diff options
| -rw-r--r-- | src/tools/miri/src/clock.rs | 25 | ||||
| -rw-r--r-- | src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs | 16 |
2 files changed, 34 insertions, 7 deletions
diff --git a/src/tools/miri/src/clock.rs b/src/tools/miri/src/clock.rs index fd0c121626b..c18e1bc7a9e 100644 --- a/src/tools/miri/src/clock.rs +++ b/src/tools/miri/src/clock.rs @@ -6,7 +6,7 @@ use std::time::{Duration, Instant as StdInstant}; /// This number is pretty random, but it has been shown to approximately cause /// some sample programs to run within an order of magnitude of real time on desktop CPUs. /// (See `tests/pass/shims/time-with-isolation*.rs`.) -const NANOSECONDS_PER_BASIC_BLOCK: u64 = 5000; +const NANOSECONDS_PER_BASIC_BLOCK: u128 = 5000; #[derive(Debug)] pub struct Instant { @@ -16,7 +16,7 @@ pub struct Instant { #[derive(Debug)] enum InstantKind { Host(StdInstant), - Virtual { nanoseconds: u64 }, + Virtual { nanoseconds: u128 }, } impl Instant { @@ -25,9 +25,8 @@ impl Instant { InstantKind::Host(instant) => instant.checked_add(duration).map(|i| Instant { kind: InstantKind::Host(i) }), InstantKind::Virtual { nanoseconds } => - u128::from(nanoseconds) + nanoseconds .checked_add(duration.as_nanos()) - .and_then(|n| u64::try_from(n).ok()) .map(|nanoseconds| Instant { kind: InstantKind::Virtual { nanoseconds } }), } } @@ -39,7 +38,19 @@ impl Instant { ( InstantKind::Virtual { nanoseconds }, InstantKind::Virtual { nanoseconds: earlier }, - ) => Duration::from_nanos(nanoseconds.saturating_sub(earlier)), + ) => { + // Trade some nanosecond precision to prevent as much overflow as possible. + let duration = match u64::try_from( + // Manually convert from nanosecond to millisecond. + // If it exceeded u64::MAX millisecond, we will just use u64::MAX millisecond, + // Duration can't take in more than u64::MAX millisecond. + nanoseconds.saturating_sub(earlier).saturating_div(1_000_000), + ) { + Ok(millisecond) => Duration::from_millis(millisecond), + _ => Duration::from_millis(u64::MAX), + }; + Duration::new(duration.as_secs(), duration.subsec_nanos()) + } _ => panic!("all `Instant` must be of the same kind"), } } @@ -59,7 +70,7 @@ enum ClockKind { }, Virtual { /// The "current virtual time". - nanoseconds: Cell<u64>, + nanoseconds: Cell<u128>, }, } @@ -93,7 +104,7 @@ impl Clock { ClockKind::Host { .. } => std::thread::sleep(duration), ClockKind::Virtual { nanoseconds } => { // Just pretend that we have slept for some time. - let nanos: u64 = duration.as_nanos().try_into().unwrap(); + let nanos: u128 = duration.as_nanos().try_into().unwrap(); nanoseconds.update(|x| x + nanos); } } diff --git a/src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs b/src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs index d21f953672d..59319b93748 100644 --- a/src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs +++ b/src/tools/miri/tests/pass-dep/concurrency/linux-futex.rs @@ -280,7 +280,23 @@ fn concurrent_wait_wake() { assert!(woken > 0 && woken < rounds); } +// Reproduce of https://github.com/rust-lang/miri/issues/3647. +fn large_timeout() { + let futex: i32 = 123; + + unsafe { + libc::syscall( + libc::SYS_futex, + addr_of!(futex), + libc::FUTEX_WAIT, + 123, + &libc::timespec { tv_sec: 184467440839020, tv_nsec: 117558982 }, + ); + } +} + fn main() { + large_timeout(); wake_nobody(); wake_dangling(); wait_wrong_val(); |