From a4bdf6cbff7b5fce39aef18765396cc0aab26bf0 Mon Sep 17 00:00:00 2001
From: batt <batt@38d2e660-2303-0410-9eaa-f027e97ec537>
Date: Fri, 29 Aug 2008 15:21:53 +0000
Subject: [PATCH] Restore preempt_forbid_cnt as private; supply an accessor
 macro.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@1751 38d2e660-2303-0410-9eaa-f027e97ec537
---
 bertos/kern/preempt.c |  9 +++++----
 bertos/kern/proc.h    | 31 ++++++++++++++++++++++---------
 bertos/kern/signal.c  |  5 +----
 3 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/bertos/kern/preempt.c b/bertos/kern/preempt.c
index c3d212d4..2c44373b 100644
--- a/bertos/kern/preempt.c
+++ b/bertos/kern/preempt.c
@@ -65,7 +65,8 @@ CONFIG_DEPEND(CONFIG_KERN_PREEMPT,    CONFIG_KERN_SCHED && CONFIG_TIMER_EVENTS &
 
 MOD_DEFINE(preempt)
 
-int preempt_forbid_cnt;
+/** Global preemption disabling nesting counter */
+int _preempt_forbid_cnt;
 
 static Timer preempt_timer;
 
@@ -74,7 +75,7 @@ void proc_schedule(void)
 {
 	IRQ_DISABLE;
 
-	ASSERT(preempt_forbid_cnt == 0);
+	ASSERT(proc_allowed());
 	LIST_ASSERT_VALID(&ProcReadyList);
 	CurrentProcess = (struct Process *)list_remHead(&ProcReadyList);
 	ASSERT2(CurrentProcess, "no idle proc?");
@@ -86,7 +87,7 @@ void proc_schedule(void)
 
 void proc_preempt(UNUSED_ARG(void *, param))
 {
-	if (!preempt_forbid_cnt)
+	if (proc_allowed())
 	{
 		IRQ_DISABLE;
 
@@ -122,7 +123,7 @@ void proc_switch(void)
 
 	/* Sleeping with IRQs disabled or preemption forbidden is illegal */
 	IRQ_ASSERT_ENABLED();
-	ASSERT(preempt_forbid_cnt == 0);
+	ASSERT(proc_allowed());
 
 	// Will invoke proc_switch() in interrupt context
 	kill(0, SIGUSR1);
diff --git a/bertos/kern/proc.h b/bertos/kern/proc.h
index f8de758f..1a358346 100644
--- a/bertos/kern/proc.h
+++ b/bertos/kern/proc.h
@@ -85,9 +85,6 @@ const char *proc_currentName(void);
 	}
 #endif
 
-/** Global preemption disable nesting counter. */
-extern int preempt_forbid_cnt;
-
 /**
  * Disable preemptive task switching.
  *
@@ -108,11 +105,12 @@ extern int preempt_forbid_cnt;
 INLINE void proc_forbid(void)
 {
 	#if CONFIG_KERN_PREEMPT
+		extern int _preempt_forbid_cnt;
 		// No need to protect against interrupts here.
-		++preempt_forbid_cnt;
+		++_preempt_forbid_cnt;
 
 		/*
-		 * Make sure preempt_forbid_cnt is flushed to memory so the
+		 * Make sure _preempt_forbid_cnt is flushed to memory so the
 		 * preemption softirq will see the correct value from now on.
 		 */
 		MEMORY_BARRIER;
@@ -133,13 +131,13 @@ INLINE void proc_permit(void)
 		 * flushed to memory before task switching is re-enabled.
 		 */
 		MEMORY_BARRIER;
-
+		extern int _preempt_forbid_cnt;
 		/* No need to protect against interrupts here. */
-		--preempt_forbid_cnt;
-		ASSERT(preempt_forbid_cnt >= 0);
+		--_preempt_forbid_cnt;
+		ASSERT(_preempt_forbid_cnt >= 0);
 
 		/*
-		 * This ensures preempt_forbid_cnt is flushed to memory immediately
+		 * This ensures _preempt_forbid_cnt is flushed to memory immediately
 		 * so the preemption interrupt sees the correct value.
 		 */
 		MEMORY_BARRIER;
@@ -147,6 +145,21 @@ INLINE void proc_permit(void)
 	#endif
 }
 
+/**
+ * \return true if preemptive task switching is allowed.
+ * \note This accessor is needed because _preempt_forbid_cnt
+ *       must be absoultely private.
+ */
+INLINE bool proc_allowed(void)
+{
+	#if CONFIG_KERN_PREEMPT
+		extern int _preempt_forbid_cnt;
+		return (_preempt_forbid_cnt == 0);
+	#else
+		return true;
+	#endif
+}
+
 /**
  * Execute a block of \a CODE atomically with respect to task scheduling.
  */
diff --git a/bertos/kern/signal.c b/bertos/kern/signal.c
index 948d68f1..9785958d 100644
--- a/bertos/kern/signal.c
+++ b/bertos/kern/signal.c
@@ -139,10 +139,7 @@ sigmask_t sig_wait(sigmask_t sigs)
 
 	/* Sleeping with IRQs disabled or preemption forbidden is illegal */
 	IRQ_ASSERT_ENABLED();
-
-	#if CONFIG_KERN_PREEMPT
-	ASSERT(preempt_forbid_cnt == 0);
-	#endif
+	ASSERT(proc_allowed());
 
 	/*
 	 * This is subtle: there's a race condition where a concurrent
-- 
2.25.1