Fix #12, Add tick to microsec rounding warning, update comments

nasa · Apr 20, 2020 · 3d4e486 · 3d4e486
1 parent 20a83c4
commit 3d4e486
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Showing 3 changed files with 18 additions and 3 deletions.
diff --git a/src/os/posix/ostimer.c b/src/os/posix/ostimer.c
@@ -285,9 +285,10 @@ int32 OS_Posix_TimeBaseAPI_Impl_Init(void)
        }
 
        /*
-        * Calculate microseconds per tick - Rounding UP
-        *  - If the ratio is not an integer, this will choose the next higher value
-        *  - The result is guaranteed not to be zero.
+        * Calculate microseconds per tick 
+        *  - If the ratio is not an integer, this will round to the nearest integer value
+        *  - This is used internally for reporting accuracy,
+        *  - TicksPerSecond values over 2M will return zero
         */
        OS_SharedGlobalVars.MicroSecPerTick = (1000000 + (OS_SharedGlobalVars.TicksPerSecond / 2)) /
              OS_SharedGlobalVars.TicksPerSecond;

diff --git a/src/os/shared/osapi-common.c b/src/os/shared/osapi-common.c
@@ -64,6 +64,7 @@ int32 OS_API_Init(void)
 {
    int32  return_code = OS_SUCCESS;
    uint32 idtype;
+   uint32 microSecPerSec;
 
    if (OS_SharedGlobalVars.Initialized != false)
    {
@@ -161,6 +162,14 @@ int32 OS_API_Init(void)
       return_code = OS_ERROR;
    }
 
+   microSecPerSec = OS_SharedGlobalVars.MicroSecPerTick * OS_SharedGlobalVars.TicksPerSecond;
+
+   if ( microSecPerSec != 1000000 )
+   {   
+      OS_DEBUG("Warning: Microsecs per sec value of %lu does not equal 1000000 (MicroSecPerTick: %ld   TicksPerSecond: %ld)\n", 
+                (unsigned long) microSecPerSec, (long) OS_SharedGlobalVars.MicroSecPerTick, (long) OS_SharedGlobalVars.TicksPerSecond);
+   }
+
    return(return_code);
 } /* end OS_API_Init */
 

diff --git a/src/unit-test-coverage/shared/src/coveragetest-common.c b/src/unit-test-coverage/shared/src/coveragetest-common.c
@@ -97,6 +97,11 @@ void Test_OS_API_Init(void)
     OS_SharedGlobalVars.Initialized = false;
     OSAPI_TEST_FUNCTION_RC(OS_API_Init(), OS_SUCCESS);
 
+    Test_MicroSecPerTick = 1000;
+    Test_TicksPerSecond = 1001;
+    OS_SharedGlobalVars.Initialized = false;
+    OSAPI_TEST_FUNCTION_RC(OS_API_Init(), OS_SUCCESS);
+
     /* Second call should return ERROR */
     OSAPI_TEST_FUNCTION_RC(OS_API_Init(), OS_ERROR);