vendor/crossbeam/src/lib.rs

   1 //! Tools for concurrent programming.
   2 //!
   3 //! ## Atomics
   4 //!
   5 //! * [`AtomicCell`], a thread-safe mutable memory location.
   6 //! * [`AtomicConsume`], for reading from primitive atomic types with "consume" ordering.
   7 //!
   8 //! ## Data structures
   9 //!
  10 //! * [`deque`], work-stealing deques for building task schedulers.
  11 //! * [`ArrayQueue`], a bounded MPMC queue that allocates a fixed-capacity buffer on construction.
  12 //! * [`SegQueue`], an unbounded MPMC queue that allocates small buffers, segments, on demand.
  13 //!
  14 //! ## Memory management
  15 //!
  16 //! * [`epoch`], an epoch-based garbage collector.
  17 //!
  18 //! ## Thread synchronization
  19 //!
  20 //! * [`channel`], multi-producer multi-consumer channels for message passing.
  21 //! * [`Parker`], a thread parking primitive.
  22 //! * [`ShardedLock`], a sharded reader-writer lock with fast concurrent reads.
  23 //! * [`WaitGroup`], for synchronizing the beginning or end of some computation.
  24 //!
  25 //! ## Utilities
  26 //!
  27 //! * [`Backoff`], for exponential backoff in spin loops.
  28 //! * [`CachePadded`], for padding and aligning a value to the length of a cache line.
  29 //! * [`scope`], for spawning threads that borrow local variables from the stack.
  30 //!
  31 //! [`AtomicCell`]: atomic::AtomicCell
  32 //! [`AtomicConsume`]: atomic::AtomicConsume
  33 //! [`ArrayQueue`]: queue::ArrayQueue
  34 //! [`SegQueue`]: queue::SegQueue
  35 //! [`Parker`]: sync::Parker
  36 //! [`ShardedLock`]: sync::ShardedLock
  37 //! [`WaitGroup`]: sync::WaitGroup
  38 //! [`Backoff`]: utils::Backoff
  39 //! [`CachePadded`]: utils::CachePadded
  40
  41 #![doc(test(
  42     no_crate_inject,
  43     attr(
  44         deny(warnings, rust_2018_idioms),
  45         allow(dead_code, unused_assignments, unused_variables)
  46     )
  47 ))]
  48 #![warn(
  49     missing_docs,
  50     missing_debug_implementations,
  51     rust_2018_idioms,
  52     unreachable_pub
  53 )]
  54 #![cfg_attr(not(feature = "std"), no_std)]
  55
  56 pub use crossbeam_utils::atomic;
  57
  58 pub mod utils {
  59     //! Miscellaneous utilities.
  60     //!
  61     //! * [`Backoff`], for exponential backoff in spin loops.
  62     //! * [`CachePadded`], for padding and aligning a value to the length of a cache line.
  63
  64     pub use crossbeam_utils::Backoff;
  65     pub use crossbeam_utils::CachePadded;
  66 }
  67
  68 use cfg_if::cfg_if;
  69
  70 cfg_if! {
  71     if #[cfg(feature = "alloc")] {
  72         #[doc(inline)]
  73         pub use crossbeam_epoch as epoch;
  74
  75         #[doc(inline)]
  76         pub use crossbeam_queue as queue;
  77     }
  78 }
  79
  80 cfg_if! {
  81     if #[cfg(feature = "std")] {
  82         #[doc(inline)]
  83         pub use crossbeam_deque as deque;
  84
  85         #[doc(inline)]
  86         pub use crossbeam_channel as channel;
  87         pub use crossbeam_channel::select;
  88
  89         pub use crossbeam_utils::sync;
  90
  91         #[cfg(not(crossbeam_loom))]
  92         pub use crossbeam_utils::thread;
  93         #[cfg(not(crossbeam_loom))]
  94         pub use crossbeam_utils::thread::scope;
  95     }
  96 }