiles[i]->my_offset;

		// Update the next-start-address ...
		PhastaIOActiveFiles[i]->next_start_address = offset_value +
			number_of_items * type_size +
			DB_HEADER_SIZE;
		MPI_Bcast( &(PhastaIOActiveFiles[i]->next_start_address),
				1,
				MPI_LONG_LONG_INT,
				PhastaIOActiveFiles[i]->local_numprocs-1,
				PhastaIOActiveFiles[i]->local_comm );

		// Prepare datablock header ...
		int _newline = (*ndataItems>0)?sizeof(char):0;
		unsigned int size_of_nextblock = type_size * (*ndataItems) + _newline;

		//char datablock_header[255];
		//bzero((void*)datablock_header,255);
		char datablock_header[DB_HEADER_SIZE];
		bzero((void*)datablock_header,DB_HEADER_SIZE);

		PhastaIOActiveFiles[i]->GPid = PhastaIOActiveFiles[i]->nppp*PhastaIOActiveFiles[i]->myrank+PhastaIOActiveFiles[i]->part_count;
		sprintf( datablock_header,
				"\n%s : < %u >",
				keyphrase,
				size_of_nextblock );

		for ( int j = 0; j < *nItems; j++ )
		{
			sprintf( datablock_header,
					"%s %d ",
					datablock_header,
					*((int*)((int*)valueArray+j)));
		}
		sprintf( datablock_header,
				"%s\n ",
				datablock_header );

		// Write datablock header ...
		//MR CHANGE
		// 	if ( cscompare(datatype,"double") )
		char* ts1 = StringStripper( datatype );
		if ( cscompare("double",ts1) )
			//MR CHANGE END
		{
			free ( PhastaIOActiveFiles[i]->double_chunk );
			PhastaIOActiveFiles[i]->double_chunk = ( double * )malloc( (sizeof( double )*number_of_items+ DB_HEADER_SIZE));
			//PhastaIOActiveFiles[i]->double_chunk = ( double * ) malloc( sizeof( double )*number_of_items+ DB_HEADER_SIZE + pool_align );
			//mem_address = (long long )PhastaIOActiveFiles[i]->double_chunk;
			//if( mem_address & (pool_align -1) )
			// PhastaIOActiveFiles[i]->double_chunk += pool_align - (mem_address & (pool_align -1));

			double * aa = ( double * )datablock_header;
			memcpy(PhastaIOActiveFiles[i]->double_chunk, aa, DB_HEADER_SIZE);
		}
		//MR CHANGE
		// 	if  ( cscompare(datatype,"integer") )
		else if ( cscompare("integer",ts1) )
			//MR CHANGE END
		{
			free ( PhastaIOActiveFiles[i]->int_chunk );
			PhastaIOActiveFiles[i]->int_chunk = ( int * )malloc( (sizeof( int )*number_of_items+ DB_HEADER_SIZE));
			//PhastaIOActiveFiles[i]->int_chunk = ( int * ) malloc( sizeof( int )*number_of_items+ DB_HEADER_SIZE + pool_align );
			//mem_address = (long long )PhastaIOActiveFiles[i]->int_chunk;
			//if( mem_address & (pool_align -1) )
			// PhastaIOActiveFiles[i]->int_chunk += pool_align - (mem_address & ( pool_align -1));

			int * aa = ( int * )datablock_header;
			memcpy(PhastaIOActiveFiles[i]->int_chunk, aa, DB_HEADER_SIZE);
		}
		else {
			//             *fileDescriptor = DATA_TYPE_ILLEGAL;
			printf("writeheader - DATA_TYPE_ILLEGAL - %s\n",datatype);
                        endTimer(&timer_end);
                        printPerf("writeheader", timer_start, timer_end, 0, 0, "");
			return;
		}
		free(ts1);

