posix: Improve clock_gettime()

Return CPU usage values for CLOCK_PROCESS_CPUTIME_ID and
CLOCK_THREAD_CPUTIME_ID.

cpukit/libmisc/cpuuse/cpuusagedata.c

@@ -39,6 +39,6 @@
 #include "config.h"
 #endif
 
-#include "cpuuseimpl.h"
+#include <rtems/cpuuseimpl.h>
 
 Timestamp_Control  CPU_usage_Uptime_at_last_reset;

cpukit/libmisc/cpuuse/cpuusagereport.c

@@ -46,12 +46,11 @@
 #include <inttypes.h>
 
 #include <rtems/cpuuse.h>
+#include <rtems/cpuuseimpl.h>
 #include <rtems/printer.h>
 #include <rtems/score/threadimpl.h>
 #include <rtems/score/todimpl.h>
 
-#include "cpuuseimpl.h"
-
 typedef struct {
   const rtems_printer *printer;
   Timestamp_Control    total;

cpukit/libmisc/cpuuse/cpuusagereset.c

@@ -40,14 +40,13 @@
 #endif
 
 #include <rtems/cpuuse.h>
+#include <rtems/cpuuseimpl.h>
 #include <rtems/rtems/scheduler.h>
 #include <rtems/score/percpu.h>
 #include <rtems/score/todimpl.h>
 #include <rtems/score/schedulerimpl.h>
 #include <rtems/score/watchdogimpl.h>
 
-#include "cpuuseimpl.h"
-
 static bool CPU_usage_Per_thread_handler(
   Thread_Control *the_thread,
   void           *arg

cpukit/libmisc/cpuuse/cpuusagetop.c

@@ -53,6 +53,7 @@
 #include <inttypes.h>
 
 #include <rtems/cpuuse.h>
+#include <rtems/cpuuseimpl.h>
 #include <rtems/printer.h>
 #include <rtems/malloc.h>
 #include <rtems/score/objectimpl.h>
@@ -64,8 +65,6 @@
 #include <rtems/score/wkspace.h>
 #include <rtems/rtems/tasksimpl.h>
 
-#include "cpuuseimpl.h"
-
 /*
  * Use a struct for all data to allow more than one top and to support the
  * thread iterator.

cpukit/posix/src/clockgettime.c

@@ -5,10 +5,12 @@
  *
  * @ingroup POSIXAPI
  *
- * @brief Retrieves the Specified Clock Time
+ * @brief This source file contains the implementation of clock_gettime().
  */
 
 /*
+ * Copyright (C) 2024 embedded brains GmbH & Co. KG
+ *
  *  COPYRIGHT (c) 1989-2007.
  *  On-Line Applications Research Corporation (OAR).
  *
@@ -41,6 +43,9 @@
 #include <time.h>
 #include <errno.h>
 
+#include <rtems/cpuuseimpl.h>
+#include <rtems/score/threadimpl.h>
+#include <rtems/score/timestampimpl.h>
 #include <rtems/score/todimpl.h>
 #include <rtems/seterr.h>
 
@@ -70,17 +75,29 @@ int clock_gettime(
 
 #ifdef _POSIX_CPUTIME
   if ( clock_id == CLOCK_PROCESS_CPUTIME_ID ) {
-    _Timecounter_Nanouptime( tp );
+    Timestamp_Control uptime;
+    Timestamp_Control last_reset;
+    Timestamp_Control process_time;
+
+    last_reset = CPU_usage_Uptime_at_last_reset;
+    _TOD_Get_uptime( &uptime );
+    _Timestamp_Subtract( &last_reset, &uptime, &process_time );
+    _Timestamp_To_timespec( &process_time, tp );
     return 0;
   }
 #endif
 
 #ifdef _POSIX_THREAD_CPUTIME
-  if ( clock_id == CLOCK_THREAD_CPUTIME_ID )
-    rtems_set_errno_and_return_minus_one( ENOSYS );
+  if ( clock_id == CLOCK_THREAD_CPUTIME_ID ) {
+    Timestamp_Control used;
+
+    used = _Thread_Get_CPU_time_used_after_last_reset(
+      _Thread_Get_executing()
+    );
+    _Timestamp_To_timespec( &used, tp );
+    return 0;
+  }
 #endif
 
   rtems_set_errno_and_return_minus_one( EINVAL );
-
-  return 0;
 }

testsuites/psxtests/psxclock/init.c

@@ -386,7 +386,19 @@ static rtems_task Init(
   /* print new times to make sure it has changed and we can get the realtime */
   sc = clock_gettime( CLOCK_PROCESS_CPUTIME_ID, &tv );
   rtems_test_assert( !sc );
-  printf("Time since boot: (%" PRIdtime_t ", %ld)\n", tv.tv_sec,tv.tv_nsec );
+  printf(
+    "Time since last CPU usage reset: (%" PRIdtime_t ", %ld)\n",
+    tv.tv_sec,
+    tv.tv_nsec
+  );
+
+  sc = clock_gettime( CLOCK_THREAD_CPUTIME_ID, &tv );
+  rtems_test_assert( !sc );
+  printf(
+    "CPU time used since last CPU usage reset: (%" PRIdtime_t ", %ld)\n",
+    tv.tv_sec,
+    tv.tv_nsec
+  );
 
   sc = clock_gettime( CLOCK_REALTIME, &tv );
   rtems_test_assert( !sc );
@@ -499,14 +511,6 @@ static rtems_task Init(
   printf( ctime( &tv.tv_sec ) );
 
   empty_line();
-  puts( "clock_gettime - CLOCK_THREAD_CPUTIME_ID -- ENOSYS" );
-  #if defined(_POSIX_THREAD_CPUTIME)
-    {
-      struct timespec tp;
-      sc = clock_gettime( CLOCK_THREAD_CPUTIME_ID, &tp );
-      check_enosys( sc );
-    }
-  #endif
 
   puts( "clock_settime - CLOCK_PROCESS_CPUTIME_ID -- ENOSYS" );
   #if defined(_POSIX_CPUTIME)