Rtos API example

Revision:
0:9fca2b23d0ba
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/events/equeue/equeue_mbed.cpp	Sat Feb 23 12:13:36 2019 +0000
@@ -0,0 +1,167 @@
+/*
+ * Implementation for the mbed library
+ * https://github.com/mbedmicro/mbed
+ *
+ * Copyright (c) 2016 Christopher Haster
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "equeue/equeue_platform.h"
+
+#if defined(EQUEUE_PLATFORM_MBED)
+
+#include <stdbool.h>
+#include "mbed.h"
+
+#if MBED_CONF_EVENTS_USE_LOWPOWER_TIMER_TICKER
+#define ALIAS_TIMER      LowPowerTimer
+#define ALIAS_TICKER     LowPowerTicker
+#define ALIAS_TIMEOUT    LowPowerTimeout
+#else
+#define ALIAS_TIMER      Timer
+#define ALIAS_TICKER     Ticker
+#define ALIAS_TIMEOUT    Timeout
+#endif
+
+// Ticker operations
+static bool equeue_tick_inited = false;
+static volatile unsigned equeue_minutes = 0;
+static unsigned equeue_timer[
+        (sizeof(ALIAS_TIMER)+sizeof(unsigned)-1)/sizeof(unsigned)];
+static unsigned equeue_ticker[
+        (sizeof(ALIAS_TICKER)+sizeof(unsigned)-1)/sizeof(unsigned)];
+
+static void equeue_tick_update() {
+    equeue_minutes += reinterpret_cast<ALIAS_TIMER*>(equeue_timer)->read_ms();
+    reinterpret_cast<ALIAS_TIMER*>(equeue_timer)->reset();
+}
+
+static void equeue_tick_init() {
+    MBED_STATIC_ASSERT(sizeof(equeue_timer) >= sizeof(ALIAS_TIMER),
+            "The equeue_timer buffer must fit the class Timer");
+    MBED_STATIC_ASSERT(sizeof(equeue_ticker) >= sizeof(ALIAS_TICKER),
+            "The equeue_ticker buffer must fit the class Ticker");
+    ALIAS_TIMER *timer = new (equeue_timer) ALIAS_TIMER;
+    ALIAS_TICKER *ticker = new (equeue_ticker) ALIAS_TICKER;
+
+    equeue_minutes = 0;
+    timer->start();
+    ticker->attach_us(equeue_tick_update, 1000 << 16);
+
+    equeue_tick_inited = true;
+}
+
+unsigned equeue_tick() {
+    if (!equeue_tick_inited) {
+        equeue_tick_init();
+    }
+
+    unsigned minutes;
+    unsigned ms;
+
+    do {
+        minutes = equeue_minutes;
+        ms = reinterpret_cast<ALIAS_TIMER*>(equeue_timer)->read_ms();
+    } while (minutes != equeue_minutes);
+
+    return minutes + ms;
+}
+
+
+// Mutex operations
+int equeue_mutex_create(equeue_mutex_t *m) { return 0; }
+void equeue_mutex_destroy(equeue_mutex_t *m) { }
+
+void equeue_mutex_lock(equeue_mutex_t *m) {
+    core_util_critical_section_enter();
+}
+
+void equeue_mutex_unlock(equeue_mutex_t *m) {
+    core_util_critical_section_exit();
+}
+
+
+// Semaphore operations
+#ifdef MBED_CONF_RTOS_PRESENT
+
+int equeue_sema_create(equeue_sema_t *s) {
+    osEventFlagsAttr_t attr;
+    memset(&attr, 0, sizeof(attr));
+    attr.cb_mem = &s->mem;
+    attr.cb_size = sizeof(s->mem);
+
+    s->id = osEventFlagsNew(&attr);
+    return !s->id ? -1 : 0;
+}
+
+void equeue_sema_destroy(equeue_sema_t *s) {
+    osEventFlagsDelete(s->id);
+}
+
+void equeue_sema_signal(equeue_sema_t *s) {
+    osEventFlagsSet(s->id, 1);
+}
+
+bool equeue_sema_wait(equeue_sema_t *s, int ms) {
+    if (ms < 0) {
+        ms = osWaitForever;
+    }
+
+    return (osEventFlagsWait(s->id, 1, osFlagsWaitAny, ms) == 1);
+}
+
+#else
+
+// Semaphore operations
+int equeue_sema_create(equeue_sema_t *s) {
+    *s = false;
+    return 0;
+}
+
+void equeue_sema_destroy(equeue_sema_t *s) {
+}
+
+void equeue_sema_signal(equeue_sema_t *s) {
+    *s = 1;
+}
+
+static void equeue_sema_timeout(equeue_sema_t *s) {
+    *s = -1;
+}
+
+bool equeue_sema_wait(equeue_sema_t *s, int ms) {
+    int signal = 0;
+    ALIAS_TIMEOUT timeout;
+    if (ms == 0) {
+        return false;
+    } else if (ms > 0) {
+        timeout.attach_us(callback(equeue_sema_timeout, s), ms*1000);
+    }
+
+    core_util_critical_section_enter();
+    while (!*s) {
+        sleep();
+        core_util_critical_section_exit();
+        core_util_critical_section_enter();
+    }
+
+    signal = *s;
+    *s = false;
+    core_util_critical_section_exit();
+
+    return (signal > 0);
+}
+
+#endif
+
+#endif