我正在处理一个项目，我必须处理多个传感器，并将错误值打印到文本文件中。目前我正在做随机生成器，只生成一些虚拟值。这里的问题是，相同的错误存储在文本文件中，因为代码运行速度很快且循环运行。所以我想要制作一个计时器来处理当前传感器的最后存储数据。我不确定这是不是一个好主意，因为它听起来不容易，因为最后我将不得不处理大约30种不同的传感器。知道如何在我的代码中实现这样的逻辑吗？
struct arg_struct{ //store the these data into the textfile
char *sensorname;
double sensorvalue;
int faultcode;
};
//insert the data into the textfile with the arguments from detect_error
void *write_sens_error(void *arguments){
struct arg_struct *args = arguments;
struct tm *local;
time_t t;
t = time(NULL);
local = localtime(&t);
FILE *fp;
fp = fopen("/home/sal/Desktop/sensors.txt","a");
fprintf(fp, "%s %s %f %s %d %s %s", args -> sensorname, "\t",args -> sensorvalue, "\t", args -> faultcode,"\t",asctime(local));
fclose(fp);
pthread_exit(NULL);
return NULL;
}
//create a new thread, so the second thread will handle the errorvalue storage
void detect_error(char *sensorname, double sensorvalue, int faultcode){
pthread_t thread_error1;
struct arg_struct args;
args.sensorname = malloc(7);
strcpy(args.sensorname, sensorname);
args.sensorvalue = sensorvalue;
args.faultcode = faultcode;
pthread_create(&thread_error1, NULL, &write_sens_error, (void *)&args);
pthread_join(thread_error1, NULL);
free(args.sensorname);
}
//generate random values and check for error
void rand_temperature_sensor(double EXTS[8], int FTS, int CTS, int OTS){
int i;
for (i = 0; i < 8; i++){
EXTS[i] = rand() % 10 + 820;
if(EXTS[i]>800){
char name[6];
sprintf(name, "EXTS%d", i+1);
detect_error(name,EXTS[i],((EXTS[i]>850) ? 2 : 1));
}
}
printf("%s,%f,%f,%f,%f,%f,%f,%f,%f\n","Temp",EXTS[0],EXTS[1],EXTS[2],EXTS[3],EXTS[4],EXTS[5],EXTS[6],EXTS[7];
}
这是此代码生成的日志片段。从日志中可以看出，相同的传感器在一秒钟内存储三次。这就是我想要避免的，所以传感器的错误只会在上一次错误捕获后5秒后存储。
EXTS0 823.000000 1 Tue Apr 28 23:43:57 2015
EXTS1 820.000000 1 Tue Apr 28 23:43:57 2015
EXTS2 826.000000 1 Tue Apr 28 23:43:57 2015
EXTS3 827.000000 1 Tue Apr 28 23:43:57 2015
EXTS4 829.000000 1 Tue Apr 28 23:43:57 2015
EXTS5 826.000000 1 Tue Apr 28 23:43:57 2015
EXTS6 820.000000 1 Tue Apr 28 23:43:57 2015
EXTS7 823.000000 1 Tue Apr 28 23:43:57 2015
EXTS0 827.000000 1 Tue Apr 28 23:43:57 2015
EXTS1 828.000000 1 Tue Apr 28 23:43:57 2015
EXTS2 822.000000 1 Tue Apr 28 23:43:57 2015
EXTS3 826.000000 1 Tue Apr 28 23:43:57 2015
EXTS4 822.000000 1 Tue Apr 28 23:43:57 2015
EXTS5 822.000000 1 Tue Apr 28 23:43:57 2015
EXTS6 829.000000 1 Tue Apr 28 23:43:57 2015
EXTS7 826.000000 1 Tue Apr 28 23:43:57 2015
EXTS0 821.000000 1 Tue Apr 28 23:43:57 2015
EXTS1 823.000000 1 Tue Apr 28 23:43:57 2015
EXTS2 822.000000 1 Tue Apr 28 23:43:57 2015
EXTS3 824.000000 1 Tue Apr 28 23:43:57 2015
EXTS4 826.000000 1 Tue Apr 28 23:43:57 2015
EXTS5 826.000000 1 Tue Apr 28 23:43:57 2015
EXTS6 821.000000 1 Tue Apr 28 23:43:57 2015
EXTS7 824.000000 1 Tue Apr 28 23:43:57 2015
我真的不希望这个问题令人困惑。如果我需要清除一些东西，请告诉我。完整代码已粘贴here。
答案 0 :(得分：1)
我建议你添加一个“pthread_mutex_t”来处理文件写入：
1.将mutex_writing声明为全局变量
2. is_writing [EXTS_LIMIT]作为每个传感器的全局变量//：表示写入状态的布尔值
3. writingtime [EXTS_LIMIT] //存储给定传感器的最后写入时间
4. index //添加到arg_struct以识别传感器并修改is_writing
5.在写作时锁定mutex_writing然后解锁
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <time.h>
#define EXTS_limit 1000
#define CPS_limit 200
#define MAF1_limit 700
#define MAF2_limit 130
#define KS_limit 20
#define FTS_limit 100
#define CTS_limit 105
#define OTS_limit 100
#define OPS_limit 11
#define FPS_limit 11
#define MAP_limit 5
/****/
#define MILLISECONDES 1000
#define FIVESECS 5000*MILLISECONDES
pthread_mutex_t mutex_writing = PTHREAD_MUTEX_INITIALIZER;
int is_writing[EXTS_limit];
clock_t writingtime[EXTS_limit];
/***/
struct arg_struct{
char *sensorname;
double sensorvalue;
int faultcode;
int index;
};
void *write_sens_error(void *arguments)
{
pthread_mutex_lock(&mutex_writing);
struct arg_struct *args = arguments;
struct tm *local;
time_t t;
t = time(NULL);
local = localtime(&t);
FILE *fp;
fp = fopen("/home/sal/Desktop/sensor_data.txt","a"); //PATH TO THE TEXTFILE.
