main.c

extremeDB s sample code,useful for you

/*****************************************************************
 *                                                               *
 * Copyright (c) 2001-2006 McObject LLC. All Right Reserved.     *
 *                                                               *
 *****************************************************************/

/*
 * This sample demonstrates McObject multi-threaded functionality -
 * transaction queue.
 * Multiple OS threads open "read-only" and "read-write" transactions.
 * Some of "read-only" transactions get upgraded to "read-write". Separate
 * "reporter" thread is used to collect thread data and print out
 * reports. The output frequency is regulated by changing REPORTER_DELAY
 * constant (threads.c)
 *
 * No acctual read/writes are performed in this examle; instead the worker threads
 * simply call Sleep() to simulate database activity. The wait time and the number
 * of worker threads could be easily changed by setting the appropriate constatns in
 * threads.c:
 * #define MAXREADERS 10
 * #define MAXWRITERS 4
 * #define WRITER_DELAY   200 // msec
 * #define READER_DELAY   10  // msec
 *
 * This sample could be used as a framework for some real application
 * with miltiple input and output streams.
 *
 */
#include "platform.h"
#include <stdio.h>
#include <stdlib.h>
#include "samples.h"

char   dbname[] = "SimpleDb";
static const int        FIRST_SEGSZ = 1024 * 8000UL;
#ifndef MCO_PLATFORM_X64
static const int        PAGESIZE = 96;
#else
static const int        PAGESIZE = 192;
#endif


const int MAP_ADDRESS =  0x20000000;

void threads( char * name , int inTestMode );

static void _SH_(void) {

	char text[] = {

		"\nThis sample demonstrates eXtremeDB multi-threaded functionality-\n"
		"the transaction queue.Multiple OS threads open \"read-only\" and \"read-write\"\n"
		"transactions. Some of \"read-only\" transactions get upgraded to \"read-write\".\n"
		"Separate \"reporter\" thread is used to collect thread data and print out\n"
		"reports. No actual database reads or writes are performed in this sample;\n"
		"instead the worker threads simply call Sleep() to simulate database activity.\n"
	};

	char text1[] = {
		"Copyright (c) 2001-2006 McObject LLC. All Right Reserved.\n\n"
	};

	printf("%s\neXtremeDB runtime version %d.%d, build %d\n%s\n\nPress Enter to start",
		text, MCO_COMP_VER_MAJOR, MCO_COMP_VER_MINOR, MCO_COMP_BUILD_NUM,text1);

	getchar();
}


void showMem( mco_db_h db ) {
	mco_puint  freepg, totalpg;

	mco_db_free_pages( db, &freepg );
	mco_db_total_pages( db, &totalpg );

	printf(	"\n\tMemory Report:\n\ttotal pages=%d (%dK)\n\tfree pages=%d (%dK)\n\tused %dK\n",
		totalpg,
		totalpg * PAGESIZE / 1024,
		freepg,
		freepg * PAGESIZE / 1024,
		(totalpg - freepg) * PAGESIZE / 1024
		);
}


/* fatal error handler */
static void errhandler( int n ) {
	printf( "\nFatal error: %d", n );
	getchar();
	exit( -1 );
}


int main( int argc, char **argv ) 
 {
	MCO_RET     rc;
	mco_db_h    db = 0;
	mco_runtime_info_t info;
	char * start_mem;
	int inTestMode = 0;

	if (argc>1 && strstr(argv[1],"--test")) inTestMode=1;
	_SH_();
	/* check wheather evants are supported by the runtime */
	mco_get_runtime_info( &info);
	if (!info.mco_multithreaded) {
		printf("This sample requires multi-threaded runtime\n");
		exit(1);
	}

	if ( info.mco_shm_supported ) {
		start_mem = (char*)MAP_ADDRESS;
	}
	else {
		start_mem = (char*)malloc(FIRST_SEGSZ);
		if (!start_mem) {
			printf("Couldn't allocated memory\n");
			exit (1);
		}
	};

	rc = mco_runtime_start();
	rc = mco_db_open( dbname, simple_get_dictionary(), start_mem, FIRST_SEGSZ, (uint2) PAGESIZE );

	if ( rc ) {
		printf( "\nerror creating database" );
		if ( !info.mco_shm_supported )
			free( start_mem );
		exit( 1 );
	}

	/* set application's error handler */
	mco_error_set_handler( &errhandler );

	threads( dbname , inTestMode);

	/* destroy the database */
	mco_db_close( dbname );

	mco_runtime_stop();

	if ( !info.mco_shm_supported )
		free( start_mem );

	printf( "\npress Enter to finish\n" );
	getchar();
	PROG_EXIT(0);
}