Add Chrono support to Mutex

Author: kjbracey

rtos/Mutex.h

@@ -27,6 +27,7 @@
 #include "rtos/mbed_rtos_types.h"
 #include "rtos/mbed_rtos1_types.h"
 #include "rtos/mbed_rtos_storage.h"
+#include "rtos/Kernel.h"
 
 #include "platform/NonCopyable.h"
 #include "platform/ScopedLock.h"
@@ -105,9 +106,23 @@ class Mutex : private mbed::NonCopyable<Mutex> {
             the lock attempt will time out earlier than specified.
 
       @note You cannot call this function from ISR context.
+      @deprecated Pass a chrono duration, not an integer millisecond count. For example use `5s` rather than `5000`.
      */
+    MBED_DEPRECATED_SINCE("mbed-os-6.0.0", "Pass a chrono duration, not an integer millisecond count. For example use `5s` rather than `5000`.")
     bool trylock_for(uint32_t millisec);
 
+    /** Try to lock the mutex for a specified time
+      @param   rel_time  timeout value.
+      @return true if the mutex was acquired, false otherwise.
+      @note the underlying RTOS may have a limit to the maximum wait time
+            due to internal 32-bit computations, but this is guaranteed to work if the
+            wait is <= 0x7fffffff milliseconds (~24 days). If the limit is exceeded,
+            the lock attempt will time out earlier than specified.
+
+      @note You cannot call this function from ISR context.
+     */
+    bool trylock_for(Kernel::Clock::duration_u32 rel_time);
+
     /** Try to lock the mutex until specified time
       @param   millisec  absolute timeout time, referenced to Kernel::get_ms_count()
       @return true if the mutex was acquired, false otherwise.
@@ -117,9 +132,24 @@ class Mutex : private mbed::NonCopyable<Mutex> {
             the lock attempt will time out earlier than specified.
 
       @note You cannot call this function from ISR context.
+      @deprecated Pass a chrono time_point, not an integer millisecond count. For example use
+                  `Kernel::Clock::now() + 5s` rather than `Kernel::get_ms_count() + 5000`.
      */
+    MBED_DEPRECATED_SINCE("mbed-os-6.0.0", "Pass a chrono time_point, not an integer millisecond count. For example use `Kernel::Clock::now() + 5s` rather than `Kernel::get_ms_count() + 5000`.")
     bool trylock_until(uint64_t millisec);
 
+    /** Try to lock the mutex until specified time
+      @param   abs_time  absolute timeout time, referenced to Kernel::get_ms_count()
+      @return true if the mutex was acquired, false otherwise.
+      @note the underlying RTOS may have a limit to the maximum wait time
+            due to internal 32-bit computations, but this is guaranteed to work if the
+            wait is <= 0x7fffffff milliseconds (~24 days). If the limit is exceeded,
+            the lock attempt will time out earlier than specified.
+
+      @note You cannot call this function from ISR context.
+     */
+    bool trylock_until(Kernel::Clock::time_point abs_time);
+
     /**
       Unlock the mutex that has previously been locked by the same thread
 
@@ -178,11 +208,21 @@ inline bool Mutex::trylock_for(uint32_t)
     return true;
 }
 
+inline bool Mutex::trylock_for(Kernel::Clock::duration_u32)
+{
+    return true;
+}
+
 inline bool Mutex::trylock_until(uint64_t)
 {
     return true;
 }
 
+inline bool Mutex::trylock_until(Kernel::Clock::time_point)
+{
+    return true;
+}
+
 inline void Mutex::unlock()
 {
 }

rtos/source/Mutex.cpp

@@ -29,6 +29,10 @@
 
 #if MBED_CONF_RTOS_PRESENT
 
+using namespace std::chrono_literals;
+using std::milli;
+using std::chrono::duration;
+
 namespace rtos {
 
 Mutex::Mutex()
@@ -71,20 +75,25 @@ void Mutex::lock(void)
 
 bool Mutex::trylock()
 {
-    return trylock_for(0);
+    return trylock_for(0s);
 }
 
 bool Mutex::trylock_for(uint32_t millisec)
 {
-    osStatus status = osMutexAcquire(_id, millisec);
+    return trylock_for(duration<uint32_t, milli>(millisec));
+}
+
+bool Mutex::trylock_for(Kernel::Clock::duration_u32 rel_time)
+{
+    osStatus status = osMutexAcquire(_id, rel_time.count());
     if (status == osOK) {
         _count++;
         return true;
     }
 
     bool success = (status == osOK ||
-                    (status == osErrorResource && millisec == 0) ||
-                    (status == osErrorTimeout && millisec != osWaitForever));
+                    (status == osErrorResource && rel_time == rel_time.zero()) ||
+                    (status == osErrorTimeout && rel_time <= Kernel::wait_for_u32_max));
 
     if (!success && !mbed_get_error_in_progress()) {
         MBED_ERROR1(MBED_MAKE_ERROR(MBED_MODULE_KERNEL, MBED_ERROR_CODE_MUTEX_LOCK_FAILED), "Mutex lock failed", status);
@@ -95,15 +104,20 @@ bool Mutex::trylock_for(uint32_t millisec)
 
 bool Mutex::trylock_until(uint64_t millisec)
 {
-    uint64_t now = Kernel::get_ms_count();
+    return trylock_until(Kernel::Clock::time_point(duration<uint64_t, milli>(millisec)));
+}
+
+bool Mutex::trylock_until(Kernel::Clock::time_point abs_time)
+{
+    Kernel::Clock::time_point now = Kernel::Clock::now();
 
-    if (now >= millisec) {
+    if (now >= abs_time) {
         return trylock();
-    } else if (millisec - now >= osWaitForever) {
+    } else if (abs_time - now > Kernel::wait_for_u32_max) {
         // API permits early return
-        return trylock_for(osWaitForever - 1);
+        return trylock_for(Kernel::wait_for_u32_max);
     } else {
-        return trylock_for(millisec - now);
+        return trylock_for(abs_time - now);
     }
 }