Knight KE / Mbed OS Game_Master

游戏王对战板，目前code还是空的

mbed-os/platform/mbed_poll.cpp@0:9b3d4731edbb, 2018-06-21 (annotated)

Committer:
WFKnight
Date:
Thu Jun 21 13:51:43 2018 +0000
Revision:
0:9b3d4731edbb
UART, RTOS, LED

Who changed what in which revision?

UserRevisionLine numberNew contents of line
WFKnight 0:9b3d4731edbb 1 /* mbed Microcontroller Library
WFKnight 0:9b3d4731edbb 2 * Copyright (c) 2017 ARM Limited
WFKnight 0:9b3d4731edbb 3 *
WFKnight 0:9b3d4731edbb 4 * Licensed under the Apache License, Version 2.0 (the "License");
WFKnight 0:9b3d4731edbb 5 * you may not use this file except in compliance with the License.
WFKnight 0:9b3d4731edbb 6 * You may obtain a copy of the License at
WFKnight 0:9b3d4731edbb 7 *
WFKnight 0:9b3d4731edbb 8 * http://www.apache.org/licenses/LICENSE-2.0
WFKnight 0:9b3d4731edbb 9 *
WFKnight 0:9b3d4731edbb 10 * Unless required by applicable law or agreed to in writing, software
WFKnight 0:9b3d4731edbb 11 * distributed under the License is distributed on an "AS IS" BASIS,
WFKnight 0:9b3d4731edbb 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
WFKnight 0:9b3d4731edbb 13 * See the License for the specific language governing permissions and
WFKnight 0:9b3d4731edbb 14 * limitations under the License.
WFKnight 0:9b3d4731edbb 15 */
WFKnight 0:9b3d4731edbb 16 #include "mbed_poll.h"
WFKnight 0:9b3d4731edbb 17 #include "FileHandle.h"
WFKnight 0:9b3d4731edbb 18 #if MBED_CONF_RTOS_PRESENT
WFKnight 0:9b3d4731edbb 19 #include "rtos/Kernel.h"
WFKnight 0:9b3d4731edbb 20 #include "rtos/Thread.h"
WFKnight 0:9b3d4731edbb 21 using namespace rtos;
WFKnight 0:9b3d4731edbb 22 #else
WFKnight 0:9b3d4731edbb 23 #include "Timer.h"
WFKnight 0:9b3d4731edbb 24 #include "LowPowerTimer.h"
WFKnight 0:9b3d4731edbb 25 #endif
WFKnight 0:9b3d4731edbb 26
WFKnight 0:9b3d4731edbb 27 namespace mbed {
WFKnight 0:9b3d4731edbb 28
WFKnight 0:9b3d4731edbb 29 // timeout -1 forever, or milliseconds
WFKnight 0:9b3d4731edbb 30 int poll(pollfh fhs[], unsigned nfhs, int timeout)
WFKnight 0:9b3d4731edbb 31 {
WFKnight 0:9b3d4731edbb 32 /**
WFKnight 0:9b3d4731edbb 33 * TODO Proper wake-up mechanism.
WFKnight 0:9b3d4731edbb 34 * In order to correctly detect availability of read/write a FileHandle, we needed
WFKnight 0:9b3d4731edbb 35 * a select or poll mechanisms. We opted for poll as POSIX defines in
WFKnight 0:9b3d4731edbb 36 * http://pubs.opengroup.org/onlinepubs/009695399/functions/poll.html Currently,
WFKnight 0:9b3d4731edbb 37 * mbed::poll() just spins and scans filehandles looking for any events we are
