samplecode/thread/enclave/src/lib.rs

// Copyright (c) 2017 Baidu, Inc. All Rights Reserved.
//
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// modification, are permitted provided that the following conditions
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//
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//  * Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in
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#![crate_name = "enclave"]
#![crate_type = "staticlib"]

#![no_std]
#![feature(const_fn, alloc)]

extern crate alloc;
use alloc::boxed::Box;
use core::sync::atomic::{AtomicPtr, Ordering};

extern crate sgx_types;
extern crate sgx_trts;
extern crate sgx_tstdc;

use sgx_types::*;
use sgx_tstdc::*;

extern {
    fn ocall_print_string(str: *const c_uchar, len: size_t);
}

const BUFFER_SIZE: usize      = 50;
const LOOPS_PER_THREAD: usize = 500;

struct CondBuffer{
    buf: [usize; BUFFER_SIZE],
    occupied: i32,
    nextin: usize,
    nextout: usize,
}

impl Default for CondBuffer {
    fn default() -> CondBuffer {
        CondBuffer {
            buf: [0; BUFFER_SIZE],
            occupied: 0,
            nextin: 0,
            nextout: 0,
        }
    }
}

static GLOBAL_COND_BUFFER: AtomicPtr<()> = AtomicPtr::new(0 as * mut ());

#[no_mangle]
pub extern "C" fn ecall_initialize() {

    let lock = Box::new((SgxMutex::<CondBuffer>::new(CondBuffer::default()), SgxCond::new(), SgxCond::new()));
    let ptr = Box::into_raw(lock);
    GLOBAL_COND_BUFFER.store(ptr as *mut (), Ordering::SeqCst);
}

#[no_mangle]
pub extern "C" fn ecall_uninitialize() {

    let ptr = GLOBAL_COND_BUFFER.swap(0 as * mut (), Ordering::SeqCst) as * mut (SgxMutex<CondBuffer>, SgxCond, SgxCond);
    if ptr.is_null() {
       return;
    }
    let _ = unsafe { Box::from_raw(ptr) };
}

fn get_ref_cond_buffer() -> Option<&'static (SgxMutex<CondBuffer>, SgxCond, SgxCond)>
{
    let ptr = GLOBAL_COND_BUFFER.load(Ordering::SeqCst) as * mut (SgxMutex<CondBuffer>, SgxCond, SgxCond);
    if ptr.is_null() {
        None
    } else {
        Some(unsafe { &* ptr })
    }
}

#[no_mangle]
pub extern "C" fn ecall_producer() {

    let max_index = 4 * LOOPS_PER_THREAD;
    let &(ref mutex, ref more, ref less) = get_ref_cond_buffer().unwrap();

    for _ in 0..max_index {

        let mut guard = mutex.lock().unwrap();

        while guard.occupied >= BUFFER_SIZE as i32 {
            guard = less.wait(guard).unwrap();
        }

        let index = guard.nextin;
        guard.buf[index] = guard.nextin;
        guard.nextin += 1;
        guard.nextin %= BUFFER_SIZE;
        guard.occupied += 1;

        let _ = more.signal();
    }
}

#[no_mangle]
pub extern "C" fn ecall_consumer() {

    let max_index = 4 * LOOPS_PER_THREAD;
    let &(ref mutex, ref more, ref less) = get_ref_cond_buffer().unwrap();

    for _ in 0..max_index {

        let mut guard = mutex.lock().unwrap();

        while guard.occupied <= 0 {
            guard = more.wait(guard).unwrap();
        }

        let index = guard.nextout;
        guard.buf[index] = 0;
        guard.nextout += 1;
        guard.nextout %= BUFFER_SIZE;
        guard.occupied -= 1;

        let _ = less.signal();
    }
}

#[allow(dead_code)]
fn output(outstr: &str) {
    unsafe {
        ocall_print_string(outstr.as_ptr() as *const c_uchar, outstr.len() as size_t);
    }
}