并发程序设计

ComputeTask.h：
void executeComputeTask();

ComputeTask.c:
#include "ComputeTask.h"
#include <stdio.h>
#include <stdint.h>

#define LOOP_SIZE (1024*1024*1024)

void executeComputeTask()
{
	size_t idx=0;
	size_t loopSize=LOOP_SIZE;
	
	for(idx=0;idx<loopSize;++idx)
	{
		//sum
	}
}

IOTask.h:
void executeIOTask();

IOTask.c:
#include "IOTask.h"
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>

#define BUFFER_SIZE (1024*1024*1024)

const char fileName[]="IOFile";
void executeIOTask()
{
	char* fileBuf=(char*)malloc(BUFFER_SIZE);
	int fileFd=open(fileName,O_RDWR|O_CREAT,0644);
	if(-1==fileFd)
	{
		perror("Open File Error");
	}
	memset(fileBuf,97,BUFFER_SIZE);
	size_t writeSize = write(fileFd,fileBuf,BUFFER_SIZE);
	printf("write:%lu bytes to file:%s\n",writeSize,fileName);
	free(fileBuf);
	close(fileFd);
}

mainProg.c:
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/time.h>
#include <unistd.h>

#include "ComputeTask.h"
#include "IOTask.h"

typedef enum OP{

	COMPUTE_TASK=1,
	IO_TASK
}OP_t;

typedef struct task{
	struct task *next;
	OP_t taskType;
}task_t;

int main(int argc, char *argv[])
{
	double computeTaskTimeElapse=0.0;
	double IOTaskTimeElapse=0.0;
	double totalTimeElapse=0.0;

	struct timeval computeTaskStartTime, computeTaskEndTime,IOTaskStartTime, IOTaskEndTime;
	
	pid_t fpid;
	task_t computeTask, ioTask;
	task_t* curTask = &computeTask;

	computeTask.taskType = COMPUTE_TASK;
	computeTask.next=&ioTask;
	ioTask.taskType=IO_TASK;
	ioTask.next=NULL;

	int parentProcess = 1;
	int childProcessNum = 0;

	while(NULL!=curTask)
	{
		if(curTask->taskType==IO_TASK)
			gettimeofday(&IOTaskStartTime,NULL);
		else
			gettimeofday(&computeTaskStartTime,NULL);
		fpid=fork();
		if(0==fpid)
		{//This is the child process
			parentProcess=0;
			break;
		}
		else if(-1==fpid)
		{
			printf("Generate child Process error!\n");
			exit(0);
		}

		wait(NULL);  //wait the child process finish execution
		
		if(COMPUTE_TASK==curTask->taskType)
			gettimeofday(&computeTaskEndTime,NULL);
		else
			gettimeofday(&IOTaskEndTime,NULL);
		printf("Generate child process with pid:%d\n",fpid);

		++childProcessNum;
		curTask=curTask->next;

	}

	if(parentProcess==0)
	{
		if(curTask->taskType==IO_TASK)
		{
			executeIOTask();
			printf("This is a IO task, pid:%d parent pid:%d\n",getpid(),getppid());//Print process ID and parent process ID
		}
		if(curTask->taskType==COMPUTE_TASK)
		{
			executeComputeTask();
			printf("This is a compute task, pid:%d parent pid:%d\n",getpid(),getppid());//Print process ID and parent process ID
		}
	}
	else
	{
		//Parent Process, we calculate the time for executing computing task and the time fo executing IO task
		computeTaskTimeElapse = (double)(computeTaskEndTime.tv_sec - computeTaskStartTime.tv_sec)*1000.0+(double)(computeTaskEndTime.tv_usec - computeTaskStartTime.tv_usec)/1000.0;
		IOTaskTimeElapse = (double)(IOTaskEndTime.tv_sec - IOTaskStartTime.tv_sec)*1000.0+(double)(IOTaskEndTime.tv_usec - IOTaskStartTime.tv_usec)/1000.0;
		totalTimeElapse = (double)(IOTaskEndTime.tv_sec-computeTaskStartTime.tv_sec)*1000.0+(double)(IOTaskEndTime.tv_usec-computeTaskStartTime.tv_usec)/1000.0;
		printf("Compute Task Time Consume:%fms, IO Task Time Consume: %fms, Total Time Consume:%fms \n", computeTaskTimeElapse,IOTaskTimeElapse,totalTimeElapse);
	}


}