Add SIGINT handler

hoon/scaffolding/toddler.hoon

@@ -35,7 +35,7 @@
     ::  %mean hint
     ~_  [%leaf "I am a %mean hint via ~_ from +wack"]
     ::  %hela hint
-    :: ~>  %hela
+    ~>  %hela
     ::  %memo hint
     ~+
     ?~  m  +(n)
@@ -47,13 +47,23 @@
     !.
     |=  [m=@ud n=@ud]
     ::  %hela hint
-    :: ~>  %hela
+    ~>  %hela
     ::  %memo hint
     ~+
     ?~  m  +(n)
     ?~  n
       (wack (dec m) 1)
     (wack (dec m) $(n (dec n)))
+  ++  slow
+    |=  x=@ud
+    !:
+    (slow-help x 0)
+  ++  slow-help
+    |=  [x=@ud y=@ud]
+    !.
+    ?:  .=  x  y
+      x
+    $(y .+(y))
   --  =>
   ::
   |%
@@ -65,19 +75,23 @@
     ^-  ^
     ::
     ?.  ?=(?(%crud %wack %wyrd) p.card.ovo)
-      ~>  %slog.[0 leaf+(scow %ud (wack 1 1))]
+      ~>  %slog.[0 leaf+(scow %ud (slow (bex 23)))]
       [~ ..poke]
     ::
     =/  buz
       ~>  %mean.'pith: bad wasp'
       ;;(wasp card.ovo)
     ?+  -.buz
-      ~>  %slog.[0 leaf+"default $wasp"]
+      ~>  %slog.[0 leaf+(scow %ud (wack 1 1))]
       [~ ..poke]
     ::
       %crud
-        ~>  %slog.[0 goof.buz]
+        =/  tang  tang.goof.buz
+        |-
+        ?~  tang
           [~ ..poke]
+        ~>  %slog.[0 -.tang]
+        $(tang +.tang)
     ==
   --
   ::

rust/ares/Cargo.lock

@@ -20,11 +20,13 @@ dependencies = [
  "either",
  "ibig",
  "intmap",
+ "lazy_static",
  "libc",
  "memmap",
  "murmur3",
  "num-derive",
  "num-traits",
+ "signal-hook",
  "static_assertions",
 ]
 
@@ -569,6 +571,25 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "signal-hook"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8621587d4798caf8eb44879d42e56b9a93ea5dcd315a6487c357130095b62801"
+dependencies = [
+ "libc",
+ "signal-hook-registry",
+]
+
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8229b473baa5980ac72ef434c4415e70c4b5e71b423043adb4ba059f89c99a1"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "static_assertions"
 version = "1.1.0"

rust/ares/Cargo.toml

@@ -11,18 +11,20 @@ edition = "2018"
 
 [dependencies]
 ares_macros = { path = "../ares_macros" }
-bitvec = "1.0.0"
-either = "1.9.0"
-libc = "0.2.126"
-murmur3 = { git = "https://github.com/tloncorp/murmur3", rev = "7878a0f" }
-memmap = "0.7.0"
-intmap = "1.1.0"
-num-traits = "0.2"
-num-derive = "0.3"
-criterion = "0.4"
-static_assertions = "1.1.0"
-ibig = { path = "../ibig-rs" }
 assert_no_alloc = "1.1.2"
+bitvec = "1.0.0"
+criterion = "0.4"
+either = "1.9.0"
+ibig = { path = "../ibig-rs" }
+intmap = "1.1.0"
+lazy_static = "1.4.0"
+libc = "0.2.126"
+memmap = "0.7.0"
+murmur3 = { git = "https://github.com/tloncorp/murmur3", rev = "7878a0f" }
+num-derive = "0.3"
+num-traits = "0.2"
+signal-hook = "0.3"
+static_assertions = "1.1.0"
 
 [build-dependencies]
 cc = "1.0.79"

rust/ares/src/interpreter.rs

@@ -7,10 +7,13 @@ use crate::mem::NockStack;
 use crate::newt::Newt;
 use crate::noun;
 use crate::noun::{tape, Atom, Cell, IndirectAtom, Noun, Slots, D, T};
+use crate::serf::TERMINATOR;
 use ares_macros::tas;
 use assert_no_alloc::assert_no_alloc;
 use bitvec::prelude::{BitSlice, Lsb0};
 use either::Either::*;
+use std::sync::atomic::Ordering;
+use std::sync::Arc;
 
 crate::gdb!();
 
