src/shims/time.rs

   1 use std::time::{Duration, SystemTime, Instant};
   2 use std::convert::TryFrom;
   3
   4 use crate::stacked_borrows::Tag;
   5 use crate::*;
   6 use helpers::immty_from_int_checked;
   7
   8 /// Returns the time elapsed between the provided time and the unix epoch as a `Duration`.
   9 pub fn system_time_to_duration<'tcx>(time: &SystemTime) -> InterpResult<'tcx, Duration> {
  10     time.duration_since(SystemTime::UNIX_EPOCH)
  11         .map_err(|_| err_unsup_format!("times before the Unix epoch are not supported").into())
  12 }
  13
  14 impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
  15 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
  16     fn clock_gettime(
  17         &mut self,
  18         clk_id_op: OpTy<'tcx, Tag>,
  19         tp_op: OpTy<'tcx, Tag>,
  20     ) -> InterpResult<'tcx, i32> {
  21         let this = self.eval_context_mut();
  22
  23         this.assert_target_os("linux", "clock_gettime");
  24         this.check_no_isolation("clock_gettime")?;
  25
  26         let clk_id = this.read_scalar(clk_id_op)?.to_i32()?;
  27         let tp = this.deref_operand(tp_op)?;
  28
  29         let duration = if clk_id == this.eval_libc_i32("CLOCK_REALTIME")? {
  30             system_time_to_duration(&SystemTime::now())?
  31         } else if clk_id == this.eval_libc_i32("CLOCK_MONOTONIC")? {
  32             // Absolute time does not matter, only relative time does, so we can just
  33             // use our own time anchor here.
  34             Instant::now().duration_since(this.machine.time_anchor)
  35         } else {
  36             let einval = this.eval_libc("EINVAL")?;
  37             this.set_last_error(einval)?;
  38             return Ok(-1);
  39         };
  40
  41         let tv_sec = duration.as_secs();
  42         let tv_nsec = duration.subsec_nanos();
  43
  44         let imms = [
  45             immty_from_int_checked(tv_sec, this.libc_ty_layout("time_t")?)?,
  46             immty_from_int_checked(tv_nsec, this.libc_ty_layout("c_long")?)?,
  47         ];
  48
  49         this.write_packed_immediates(tp, &imms)?;
  50
  51         Ok(0)
  52     }
  53
  54     fn gettimeofday(
  55         &mut self,
  56         tv_op: OpTy<'tcx, Tag>,
  57         tz_op: OpTy<'tcx, Tag>,
  58     ) -> InterpResult<'tcx, i32> {
  59         let this = self.eval_context_mut();
  60
  61         this.assert_target_os("macos", "gettimeofday");
  62         this.check_no_isolation("gettimeofday")?;
  63
  64         // Using tz is obsolete and should always be null
  65         let tz = this.read_scalar(tz_op)?.not_undef()?;
  66         if !this.is_null(tz)? {
  67             let einval = this.eval_libc("EINVAL")?;
  68             this.set_last_error(einval)?;
  69             return Ok(-1);
  70         }
  71
  72         let tv = this.deref_operand(tv_op)?;
  73
  74         let duration = system_time_to_duration(&SystemTime::now())?;
  75         let tv_sec = duration.as_secs();
  76         let tv_usec = duration.subsec_micros();
  77
  78         let imms = [
  79             immty_from_int_checked(tv_sec, this.libc_ty_layout("time_t")?)?,
  80             immty_from_int_checked(tv_usec, this.libc_ty_layout("suseconds_t")?)?,
  81         ];
  82
  83         this.write_packed_immediates(tv, &imms)?;
  84
  85         Ok(0)
  86     }
  87
  88     fn mach_absolute_time(&self) -> InterpResult<'tcx, u64> {
  89         let this = self.eval_context_ref();
  90
  91         this.assert_target_os("macos", "mach_absolute_time");
  92         this.check_no_isolation("mach_absolute_time")?;
  93
  94         // This returns a u64, with time units determined dynamically by `mach_timebase_info`.
  95         // We return plain nanoseconds.
  96         let duration = Instant::now().duration_since(this.machine.time_anchor);
  97         u64::try_from(duration.as_nanos())
  98             .map_err(|_| err_unsup_format!("programs running longer than 2^64 nanoseconds are not supported").into())
  99     }
 100 }