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
//! See [`JobState`].
use std::{cell::Cell, marker, sync::Arc};
use cargo_util::ProcessBuilder;
use crate::core::compiler::context::OutputFile;
use crate::core::compiler::future_incompat::FutureBreakageItem;
use crate::util::Queue;
use crate::CargoResult;
use super::{Artifact, DiagDedupe, Job, JobId, Message};
/// A `JobState` is constructed by `JobQueue::run` and passed to `Job::run`. It includes everything
/// necessary to communicate between the main thread and the execution of the job.
///
/// The job may execute on either a dedicated thread or the main thread. If the job executes on the
/// main thread, the `output` field must be set to prevent a deadlock.
pub struct JobState<'a, 'cfg> {
/// Channel back to the main thread to coordinate messages and such.
///
/// When the `output` field is `Some`, care must be taken to avoid calling `push_bounded` on
/// the message queue to prevent a deadlock.
messages: Arc<Queue<Message>>,
/// Normally output is sent to the job queue with backpressure. When the job is fresh
/// however we need to immediately display the output to prevent a deadlock as the
/// output messages are processed on the same thread as they are sent from. `output`
/// defines where to output in this case.
///
/// Currently the `Shell` inside `Config` is wrapped in a `RefCell` and thus can't be passed
/// between threads. This means that it isn't possible for multiple output messages to be
/// interleaved. In the future, it may be wrapped in a `Mutex` instead. In this case
/// interleaving is still prevented as the lock would be held for the whole printing of an
/// output message.
output: Option<&'a DiagDedupe<'cfg>>,
/// The job id that this state is associated with, used when sending
/// messages back to the main thread.
id: JobId,
/// Whether or not we're expected to have a call to `rmeta_produced`. Once
/// that method is called this is dynamically set to `false` to prevent
/// sending a double message later on.
rmeta_required: Cell<bool>,
// Historical versions of Cargo made use of the `'a` argument here, so to
// leave the door open to future refactorings keep it here.
_marker: marker::PhantomData<&'a ()>,
}
impl<'a, 'cfg> JobState<'a, 'cfg> {
pub(super) fn new(
id: JobId,
messages: Arc<Queue<Message>>,
output: Option<&'a DiagDedupe<'cfg>>,
rmeta_required: bool,
) -> Self {
Self {
id,
messages,
output,
rmeta_required: Cell::new(rmeta_required),
_marker: marker::PhantomData,
}
}
pub fn running(&self, cmd: &ProcessBuilder) {
self.messages.push(Message::Run(self.id, cmd.to_string()));
}
pub fn build_plan(
&self,
module_name: String,
cmd: ProcessBuilder,
filenames: Arc<Vec<OutputFile>>,
) {
self.messages
.push(Message::BuildPlanMsg(module_name, cmd, filenames));
}
pub fn stdout(&self, stdout: String) -> CargoResult<()> {
if let Some(dedupe) = self.output {
writeln!(dedupe.config.shell().out(), "{}", stdout)?;
} else {
self.messages.push_bounded(Message::Stdout(stdout));
}
Ok(())
}
pub fn stderr(&self, stderr: String) -> CargoResult<()> {
if let Some(dedupe) = self.output {
let mut shell = dedupe.config.shell();
shell.print_ansi_stderr(stderr.as_bytes())?;
shell.err().write_all(b"\n")?;
} else {
self.messages.push_bounded(Message::Stderr(stderr));
}
Ok(())
}
/// See [`Message::Diagnostic`] and [`Message::WarningCount`].
pub fn emit_diag(&self, level: String, diag: String, fixable: bool) -> CargoResult<()> {
if let Some(dedupe) = self.output {
let emitted = dedupe.emit_diag(&diag)?;
if level == "warning" {
self.messages.push(Message::WarningCount {
id: self.id,
emitted,
fixable,
});
}
} else {
self.messages.push_bounded(Message::Diagnostic {
id: self.id,
level,
diag,
fixable,
});
}
Ok(())
}
/// See [`Message::Warning`].
pub fn warning(&self, warning: String) -> CargoResult<()> {
self.messages.push_bounded(Message::Warning {
id: self.id,
warning,
});
Ok(())
}
/// A method used to signal to the coordinator thread that the rmeta file
/// for an rlib has been produced. This is only called for some rmeta
/// builds when required, and can be called at any time before a job ends.
/// This should only be called once because a metadata file can only be
/// produced once!
pub fn rmeta_produced(&self) {
self.rmeta_required.set(false);
self.messages
.push(Message::Finish(self.id, Artifact::Metadata, Ok(())));
}
/// Drives a [`Job`] to finish. This ensures that a [`Message::Finish`] is
/// sent even if our job panics.
pub(super) fn run_to_finish(self, job: Job) {
let mut sender = FinishOnDrop {
messages: &self.messages,
id: self.id,
result: None,
};
sender.result = Some(job.run(&self));
// If the `rmeta_required` wasn't consumed but it was set
// previously, then we either have:
//
// 1. The `job` didn't do anything because it was "fresh".
// 2. The `job` returned an error and didn't reach the point where
// it called `rmeta_produced`.
// 3. We forgot to call `rmeta_produced` and there's a bug in Cargo.
//
// Ruling out the third, the other two are pretty common for 2
// we'll just naturally abort the compilation operation but for 1
// we need to make sure that the metadata is flagged as produced so
// send a synthetic message here.
if self.rmeta_required.get() && sender.result.as_ref().unwrap().is_ok() {
self.messages
.push(Message::Finish(self.id, Artifact::Metadata, Ok(())));
}
// Use a helper struct with a `Drop` implementation to guarantee
// that a `Finish` message is sent even if our job panics. We
// shouldn't panic unless there's a bug in Cargo, so we just need
// to make sure nothing hangs by accident.
struct FinishOnDrop<'a> {
messages: &'a Queue<Message>,
id: JobId,
result: Option<CargoResult<()>>,
}
impl Drop for FinishOnDrop<'_> {
fn drop(&mut self) {
let result = self
.result
.take()
.unwrap_or_else(|| Err(anyhow::format_err!("worker panicked")));
self.messages
.push(Message::Finish(self.id, Artifact::All, result));
}
}
}
pub fn future_incompat_report(&self, report: Vec<FutureBreakageItem>) {
self.messages
.push(Message::FutureIncompatReport(self.id, report));
}
}