		PhastaIOActiveFiles[i]->part_count++;
		if ( PhastaIOActiveFiles[i]->part_count == PhastaIOActiveFiles[i]->nppp ) {
			//A new field will be written
			if ( PhastaIOActiveFiles[i]->local_myrank == 0 ) {
				memcpy( PhastaIOActiveFiles[i]->master_header +
						PhastaIOActiveFiles[i]->field_count *
						MAX_FIELDS_NAME_LENGTH +
						MAX_FIELDS_NAME_LENGTH * 2,
						mpi_tag,
						MAX_FIELDS_NAME_LENGTH-1);
			}
			PhastaIOActiveFiles[i]->field_count++;
			PhastaIOActiveFiles[i]->part_count=0;
		}
                free(buffer);
	}

	endTimer(&timer_end);
	printPerf("writeheader", timer_start, timer_end, 0, 0, "");
}

void writedatablock( const int* fileDescriptor,
                      const char keyphrase[],
                      const void* valueArray,
                      const int* nItems,
                      const char datatype[],
                      const char iotype[] )
{
	//if(irank == 0) printf("entering writedatablock()\n");

	unsigned long long data_size = 0;
	double timer_start, timer_end;
	startTimer(&timer_start);

	int i = *fileDescriptor;
	checkFileDescriptor("writedatablock",&i);

	if ( PhastaIONextActiveIndex == 0 ) {
		int filePtr = *fileDescriptor - 1;

		if ( *fileDescriptor < 1 || *fileDescriptor > (int)fileArray.size() ) {
			fprintf(stderr,"No file associated with Descriptor %d\n",*fileDescriptor);
			fprintf(stderr,"openfile_ function has to be called before \n") ;
			fprintf(stderr,"acessing the file\n ") ;
			fprintf(stderr,"fatal error: cannot continue, returning out of call\n");
                        endTimer(&timer_end);
                        printPerf("writedatablock", timer_start, timer_end, 0, 0, "");
			return;
		}
		// since we require that a consistant header always preceed the data block
		// let us check to see that it is actually the case.

		if ( ! cscompare( LastHeaderKey[ filePtr ], keyphrase ) ) {
			fprintf(stderr, "Header not consistant with data block\n");
			fprintf(stderr, "Header: %s\n", LastHeaderKey[ filePtr ] );
			fprintf(stderr, "DataBlock: %s\n ", keyphrase );
			fprintf(stderr, "Please recheck write sequence \n");
			if( Strict_Error ) {
				fprintf(stderr, "fatal error: cannot continue, returning out of call\n");
                                endTimer(&timer_end);
                                printPerf("writedatablock", timer_start, timer_end, 0, 0, "");
				return;
			}
		}

		FILE* fileObject =  fileArray[ filePtr ] ;
		size_t type_size=typeSize( datatype );
		isBinary( iotype );

                free(LastHeaderKey[filePtr]);
                LastHeaderKey.erase(filePtr);

		if ( header_type[filePtr] != (int)type_size ) {
			fprintf(stderr,"header and datablock differ on typeof data in the block for\n");
			fprintf(stderr,"keyphrase : %s\n", keyphrase);
			if( Strict_Error ) {
				fprintf(stderr,"fatal error: cannot continue, returning out of call\n" );
                                endTimer(&timer_end);
                                printPerf("writedatablock", timer_start, timer_end, 0, 0, "");
				return;
			}
		}

		int nUnits = *nItems;

		if ( nUnits != DataSize ) {
			fprintf(stderr,"header and datablock differ on number of data items for\n");
			fprintf(stderr,"keyphrase : %s\n", keyphrase);
			if( Strict_Error ) {
				fprintf(stderr,"fatal error: cannot continue, returning out of call\n" );
                                endTimer(&timer_end);
                                printPerf("writedatablock", timer_start, timer_end, 0, 0, "");
				return;
			}
		}

		if ( binary_format ) {

			fwrite( valueArray, type_size, nUnits, fileObject );
			fprintf( fileObject,"\n");

		} else {

			char* ts1 = StringStripper( datatype );
			if ( cscompare( "integer", ts1 ) ) {
				for( int n=0; n < nUnits ; n++ )
					fprintf(fileObject,"%d\n",*((int*)((int*)valueArray+n)));
			} else if ( cscompare( "double", ts1 ) ) {
				for( int n=0; n < nUnits ; n++ )
					fprintf(fileObject,"%lf\n",*((double*)((double*)valueArray+n)));
			}
			free (ts1);
		}
		//return ;
	}
	else {  // syncIO case
		MPI_Status write_data_status;
		isBinary( iotype );
		int nUnits = *nItems;

