Nicolas Borla / Mbed OS BBR_1Ebene

BBR 1 Ebene

mbed-os/rtos/Kernel.cpp@0:fbdae7e6d805, 2018-05-14 (annotated)

Committer:
borlanic
Date:
Mon May 14 11:29:06 2018 +0000
Revision:
0:fbdae7e6d805
BBR

Who changed what in which revision?

UserRevisionLine numberNew contents of line
borlanic 0:fbdae7e6d805 1 /* mbed Microcontroller Library
borlanic 0:fbdae7e6d805 2 * Copyright (c) 2017 ARM Limited
borlanic 0:fbdae7e6d805 3 *
borlanic 0:fbdae7e6d805 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
borlanic 0:fbdae7e6d805 5 * of this software and associated documentation files (the "Software"), to deal
borlanic 0:fbdae7e6d805 6 * in the Software without restriction, including without limitation the rights
borlanic 0:fbdae7e6d805 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
borlanic 0:fbdae7e6d805 8 * copies of the Software, and to permit persons to whom the Software is
borlanic 0:fbdae7e6d805 9 * furnished to do so, subject to the following conditions:
borlanic 0:fbdae7e6d805 10 *
borlanic 0:fbdae7e6d805 11 * The above copyright notice and this permission notice shall be included in
borlanic 0:fbdae7e6d805 12 * all copies or substantial portions of the Software.
borlanic 0:fbdae7e6d805 13 *
borlanic 0:fbdae7e6d805 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
borlanic 0:fbdae7e6d805 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
borlanic 0:fbdae7e6d805 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
borlanic 0:fbdae7e6d805 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
borlanic 0:fbdae7e6d805 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
borlanic 0:fbdae7e6d805 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
borlanic 0:fbdae7e6d805 20 * SOFTWARE.
borlanic 0:fbdae7e6d805 21 */
borlanic 0:fbdae7e6d805 22
borlanic 0:fbdae7e6d805 23 #include "rtos/Kernel.h"
borlanic 0:fbdae7e6d805 24
borlanic 0:fbdae7e6d805 25 #include "mbed.h"
borlanic 0:fbdae7e6d805 26
borlanic 0:fbdae7e6d805 27 namespace rtos {
borlanic 0:fbdae7e6d805 28
borlanic 0:fbdae7e6d805 29 uint64_t Kernel::get_ms_count() {
borlanic 0:fbdae7e6d805 30 // CMSIS-RTOS 2.1.0 and 2.1.1 differ in the time type. We assume
borlanic 0:fbdae7e6d805 31 // our header at least matches the implementation, so we don't try looking
borlanic 0:fbdae7e6d805 32 // at the run-time version report. (There's no compile-time version report)
borlanic 0:fbdae7e6d805 33
borlanic 0:fbdae7e6d805 34 // 2.1.0 uint64_t osKernelGetTickCount(void), not documented as callable from ISR (but RTX does allow)
borlanic 0:fbdae7e6d805 35 // 2.1.1 uint32_t osKernelGetTickCount(void), callable from ISR
borlanic 0:fbdae7e6d805 36 // 2.1.x who knows? We assume could go back to uint64_t
borlanic 0:fbdae7e6d805 37 if (sizeof osKernelGetTickCount() == sizeof(uint64_t)) {
borlanic 0:fbdae7e6d805 38 return osKernelGetTickCount();
borlanic 0:fbdae7e6d805 39 } else /* assume 32-bit */ {
borlanic 0:fbdae7e6d805 40 // Based on suggestion in CMSIS-RTOS 2.1.1 docs, but with reentrancy
borlanic 0:fbdae7e6d805 41 // protection for the tick memory. We use critical section rather than a
borlanic 0:fbdae7e6d805 42 // mutex, as hopefully this method can be callable from interrupt later -
borlanic 0:fbdae7e6d805 43 // only thing currently preventing it is that pre CMSIS RTOS 2.1.1, it's
borlanic 0:fbdae7e6d805 44 // not defined as safe.
borlanic 0:fbdae7e6d805 45 // We assume this is called multiple times per 32-bit wrap period (49 days).
borlanic 0:fbdae7e6d805 46 static uint32_t tick_h, tick_l;
borlanic 0:fbdae7e6d805 47
borlanic 0:fbdae7e6d805 48 core_util_critical_section_enter();
borlanic 0:fbdae7e6d805 49 // The 2.1.1 API says this is legal from an ISR - we assume this means
borlanic 0:fbdae7e6d805 50 // it's also legal with interrupts disabled. RTX implementation kind
borlanic 0:fbdae7e6d805 51 // of conflates the two.
borlanic 0:fbdae7e6d805 52 uint32_t tick32 = osKernelGetTickCount();
borlanic 0:fbdae7e6d805 53 if (tick32 < tick_l) {
borlanic 0:fbdae7e6d805 54 tick_h++;
borlanic 0:fbdae7e6d805 55 }
borlanic 0:fbdae7e6d805 56 tick_l = tick32;
borlanic 0:fbdae7e6d805 57 uint64_t ret = ((uint64_t) tick_h << 32) | tick_l;
borlanic 0:fbdae7e6d805 58 core_util_critical_section_exit();
borlanic 0:fbdae7e6d805 59 return ret;
borlanic 0:fbdae7e6d805 60 }
borlanic 0:fbdae7e6d805 61 }
borlanic 0:fbdae7e6d805 62
borlanic 0:fbdae7e6d805 63 }