      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
     76
     77
     78
     79
     80
     81
     82
     83
     84
     85
     86
     87
     88
     89
     90
     91
     92
     93
     94
     95
     96
     97
     98
     99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144
    145
    146
    147
    148
    149
    150
    151
    152
    153
    154
    155
    156
    157
    158
    159
    160
    161
    162
    163
    164
    165
    166
    167
    168
    169
    170
    171
    172
    173
    174
    175
    176
    177
    178
    179
    180
    181
    182
    183
    184
    185
    186
    187
    188
    189
    190
    191
    192
    193
    194
    195
    196
    197
    198
    199
    200
    201
    202
    203
    204
    205
    206
    207
    208
    209
    210
    211
    212
    213
    214
    215
    216
    217
    218
    219
    220
    221
    222
    223
    224
    225
    226
    227
    228
    229
    230
    231
    232
    233
    234
    235
    236
    237
    238
    239
    240
    241
    242
    243
    244
    245
    246
    247
    248
    249
    250
    251
    252
    253
    254
    255
    256
    257
    258
    259
    260
    261
    262
    263
    264
    265
    266
    267
    268
    269
    270
    271
    272
    273
    274
    275
    276
    277
    278
    279
    280
    281
    282
    283
    284
    285
    286
    287
    288
    289
    290
    291
    292
    293
    294
    295
    296
    297
    298
    299
    300
    301
    302
    303
    304
    305
    306
    307
    308
    309
    310
    311
    312
    313
    314
    315
    316
    317
    318
    319
    320
    321
    322
    323
    324
    325
    326
    327
    328
    329
    330
    331
    332
    333
    334
    335
    336
    337
    338
    339
    340
    341
    342
    343
    344
    345
    346
    347
    348
    349
    350
    351
    352
    353
    354
    355
    356
    357
    358
    359
    360
    361
    362
    363
    364
    365
    366
    367
    368
    369
    370
    371
    372
    373
    374
    375
    376
    377
    378
    379
    380
    381
    382
    383
    384
    385
    386
    387
    388
    389
    390
    391
    392
    393
    394
    395
    396
    397
    398
    399
    400
    401
    402
    403
    404
    405
    406
    407
    408
    409
    410
    411
    412
    413
    414
    415
    416
    417
    418
    419
    420

    // Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
    // file at the top-level directory of this distribution and at
    // http://rust-lang.org/COPYRIGHT.
    //
    // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
    // http://www.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 alloc::boxed::FnBox;
    use cmp;
    use ffi::CStr;
    use io;
    use libc;
    use mem;
    use ptr;
    use sys::os;
    use time::Duration;

    use sys_common::thread::*;

    #[cfg(not(target_os = "l4re"))]
    pub const DEFAULT_MIN_STACK_SIZE: usize = 2 * 1024 * 1024;
    #[cfg(target_os = "l4re")]
    pub const DEFAULT_MIN_STACK_SIZE: usize = 1024 * 1024;

    pub struct Thread {
        id: libc::pthread_t,
    }

    // Some platforms may have pthread_t as a pointer in which case we still want
    // a thread to be Send/Sync
    unsafe impl Send for Thread {}
    unsafe impl Sync for Thread {}

    // The pthread_attr_setstacksize symbol doesn't exist in the emscripten libc,
    // so we have to not link to it to satisfy emcc's ERROR_ON_UNDEFINED_SYMBOLS.
    #[cfg(not(target_os = "emscripten"))]
    unsafe fn pthread_attr_setstacksize(attr: *mut libc::pthread_attr_t,
                                        stack_size: libc::size_t) -> libc::c_int {
        libc::pthread_attr_setstacksize(attr, stack_size)
    }

    #[cfg(target_os = "emscripten")]
    unsafe fn pthread_attr_setstacksize(_attr: *mut libc::pthread_attr_t,
                                        _stack_size: libc::size_t) -> libc::c_int {
        panic!()
    }

    impl Thread {
        pub unsafe fn new<'a>(stack: usize, p: Box<FnBox() + 'a>)
                              -> io::Result<Thread> {
            let p = box p;
            let mut native: libc::pthread_t = mem::zeroed();
            let mut attr: libc::pthread_attr_t = mem::zeroed();
            assert_eq!(libc::pthread_attr_init(&mut attr), 0);

            let stack_size = cmp::max(stack, min_stack_size(&attr));

