[apple/libc.git] / gen / clock_gettime.c

/*
 * Copyright (c) 2016 Apple Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * This file contains Original Code and/or Modifications of Original Code
 * as defined in and that are subject to the Apple Public Source License
 * Version 2.0 (the 'License'). You may not use this file except in
 * compliance with the License. Please obtain a copy of the License at
 * http://www.opensource.apple.com/apsl/ and read it before using this
 * file.
 * 
 * The Original Code and all software distributed under the License are
 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
 * Please see the License for the specific language governing rights and
 * limitations under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */

#include <errno.h>
#include <stdatomic.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <mach/mach_error.h>
#include <mach/mach_time.h>
#include <os/base_private.h>

extern uint64_t __thread_selfusage(void);

#define timeval2nsec(tv) (tv.tv_sec * NSEC_PER_SEC + tv.tv_usec * NSEC_PER_USEC)

static uint64_t
_boottime_fallback_usec(void)
{
    struct timeval tv;
    size_t len = sizeof(tv);
    int ret = sysctlbyname("kern.boottime", &tv, &len, NULL, 0);
    if (ret == -1) return 0;
    return (uint64_t)tv.tv_sec * USEC_PER_SEC + (uint64_t)tv.tv_usec;
}

static int
_mach_boottime_usec(uint64_t *boottime, struct timeval *realtime)
{
    uint64_t bt1 = 0, bt2 = 0;
    int ret;
    do {
        bt1 = mach_boottime_usec();
        if (os_slowpath(bt1 == 0)) bt1 = _boottime_fallback_usec();

        atomic_thread_fence(memory_order_seq_cst);

        ret = gettimeofday(realtime, NULL);
        if (ret != 0) return ret;

        atomic_thread_fence(memory_order_seq_cst);

        bt2 = mach_boottime_usec();
        if (os_slowpath(bt2 == 0)) bt2 = _boottime_fallback_usec();
    } while (os_slowpath(bt1 != bt2));
    *boottime = bt1;
    return 0;
}

uint64_t
clock_gettime_nsec_np(clockid_t clock_id)
{
    switch(clock_id){
    case CLOCK_REALTIME: {
        struct timeval tv;
        int ret = gettimeofday(&tv, NULL);
        if (ret) return 0;
        return timeval2nsec(tv);
    }
    case CLOCK_MONOTONIC: {
        struct timeval tv;
        uint64_t boottime;
        int ret = _mach_boottime_usec(&boottime, &tv);
        if (ret) return 0;
        boottime *= NSEC_PER_USEC;
        return timeval2nsec(tv) - boottime;
    }
    case CLOCK_PROCESS_CPUTIME_ID: {
        struct rusage ru;
        int ret = getrusage(RUSAGE_SELF, &ru);
        if (ret) return 0;
        return timeval2nsec(ru.ru_utime) + timeval2nsec(ru.ru_stime);
    }
    default:
        // calls that use mach_absolute_time units fall through into a common path
        break;
    }

    // Mach Absolute Time unit-based calls
    mach_timebase_info_data_t tb_info;
    if (mach_timebase_info(&tb_info)) return 0;
    uint64_t mach_time;

    switch(clock_id){
    case CLOCK_MONOTONIC_RAW:
        mach_time = mach_continuous_time();
        break;
    case CLOCK_MONOTONIC_RAW_APPROX:
        mach_time = mach_continuous_approximate_time();
        break;
    case CLOCK_UPTIME_RAW:
        mach_time = mach_absolute_time();
        break;
    case CLOCK_UPTIME_RAW_APPROX:
        mach_time = mach_approximate_time();
        break;
    case CLOCK_THREAD_CPUTIME_ID:
        mach_time = __thread_selfusage();
        break;
    default:
        errno = EINVAL;
        return 0;
    }