WFKnight 0:9b3d4731edbb 38 * interested in. In future, his spinning behaviour will be replaced with
WFKnight 0:9b3d4731edbb 39 * condition variables.
WFKnight 0:9b3d4731edbb 40 */
WFKnight 0:9b3d4731edbb 41 #if MBED_CONF_RTOS_PRESENT
WFKnight 0:9b3d4731edbb 42 uint64_t start_time = 0;
WFKnight 0:9b3d4731edbb 43 if (timeout > 0) {
WFKnight 0:9b3d4731edbb 44 start_time = Kernel::get_ms_count();
WFKnight 0:9b3d4731edbb 45 }
WFKnight 0:9b3d4731edbb 46 #define TIME_ELAPSED() int64_t(Kernel::get_ms_count() - start_time)
WFKnight 0:9b3d4731edbb 47 #else
WFKnight 0:9b3d4731edbb 48 #if MBED_CONF_PLATFORM_POLL_USE_LOWPOWER_TIMER
WFKnight 0:9b3d4731edbb 49 LowPowerTimer timer;
WFKnight 0:9b3d4731edbb 50 #else
WFKnight 0:9b3d4731edbb 51 Timer timer;
WFKnight 0:9b3d4731edbb 52 #endif
WFKnight 0:9b3d4731edbb 53 if (timeout > 0) {
WFKnight 0:9b3d4731edbb 54 timer.start();
WFKnight 0:9b3d4731edbb 55 }
WFKnight 0:9b3d4731edbb 56 #define TIME_ELAPSED() timer.read_ms()
WFKnight 0:9b3d4731edbb 57 #endif // MBED_CONF_RTOS_PRESENT
WFKnight 0:9b3d4731edbb 58
WFKnight 0:9b3d4731edbb 59 int count = 0;
WFKnight 0:9b3d4731edbb 60 for (;;) {
WFKnight 0:9b3d4731edbb 61 /* Scan the file handles */
WFKnight 0:9b3d4731edbb 62 for (unsigned n = 0; n < nfhs; n++) {
WFKnight 0:9b3d4731edbb 63 FileHandle *fh = fhs[n].fh;
WFKnight 0:9b3d4731edbb 64 short mask = fhs[n].events | POLLERR | POLLHUP | POLLNVAL;
WFKnight 0:9b3d4731edbb 65 if (fh) {
WFKnight 0:9b3d4731edbb 66 fhs[n].revents = fh->poll(mask) & mask;
WFKnight 0:9b3d4731edbb 67 } else {
WFKnight 0:9b3d4731edbb 68 fhs[n].revents = POLLNVAL;
WFKnight 0:9b3d4731edbb 69 }
WFKnight 0:9b3d4731edbb 70 if (fhs[n].revents) {
WFKnight 0:9b3d4731edbb 71 count++;
WFKnight 0:9b3d4731edbb 72 }
WFKnight 0:9b3d4731edbb 73 }
WFKnight 0:9b3d4731edbb 74
WFKnight 0:9b3d4731edbb 75 if (count) {
WFKnight 0:9b3d4731edbb 76 break;
WFKnight 0:9b3d4731edbb 77 }
WFKnight 0:9b3d4731edbb 78
WFKnight 0:9b3d4731edbb 79 /* Nothing selected - this is where timeout handling would be needed */
WFKnight 0:9b3d4731edbb 80 if (timeout == 0 || (timeout > 0 && TIME_ELAPSED() > timeout)) {
WFKnight 0:9b3d4731edbb 81 break;
WFKnight 0:9b3d4731edbb 82 }
WFKnight 0:9b3d4731edbb 83 #ifdef MBED_CONF_RTOS_PRESENT
WFKnight 0:9b3d4731edbb 84 // TODO - proper blocking
WFKnight 0:9b3d4731edbb 85 // wait for condition variable, wait queue whatever here
WFKnight 0:9b3d4731edbb 86 rtos::Thread::wait(1);
WFKnight 0:9b3d4731edbb 87 #endif
WFKnight 0:9b3d4731edbb 88 }
WFKnight 0:9b3d4731edbb 89 return count;
WFKnight 0:9b3d4731edbb 90 }
WFKnight 0:9b3d4731edbb 91
WFKnight 0:9b3d4731edbb 92 } // namespace mbed