@@ -265,10 +268,12 @@ pub fn interpret(
     mut subject: Noun,
     formula: Noun,
 ) -> Result<Noun, Tone> {
+    let terminator = Arc::clone(&TERMINATOR);
     let mut res: Noun = D(0);
     let mut cache = Hamt::<Noun>::new();
     // XX: Should this come after initial frame_push()?
     let virtual_frame = stack.get_frame_pointer();
+    let virtual_trace = stack.get_mean_stack();
 
     stack.frame_push(0);
     unsafe {
@@ -323,6 +328,7 @@ pub fn interpret(
                         res = noun;
                         stack.pop::<NockWork>();
                     } else {
+                        // Axis invalid for input Noun
                         break Err(NockErr::Deterministic);
                     }
                 }
@@ -330,7 +336,12 @@ pub fn interpret(
                     res = once.noun;
                     stack.pop::<NockWork>();
                 }
-                NockWork::Work2(mut vale) => match vale.todo {
+                NockWork::Work2(mut vale) => {
+                    if (*terminator).load(Ordering::Relaxed) {
+                        break Err(NockErr::NonDeterministic);
+                    }
+
+                    match vale.todo {
                         Todo2::ComputeSubject => {
                             vale.todo = Todo2::ComputeFormula;
                             *stack.top() = NockWork::Work2(vale);
@@ -360,7 +371,8 @@ pub fn interpret(
                             subject = vale.subject;
                             stack.pop::<NockWork>();
                         }
-                },
+                    }
+                }
                 NockWork::Work3(mut thee) => match thee.todo {
                     Todo3::ComputeChild => {
                         thee.todo = Todo3::ComputeType;
@@ -481,7 +493,12 @@ pub fn interpret(
                         stack.pop::<NockWork>();
                     }
                 },
-                NockWork::Work9(mut kale) => match kale.todo {
+                NockWork::Work9(mut kale) => {
+                    if (*terminator).load(Ordering::Relaxed) {
+                        break Err(NockErr::NonDeterministic);
+                    }
+
+                    match kale.todo {
                         Todo9::ComputeCore => {
                             kale.todo = Todo9::ComputeResult;
                             *stack.top() = NockWork::Work9(kale);
@@ -511,7 +528,8 @@ pub fn interpret(
                             subject = kale.core;
                             stack.pop::<NockWork>();
                         }
-                },
+                    }
+                }
                 NockWork::Work10(mut diet) => {
                     match diet.todo {
                         Todo10::ComputeTree => {
@@ -623,7 +641,13 @@ pub fn interpret(
 
     match nock {
         Ok(res) => Ok(res),
-        Err(err) => Err(exit_early(stack, &mut cache, virtual_frame, err)),
+        Err(err) => Err(exit_early(
+            stack,
+            &mut cache,
+            virtual_frame,
+            virtual_trace,
+            err,
+        )),
     }
 }
 
@@ -830,6 +854,7 @@ pub fn exit_early(
     stack: &mut NockStack,
     cache: &mut Hamt<Noun>,
     virtual_frame: *const u64,
+    virtual_trace: Noun,
     error: NockErr,
 ) -> Tone {
     let mut trace = stack.get_mean_stack();
@@ -839,6 +864,9 @@ pub fn exit_early(
             stack.preserve(cache);
             stack.frame_pop();
         }
+        while !stack.get_mean_stack().raw_equals(virtual_trace) {
+            stack.trace_pop();
+        }
     };
     Tone::Error(error, trace)
 }
@@ -1026,6 +1054,11 @@ fn match_hint_pre_nock(
             Ok(None)
         }
         tas!(b"hand") | tas!(b"hunk") | tas!(b"lose") | tas!(b"mean") | tas!(b"spot") => {
+            let terminator = Arc::clone(&TERMINATOR);
+            if (*terminator).load(Ordering::Relaxed) {
+                return Err(NockErr::NonDeterministic);
+            }
+
             let trace = T(stack, &[tag.as_noun(), res.ok_or(NockErr::Deterministic)?]);
             stack.trace_push(trace);
             Ok(None)

rust/ares/src/jets/nock.rs

@@ -23,6 +23,7 @@ pub fn jet_mink(
     let v_formula = slot(arg, 5)?;
     let _scry = slot(arg, 3)?;
 
+    //  XX: no partial traces; all of our traces go down to the "home road"
     match interpret(stack, newt, v_subject, v_formula) {
         Ok(res) => Ok(T(stack, &[D(0), res])),
         Err(err) => match err {
@@ -61,11 +62,6 @@ pub mod util {
         let tag = tone.head().as_direct()?;
         let original_list = tone.tail();
 