            match pthread_attr_setstacksize(&mut attr,
                                            stack_size) {
                0 => {}
                n => {
                    assert_eq!(n, libc::EINVAL);
                    // EINVAL means |stack_size| is either too small or not a
                    // multiple of the system page size.  Because it's definitely
                    // >= PTHREAD_STACK_MIN, it must be an alignment issue.
                    // Round up to the nearest page and try again.
                    let page_size = os::page_size();
                    let stack_size = (stack_size + page_size - 1) &
                                     (-(page_size as isize - 1) as usize - 1);
                    assert_eq!(libc::pthread_attr_setstacksize(&mut attr,
                                                               stack_size), 0);
                }
            };

            let ret = libc::pthread_create(&mut native, &attr, thread_start,
                                           &*p as *const _ as *mut _);
            assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);

            return if ret != 0 {
                Err(io::Error::from_raw_os_error(ret))
            } else {
                mem::forget(p); // ownership passed to pthread_create
                Ok(Thread { id: native })
            };

            extern fn thread_start(main: *mut libc::c_void) -> *mut libc::c_void {
                unsafe { start_thread(main as *mut u8); }
                ptr::null_mut()
            }
        }

        pub fn yield_now() {
            let ret = unsafe { libc::sched_yield() };
            debug_assert_eq!(ret, 0);
        }

        #[cfg(any(target_os = "linux",
                  target_os = "android"))]
        pub fn set_name(name: &CStr) {
            const PR_SET_NAME: libc::c_int = 15;
            // pthread wrapper only appeared in glibc 2.12, so we use syscall
            // directly.
            unsafe {
                libc::prctl(PR_SET_NAME, name.as_ptr() as libc::c_ulong, 0, 0, 0);
            }
        }

        #[cfg(any(target_os = "freebsd",
                  target_os = "dragonfly",
                  target_os = "bitrig",
                  target_os = "openbsd"))]
        pub fn set_name(name: &CStr) {
            unsafe {
                libc::pthread_set_name_np(libc::pthread_self(), name.as_ptr());
            }
        }

        #[cfg(any(target_os = "macos", target_os = "ios"))]
        pub fn set_name(name: &CStr) {
            unsafe {
                libc::pthread_setname_np(name.as_ptr());
            }
        }

        #[cfg(target_os = "netbsd")]
        pub fn set_name(name: &CStr) {
            use ffi::CString;
            let cname = CString::new(&b"%s"[..]).unwrap();
            unsafe {
                libc::pthread_setname_np(libc::pthread_self(), cname.as_ptr(),
                                         name.as_ptr() as *mut libc::c_void);
            }
        }
        #[cfg(any(target_env = "newlib",
                  target_os = "solaris",
                  target_os = "haiku",
                  target_os = "l4re",
                  target_os = "emscripten"))]
        pub fn set_name(_name: &CStr) {
            // Newlib, Illumos, Haiku, and Emscripten have no way to set a thread name.
        }
        #[cfg(target_os = "fuchsia")]
        pub fn set_name(_name: &CStr) {
            // FIXME: determine whether Fuchsia has a way to set a thread name.
        }

        pub fn sleep(dur: Duration) {
            let mut secs = dur.as_secs();
            let mut nsecs = dur.subsec_nanos() as _;

            // If we're awoken with a signal then the return value will be -1 and
            // nanosleep will fill in `ts` with the remaining time.
            unsafe {
                while secs > 0 || nsecs > 0 {
                    let mut ts = libc::timespec {
                        tv_sec: cmp::min(libc::time_t::max_value() as u64, secs) as libc::time_t,
                        tv_nsec: nsecs,
                    };
                    secs -= ts.tv_sec as u64;
                    if libc::nanosleep(&ts, &mut ts) == -1 {
                        assert_eq!(os::errno(), libc::EINTR);
                        secs += ts.tv_sec as u64;
                        nsecs = ts.tv_nsec;
                    } else {
                        nsecs = 0;
                    }
                }
            }
        }

        pub fn join(self) {
            unsafe {
                let ret = libc::pthread_join(self.id, ptr::null_mut());
                mem::forget(self);
                assert!(ret == 0,
                        "failed to join thread: {}", io::Error::from_raw_os_error(ret));
            }
        }

        pub fn id(&self) -> libc::pthread_t { self.id }

        pub fn into_id(self) -> libc::pthread_t {
            let id = self.id;
            mem::forget(self);
            id
        }
    }

    impl Drop for Thread {
        fn drop(&mut self) {
            let ret = unsafe { libc::pthread_detach(self.id) };
            debug_assert_eq!(ret, 0);
        }
    }

