curses.rs

#![feature(concat_idents,duration_as_u128)]

extern crate pyo3;

use std::thread;
use std::time;

use pyo3::prelude::*;
use pyo3::ffi::*;
use std::ffi::CString;


fn import_capsule(thread: i32, call: i32) {
    println!("Importing capsule ({}, {})", thread, call);
    let PyDateTime_CAPSULE_NAME = CString::new("_curses._C_API").unwrap();

    unsafe {
        PyCapsule_Import(PyDateTime_CAPSULE_NAME.as_ptr(), 0);
    }
    println!("Imported ({}, {})", thread, call);
}

fn sleep_import(thread: i32, call: i32) {
    println!("GIL Acquisition: ({}, {})", thread, call);
    let gil = Python::acquire_gil();
    let py = gil.python();
    thread::sleep(time::Duration::from_millis(100));

    import_capsule(thread, call);
}


fn main() {
    let now = time::Instant::now();
    let mut handles  = Vec::new();
    for _thread in 8..10 {
        println!("Spawning thread {}", _thread);
        let handle = thread::spawn(move || {
            for _call in 0..1 {
                println!("Starting datetime call {} from thread {}", _thread, _call);
                sleep_import(_thread, _call);

                // let dt = make_datetime();
                println!("Finished call {}", _call);
            }
        });
        handles.push(handle);
    }

    for handle in handles.into_iter() {
        handle.join().unwrap();
    }

    println!("Done in {}us", now.elapsed().as_micros())

    // Result:
    // ----------------
    // Spawning thread 8
    // Spawning thread 9
    // Starting datetime call 9 from thread 0
    // GIL Acquisition: (9, 0)
    // Starting datetime call 8 from thread 0
    // GIL Acquisition: (8, 0)
    // Acquiring GIL
    // Acquired!
    // Acquiring GIL
    // Importing capsule (9, 0)
    // Acquired!
    // Importing capsule (8, 0)
    // Imported (9, 0)
    // Releasing GIL!
    // Released!
    // Finished call 0
    // Imported (8, 0)
    // Releasing GIL!
    // Released!
    // Finished call 0
    // Done in 222683us
    
    /// And if you comment out the PyCapsule_Import line:
        /// Commenting out the PyCapsule_Import line:
    // Spawning thread 8
    // Spawning thread 9
    // Starting datetime call 8 from thread 0
    // GIL Acquisition: (8, 0)
    // Starting datetime call 9 from thread 0
    // GIL Acquisition: (9, 0)
    // Acquiring GIL
    // Acquired!
    // Acquiring GIL
    // Importing capsule (8, 0)
    // Imported (8, 0)
    // Releasing GIL!
    // Acquired!
    // Released!
    // Finished call 0
    // Importing capsule (9, 0)
    // Imported (9, 0)
    // Releasing GIL!
    // Released!
    // Finished call 0
    // Done in 221164us

}

datetime_thread_mwe.rs

#![feature(concat_idents,duration_as_u128)]

extern crate pyo3;

use std::thread;
use std::time;

use pyo3::prelude::*;
use pyo3::ffi::*;


fn make_datetime() -> Py<PyDateTime> {
    let gil = Python::acquire_gil();
    let py = gil.python();
    println!("Datetime acquiring gil");

    let rv = PyDateTime::new(py, 2011, 1, 1, 0, 0, 0, 0, None).unwrap();
    println!("Datetime releasing gil");
    rv
}


fn main() {
    let now = time::Instant::now();
    let mut handles  = Vec::new();
    for _thread in 0..2 {
        println!("Spawning thread {}", _thread);
        let handle = thread::spawn(move || {
            for _call in 0..2 {
                println!("Starting datetime call {} from thread {}", _thread, _call);
                let dt = make_datetime();
                println!("Finished call {}", _call);
            }
        });
        handles.push(handle);
    }

    for handle in handles.into_iter() {
        handle.join().unwrap();
    }

    println!("Done in {}us", now.elapsed().as_micros())

    // Result:
    // ----------------
    // Spawning thread 0
    // Spawning thread 1
    // Starting datetime call 0 from thread 0
    // Starting datetime call 1 from thread 0
    // Acquiring GIL
    // Acquired!
    // Datetime acquiring gil
    // Importing datetime!
    // Acquiring GIL
    // Acquired!
    // Datetime acquiring gil
}