2.编译时遇到 “implicit declaration of function 'udelay' ”问题,一般是由于头文件的问题; (二)sleep函数 1.msleep、ssleep 头文件:#include <linux/delay.h> 原型:void msleep(unsigned int millisecs); void ssleep(unsigned int seconds); 注意:1.获取指定(或略长)的延时时间,但不会忙等待; 2.调用时...
hello3.c:16:9: warning: implicit declaration of function 'write' is invalid in C99 [-Wimplicit-function-declaration] write(1,"*",1); ^ hello3.c:17:9: warning: implicit declaration of function 'sleep' is invalid in C99 [-Wimplicit-function-declaration] sleep(1); ^ 2 warnings generate...
thread_create.c:18:2: warning:implicitdeclaration of function ‘sleep’ [-Wimplicit-function-declaration] 原因是缺少头文件unistd.h,完整的代码如下: 1#include<stdio.h>2#include<stdlib.h>3#include<pthread.h>4#include<unistd.h>5void* callback(void*arg){6printf("子线程id:%ld\n",pthread_self...
delay函数是忙则等待,占用CPU时间;而sleep函数使调用的进程进行休眠。 3.)udelay() mdelay() ndelay() 区别: udelay(); mdelay(); ndelay();实现的原理本质上都是忙等待,ndelay和mdelay都是通过udelay衍生出来的。 我们使用这些函数的实现往往会碰到编译器的警告implicit declaration of function 'udelay',这往往...
udelay(); mdelay(); ndelay();实现的原理本质上都是忙等待,ndelay和mdelay都是通过udelay衍生出来的,我们使用这些函数的实现往往会碰到编译器的警告implicitdeclarationoffunction'udelay',这往往是由于头文件的使用不当造成的。在include/asm-/delay.h中定义了udelay(),而在include/linux/delay.h中定义了mdelay和nde...
hello.c: In function 'main': hello.c:10:5: error: implicit declaration of function 'printf' [-Werror=implicit-function-declaration] printf("Hello, world!\n"); 这通常是因为缺少标准库头文件。可以通过添加#include <stdio.h>来解决: #include <stdio.h> int main() { printf("Hello, world!
/home/pi/Downloads/LINUX/ch9344.c: In function ‘ch9344_init’: /home/pi/Downloads/LINUX/ch9344.c:2200:22:error: implicit declaration of function ‘alloc_tty_driver’ [-Werror=implicit-function-declaration] 2200 | ch9344_tty_driver = alloc_tty_driver(CH9344_TTY_MINORS); | ^~~~ /ho...
kernel/workqueue.c:4840:5: error: implicit declaration of function ‘printk_deferred_enter’ [-W...
c: 在函数‘main’中: k.c:43:7: 警告：隐式声明函数‘usleep’ [-Wimplicit-function-declaration...
HAVE_SCAN_BW 0" >> qcsapi_caps.h cc1: warnings being treated as errors qh_curl_ws.c: In function âws_connect_cbâ: qh_curl_ws.c:556: warning: implicit declaration of function âSHA1â make[4]: *** [qh_curl_ws.o] Error 1 make[4]: *** Waiting for unfinished jobs... ...