c – CLOCK_THREAD_CPUTIME_ID在MacOSX上

发布时间：2020-12-16 07:04:57 所属栏目：百科来源：网络整理

导读：我有一个函数,我正在从 Linux移植到MacOSX,它利用clock_gettime和CLOCK_THREAD_CPUTIME_ID来测量在进程上花费的时间. 我在互联网上发现这个代码会给我相当于CLOCK_REALTIME： #ifdef __MACH__ // OS X does not have clock_gettime,use clock_get_time clock

我有一个函数,我正在从 Linux移植到MacOSX,它利用clock_gettime和CLOCK_THREAD_CPUTIME_ID来测量在进程上花费的时间.
我在互联网上发现这个代码会给我相当于CLOCK_REALTIME：

#ifdef __MACH__ // OS X does not have clock_gettime,use clock_get_time
    clock_serv_t cclock;
    mach_timespec_t ts;
    host_get_clock_service(mach_host_self(),CALENDAR_CLOCK,&cclock);
    clock_get_time(cclock,&ts);
    mach_port_deallocate(mach_task_self(),cclock);
#else
    timespec ts;
    clock_gettime(CLOCK_REALTIME,ts);
#endif

但我似乎无法找到一个简单的方法来获取clock_gettime(CLOCK_THREAD_CPUTIME_ID,ts);
有谁知道这个很好的解决方案？

解决方法

最近我将一些pcsx2项目移植到Darwin / OSX,我也需要类似于CLOCK_THREAD_CPUTIME_ID的东西.这就是我想出的：

#include <stdint.h>

#include <mach/mach_init.h>
#include <mach/thread_act.h>
#include <mach/mach_port.h>

typedef uint64_t u64;

// gets the CPU time used by the current thread (both system and user),in
// microseconds,returns 0 on failure
static u64 getthreadtime(thread_port_t thread) {
    mach_msg_type_number_t count = THREAD_BASIC_INFO_COUNT;
    thread_basic_info_data_t info;

    int kr = thread_info(thread,THREAD_BASIC_INFO,(thread_info_t) &info,&count);
    if (kr != KERN_SUCCESS) {
        return 0;
    }

    // add system and user time
    return (u64) info.user_time.seconds * (u64) 1e6 +
        (u64) info.user_time.microseconds +
        (u64) info.system_time.seconds * (u64) 1e6 +
        (u64) info.system_time.microseconds;
}

// Returns the CPU time the calling thread has used (system + user) in
// units of 100 nanoseconds. The weird units are to mirror the Windows
// counterpart in WinThreads.cpp,which uses the GetThreadTimes() API.  On
// OSX/Darwin,this is only accurate up until 1ms (and possibly less),so
// not very good.
u64 Threading::GetThreadCpuTime() {
    thread_port_t thread = mach_thread_self();
    u64 us = getthreadtime(thread);
    mach_port_deallocate(mach_task_self(),thread);
    return us * 10ULL;
}

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!