Critical Section Monitor: Add low level timer support for simulation. Fix serial bugs and logic errors in initial implementation. Still does not work; takes assertions.

arch/sim/src/Makefile

@@ -1,7 +1,8 @@
 ############################################################################
 # arch/sim/src/Makefile
 #
-#   Copyright (C) 2007, 2008, 2011-2012, 2014, 2016 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2007, 2008, 2011-2012, 2014, 2016, 2018 Gregory Nutt. All
+#     rights reserved.
 #   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
@@ -91,6 +92,10 @@ ifeq ($(CONFIG_ONESHOT),y)
   CSRCS += up_oneshot.c
 endif
 
+ifeq ($(CONFIG_SCHED_CRITMONITOR),y)
+  HOSTSRCS += up_critmon.c
+endif
+
 ifeq ($(CONFIG_NX_LCDDRIVER),y)
   CSRCS += board_lcd.c
 else

arch/sim/src/nuttx-names.dat

@@ -6,6 +6,7 @@ basename       NXbasename
 calloc         NXcalloc
 chdir          NXchdir
 clearenv       NXclearenv
+clock          NXclock
 clock_gettime  NXclock_gettime
 close          NXclose
 closedir       NXclosedir

fs/procfs/fs_procfscritmon.c

@@ -304,19 +304,24 @@ static ssize_t critmon_read(FAR struct file *filep, FAR char *buffer,
   attr = (FAR struct critmon_file_s *)filep->f_priv;
   DEBUGASSERT(attr);
 
-  ret = 0;
+  ret    = 0;
+  offset = filep->f_pos;
 
 #ifdef CONFIG_SMP
   /* Get the status for each CPU  */
 
   for (cpu = 0; cpu < CONFIG_SMP_NCPUS; cpu++)
     {
-      ret += critmon_read_cpu(attr, buffer + ret, buflen -ret,
-                                  &offset, cpu);
+      ssize_t nbytes = critmon_read_cpu(attr, buffer + ret, buflen - ret,
+                                        &offset, cpu);
+
+      ret += nbytes;
       if (ret > buflen)
         {
           break;
         }
+
+      offset += nbytes;
     }
 
 #else

include/nuttx/sched.h

@@ -637,7 +637,8 @@ struct tcb_s
 #endif
   uint16_t flags;                        /* Misc. general status flags          */
   int16_t  lockcount;                    /* 0=preemptable (not-locked)          */
-#ifdef CONFIG_SMP
+#if defined(CONFIG_SMP) || defined(CONFIG_SCHED_CRITMONITOR) || \
+    defined(CONFIG_SCHED_INSTRUMENTATION_CSECTION)
   int16_t  irqcount;                     /* 0=Not in critical section           */
 #endif
 #ifdef CONFIG_CANCELLATION_POINTS

sched/irq/irq_csection.c

@@ -411,14 +411,22 @@ irqstate_t enter_critical_section(void)
       FAR struct tcb_s *rtcb = this_task();
       DEBUGASSERT(rtcb != NULL);
 
-      /* Yes.. Note that we have entered the critical section */
+      /* Have we just entered the critical section?  Or is this a nested
+       * call to enter_critical_section.
+       */
+
+      DEBUGASSERT(rtcb->irqcount >= 0 && rtcb->irqcount < UINT16_MAX);
+      if (++rtcb->irqcount == 1)
+        {
+          /* Note that we have entered the critical section */
 
 #ifdef CONFIG_SCHED_CRITMONITOR
-      sched_critmon_csection(rtcb, true);
+          sched_critmon_csection(rtcb, true);
 #endif
 #ifdef CONFIG_SCHED_INSTRUMENTATION_CSECTION
-      sched_note_csection(rtcb, true);
+          sched_note_csection(rtcb, true);
 #endif
+        }
     }
 
   /* Return interrupt status */
@@ -591,14 +599,20 @@ void leave_critical_section(irqstate_t flags)
       FAR struct tcb_s *rtcb = this_task();
       DEBUGASSERT(rtcb != NULL);
 
-      /* Yes.. Note that we have left the critical section */
+      /* Have we left entered the critical section?  Or are we still nested. */
+
+      DEBUGASSERT(rtcb->irqcount > 0);
+      if (--rtcb->irqcount <= 0)
+        {
+          /* Note that we have left the critical section */
 
 #ifdef CONFIG_SCHED_CRITMONITOR
-      sched_critmon_csection(rtcb, false);
+          sched_critmon_csection(rtcb, false);
 #endif
 #ifdef CONFIG_SCHED_INSTRUMENTATION_CSECTION
-      sched_note_csection(rtcb, false);
+          sched_note_csection(rtcb, false);
 #endif
+        }
     }
 
   /* Restore the previous interrupt state. */

sched/sched/sched_critmonitor.c

@@ -52,11 +52,11 @@
 #define CRITMON_PREEMPT       (1 << 0)  /* Bit 0:  Pre-emption is disabled */
 #define CRITMON_CSECTION      (1 << 1)  /* Bit 1:  In a critical section */
 
-#define DISABLE_PREEMPT(t)    do { (t)->flags |= CRITMON_PREEMPT; } while (0)
-#define ENTER_CSECTION(t)     do { (t)->flags |= CRITMON_PREEMPT; } while (0)
+#define DISABLE_PREEMPT(t)    do { (t)->crit_flags |= CRITMON_PREEMPT; } while (0)
+#define ENTER_CSECTION(t)     do { (t)->crit_flags |= CRITMON_CSECTION; } while (0)
 
-#define ENABLE_PREEMPT(t)     do { (t)->flags &= ~CRITMON_PREEMPT; } while (0)
-#define LEAVE_CSECTION(t)     do { (t)->flags &= ~CRITMON_PREEMPT; } while (0)
+#define ENABLE_PREEMPT(t)     do { (t)->crit_flags &= ~CRITMON_PREEMPT; } while (0)
+#define LEAVE_CSECTION(t)     do { (t)->crit_flags &= ~CRITMON_CSECTION; } while (0)
 
 #define PREEMPT_ISDISABLED(t) (((t)->crit_flags & CRITMON_PREEMPT) != 0)
 #define IN_CSECTION(t)        (((t)->crit_flags & CRITMON_CSECTION) != 0)

sched/signal/sig_notification.c

@@ -77,7 +77,7 @@
 int nxsig_notification(pid_t pid, FAR struct sigevent *event, int code)
 {
   sinfo("pid=%p signo=%d code=%d sival_ptr=%p\n",
-         pid, event->sigev_signo, code, event->value.sival_ptr);
+         pid, event->sigev_signo, code, event->sigev_value.sival_ptr);
 
   /* Notify client via a signal? */