ozO
Deno•2y ago•
1 reply
oz

Which CLOCK does `Temporal` API implementation use in a deno runtime?

How is the following 
typescript
 line implemented in the 
deno
 runtime to get the 
nano
seconds from epoch, which system 
CLOCK
 or 
SYSCALL
 does it use, is it possible for a 
deno
 contributor to point me towards the (rust?) source code for the implementation?

return Temporal.Now.instant().epochNanoseconds;


Details:

I'm writing an extternal process that uses 
ffi
 to integrate with a 
typescript
 process in a 
deno
 runtime. I want to get nanosecond-precision timestamps in my 
ffi
 process that are consistent with the timestamps in 
ts
. When I use 
REALTIME
 as the clock:

- On 
ubuntu
 I get 
nano
seconds from epoch resolution, and I'm good. :check:
- On 
macosx
 I get 
micro
seconds from epoch resolution, and that's a problem. :no:

Below I've read the various clocks on 
macosx
 preceeded by their resolutions.

Notice 
.nsec
 field in the first 
res
 line for a clock gives the resolution in nanoseconds, and the 
.sec
 + 
.nsec
 fields in the second 
now
 line for a clock reading give the current time stamp for that clock.

Notice only 
REALTIME
 clock has the proper time since epoch, but has it in 
1000
 
.nsec
 => 
micro
second resolution so returns 
000
 for the last three digits of 
.nsec
 in the reading.

The other clocks will drift from real time over time, and I may not get consistent readings in the 
ffi
 process as in the 
deno
 typescript process.

REALTIME
  res: c.timespec__struct_1709{ .sec = 0, .nsec = 1000 }
  now: c.timespec__struct_1709{ .sec = 1723929530, .nsec = 899220000 }
MONOTONIC
  res: c.timespec__struct_1709{ .sec = 0, .nsec = 1000 }
  now: c.timespec__struct_1709{ .sec = 2251, .nsec = 728543000 }
MONOTONIC_RAW
  res: c.timespec__struct_1709{ .sec = 0, .nsec = 1 }
  now: c.timespec__struct_1709{ .sec = 2253, .nsec = 810452119 }
MONOTONIC_RAW_APPROX
  res: c.timespec__struct_1709{ .sec = 0, .nsec = 1 }
  now: c.timespec__struct_1709{ .sec = 2253, .nsec = 810428836 }
UPTIME_RAW
  res: c.timespec__struct_1709{ .sec = 0, .nsec = 1 }
  now: c.timespec__struct_1709{ .sec = 2253, .nsec = 810461026 }
UPTIME_RAW_APPROX
  res: c.timespec__struct_1709{ .sec = 0, .nsec = 1 }
  now: c.timespec__struct_1709{ .sec = 2253, .nsec = 810428836 }
PROCESS_CPUTIME_ID
  res: c.timespec__struct_1709{ .sec = 0, .nsec = 1000 }
  now: c.timespec__struct_1709{ .sec = 0, .nsec = 874756000 }
THREAD_CPUTIME_ID
  res: c.timespec__struct_1709{ .sec = 0, .nsec = 1 }
  now: c.timespec__struct_1709{ .sec = 0, .nsec = 874763051 }


Question

How is the following 
typescript
 line implemented in the 
deno
 runtime to get the 
nano
seconds from epoch, which system 
CLOCK
 or 
SYSCALL
 does it use, is it possible for a 
deno
 contributor to point me towards the (rust?) source code for the implementation?

return Temporal.Now.instant().epochNanoseconds;
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