    return (mach_time * tb_info.numer) / tb_info.denom;
}

int
clock_gettime(clockid_t clk_id, struct timespec *tp)
{
    switch(clk_id){
    case CLOCK_REALTIME: {
        struct timeval tv;
        int ret = gettimeofday(&tv, NULL);
        TIMEVAL_TO_TIMESPEC(&tv, tp);
        return ret;
    }
    case CLOCK_MONOTONIC: {
        struct timeval tv;
        uint64_t boottime_usec;
        int ret = _mach_boottime_usec(&boottime_usec, &tv);
        struct timeval boottime = {
            .tv_sec = boottime_usec / USEC_PER_SEC,
            .tv_usec = boottime_usec % USEC_PER_SEC
        };
        timersub(&tv, &boottime, &tv);
        TIMEVAL_TO_TIMESPEC(&tv, tp);
        return ret;
    }
    case CLOCK_PROCESS_CPUTIME_ID: {
        struct rusage ru;
        int ret = getrusage(RUSAGE_SELF, &ru);
        timeradd(&ru.ru_utime, &ru.ru_stime, &ru.ru_utime);
        TIMEVAL_TO_TIMESPEC(&ru.ru_utime, tp);
        return ret;
    }
    case CLOCK_MONOTONIC_RAW:
    case CLOCK_MONOTONIC_RAW_APPROX:
    case CLOCK_UPTIME_RAW:
    case CLOCK_UPTIME_RAW_APPROX:
    case CLOCK_THREAD_CPUTIME_ID: {
        uint64_t ns = clock_gettime_nsec_np(clk_id);
        if (!ns) return -1;

        tp->tv_sec = ns/NSEC_PER_SEC;
        tp->tv_nsec = ns % NSEC_PER_SEC;
        return 0;
    }
    default:
        errno = EINVAL;
        return -1;
    }
}

int
clock_getres(clockid_t clk_id, struct timespec *res)
{
    switch(clk_id){
    case CLOCK_REALTIME:
    case CLOCK_MONOTONIC:
    case CLOCK_PROCESS_CPUTIME_ID:
        res->tv_nsec = NSEC_PER_USEC;
        res->tv_sec = 0;
        return 0;

    case CLOCK_MONOTONIC_RAW:
    case CLOCK_MONOTONIC_RAW_APPROX:
    case CLOCK_UPTIME_RAW:
    case CLOCK_UPTIME_RAW_APPROX:
    case CLOCK_THREAD_CPUTIME_ID: {
        mach_timebase_info_data_t tb_info;
        if (mach_timebase_info(&tb_info)){
            return -1;
        }
        res->tv_nsec = tb_info.numer / tb_info.denom + (tb_info.numer % tb_info.denom != 0);
        res->tv_sec = 0;
        return 0;
    }

