创建输入引脚

此示例创建了一个名为 pins 的组件，并使用 hal_pin_float_new 向其注册了一个接受浮点值的输入引脚。每个 HAL 引脚都需要一些内存来存储其值，这通过 hal_malloc 完成。

可以使用类似此处的 HAL 文件将示例加载到 LinuxCNC 中

请注意，出于简洁起见，此示例中没有错误处理。

use linuxcnc_hal_sys::*;
use signal_hook::iterator::Signals;
use std::ffi::CString;
use std::mem;
use std::thread;
use std::time::Duration;

unsafe {
    let id = hal_init(CString::new("pins").unwrap().as_ptr() as *const i8);

    println!("ID {}", id);

    let signals = Signals::new(&[signal_hook::SIGTERM, signal_hook::SIGINT]).unwrap();

    let storage = hal_malloc(mem::size_of::<*mut f64>() as i64) as *mut *mut f64;

    println!("Storage {:?}", storage);

    let pin_name = CString::new("pins.input-1").unwrap();

    let ret = hal_pin_float_new(
        pin_name.as_ptr() as *const i8,
        hal_pin_dir_t_HAL_IN,
        storage,
        id,
    );

    println!("Pin init {}", ret);

    let ret = hal_ready(id);

    println!("Ready {}", ret);

    while !signals.pending().any(|signal| match signal {
        signal_hook::SIGTERM | signal_hook::SIGINT | signal_hook::SIGKILL => true,
        _ => false,
    }) {
        println!("Input {:?}", **storage);

        thread::sleep(Duration::from_millis(500));
    }
}

错误处理

此 crate 中的错误处理方式与 C 代码中的方式相同。导出了一些常量，如 EINVAL 和 EPERM，以便匹配返回的错误代码。

use linuxcnc_hal_sys::*;
use signal_hook::iterator::Signals;
use std::ffi::CString;
use std::mem;
use std::thread;
use std::time::Duration;

unsafe {
    let ret = hal_init(CString::new("pins").unwrap().as_ptr() as *const i8);

    // Check that component was created successfully
    let component_id = match ret {
        x if x == -(EINVAL as i32) => panic!("Failed to initialise component"),
        x if x == -(ENOMEM as i32) => panic!("Not enough memory to initialise component"),
        id if id > 0 => id,
        code => unreachable!("Hit unreachable error code {}", code),
    };

    println!("Component registered with ID {}", component_id);

    let signals = Signals::new(&[signal_hook::SIGTERM, signal_hook::SIGINT]).unwrap();

    let storage = hal_malloc(mem::size_of::<*mut f64>() as i64) as *mut *mut f64;

    if storage.is_null() {
        panic!("Failed to allocate storage");
    }

    let pin_name = CString::new("pins.input-1").unwrap();

    let ret = hal_pin_float_new(
        pin_name.as_ptr() as *const i8,
        hal_pin_dir_t_HAL_IN,
        storage,
        component_id,
    );

    // Check that pin was registered successfully
    match ret {
        0 => println!("Pin registered successfully"),
        x if x == -(EINVAL as i32) => panic!("Failed to register pin"),
        x if x == -(EPERM as i32) => {
            panic!("HAL is locked. Register pins before calling hal_ready()`")
        }
        x if x == -(ENOMEM as i32) => panic!("Failed to register pin"),
        code => unreachable!("Hit unreachable error code {}", code),
    }

    let ret = hal_ready(component_id);

    // Check that component is ready
    match ret {
        0 => println!("Component is ready"),
        x if x == -(EINVAL as i32) => panic!("HAL component was not found or is already ready"),
        code => unreachable!("Hit unreachable error code {}", code),
    }

    while !signals.pending().any(|signal| match signal {
        signal_hook::SIGTERM | signal_hook::SIGINT | signal_hook::SIGKILL => true,
        _ => false,
    }) {
        println!("Input {:?}", **storage);

        thread::sleep(Duration::from_millis(500));
    }
}

许可证

根据您的要求，许可为以下之一

• Apache License，版本 2.0 (LICENSE-APACHE 或 https://apache.ac.cn/licenses/LICENSE-2.0)
• MIT 许可证 (LICENSE-MIT 或 http://opensource.org/licenses/MIT)

任选。

贡献

除非您明确声明，否则任何有意提交以包含在您的工作中的贡献，根据 Apache-2.0 许可证定义，将按上述方式双重许可，不附加任何额外条款或条件。