Refurbished extendr#635 (extendr#658)

fix: don't need to \0 terminate strings with `CString`

.github/workflows/msrv.yml

@@ -23,11 +23,17 @@ permissions:
 
 jobs:
   test-min-rust-version:
+    # PowerShell core is available on all platforms and can be used to unify scripts
+    defaults:
+      run:
+        shell: pwsh
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
       - uses: baptiste0928/cargo-install@v2
         with:
           crate: cargo-msrv
       - name: Verify minimum rust version
-        run: cargo-msrv --path extendr-api/ verify
+        run: |
+          . ./ci-cargo.ps1
+          ci-cargo msrv --path extendr-api/ verify -ActionName "Verify Rust MSRV"

extendr-api/src/lang_macros.rs

@@ -1,11 +1,10 @@
 //! Argument parsing and checking.
 //!
 
-use libR_sys::*;
-//use crate::robj::*;
 use crate::robj::GetSexp;
 use crate::robj::Robj;
 use crate::single_threaded;
+use libR_sys::*;
 
 /// Convert a list of tokens to an array of tuples.
 #[doc(hidden)]

extendr-api/src/lib.rs

@@ -387,9 +387,7 @@ pub use lang_macros::*;
 pub use na::*;
 pub use rmacros::*;
 pub use robj::*;
-pub use thread_safety::{
-    catch_r_error, handle_panic, single_threaded, this_thread_id, throw_r_error,
-};
+pub use thread_safety::{catch_r_error, handle_panic, single_threaded, throw_r_error};
 pub use wrapper::*;
 
 pub use extendr_macros::*;

extendr-api/src/ownership.rs

@@ -4,9 +4,9 @@
 //! A single preserved vector holds ownership of all protected objects.
 //!
 //! Objects are reference counted, so multiple calls are possible,
-//! unlike R_PreserveObject.
+//! unlike `R_PreserveObject`.
 //!
-//! This module exports two functions, protect(sexp) and unprotect(sexp).
+//! This module exports two functions, `protect(sexp)` and `unprotect(sexp)`.
 
 use once_cell::sync::Lazy;
 use std::collections::hash_map::{Entry, HashMap};

extendr-api/src/prelude.rs

@@ -53,9 +53,7 @@ pub use super::robj::{
     RobjItertools, Slices, Types,
 };
 
-pub use super::thread_safety::{
-    catch_r_error, handle_panic, single_threaded, this_thread_id, throw_r_error,
-};
+pub use super::thread_safety::{catch_r_error, handle_panic, single_threaded, throw_r_error};
 
 pub use super::wrapper::{
     Complexes, Dataframe, Doubles, EnvIter, Environment, Expressions, ExternalPtr, FromList,

extendr-api/src/thread_safety.rs

@@ -6,35 +6,12 @@ use crate::*;
 /// It is not tied to an actual instance of R.
 static R_API_LOCK: parking_lot::ReentrantMutex<()> = parking_lot::ReentrantMutex::new(());
 
-// Get an integer 1.. for each thread that calls this.
-pub fn this_thread_id() -> u32 {
-    THREAD_ID.with(|&v| v)
-}
-
-/// Run a function single threaded.
-/// Note: This will fail badly if the called function panics or calls RF_error.
+/// Run `f` while ensuring that `f` runs in a single-threaded manner.
 ///
-/// ```
-/// use extendr_api::prelude::*;
-/// use std::sync::atomic::{AtomicU32, Ordering};
-/// static GLOBAL_THREAD_COUNT: AtomicU32 = AtomicU32::new(0);
+/// This is intended for single-threaded access of the R's C-API.
+/// It is possible to have nested calls of `single_threaded` without deadlocking.
 ///
-/// let threads : Vec<_> = (0..100).map(|_| {
-///    std::thread::spawn(move|| {
-///       single_threaded(|| {
-///         // check that we are single threaded.
-///         let old_thread_count = GLOBAL_THREAD_COUNT.fetch_add(1, Ordering::AcqRel);
-///         assert_eq!(old_thread_count, 0);
-///         std::thread::sleep(std::time::Duration::from_millis(1));
-///         GLOBAL_THREAD_COUNT.fetch_sub(1, Ordering::AcqRel);
-///         // recursive calls are ok.
-///         assert_eq!(single_threaded(|| {
-///           1
-///         }), 1);    
-///       })
-///    })
-/// }).collect();
-/// ```
+/// Note: This will fail badly if the called function `f` panics or calls `Rf_error`.
 pub fn single_threaded<F, R>(f: F) -> R
 where
     F: FnOnce() -> R,
@@ -73,7 +50,7 @@ pub fn throw_r_error<S: AsRef<str>>(s: S) -> ! {
     };
 }
 
-/// Wrap an R function such as Rf_findFunction and convert errors and panics into results.
+/// Wrap an R function such as `Rf_findFunction` and convert errors and panics into results.
 /// ```ignore
 /// use extendr_api::prelude::*;
 /// test! {

extendr-macros/src/wrappers.rs

@@ -204,7 +204,7 @@ pub fn make_function_wrappers(
                     // included in panic. The advantage would be the panic cause could be included
                     // in the R terminal error message and not only via std-err.
                     // but it should be handled in a separate function and not in-lined here.
-                    let err_string = format!("user function panicked: {}\0",#r_name_str);
+                    let err_string = format!("user function panicked: {}",#r_name_str);
                     // cannot use throw_r_error here for some reason.
                     // handle_panic() exports err string differently than throw_r_error.
                     extendr_api::handle_panic(err_string.as_str(), || panic!());