Files
adler32
aho_corasick
alga
approx
ascii
atty
backtrace
backtrace_sys
base64
bitflags
blas_src
block_buffer
block_padding
brotli2
brotli_sys
buf_redux
byte_tools
byteorder
cauchy
cblas_sys
cfg_if
chrono
chunked_transfer
colored
crc32fast
crossbeam
crossbeam_channel
crossbeam_deque
crossbeam_epoch
crossbeam_queue
crossbeam_utils
ctrlc
deflate
digest
dirs
error_chain
filetime
futures
generic_array
getrandom
gzip_header
hex
httparse
hyper
idna
itoa
language_tags
lapack_src
lapacke
lapacke_sys
lazy_static
libc
libm
linked_hash_map
log
matches
matrixmultiply
maybe_uninit
md5
memchr
memoffset
mime
mime_guess
multipart
nalgebra
base
geometry
linalg
ndarray
ndarray_linalg
net2
netlib_src
nix
num_complex
num_cpus
num_integer
num_rational
num_traits
opaque_debug
percent_encoding
phf
phf_shared
ppv_lite86
proc_macro2
quick_error
quote
rand
rand_chacha
rand_core
rand_distr
rawpointer
regex
regex_syntax
remove_dir_all
rosrust
rosrust_codegen
rosrust_msg
rouille
rustc_demangle
rustros_tf
ryu
safemem
scopeguard
serde
serde_bytes
serde_derive
serde_json
serde_xml_rs
sha1
siphasher
smallvec
syn
tempdir
term
thread_local
threadpool
time
tiny_http
traitobject
twoway
typeable
typenum
ucd_util
unicase
unicode_bidi
unicode_normalization
unicode_xid
url
utf8_ranges
void
xml
xml_rpc
yaml_rust
 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
// Copyright 2017 Amanieu d'Antras
//
// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
// http://opensource.org/licenses/MIT>, at your option. This file may not be
// copied, modified, or distributed except according to those terms.

use std::collections::BinaryHeap;
use std::sync::Mutex;
use std::usize;

// Thread ID manager which allocates thread IDs. It attempts to aggressively
// reuse thread IDs where possible to avoid cases where a ThreadLocal grows
// indefinitely when it is used by many short-lived threads.
struct ThreadIdManager {
    limit: usize,
    free_list: BinaryHeap<usize>,
}
impl ThreadIdManager {
    fn new() -> ThreadIdManager {
        ThreadIdManager {
            limit: usize::MAX,
            free_list: BinaryHeap::new(),
        }
    }
    fn alloc(&mut self) -> usize {
        if let Some(id) = self.free_list.pop() {
            id
        } else {
            let id = self.limit;
            self.limit = self.limit.checked_sub(1).expect("Ran out of thread IDs");
            id
        }
    }
    fn free(&mut self, id: usize) {
        self.free_list.push(id);
    }
}
lazy_static! {
    static ref THREAD_ID_MANAGER: Mutex<ThreadIdManager> = Mutex::new(ThreadIdManager::new());
}

// Non-zero integer which is unique to the current thread while it is running.
// A thread ID may be reused after a thread exits.
struct ThreadId(usize);
impl ThreadId {
    fn new() -> ThreadId {
        ThreadId(THREAD_ID_MANAGER.lock().unwrap().alloc())
    }
}
impl Drop for ThreadId {
    fn drop(&mut self) {
        THREAD_ID_MANAGER.lock().unwrap().free(self.0);
    }
}
thread_local!(static THREAD_ID: ThreadId = ThreadId::new());

/// Returns a non-zero ID for the current thread
pub fn get() -> usize {
    THREAD_ID.with(|x| x.0)
}