    #[cfg(all(not(all(target_os = "linux", not(target_env = "musl"))),
              not(target_os = "freebsd"),
              not(target_os = "macos"),
              not(target_os = "bitrig"),
              not(all(target_os = "netbsd", not(target_vendor = "rumprun"))),
              not(target_os = "openbsd"),
              not(target_os = "solaris")))]
    #[cfg_attr(test, allow(dead_code))]
    pub mod guard {
        use ops::Range;
        pub type Guard = Range<usize>;
        pub unsafe fn current() -> Option<Guard> { None }
        pub unsafe fn init() -> Option<Guard> { None }
    }

    #[cfg(any(all(target_os = "linux", not(target_env = "musl")),
              target_os = "freebsd",
              target_os = "macos",
              target_os = "bitrig",
              all(target_os = "netbsd", not(target_vendor = "rumprun")),
              target_os = "openbsd",
              target_os = "solaris"))]
    #[cfg_attr(test, allow(dead_code))]
    pub mod guard {
        use libc;
        use libc::mmap;
        use libc::{PROT_NONE, MAP_PRIVATE, MAP_ANON, MAP_FAILED, MAP_FIXED};
        use ops::Range;
        use sys::os;

        // This is initialized in init() and only read from after
        static mut PAGE_SIZE: usize = 0;

        pub type Guard = Range<usize>;

        #[cfg(target_os = "solaris")]
        unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
            let mut current_stack: libc::stack_t = ::mem::zeroed();
            assert_eq!(libc::stack_getbounds(&mut current_stack), 0);
            Some(current_stack.ss_sp)
        }

        #[cfg(target_os = "macos")]
        unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
            let stackaddr = libc::pthread_get_stackaddr_np(libc::pthread_self()) as usize -
                 libc::pthread_get_stacksize_np(libc::pthread_self());
            Some(stackaddr as *mut libc::c_void)
        }

        #[cfg(any(target_os = "openbsd", target_os = "bitrig"))]
        unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
            let mut current_stack: libc::stack_t = ::mem::zeroed();
            assert_eq!(libc::pthread_stackseg_np(libc::pthread_self(),
                                                 &mut current_stack), 0);

            let extra = if cfg!(target_os = "bitrig") {3} else {1} * PAGE_SIZE;
            let stackaddr = if libc::pthread_main_np() == 1 {
                // main thread
                current_stack.ss_sp as usize - current_stack.ss_size + extra
            } else {
                // new thread
                current_stack.ss_sp as usize - current_stack.ss_size
            };
            Some(stackaddr as *mut libc::c_void)
        }

        #[cfg(any(target_os = "android", target_os = "freebsd",
                  target_os = "linux", target_os = "netbsd", target_os = "l4re"))]
        unsafe fn get_stack_start() -> Option<*mut libc::c_void> {
            let mut ret = None;
            let mut attr: libc::pthread_attr_t = ::mem::zeroed();
            assert_eq!(libc::pthread_attr_init(&mut attr), 0);
            #[cfg(target_os = "freebsd")]
                let e = libc::pthread_attr_get_np(libc::pthread_self(), &mut attr);
            #[cfg(not(target_os = "freebsd"))]
                let e = libc::pthread_getattr_np(libc::pthread_self(), &mut attr);
            if e == 0 {
                let mut stackaddr = ::ptr::null_mut();
                let mut stacksize = 0;
                assert_eq!(libc::pthread_attr_getstack(&attr, &mut stackaddr,
                                                       &mut stacksize), 0);
                ret = Some(stackaddr);
            }
            assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);
            ret
        }

        pub unsafe fn init() -> Option<Guard> {
            PAGE_SIZE = os::page_size();

            let mut stackaddr = get_stack_start()?;

            // Ensure stackaddr is page aligned! A parent process might
            // have reset RLIMIT_STACK to be non-page aligned. The
            // pthread_attr_getstack() reports the usable stack area
            // stackaddr < stackaddr + stacksize, so if stackaddr is not
            // page-aligned, calculate the fix such that stackaddr <
            // new_page_aligned_stackaddr < stackaddr + stacksize
            let remainder = (stackaddr as usize) % PAGE_SIZE;
            if remainder != 0 {
                stackaddr = ((stackaddr as usize) + PAGE_SIZE - remainder)
                    as *mut libc::c_void;
            }