    default:
        errno = EINVAL;
        return -1;
    }
}

int
clock_settime(clockid_t clk_id, const struct timespec *tp)
{
    switch(clk_id){
    case CLOCK_REALTIME: {
        struct timeval tv = {
            .tv_sec = (time_t)tp->tv_sec,
            .tv_usec = (suseconds_t)(tp->tv_nsec / NSEC_PER_USEC)
        };
        return settimeofday(&tv, NULL);
    }
    default:
        errno = EINVAL;
        return -1;
    }
}
Commit	Line	Data
974e3884 A	1	/*
	2	* Copyright (c) 2016 Apple Inc. All rights reserved.
	3	*
	4	* @APPLE_LICENSE_HEADER_START@
	5	*
	6	* This file contains Original Code and/or Modifications of Original Code
	7	* as defined in and that are subject to the Apple Public Source License
	8	* Version 2.0 (the 'License'). You may not use this file except in
	9	* compliance with the License. Please obtain a copy of the License at
	10	* http://www.opensource.apple.com/apsl/ and read it before using this
	11	* file.
	12	*
	13	* The Original Code and all software distributed under the License are
	14	* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	15	* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	16	* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	17	* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	18	* Please see the License for the specific language governing rights and
	19	* limitations under the License.
	20	*
	21	* @APPLE_LICENSE_HEADER_END@
	22	*/
	23
	24	#include <errno.h>
	25	#include <stdatomic.h>
	26	#include <stdio.h>
	27	#include <stdlib.h>
	28	#include <stdint.h>
	29	#include <string.h>
	30	#include <time.h>
	31	#include <unistd.h>
	32	#include <sys/time.h>
	33	#include <sys/types.h>
	34	#include <sys/sysctl.h>
	35	#include <mach/mach_error.h>
	36	#include <mach/mach_time.h>
	37	#include <os/base_private.h>
	38
	39	extern uint64_t __thread_selfusage(void);
	40
	41	#define timeval2nsec(tv) (tv.tv_sec * NSEC_PER_SEC + tv.tv_usec * NSEC_PER_USEC)
	42
	43	static uint64_t
	44	_boottime_fallback_usec(void)
	45	{
	46	struct timeval tv;
	47	size_t len = sizeof(tv);
	48	int ret = sysctlbyname("kern.boottime", &tv, &len, NULL, 0);
	49	if (ret == -1) return 0;
	50	return (uint64_t)tv.tv_sec * USEC_PER_SEC + (uint64_t)tv.tv_usec;
	51	}
	52
	53	static int
	54	_mach_boottime_usec(uint64_t boottime, struct timeval realtime)
	55	{
	56	uint64_t bt1 = 0, bt2 = 0;
	57	int ret;
	58	do {
	59	bt1 = mach_boottime_usec();
	60	if (os_slowpath(bt1 == 0)) bt1 = _boottime_fallback_usec();
	61
	62	atomic_thread_fence(memory_order_seq_cst);
	63
	64	ret = gettimeofday(realtime, NULL);
65	if (ret != 0) return ret;
66
67	atomic_thread_fence(memory_order_seq_cst);
68
69	bt2 = mach_boottime_usec();
70	if (os_slowpath(bt2 == 0)) bt2 = _boottime_fallback_usec();
71	} while (os_slowpath(bt1 != bt2));
72	*boottime = bt1;
73	return 0;
74	}
75
76	uint64_t
77	clock_gettime_nsec_np(clockid_t clock_id)
78	{
79	switch(clock_id){
80	case CLOCK_REALTIME: {
81	struct timeval tv;
82	int ret = gettimeofday(&tv, NULL);
83	if (ret) return 0;
84	return timeval2nsec(tv);
85	}
86	case CLOCK_MONOTONIC: {
87	struct timeval tv;
88	uint64_t boottime;
89	int ret = _mach_boottime_usec(&boottime, &tv);
90	if (ret) return 0;
91	boottime *= NSEC_PER_USEC;
92	return timeval2nsec(tv) - boottime;
93	}
94	case CLOCK_PROCESS_CPUTIME_ID: {
