miri/shims/unix/
thread.rs

1use rustc_abi::ExternAbi;
2
3use crate::*;
4
5#[derive(Debug, Clone, PartialEq, Eq)]
6pub enum ThreadNameResult {
7    Ok,
8    NameTooLong,
9    ThreadNotFound,
10}
11
12impl<'tcx> EvalContextExt<'tcx> for crate::MiriInterpCx<'tcx> {}
13pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
14    fn pthread_create(
15        &mut self,
16        thread: &OpTy<'tcx>,
17        _attr: &OpTy<'tcx>,
18        start_routine: &OpTy<'tcx>,
19        arg: &OpTy<'tcx>,
20    ) -> InterpResult<'tcx, ()> {
21        let this = self.eval_context_mut();
22
23        let thread_info_place = this.deref_pointer_as(thread, this.libc_ty_layout("pthread_t"))?;
24
25        let start_routine = this.read_pointer(start_routine)?;
26
27        let func_arg = this.read_immediate(arg)?;
28
29        this.start_regular_thread(
30            Some(thread_info_place),
31            start_routine,
32            ExternAbi::C { unwind: false },
33            func_arg,
34            this.machine.layouts.mut_raw_ptr,
35        )?;
36
37        interp_ok(())
38    }
39
40    fn pthread_join(
41        &mut self,
42        thread: &OpTy<'tcx>,
43        retval: &OpTy<'tcx>,
44        return_dest: &MPlaceTy<'tcx>,
45    ) -> InterpResult<'tcx> {
46        let this = self.eval_context_mut();
47
48        if !this.ptr_is_null(this.read_pointer(retval)?)? {
49            // FIXME: implement reading the thread function's return place.
50            throw_unsup_format!("Miri supports pthread_join only with retval==NULL");
51        }
52
53        let thread = this.read_scalar(thread)?.to_int(this.libc_ty_layout("pthread_t").size)?;
54        let Ok(thread) = this.thread_id_try_from(thread) else {
55            this.write_scalar(this.eval_libc("ESRCH"), return_dest)?;
56            return interp_ok(());
57        };
58
59        this.join_thread_exclusive(
60            thread,
61            /* success_retval */ Scalar::from_u32(0),
62            return_dest,
63        )
64    }
65
66    fn pthread_detach(&mut self, thread: &OpTy<'tcx>) -> InterpResult<'tcx, Scalar> {
67        let this = self.eval_context_mut();
68
69        let thread = this.read_scalar(thread)?.to_int(this.libc_ty_layout("pthread_t").size)?;
70        let Ok(thread) = this.thread_id_try_from(thread) else {
71            return interp_ok(this.eval_libc("ESRCH"));
72        };
73        this.detach_thread(thread, /*allow_terminated_joined*/ false)?;
74
75        interp_ok(Scalar::from_u32(0))
76    }
77
78    fn pthread_self(&mut self) -> InterpResult<'tcx, Scalar> {
79        let this = self.eval_context_mut();
80
81        let thread_id = this.active_thread();
82        interp_ok(Scalar::from_uint(thread_id.to_u32(), this.libc_ty_layout("pthread_t").size))
83    }
84
85    /// Set the name of the specified thread. If the name including the null terminator
86    /// is longer or equals to `name_max_len`, then if `truncate` is set the truncated name
87    /// is used as the thread name, otherwise [`ThreadNameResult::NameTooLong`] is returned.
88    /// If the specified thread wasn't found, [`ThreadNameResult::ThreadNotFound`] is returned.
89    fn pthread_setname_np(
90        &mut self,
91        thread: Scalar,
92        name: Scalar,
93        name_max_len: u64,
94        truncate: bool,
95    ) -> InterpResult<'tcx, ThreadNameResult> {
96        let this = self.eval_context_mut();
97
98        let thread = thread.to_int(this.libc_ty_layout("pthread_t").size)?;
99        let Ok(thread) = this.thread_id_try_from(thread) else {
100            return interp_ok(ThreadNameResult::ThreadNotFound);
101        };
102        let name = name.to_pointer(this)?;
103        let mut name = this.read_c_str(name)?.to_owned();
104
105        // Comparing with `>=` to account for null terminator.
106        if name.len().to_u64() >= name_max_len {
107            if truncate {
108                name.truncate(name_max_len.saturating_sub(1).try_into().unwrap());
109            } else {
110                return interp_ok(ThreadNameResult::NameTooLong);
111            }
112        }
113
114        this.set_thread_name(thread, name);
115
116        interp_ok(ThreadNameResult::Ok)
117    }
118
119    /// Get the name of the specified thread. If the thread name doesn't fit
120    /// the buffer, then if `truncate` is set the truncated name is written out,
121    /// otherwise [`ThreadNameResult::NameTooLong`] is returned. If the specified
122    /// thread wasn't found, [`ThreadNameResult::ThreadNotFound`] is returned.
123    fn pthread_getname_np(
124        &mut self,
125        thread: Scalar,
126        name_out: Scalar,
127        len: Scalar,
128        truncate: bool,
129    ) -> InterpResult<'tcx, ThreadNameResult> {
130        let this = self.eval_context_mut();
131
132        let thread = thread.to_int(this.libc_ty_layout("pthread_t").size)?;
133        let Ok(thread) = this.thread_id_try_from(thread) else {
134            return interp_ok(ThreadNameResult::ThreadNotFound);
135        };
136        let name_out = name_out.to_pointer(this)?;
137        let len = len.to_target_usize(this)?;
138
139        // FIXME: we should use the program name if the thread name is not set
140        let name = this.get_thread_name(thread).unwrap_or(b"<unnamed>").to_owned();
141        let name = match truncate {
142            true => &name[..name.len().min(len.try_into().unwrap_or(usize::MAX).saturating_sub(1))],
143            false => &name,
144        };
145
146        let (success, _written) = this.write_c_str(name, name_out, len)?;
147        let res = if success { ThreadNameResult::Ok } else { ThreadNameResult::NameTooLong };
148
149        interp_ok(res)
150    }
151
152    fn sched_yield(&mut self) -> InterpResult<'tcx, ()> {
153        let this = self.eval_context_mut();
154
155        this.yield_active_thread();
156
157        interp_ok(())
158    }
159}
miri/shims/unix/thread.rs

miri/shims/unix/
thread.rs
