功能描述:
获得进程的相关资源信息。如:用户开销时间,系统开销时间,接收的信号量等等;
用法:
#include< sys/types.h>
#include< sys/time.h>
#include< sys/resource.h>
#define RUSAGE_SELF 0
#define RUSAGE_CHILDREN -1
int getrusage(int who, struct rusage *usage);
当调用成功后,返回0,否则-1;
参数:
who:可能选择有
RUSAGE_SELF:获取当前进程的资源使用信息。以当前进程的相关信息来填充rusage(数据)结构
RUSAGE_CHILDREN:获取子进程的资源使用信息。rusage结构中的数据都将是当前进程的子进程的信息
usage:指向存放资源使用信息的结构指针。
rusage(数据)结构定义在/usr/include/sys/resource.h中,下面是rusage的结构:
struct rusage {
struct timeval ru_utime; // user time used
struct timeval ru_stime; // system time used
long ru_maxrss; // maximum resident set size
long ru_ixrss; // integral shared memory size
long ru_idrss; // integral unshared data size
long ru_isrss; // integral unshared stack size
long ru_minflt; // page reclaims
long ru_majflt; // page faults
long ru_nswap;// swaps
long ru_inblock; // block input operations
long ru_oublock; // block output operations
long ru_msgsnd; // messages sent
long ru_msgrcv; //messages received
long ru_nsignals; // signals received
long ru_nvcsw; // voluntary context switches
long ru_nivcsw; // involuntary context switches
};
举个例子:
int who = RUSAGE_SELF;
struct rusage usage;
int ret;
ret = getrusage(who, &usage);
这样你就可以用usage获取你想要的东西了;
同样wait3()和wait4()两个函数也可以得到进程资源信息.
得到CPU使用时间的用法:
struct rusage rup;
getrusage(RUSAGE_SELF, &rup);
long sec = rup.ru_utime.tv_sec + rup.ru_stime.tv_sec;
long usec = rup.ru_utime.tv_usec + rup.ru_stime.tv_usec;
sec += usec/1000000;
usec %= 1000000;
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