OctagonSignPosts.m   [plain text]

/*
* Copyright (c) 2019 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@
*/

#import <Foundation/Foundation.h>
#import <mach/mach_time.h>

#import "OctagonSignPosts.h"

os_log_t _OctagonSignpostLogSystem(void) {
static os_log_t log = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
log = os_log_create("com.apple.security", "signpost");
});
return log;
}

#pragma mark - Signpost Methods

OctagonSignpost _OctagonSignpostCreate(os_log_t subsystem) {
os_signpost_id_t identifier = os_signpost_id_generate(subsystem);
uint64_t timestamp = mach_continuous_time();
return (OctagonSignpost){
.identifier = identifier,
.timestamp = timestamp,
};
}

uint64_t _OctagonSignpostGetNanoseconds(OctagonSignpost signpost) {
static struct mach_timebase_info timebase_info;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
mach_timebase_info(&timebase_info);
});

uint64_t interval = mach_continuous_time() - signpost.timestamp;

return (uint64_t)(interval *
((double)timebase_info.numer / timebase_info.denom));
}