-        // if tag.data() < 2 {
-        //     return Ok(tone);
-        // } else if tag.data() > 2 {
-        //     return Err(JetErr::Deterministic);
-        // }
         match tag.data() {
             x if x < 2 => return Ok(tone),
             x if x > 2 => return Err(JetErr::Deterministic),
@@ -260,6 +256,21 @@ pub mod util {
 mod tests {
     use super::*;
     use crate::jets::util::test::{assert_jet, init_stack};
+    use crate::serf::TERMINATOR;
+    use std::sync::Arc;
+
+    #[test]
+    fn init() {
+        // This needs to be done because TERMINATOR is lazy allocated, and if you don't
+        // do it before you call the unit tests it'll get allocated on the Rust heap
+        // inside an assert_no_alloc block.
+        //
+        // Also Rust has no primitive for pre-test setup / post-test teardown, so we
+        // do it in a test that we rely on being called before any other in this file,
+        // since we're already using single-threaded test mode to avoid race conditions
+        // (because Rust doesn't support test order dependencies either).
+        let _ = Arc::clone(&TERMINATOR);
+    }
 
     #[test]
     fn test_mink_success() {

rust/ares/src/lib.rs

@@ -1,5 +1,7 @@
 extern crate num_derive;
 #[macro_use]
+extern crate lazy_static;
+#[macro_use]
 extern crate static_assertions;
 pub mod interpreter;
 pub mod jets;

rust/ares/src/serf.rs

@@ -7,12 +7,14 @@ use crate::newt::Newt;
 use crate::noun::{Cell, Noun, Slots, D, T};
 use crate::snapshot::{self, Snapshot};
 use ares_macros::tas;
+use signal_hook;
+use signal_hook::consts::SIGINT;
 use std::fs::create_dir_all;
 use std::io;
 use std::path::PathBuf;
 use std::result::Result;
-use std::thread::sleep;
+use std::sync::atomic::{AtomicBool, Ordering};
-use std::time;
+use std::sync::Arc;
 
 crate::gdb!();
 
@@ -23,12 +25,20 @@ const POKE_AXIS: u64 = 23;
 #[allow(dead_code)]
 const WISH_AXIS: u64 = 10;
 
+// Necessary because Arc::new is not const
+lazy_static! {
+    pub static ref TERMINATOR: Arc<AtomicBool> = Arc::new(AtomicBool::new(false));
+}
+
 /**
  * This is suitable for talking to the king process.  To test, change the arg_c[0] line in
  * u3_lord_init in vere to point at this binary and start vere like normal.
  */
 pub fn serf() -> io::Result<()> {
-    sleep(time::Duration::from_secs(0));
+    // Register SIGTERM signal hook to set flag first time, shutdown second time
+    signal_hook::flag::register_conditional_shutdown(SIGINT, 1, Arc::clone(&TERMINATOR))?;
+    signal_hook::flag::register(SIGINT, Arc::clone(&TERMINATOR))?;
+
     let snap_path_string = std::env::args()
         .nth(2)
         .ok_or(io::Error::new(io::ErrorKind::Other, "no pier path"))?;
@@ -157,7 +167,9 @@ pub fn serf() -> io::Result<()> {
                         //  TODO: on decryption failure in aes_siv, should bail as fast as
                         //  possible, without rendering stack trace or injecting crud event.  See
                         //  c3__evil in vere.
-                        //
+
+                        clear_interrupt();
+
                         //  crud = [+(now) [%$ %arvo ~] [%crud goof ovo]]
                         let job_cell = job.as_cell().expect("serf: work: job not a cell");
                         let now = inc(
@@ -197,6 +209,8 @@ pub fn serf() -> io::Result<()> {
             }
             _ => panic!("got message with unknown tag {}", tag),
         };
+
+        clear_interrupt();
     }
 
     Ok(())
@@ -231,8 +245,9 @@ pub fn soft(
             let tang = mook(stack, &mut Some(newt), tone, false)
                 .expect("serf: soft: +mook crashed on bail")
                 .tail();
-            // TODO: shouldn't always be exit, look at the comment by u3m_bail to see how vere
+            //  XX: noun::Tone or noun::NockErr should use a bail enum system similar to u3m_bail motes;
-            // handles this
+            //      might be able to replace NockErr with mote and map determinism to individual motes;
+            //      for, always set to %exit
             let goof = T(stack, &[D(tas!(b"exit")), tang]);
             Err(goof)
         }
@@ -244,3 +259,7 @@ fn slot(noun: Noun, axis: u64) -> io::Result<Noun> {
     noun.slot(axis)
         .map_err(|_e| io::Error::new(io::ErrorKind::InvalidInput, "Bad axis"))
 }
+
+fn clear_interrupt() {
+    (*TERMINATOR).store(false, Ordering::Relaxed);
+}