     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75

    //! The default garbage collector.
    //!
    //! For each thread, a participant is lazily initialized on its first use, when the current thread
    //! is registered in the default collector.  If initialized, the thread's participant will get
    //! destructed on thread exit, which in turn unregisters the thread.

    use collector::{Collector, LocalHandle};
    use guard::Guard;

    lazy_static! {
        /// The global data for the default garbage collector.
        static ref COLLECTOR: Collector = Collector::new();
    }

    thread_local! {
        /// The per-thread participant for the default garbage collector.
        static HANDLE: LocalHandle = COLLECTOR.register();
    }

    /// Pins the current thread.
    #[inline]
    pub fn pin() -> Guard {
        with_handle(|handle| handle.pin())
    }

    /// Returns `true` if the current thread is pinned.
    #[inline]
    pub fn is_pinned() -> bool {
        with_handle(|handle| handle.is_pinned())
    }

    /// Returns the default global collector.
    pub fn default_collector() -> &'static Collector {
        &COLLECTOR
    }

    #[inline]
    fn with_handle<F, R>(mut f: F) -> R
    where
        F: FnMut(&LocalHandle) -> R,
    {
        HANDLE
            .try_with(|h| f(h))
            .unwrap_or_else(|_| f(&COLLECTOR.register()))
    }

    #[cfg(test)]
    mod tests {
        use crossbeam_utils::thread;

        #[test]
        fn pin_while_exiting() {
            struct Foo;

            impl Drop for Foo {
                fn drop(&mut self) {
                    // Pin after `HANDLE` has been dropped. This must not panic.
                    super::pin();
                }
            }

            thread_local! {
                static FOO: Foo = Foo;
            }

            thread::scope(|scope| {
                scope.spawn(|_| {
                    // Initialize `FOO` and then `HANDLE`.
                    FOO.with(|_| ());
                    super::pin();
                    // At thread exit, `HANDLE` gets dropped first and `FOO` second.
                });
            }).unwrap();
        }
    }

# Help

## Keyboard Shortcuts

`?`
  Show this help dialog
`S`
  Focus the search field
`↑`
  Move up in search results
`↓`
  Move down in search results
`↹`
  Switch tab
`⏎`
  Go to active search result
`+`
  Expand all sections
`-`
  Collapse all sections

## Search Tricks

Prefix searches with a type followed by a colon (e.g., `fn:`) to restrict the search to a given type.

Accepted types are: `fn`, `mod`, `struct`, `enum`, `trait`, `type`, `macro`, and `const`.

Search functions by type signature (e.g., `vec -> usize` or `* -> vec`)

Search multiple things at once by splitting your query with comma (e.g., `str,u8` or `String,struct:Vec,test`)