getrusage()函數 Unix/Linux
內容簡介
#include <sys/time.h>#include <sys/resource.h>
int getrusage(int who, struct rusage *usage);
描述
getrusage() 返回當前資源使用，對於無論是 RUSAGE_SELF 或 RUSAGE_CHILDREN. 前者要求所使用當前進程，後者所使用的那些其子已經終止，並且已經在等待資源的資源。
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 */
};
|
返回值
On success, zero is returned. On error, -1 is returned, and errno is set appropriately.錯誤
| 標簽 | 描述 |
|---|---|
| EFAULT | usage points outside the accessible address space. |
| EINVAL | who is invalid. |
遵循於
SVr4, 4.3BSD. POSIX.1-2001 specifies getrusage(), but only specifies the fields ru_utimeand ru_stime.注意
Including <sys/time.h> is not required these days, but increases portability. (Indeed,struct timeval is defined in <sys/time.h>.)In Linux kernel versions before 2.6.9, if the disposition of SIGCHLD is set to SIG_IGNthen the resource usages of child processes are automatically included in the value returned by RUSAGE_CHILDREN, although POSIX.1-2001 explicitly prohibits this. This non-conformance is rectified in Linux 2.6.9 and later.
The above struct was taken from 4.3BSD Reno. Not all fields are meaningful under Linux. In linux 2.4 only the fields ru_utime, ru_stime, ru_minflt, and ru_majflt are maintained. Since Linux 2.6, ru_nvcsw and ru_nivcsw are also maintained.