            if cfg!(target_os = "linux") {
                // Linux doesn't allocate the whole stack right away, and
                // the kernel has its own stack-guard mechanism to fault
                // when growing too close to an existing mapping.  If we map
                // our own guard, then the kernel starts enforcing a rather
                // large gap above that, rendering much of the possible
                // stack space useless.  See #43052.
                //
                // Instead, we'll just note where we expect rlimit to start
                // faulting, so our handler can report "stack overflow", and
                // trust that the kernel's own stack guard will work.
                let stackaddr = stackaddr as usize;
                Some(stackaddr - PAGE_SIZE..stackaddr)
            } else {
                // Reallocate the last page of the stack.
                // This ensures SIGBUS will be raised on
                // stack overflow.
                let result = mmap(stackaddr, PAGE_SIZE, PROT_NONE,
                                  MAP_PRIVATE | MAP_ANON | MAP_FIXED, -1, 0);

                if result != stackaddr || result == MAP_FAILED {
                    panic!("failed to allocate a guard page");
                }

                let guardaddr = stackaddr as usize;
                let offset = if cfg!(target_os = "freebsd") {
                    2
                } else {
                    1
                };

                Some(guardaddr..guardaddr + offset * PAGE_SIZE)
            }
        }

        #[cfg(any(target_os = "macos",
                  target_os = "bitrig",
                  target_os = "openbsd",
                  target_os = "solaris"))]
        pub unsafe fn current() -> Option<Guard> {
            let stackaddr = get_stack_start()? as usize;
            Some(stackaddr - PAGE_SIZE..stackaddr)
        }

        #[cfg(any(target_os = "android", target_os = "freebsd",
                  target_os = "linux", target_os = "netbsd", target_os = "l4re"))]
        pub unsafe fn current() -> Option<Guard> {
            let mut ret = None;
            let mut attr: libc::pthread_attr_t = ::mem::zeroed();
            assert_eq!(libc::pthread_attr_init(&mut attr), 0);
            #[cfg(target_os = "freebsd")]
                let e = libc::pthread_attr_get_np(libc::pthread_self(), &mut attr);
            #[cfg(not(target_os = "freebsd"))]
                let e = libc::pthread_getattr_np(libc::pthread_self(), &mut attr);
            if e == 0 {
                let mut guardsize = 0;
                assert_eq!(libc::pthread_attr_getguardsize(&attr, &mut guardsize), 0);
                if guardsize == 0 {
                    panic!("there is no guard page");
                }
                let mut stackaddr = ::ptr::null_mut();
                let mut size = 0;
                assert_eq!(libc::pthread_attr_getstack(&attr, &mut stackaddr,
                                                       &mut size), 0);

                let stackaddr = stackaddr as usize;
                ret = if cfg!(target_os = "freebsd") {
                    // FIXME does freebsd really fault *below* the guard addr?
                    let guardaddr = stackaddr - guardsize;
                    Some(guardaddr - PAGE_SIZE..guardaddr)
                } else if cfg!(target_os = "netbsd") {
                    Some(stackaddr - guardsize..stackaddr)
                } else if cfg!(all(target_os = "linux", target_env = "gnu")) {
                    // glibc used to include the guard area within the stack, as noted in the BUGS
                    // section of `man pthread_attr_getguardsize`.  This has been corrected starting
                    // with glibc 2.27, and in some distro backports, so the guard is now placed at the
                    // end (below) the stack.  There's no easy way for us to know which we have at
                    // runtime, so we'll just match any fault in the range right above or below the
                    // stack base to call that fault a stack overflow.
                    Some(stackaddr - guardsize..stackaddr + guardsize)
                } else {
                    Some(stackaddr..stackaddr + guardsize)
                };
            }
            assert_eq!(libc::pthread_attr_destroy(&mut attr), 0);
            ret
        }
    }

    // glibc >= 2.15 has a __pthread_get_minstack() function that returns
    // PTHREAD_STACK_MIN plus however many bytes are needed for thread-local
    // storage.  We need that information to avoid blowing up when a small stack
    // is created in an application with big thread-local storage requirements.
    // See #6233 for rationale and details.
    #[cfg(target_os = "linux")]
    #[allow(deprecated)]
    fn min_stack_size(attr: *const libc::pthread_attr_t) -> usize {
        weak!(fn __pthread_get_minstack(*const libc::pthread_attr_t) -> libc::size_t);

        match __pthread_get_minstack.get() {
            None => libc::PTHREAD_STACK_MIN,
            Some(f) => unsafe { f(attr) },
        }
    }

    // No point in looking up __pthread_get_minstack() on non-glibc
    // platforms.
    #[cfg(all(not(target_os = "linux"),
              not(target_os = "netbsd")))]
    fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
        libc::PTHREAD_STACK_MIN
    }

    #[cfg(target_os = "netbsd")]
    fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
        2048 // just a guess
    }

# 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`)