fprintf(fp, "%s %s %f %s %d %s %s", args -> sensorname, "\t",args -> sensorvalue, "\t", args -> faultcode,"\t",asctime(local));
fclose(fp);
is_writing[args->index]=0;
pthread_mutex_unlock(&mutex_writing);
pthread_exit(NULL);
return NULL;
}
void detect_error(char *sensorname, double sensorvalue, int faultcode, int index){
pthread_t thread_error1;
struct arg_struct args;
args.sensorname = malloc(7);
strcpy(args.sensorname, sensorname);
args.sensorvalue = sensorvalue;
args.faultcode = faultcode;
args.index=index;
clock_t t=clock();
if(is_writing[index]==0 && ((float)t-(float)writingtime[index])>FIVESECS)
{
is_writing[index]=1;
writingtime[index]=clock();
pthread_create(&thread_error1, NULL, &write_sens_error, (void *)&args);
pthread_join(thread_error1, NULL);
}
free(args.sensorname);
}
void rand_temperature_sensor(double EXTS[8], int FTS, int CTS, int OTS){
int i;
for (i = 0; i < 8; i++){
EXTS[i] = rand() % 10 + 820;
if(EXTS[i]>EXTS_limit){
char name[6];
sprintf(name, "EXTS%d", i+1);
detect_error(name,EXTS[i],((EXTS[i]>1050) ? 2 : 1),i);
}
}
FTS = rand() % 30 + 91;
if(FTS > FTS_limit) detect_error("FTS",FTS,((FTS>120) ? 2 : 1),8);
CTS = rand() % 3 + 90;
if(CTS > CTS_limit) detect_error("CTS",CTS,((CTS>110) ? 2 : 1),9);
OTS = rand() % 30 + 91;
if(OTS > OTS_limit) detect_error("OTS",OTS,((OTS>120) ? 2 : 1),10);
printf("%s,%f,%f,%f,%f,%f,%f,%f,%f,%d,%d,%d\n","Temp",EXTS[0],EXTS[1],EXTS[2],EXTS[3],EXTS[4],EXTS[5],EXTS[6],EXTS[7],FTS,CTS,OTS);
}
void rand_CPS_LS_KS_ACC(int CPS[8], int LS[2], int KS[2],int TS[2]){
int i;
for (i = 0; i < 8; i++){
CPS[i] = rand() % 2 + 20;
}
for(i=0; i < 2; i++){
LS[i] = rand() % 3 + 30;
KS[i] = rand() % 3 + 40;
TS[i] = rand() % 40 + 100;
}
printf("%s,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d\n","CPS_LS_KS_TS", CPS[0],CPS[1],CPS[2],CPS[3],CPS[4],CPS[5],CPS[6],CPS[7],LS[0],LS[1],KS[0],KS[1],TS[0],TS[1]);
}
void rand_CAM_ACC(int CAM[4], int ACC_[2]){
int i;
for (i = 0; i < 4; i++){
CAM[i] = rand() % 7 + 10;
}
ACC_[1] = rand() % 3 + 20;
ACC_[2] = rand() % 1 + 1;
printf("%s,%d,%d,%d,%d,%d,%d\n","CAM_ACC", CAM[0],CAM[1],CAM[2],CAM[3],ACC_[1],ACC_[2]);
}
void rand_MAP_MAF_FFS_CRANK(int dash_kmt, int MAP, int MAF, int FFS, int CRANK, int OPS, int FPS){
dash_kmt = rand() % 6 + 60;
MAP = rand() % 10 + 30;
MAF = rand() % 5 + 20;
FFS = rand() % 2 + 20;
CRANK = rand() % 3 + 2;
OPS = rand() % 3 + 2;
FPS = 25;
printf("%s,%d,%d,%d,%d,%d,%d,%d\n","dash", dash_kmt,MAP,MAF,FFS,CRANK,OPS,FPS);
}
int main() {
/*Init global variables*/
int count=0;
for(count=0;count<EXTS_limit;count++)
{
is_writing[count]=0;
writingtime[count]=0;
}
/****/
int i;
setbuf(stdout, NULL); // Disable output buffering.
//setbuf(stdin, NULL); //Disable input buffering
srand ( time(NULL) ); //generate different random values
double EXTS[8]; int CPS[8],CAM[4],LS[2],KS[2],TS[2],ACC_[2],FTS, CTS, OTS;
int dash_kmt,MAP,MAF,FFS,CRANK,OPS,FPS;
int state = 1;
while(state == 1){
rand_temperature_sensor(EXTS,FTS,CTS,OTS);
rand_CPS_LS_KS_ACC(CPS,LS,KS,TS);
rand_CAM_ACC(CAM,ACC_);
rand_MAP_MAF_FFS_CRANK(dash_kmt,MAP,MAF,FFS,CRANK,OPS,FPS);
usleep(600);
}
//pthread_join(thread_error1, NULL);
return 0;
}