C/C++编程：对于C的error

曾经终败给现在 2022-12-27 01:28 129阅读 0赞

# 单线程 #

const char *acl_strerror(unsigned int errnum, char *buffer, int size);
    int main(){
        
        int _buf_size = 4096;
        char *buf = (char *) malloc(_buf_size*sizeof(char));
    
        for (int i= 1; i< 133; ++i) {
        
            printf("%d, %s\n", i, acl_strerror(i, buf, _buf_size));
        }
        free(buf);
    }
    const char *acl_strerror(unsigned int errnum, char *buffer, int size){
        
        const char *myname = "acl_strerror";
        if(buffer == NULL || size <= 0){
        
            printf("%s, %s(%d): input error",
                          __FILE__, myname, __LINE__);
            return NULL;
        }
        snprintf(buffer, size, "%s", strerror(errnum));
        return buffer;
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70]  
2. 封装

#include <stdlib.h>
    #include <stdio.h>
    #include <string.h>
    #include <errno.h>
    
    
    const char *acl_strerror(unsigned int errnum, char *buffer, int size);
    
    void acl_set_error(int errnum){
        
        errno = errnum;
    }
    int acl_last_error(void){
        
        return errno;
    }
    
    int main(){
        
        int _buf_size = 4096;
        char *buf = (char *) malloc(_buf_size*sizeof(char));
    
        for (int i = 1; i < 133; ++i) {
        
            acl_set_error(i);
            printf("%d, %s\n", acl_last_error(), acl_strerror(acl_last_error(), buf, _buf_size));
        }
        free(buf);
    }
    
    
    const char *acl_strerror(unsigned int errnum, char *buffer, int size){
        
        const char *myname = "acl_strerror";
        if(buffer == NULL || size <= 0){
        
            printf("%s, %s(%d): input error",
                   __FILE__, myname, __LINE__);
            return NULL;
        }
        snprintf(buffer, size, "%s", strerror(errnum));
        return buffer;
    }

# 多线程 #

#include <stdlib.h>
    #include <stdio.h>
    #include <string.h>
    #include <errno.h>
    #include <pthread.h>
    #include <zconf.h>
    
    
    
    void acl_set_error(int errnum){
        
        errno = errnum;
    }
    int acl_last_error(void){
        
        return errno;
    }
    
    const char *acl_strerror(unsigned int errnum, char *buffer, int size){
        
        const char *myname = "acl_strerror";
        if(buffer == NULL || size <= 0){
        
            printf("%s, %s(%d): input error",
                   __FILE__, myname, __LINE__);
            return NULL;
        }
        snprintf(buffer, size, "%s", strerror(errnum));
        return buffer;
    }
    
    
    const char *acl_strerror_1(unsigned int errnum){
        
        const char *pname = "acl_strerror_1";
        char *buf;
        static int __buf_size = 4096;
    
    
        buf = (char *) malloc(__buf_size*sizeof(char));
        if(buf == NULL){
        
            printf("%s(%d) malloc: insufficient memory: %s, len: %d", pname, __LINE__,
                   strerror(errno), (int) __buf_size);
            exit(-1);
        }
    
        return acl_strerror(errnum, buf, __buf_size);
    }
    
    int myerror = 0;
    void *  child1(void * arg){
        
        sleep(1);
        printf("child1, %s, %d, %d\n", acl_strerror_1(acl_last_error()), acl_last_error(), myerror);
        return NULL;
    }
    void *  child2(void * arg){
        
        printf("child2, %s, %d, %d\n", acl_strerror_1(acl_last_error()), acl_last_error(), myerror);
        return NULL;
    }
    int main(){
        
        myerror = 6;
        errno = 6;
        acl_set_error(1);
        pthread_t tid1,tid2;
        pthread_create(&tid1,NULL,child1,NULL);
        pthread_create(&tid2,NULL,child2,NULL);
    
        pthread_join(tid2, NULL);
        pthread_join(tid1, NULL);
    }

![在这里插入图片描述][20201207104235261.png]

经实践： error是线程专有数据，每个线程都有一个自己的副本，线程之间的error互不影响

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3poaXpoZW5nZ3Vhbg_size_16_color_FFFFFF_t_70]: /images/20221120/a349da9260e14eea9a4e379e15352c3b.png
[20201207104235261.png]: https://img-blog.csdnimg.cn/20201207104235261.png