Linux中的延时函数

应用层：

#include
<unistd.h>

1、unsigned int sleep(unsigned
int seconds); 秒级

2、int usleep(useconds_t
usec);
微秒级：1/10^-6

[align=center][/align]

#define _POSIX_C_SOURCE
199309

#include
<time.h>

3、int nanosleep(const struct
timespec *req, struct timespec *rem);

struct timespec {

time_t
tv_sec;

long
tv_nsec;

};

// The value of the nanoseconds field must be in the range 0 to
999999999.

内核层：

include
<linux/delay.h>

1、void ndelay(unsigned long
nsecs);
纳秒级：1/10^-10

2、void udelay(unsigned long
usecs);
微秒级: 1/10^-6

3、void mdelay(unsigned long
msecs);
毫秒级：1/10^-3