From 57ac39649ab1b570a12e4d7f7f41a7d41efcb472 Mon Sep 17 00:00:00 2001
From: Andrew Tridgell <tridge@samba.org>
Date: Mon, 30 Apr 2012 16:11:05 +1000
Subject: [PATCH] TimerProcess: added suspend_timer()/resume_timer()
this will be used to avoid races in driver initialisation
---
.../AP_PeriodicProcessStub.cpp | 2 ++
.../AP_PeriodicProcessStub.h | 3 ++
.../AP_PeriodicProcess/AP_TimerProcess.cpp | 28 ++++++++++++++-----
.../AP_PeriodicProcess/AP_TimerProcess.h | 3 ++
.../AP_PeriodicProcess/PeriodicProcess.h | 9 ++++--
5 files changed, 35 insertions(+), 10 deletions(-)
diff --git a/libraries/AP_PeriodicProcess/AP_PeriodicProcessStub.cpp b/libraries/AP_PeriodicProcess/AP_PeriodicProcessStub.cpp
index aa6e0483b..0e57d49a7 100644
--- a/libraries/AP_PeriodicProcess/AP_PeriodicProcessStub.cpp
+++ b/libraries/AP_PeriodicProcess/AP_PeriodicProcessStub.cpp
@@ -4,4 +4,6 @@ AP_PeriodicProcessStub::AP_PeriodicProcessStub(uint8_t period) {}
void AP_PeriodicProcessStub::init( Arduino_Mega_ISR_Registry * isr_reg ){}
void AP_PeriodicProcessStub::register_process(ap_procedure proc) {}
void AP_PeriodicProcessStub::set_failsafe(ap_procedure proc) {}
+void AP_PeriodicProcessStub::suspend_timer(void) {}
+void AP_PeriodicProcessStub::resume_timer(void) {}
void AP_PeriodicProcessStub::run(void) {}
diff --git a/libraries/AP_PeriodicProcess/AP_PeriodicProcessStub.h b/libraries/AP_PeriodicProcess/AP_PeriodicProcessStub.h
index c9e9c3567..9544a9a77 100644
--- a/libraries/AP_PeriodicProcess/AP_PeriodicProcessStub.h
+++ b/libraries/AP_PeriodicProcess/AP_PeriodicProcessStub.h
@@ -13,11 +13,14 @@ class AP_PeriodicProcessStub : public AP_PeriodicProcess
void init( Arduino_Mega_ISR_Registry * isr_reg );
void register_process(ap_procedure proc);
void set_failsafe(ap_procedure proc);
+ void suspend_timer(void);
+ void resume_timer(void);
static void run(void);
protected:
static uint8_t _period;
static void (*_proc)(void);
static void (*_failsafe)(void);
+ static bool _suspended;
};
#endif
diff --git a/libraries/AP_PeriodicProcess/AP_TimerProcess.cpp b/libraries/AP_PeriodicProcess/AP_TimerProcess.cpp
index 767efacfb..0395c5134 100644
--- a/libraries/AP_PeriodicProcess/AP_TimerProcess.cpp
+++ b/libraries/AP_PeriodicProcess/AP_TimerProcess.cpp
@@ -18,6 +18,7 @@ ap_procedure AP_TimerProcess::_proc[AP_TIMERPROCESS_MAX_PROCS];
ap_procedure AP_TimerProcess::_failsafe;
bool AP_TimerProcess::_in_timer_call;
uint8_t AP_TimerProcess::_pidx = 0;
+bool AP_TimerProcess::_suspended;
AP_TimerProcess::AP_TimerProcess(uint8_t period)
{
@@ -34,7 +35,8 @@ void AP_TimerProcess::init( Arduino_Mega_ISR_Registry * isr_reg )
TIFR2 = _BV(TOV2); // clear pending interrupts;
TIMSK2 = _BV(TOIE2); // enable the overflow interrupt
- _failsafe = NULL;
+ _failsafe = NULL;
+ _suspended = false;
_in_timer_call = false;
for (uint8_t i = 0; i < AP_TIMERPROCESS_MAX_PROCS; i++)
@@ -64,6 +66,16 @@ void AP_TimerProcess::set_failsafe(ap_procedure proc)
_failsafe = proc;
}
+void AP_TimerProcess::suspend_timer(void)
+{
+ _suspended = true;
+}
+
+void AP_TimerProcess::resume_timer(void)
+{
+ _suspended = false;
+}
+
void AP_TimerProcess::run(void)
{
// we enable the interrupt again immediately and also enable
@@ -95,12 +107,14 @@ void AP_TimerProcess::run(void)
}
_in_timer_call = true;
- // now call the timer based drivers
- for (int i = 0; i < _pidx; i++) {
- if (_proc[i] != NULL) {
- _proc[i](tnow);
- }
- }
+ if (!_suspended) {
+ // now call the timer based drivers
+ for (int i = 0; i < _pidx; i++) {
+ if (_proc[i] != NULL) {
+ _proc[i](tnow);
+ }
+ }
+ }
// and the failsafe, if one is setup
if (_failsafe != NULL) {
diff --git a/libraries/AP_PeriodicProcess/AP_TimerProcess.h b/libraries/AP_PeriodicProcess/AP_TimerProcess.h
index 140c5996f..f90fb3cbe 100644
--- a/libraries/AP_PeriodicProcess/AP_TimerProcess.h
+++ b/libraries/AP_PeriodicProcess/AP_TimerProcess.h
@@ -17,6 +17,8 @@ class AP_TimerProcess : public AP_PeriodicProcess
void init( Arduino_Mega_ISR_Registry * isr_reg );
void register_process(ap_procedure proc);
void set_failsafe(ap_procedure proc);
+ void suspend_timer(void);
+ void resume_timer(void);
static void run(void);
protected:
static uint8_t _period;
@@ -24,6 +26,7 @@ class AP_TimerProcess : public AP_PeriodicProcess
static ap_procedure _failsafe;
static uint8_t _pidx;
static bool _in_timer_call;
+ static bool _suspended;
};
#endif // __AP_TIMERPROCESS_H__
diff --git a/libraries/AP_PeriodicProcess/PeriodicProcess.h b/libraries/AP_PeriodicProcess/PeriodicProcess.h
index 021e84f06..2c5749938 100644
--- a/libraries/AP_PeriodicProcess/PeriodicProcess.h
+++ b/libraries/AP_PeriodicProcess/PeriodicProcess.h
@@ -1,3 +1,4 @@
+/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#ifndef __PERIODICPROCESS_H__
#define __PERIODICPROCESS_H__
@@ -10,9 +11,11 @@ typedef void (*ap_procedure)(uint32_t );
class AP_PeriodicProcess
{
- public:
- virtual void register_process(ap_procedure proc) = 0;
- virtual void set_failsafe(ap_procedure proc) = 0;
+public:
+ virtual void register_process(ap_procedure proc) = 0;
+ virtual void set_failsafe(ap_procedure proc) = 0;
+ virtual void suspend_timer(void) = 0;
+ virtual void resume_timer(void) = 0;
};
#endif // __PERIODICPROCESS_H__
--
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