95	struct rusage ru;
96	int ret = getrusage(RUSAGE_SELF, &ru);
97	if (ret) return 0;
98	return timeval2nsec(ru.ru_utime) + timeval2nsec(ru.ru_stime);
99	}
100	default:
101	// calls that use mach_absolute_time units fall through into a common path
102	break;
103	}
104
105	// Mach Absolute Time unit-based calls
106	mach_timebase_info_data_t tb_info;
107	if (mach_timebase_info(&tb_info)) return 0;
108	uint64_t mach_time;
109
110	switch(clock_id){
111	case CLOCK_MONOTONIC_RAW:
112	mach_time = mach_continuous_time();
113	break;
114	case CLOCK_MONOTONIC_RAW_APPROX:
115	mach_time = mach_continuous_approximate_time();
116	break;
117	case CLOCK_UPTIME_RAW:
118	mach_time = mach_absolute_time();
119	break;
120	case CLOCK_UPTIME_RAW_APPROX:
121	mach_time = mach_approximate_time();
122	break;
123	case CLOCK_THREAD_CPUTIME_ID:
124	mach_time = __thread_selfusage();
125	break;
126	default:
127	errno = EINVAL;
128	return 0;
129	}
130
131	return (mach_time * tb_info.numer) / tb_info.denom;
132	}
133
134	int
135	clock_gettime(clockid_t clk_id, struct timespec *tp)
136	{
137	switch(clk_id){
138	case CLOCK_REALTIME: {
139	struct timeval tv;
140	int ret = gettimeofday(&tv, NULL);
141	TIMEVAL_TO_TIMESPEC(&tv, tp);
142	return ret;
143	}
144	case CLOCK_MONOTONIC: {
145	struct timeval tv;
146	uint64_t boottime_usec;
147	int ret = _mach_boottime_usec(&boottime_usec, &tv);
148	struct timeval boottime = {
149	.tv_sec = boottime_usec / USEC_PER_SEC,
150	.tv_usec = boottime_usec % USEC_PER_SEC
151	};
152	timersub(&tv, &boottime, &tv);
153	TIMEVAL_TO_TIMESPEC(&tv, tp);
154	return ret;
155	}
156	case CLOCK_PROCESS_CPUTIME_ID: {
157	struct rusage ru;
158	int ret = getrusage(RUSAGE_SELF, &ru);
159	timeradd(&ru.ru_utime, &ru.ru_stime, &ru.ru_utime);
160	TIMEVAL_TO_TIMESPEC(&ru.ru_utime, tp);
161	return ret;
162	}
163	case CLOCK_MONOTONIC_RAW:
164	case CLOCK_MONOTONIC_RAW_APPROX:
165	case CLOCK_UPTIME_RAW:
166	case CLOCK_UPTIME_RAW_APPROX:
167	case CLOCK_THREAD_CPUTIME_ID: {
168	uint64_t ns = clock_gettime_nsec_np(clk_id);
169	if (!ns) return -1;
170
171	tp->tv_sec = ns/NSEC_PER_SEC;
172	tp->tv_nsec = ns % NSEC_PER_SEC;
173	return 0;
174	}
175	default:
176	errno = EINVAL;
177	return -1;
178	}
179	}
180
181	int
182	clock_getres(clockid_t clk_id, struct timespec *res)
183	{
184	switch(clk_id){
185	case CLOCK_REALTIME:
186	case CLOCK_MONOTONIC:
187	case CLOCK_PROCESS_CPUTIME_ID:
188	res->tv_nsec = NSEC_PER_USEC;
189	res->tv_sec = 0;
190	return 0;
191
192	case CLOCK_MONOTONIC_RAW:
193	case CLOCK_MONOTONIC_RAW_APPROX:
194	case CLOCK_UPTIME_RAW:
195	case CLOCK_UPTIME_RAW_APPROX:
196	case CLOCK_THREAD_CPUTIME_ID: {
197	mach_timebase_info_data_t tb_info;
198	if (mach_timebase_info(&tb_info)){
199	return -1;
200	}
201	res->tv_nsec = tb_info.numer / tb_info.denom + (tb_info.numer % tb_info.denom != 0);
202	res->tv_sec = 0;
203	return 0;
204	}
205
206	default:
207	errno = EINVAL;
208	return -1;
209	}
210	}
211
212	int
213	clock_settime(clockid_t clk_id, const struct timespec *tp)
214	{
215	switch(clk_id){
216	case CLOCK_REALTIME: {
b061a43b A	217	struct timeval tv = {
	218	.tv_sec = (time_t)tp->tv_sec,
	219	.tv_usec = (suseconds_t)(tp->tv_nsec / NSEC_PER_USEC)
	220	};
974e3884 A	221	return settimeofday(&tv, NULL);
	222	}
	223	default:
	224	errno = EINVAL;
	225	return -1;
	226	}
	227	}