main.cpp

00001 /* mbed Microcontroller Library
00002  * Copyright (c) 2017 ARM Limited
00003  *
00004  * Licensed under the Apache License, Version 2.0 (the "License");
00005  * you may not use this file except in compliance with the License.
00006  * You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 #include "mbed_events.h"
00017 #include "mbed.h"
00018 #include "rtos.h"
00019 #include "greentea-client/test_env.h"
00020 #include "unity.h"
00021 #include "utest.h"
00022 #include <cstdlib>
00023 #include <cmath>
00024 
00025 using namespace utest::v1;
00026 
00027 #if !DEVICE_USTICKER
00028 #error [NOT_SUPPORTED] test not supported
00029 #endif
00030 
00031 // Test delay
00032 #ifndef TEST_EVENTS_TIMING_TIME
00033 #define TEST_EVENTS_TIMING_TIME 20000
00034 #endif
00035 
00036 #ifndef TEST_EVENTS_TIMING_MEAN
00037 #define TEST_EVENTS_TIMING_MEAN 25
00038 #endif
00039 
00040 #ifndef M_PI
00041 #define M_PI 3.14159265358979323846264338327950288
00042 #endif
00043 
00044 // Random number generation to skew timing values
00045 float gauss(float mu, float sigma)
00046 {
00047     float x = (float)rand() / ((float)RAND_MAX + 1);
00048     float y = (float)rand() / ((float)RAND_MAX + 1);
00049     float x2pi = x * 2.0 * M_PI;
00050     float g2rad = sqrt(-2.0 * log(1.0 - y));
00051     float z = cos(x2pi) * g2rad;
00052     return mu + z * sigma;
00053 }
00054 
00055 float chisq(float sigma)
00056 {
00057     return pow(gauss(0, sqrt(sigma)), 2);
00058 }
00059 
00060 
00061 Timer timer;
00062 DigitalOut led(LED1);
00063 
00064 equeue_sema_t sema;
00065 
00066 // Timer timing test
00067 void timer_timing_test()
00068 {
00069     timer.reset();
00070     timer.start();
00071     int prev = timer.read_us();
00072 
00073     while (prev < TEST_EVENTS_TIMING_TIME * 1000) {
00074         int next = timer.read_us();
00075         if (next < prev) {
00076             printf("backwards drift %d -> %d (%08x -> %08x)\r\n",
00077                    prev, next, prev, next);
00078         }
00079         TEST_ASSERT(next >= prev);
00080         prev = next;
00081     }
00082 }
00083 
00084 // equeue tick timing test
00085 void tick_timing_test()
00086 {
00087     unsigned start = equeue_tick();
00088     int prev = 0;
00089 
00090     while (prev < TEST_EVENTS_TIMING_TIME) {
00091         int next = equeue_tick() - start;
00092         if (next < prev) {
00093             printf("backwards drift %d -> %d (%08x -> %08x)\r\n",
00094                    prev, next, prev, next);
00095         }
00096         TEST_ASSERT(next >= prev);
00097         prev = next;
00098     }
00099 }
00100 
00101 // equeue semaphore timing test
00102 void semaphore_timing_test()
00103 {
00104     srand(0);
00105     timer.reset();
00106     timer.start();
00107 
00108     int err = equeue_sema_create(&sema);
00109     TEST_ASSERT_EQUAL(0, err);
00110 
00111     while (timer.read_ms() < TEST_EVENTS_TIMING_TIME) {
00112         int delay = chisq(TEST_EVENTS_TIMING_MEAN);
00113 
00114         int start = timer.read_us();
00115         equeue_sema_wait(&sema, delay);
00116         int taken = timer.read_us() - start;
00117 
00118         if (taken < (delay * 1000 - 5000) || taken > (delay * 1000 + 5000)) {
00119             printf("delay %dms => error %dus\r\n", delay, abs(1000 * delay - taken));
00120         }
00121 
00122         TEST_ASSERT_INT_WITHIN(5000, taken, delay * 1000);
00123 
00124         led = !led;
00125     }
00126 
00127     equeue_sema_destroy(&sema);
00128 }
00129 
00130 
00131 // Test setup
00132 utest::v1::status_t test_setup(const size_t number_of_cases)
00133 {
00134     GREENTEA_SETUP((number_of_cases + 1)*TEST_EVENTS_TIMING_TIME / 1000, "default_auto");
00135     return verbose_test_setup_handler(number_of_cases);
00136 }
00137 
00138 const Case cases[] = {
00139     Case("Testing accuracy of timer", timer_timing_test),
00140     Case("Testing accuracy of equeue tick", tick_timing_test),
00141     Case("Testing accuracy of equeue semaphore", semaphore_timing_test),
00142 };
00143 
00144 Specification specification(test_setup, cases);
00145 
00146 int main()
00147 {
00148     return !Harness::run(specification);
00149 }
00150