Aditya Mehrotra / mbed-dev

Biomimetics MBED Library w/ Added Support for CAN3

Dependents:   CAN_TEST SPIne_Plus_DYNO_SENSORS SPIne_Plus_v2 SPIne_Plus_Dyno_v2

platform/mbed_poll.cpp@3:993b4d6ff61e, 2021-03-09 (annotated)

Committer:
adimmit
Date:
Tue Mar 09 20:33:24 2021 +0000
Revision:
3:993b4d6ff61e
Parent:
0:083111ae2a11 
added CAN3

Who changed what in which revision?

UserRevisionLine numberNew contents of line
saloutos 0:083111ae2a11 1 /* mbed Microcontroller Library
saloutos 0:083111ae2a11 2 * Copyright (c) 2017 ARM Limited
saloutos 0:083111ae2a11 3 *
saloutos 0:083111ae2a11 4 * Licensed under the Apache License, Version 2.0 (the "License");
saloutos 0:083111ae2a11 5 * you may not use this file except in compliance with the License.
saloutos 0:083111ae2a11 6 * You may obtain a copy of the License at
saloutos 0:083111ae2a11 7 *
saloutos 0:083111ae2a11 8 * http://www.apache.org/licenses/LICENSE-2.0
saloutos 0:083111ae2a11 9 *
saloutos 0:083111ae2a11 10 * Unless required by applicable law or agreed to in writing, software
saloutos 0:083111ae2a11 11 * distributed under the License is distributed on an "AS IS" BASIS,
saloutos 0:083111ae2a11 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
saloutos 0:083111ae2a11 13 * See the License for the specific language governing permissions and
saloutos 0:083111ae2a11 14 * limitations under the License.
saloutos 0:083111ae2a11 15 */
saloutos 0:083111ae2a11 16 #include "mbed_poll.h"
saloutos 0:083111ae2a11 17 #include "FileHandle.h"
saloutos 0:083111ae2a11 18 #include "Timer.h"
saloutos 0:083111ae2a11 19 #ifdef MBED_CONF_RTOS_PRESENT
saloutos 0:083111ae2a11 20 #include "rtos/Thread.h"
saloutos 0:083111ae2a11 21 #endif
saloutos 0:083111ae2a11 22
saloutos 0:083111ae2a11 23 namespace mbed {
saloutos 0:083111ae2a11 24
saloutos 0:083111ae2a11 25 // timeout -1 forever, or milliseconds
saloutos 0:083111ae2a11 26 int poll(pollfh fhs[], unsigned nfhs, int timeout)
saloutos 0:083111ae2a11 27 {
saloutos 0:083111ae2a11 28 /**
saloutos 0:083111ae2a11 29 * TODO Proper wake-up mechanism.
saloutos 0:083111ae2a11 30 * In order to correctly detect availability of read/write a FileHandle, we needed
saloutos 0:083111ae2a11 31 * a select or poll mechanisms. We opted for poll as POSIX defines in
saloutos 0:083111ae2a11 32 * http://pubs.opengroup.org/onlinepubs/009695399/functions/poll.html Currently,
saloutos 0:083111ae2a11 33 * mbed::poll() just spins and scans filehandles looking for any events we are
saloutos 0:083111ae2a11 34 * interested in. In future, his spinning behaviour will be replaced with
saloutos 0:083111ae2a11 35 * condition variables.
saloutos 0:083111ae2a11 36 */
saloutos 0:083111ae2a11 37 Timer timer;
saloutos 0:083111ae2a11 38 if (timeout > 0) {
saloutos 0:083111ae2a11 39 timer.start();
saloutos 0:083111ae2a11 40 }
saloutos 0:083111ae2a11 41
saloutos 0:083111ae2a11 42 int count = 0;
saloutos 0:083111ae2a11 43 for (;;) {
saloutos 0:083111ae2a11 44 /* Scan the file handles */
saloutos 0:083111ae2a11 45 for (unsigned n = 0; n < nfhs; n++) {
saloutos 0:083111ae2a11 46 FileHandle *fh = fhs[n].fh;
saloutos 0:083111ae2a11 47 short mask = fhs[n].events | POLLERR | POLLHUP | POLLNVAL;
saloutos 0:083111ae2a11 48 if (fh) {
saloutos 0:083111ae2a11 49 fhs[n].revents = fh->poll(mask) & mask;
saloutos 0:083111ae2a11 50 } else {
saloutos 0:083111ae2a11 51 fhs[n].revents = POLLNVAL;
saloutos 0:083111ae2a11 52 }
saloutos 0:083111ae2a11 53 if (fhs[n].revents) {
saloutos 0:083111ae2a11 54 count++;
saloutos 0:083111ae2a11 55 }
saloutos 0:083111ae2a11 56 }
saloutos 0:083111ae2a11 57
saloutos 0:083111ae2a11 58 if (count) {
saloutos 0:083111ae2a11 59 break;
saloutos 0:083111ae2a11 60 }
saloutos 0:083111ae2a11 61
saloutos 0:083111ae2a11 62 /* Nothing selected - this is where timeout handling would be needed */
saloutos 0:083111ae2a11 63 if (timeout == 0 || (timeout > 0 && timer.read_ms() > timeout)) {
saloutos 0:083111ae2a11 64 break;
saloutos 0:083111ae2a11 65 }
saloutos 0:083111ae2a11 66 #ifdef MBED_CONF_RTOS_PRESENT
saloutos 0:083111ae2a11 67 // TODO - proper blocking
saloutos 0:083111ae2a11 68 // wait for condition variable, wait queue whatever here
saloutos 0:083111ae2a11 69 rtos::Thread::yield();
saloutos 0:083111ae2a11 70 #endif
saloutos 0:083111ae2a11 71 }
saloutos 0:083111ae2a11 72 return count;
saloutos 0:083111ae2a11 73 }
saloutos 0:083111ae2a11 74
saloutos 0:083111ae2a11 75 } // namespace mbed