		//MR CHANGE
		// 	if ( cscompare(datatype,"double") )
		char* ts1 = StringStripper( datatype );
		if ( cscompare("double",ts1) )
			//MR CHANGE END
		{
			memcpy((PhastaIOActiveFiles[i]->double_chunk+DB_HEADER_SIZE/sizeof(double)), valueArray, nUnits*sizeof(double));
			MPI_File_write_at_all_begin( PhastaIOActiveFiles[i]->file_handle,
					PhastaIOActiveFiles[i]->my_offset,
					PhastaIOActiveFiles[i]->double_chunk,
					//BLOCK_SIZE/sizeof(double),
					nUnits+DB_HEADER_SIZE/sizeof(double),
					MPI_DOUBLE );
			MPI_File_write_at_all_end( PhastaIOActiveFiles[i]->file_handle,
					PhastaIOActiveFiles[i]->double_chunk,
					&write_data_status );
			data_size=8*nUnits;
		}
		//MR CHANGE
		// 	else if ( cscompare ( datatype, "integer"))
		else if ( cscompare("integer",ts1) )
			//MR CHANGE END
		{
			memcpy((PhastaIOActiveFiles[i]->int_chunk+DB_HEADER_SIZE/sizeof(int)), valueArray, nUnits*sizeof(int));
			MPI_File_write_at_all_begin( PhastaIOActiveFiles[i]->file_handle,
					PhastaIOActiveFiles[i]->my_offset,
					PhastaIOActiveFiles[i]->int_chunk,
					nUnits+DB_HEADER_SIZE/sizeof(int),
					MPI_INT );
			MPI_File_write_at_all_end( PhastaIOActiveFiles[i]->file_handle,
					PhastaIOActiveFiles[i]->int_chunk,
					&write_data_status );
			data_size=4*nUnits;
		}
		else {
			printf("Error: writedatablock - DATA_TYPE_ILLEGAL - %s\n",datatype);
                        endTimer(&timer_end);
                        printPerf("writedatablock", timer_start, timer_end, 0, 0, "");
			return;
		}
                free(ts1);
	}

	endTimer(&timer_end);
	char extra_msg[1024];
	memset(extra_msg, '\0', 1024);
	char* key = StringStripper(keyphrase);
	sprintf(extra_msg, " field is %s ", key);
	printPerf("writedatablock", timer_start, timer_end, data_size, 1, extra_msg);
        free(key);

}

void
SwapArrayByteOrder( void* array,
                     int   nbytes,
                     int   nItems )
{
	/* This swaps the byte order for the array of nItems each
		 of size nbytes , This will be called only locally  */
	int i,j;
	unsigned char* ucDst = (unsigned char*)array;

	for(i=0; i < nItems; i++) {
		for(j=0; j < (nbytes/2); j++)
			std::swap( ucDst[j] , ucDst[(nbytes - 1) - j] );
		ucDst += nbytes;
	}
}

void
writestring( int* fileDescriptor,
              const char inString[] )
{

	int filePtr = *fileDescriptor - 1;
	FILE* fileObject = fileArray[filePtr] ;
	fprintf(fileObject,"%s",inString );
	return;
}

void
Gather_Headers( int* fileDescriptor,
                vector< string >& headers )
{

	FILE* fileObject;
	char Line[1024];

	fileObject = fileArray[ (*fileDescriptor)-1 ];

	while( !feof(fileObject) ) {
		fgets( Line, 1024, fileObject);
		if ( Line[0] == '#' ) {
			headers.push_back( Line );
		} else {
			break;
		}
	}
	rewind( fileObject );
	clearerr( fileObject );
}
void
isWrong( void ) { (Wrong_Endian) ? fprintf(stdout,"YES\n"): fprintf(stdout,"NO\n") ; }

void
togglestrictmode( void ) { Strict_Error = !Strict_Error; }

int
isLittleEndian( void )
{
	// this function returns a 1 if the current running architecture is
	// LittleEndian Byte Ordered, else it returns a zero

	union  {
		long a;
		char c[sizeof( long )];
	} endianUnion;

	endianUnion.a = 1 ;

	if ( endianUnion.c[sizeof(long)-1] != 1 ) return 1 ;
	else return 0;
}

namespace PHASTA {
	const char* const PhastaIO_traits<int>::type_string = "integer";
	const char* const PhastaIO_traits<double>::type_string = "double";
}