Lancaster University / mbed-src

Lancaster University's (short term!) clone of mbed-src for micro:bit. This is a copy of the github branch https://github.com/lancaster-university/mbed-classic

Fork of mbed-src by mbed official

common/error.c@641:be9b2017785a, 2016-07-13 (annotated)

Committer:
LancasterUniversity
Date:
Wed Jul 13 12:52:54 2016 +0100
Revision:
641:be9b2017785a
Parent:
285:31249416b6f9 
Synchronized with git rev 1fb8ab4c

Author: James Devine

mbed-classic: BUGFIX for timer when using wait_ms from interrupt context



Previously if a user used wait[_ms,_us] in interrupt context the device would

hang indefinitely. This was due to incrementing overflowCount from

interrupt context only.



This meant that if a user used wait[_ms,_us] in an ISR with

the same or greater interrupt priority, it would result in an infinite

loop as the overflowCount variable would never be incremented, and

wait[_ms,_us] would never return.



This patch simply applies a better solution for the race condition

mentioned in the previous commit. It instead disables the timer1

interrupt and increments the overflowCount variable, preventing

the race condition whilst supporting wait[_ms,_us] in interrupt

context.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbed_official 140:ca60b7a31055 1 /* mbed Microcontroller Library
mbed_official 140:ca60b7a31055 2 * Copyright (c) 2006-2013 ARM Limited
mbed_official 140:ca60b7a31055 3 *
mbed_official 140:ca60b7a31055 4 * Licensed under the Apache License, Version 2.0 (the "License");
mbed_official 140:ca60b7a31055 5 * you may not use this file except in compliance with the License.
mbed_official 140:ca60b7a31055 6 * You may obtain a copy of the License at
mbed_official 140:ca60b7a31055 7 *
mbed_official 140:ca60b7a31055 8 * http://www.apache.org/licenses/LICENSE-2.0
mbed_official 140:ca60b7a31055 9 *
mbed_official 140:ca60b7a31055 10 * Unless required by applicable law or agreed to in writing, software
mbed_official 140:ca60b7a31055 11 * distributed under the License is distributed on an "AS IS" BASIS,
mbed_official 140:ca60b7a31055 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbed_official 140:ca60b7a31055 13 * See the License for the specific language governing permissions and
mbed_official 140:ca60b7a31055 14 * limitations under the License.
mbed_official 140:ca60b7a31055 15 */
mbed_official 140:ca60b7a31055 16 #include <stdlib.h>
mbed_official 140:ca60b7a31055 17 #include <stdarg.h>
mbed_official 140:ca60b7a31055 18 #include "device.h"
mbed_official 140:ca60b7a31055 19 #include "toolchain.h"
mbed_official 285:31249416b6f9 20 #include "mbed_error.h"
mbed_official 140:ca60b7a31055 21 #if DEVICE_STDIO_MESSAGES
mbed_official 140:ca60b7a31055 22 #include <stdio.h>
mbed_official 140:ca60b7a31055 23 #endif
mbed_official 140:ca60b7a31055 24
mbed_official 140:ca60b7a31055 25 WEAK void error(const char* format, ...) {
mbed_official 140:ca60b7a31055 26 #if DEVICE_STDIO_MESSAGES
mbed_official 140:ca60b7a31055 27 va_list arg;
mbed_official 140:ca60b7a31055 28 va_start(arg, format);
mbed_official 140:ca60b7a31055 29 vfprintf(stderr, format, arg);
mbed_official 140:ca60b7a31055 30 va_end(arg);
mbed_official 140:ca60b7a31055 31 #endif
mbed_official 140:ca60b7a31055 32 exit(1);
mbed_official 140:ca60b7a31055 33 }