RTOS/AM3358: GateMutex causing exit

fyi my GateMutex setup function looks like this:

GateMutexPri_Handle SetupGateMutex(void)
{
	GateMutexPri_Handle gate_h = NULL;
	gate_h = GateMutexPri_create(NULL, NULL);
	assert(gate_h != NULL);
	return gate_h;
}

Hi Sean,

Where is gate_key defined? It should be a local to ClaimResource and the value returned from the API. Then the value should be passed into FreeResource. The key allows gates to be recursive, so the same thread can call the enter multiple times (note: it then needs to leave the gate the same number of times).

Todd

Hi Todd, 

nope didn't help.  i changed the functions to the below and it still crashed after a few hours.  btw at this point there is only one context accessing what the GateMutesPri's are protecting.

static IArg ClaimResource(void)
{
#ifdef USE_GATE_MUTEX_PRI
	return GateMutexPri_enter(gate);
#else
	Semaphore_pend(sem, BIOS_WAIT_FOREVER);
#endif
	return 0;
}

static void FreeResource(IArg key)
{
#ifdef USE_GATE_MUTEX_PRI
	GateMutexPri_leave(gate, key);
#else
	Semaphore_post(sem);
#endif
	return;
}

thanks

Sean

Hi Todd,

The below code causes the crash reliably and instantly.

static GateMutexPri_Handle gate = NULL;

static void Task(UArg arg0, UArg arg1) {
	IArg key = GateMutexPri_enter(gate);
	GateMutexPri_leave(gate, key);
}

void idle_function(void) {
	Task_Handle task = NULL;

	// Set up and enter the gate
	gate = GateMutexPri_create(NULL, NULL);
	assert(gate != NULL);
	IArg key = GateMutexPri_enter(gate);

	//Start the task
	Task_Params taskParams;
	Task_Params_init(&taskParams);
	taskParams.priority = 6;
	task = Task_create((Task_FuncPtr)Task, &taskParams, NULL);
	assert(task != NULL);

	GateMutexPri_leave(gate, key);	// Never returns from here or goes back into Task as it should
	while(1);
}

In happens when the GateMutexPri_leave is executed in the idle loop and it never gets back into the task.  Looking in ROV you can see that the GateMutexPri is with the idle loop and its current priority is 6 because the task has requested the gate.  No exception is shown and in the task view ti shows the idle loop has been preempted and has a priority of 6 and that the other task is blocked.  There was another access to the GatMutexPri's in my full code I had missed as you can probably guess it was in the idle loop hence how i discovered this.

I have tried:

• Changing the idle loop to a priority 1 task and it worked fine.
• Just running the idle loop through without starting the task and it worked fine
• Changing the GateMutexPri to standard GateMutex, again this works fine

So it seems the issue is when the idle task inherits a higher priority due to the gate request from the task it causes SYS/BIOS to crash.  not sure what else i can do to investigate this, if you could suggest a fix that would be great and for now I will just have to work around it.

Cheers

Sean

Hi Sean,

While it's strange to have GateMutexPri_enter in an Idle function, I was not able to reproduce your problem. Your example run fine. I had nothing but the myIdleFunc function plugged into Idle (in the .cfg file). I did increase the heap and idle stack size to make sure I had no allocation or stack issues.

I ran the example and had a breakpoint the the GateMutexPri_leave in the Idle function.

Note: I had already hit the breakpoint at GateMutexPr_enter in the in the Task function.

Here is the Task->Detailed view

Again weird that Idle is at priority 6, but this should not cause a problem.

When I ran, I hit the breakpoint at GateMutexPri_leave in the Task function. Again the tasks looked fine.

I continued and when I halted I see the Task terminated and Idle stuck in the while(1) loop. 

What crash are you seeing with this setup?

Todd

Tried that and same issue I also stripped back everything else out of my project to just have that code as before I had some classes etc that would have ran before main and no luck.  Tried changing to c instead of cpp and swapping to the TI compiler and the same behaviour all the time

This is my config file btw

var Defaults = xdc.useModule('xdc.runtime.Defaults');
var Diags = xdc.useModule('xdc.runtime.Diags');
var Error = xdc.useModule('xdc.runtime.Error');
var Log = xdc.useModule('xdc.runtime.Log');
var LoggerBuf = xdc.useModule('xdc.runtime.LoggerBuf');
var Main = xdc.useModule('xdc.runtime.Main');
var SysMin = xdc.useModule('xdc.runtime.SysMin');
var System = xdc.useModule('xdc.runtime.System');
var Text = xdc.useModule('xdc.runtime.Text');
var GateAll = xdc.useModule('ti.sysbios.gates.GateAll');
var GateMutexPri = xdc.useModule('ti.sysbios.gates.GateMutexPri');
var BIOS = xdc.useModule('ti.sysbios.BIOS');
var Hwi = xdc.useModule('ti.sysbios.hal.Hwi');
var Memory = xdc.useModule('xdc.runtime.Memory');
var HeapMem = xdc.useModule('ti.sysbios.heaps.HeapMem');
var ti_sysbios_family_arm_a8_intcps_Hwi = xdc.useModule('ti.sysbios.family.arm.a8.intcps.Hwi');
var Idle = xdc.useModule('ti.sysbios.knl.Idle');
var Task = xdc.useModule('ti.sysbios.knl.Task');
var Semaphore = xdc.useModule('ti.sysbios.knl.Semaphore');
var Cache = xdc.useModule('ti.sysbios.family.arm.a8.Cache');
var Mmu = xdc.useModule('ti.sysbios.family.arm.a8.Mmu');

var ti_sysbios_family_arm_a8_TimestampProvider = xdc.useModule('ti.sysbios.family.arm.a8.TimestampProvider');
ti_sysbios_family_arm_a8_TimestampProvider.autoRefreshEnable = false;

/*
 * Disable modules enabled by default we do not want.
 */
BIOS.clockEnabled = false;
BIOS.swiEnabled = false;

/*
 * Uncomment this line to globally disable Asserts.
 * All modules inherit the default from the 'Defaults' module.  You
 * can override these defaults on a per-module basis using Module.common$. 
 * Disabling Asserts will save code space and improve runtime performance.
Defaults.common$.diags_ASSERT = Diags.ALWAYS_OFF;
 */

/*
 * Uncomment this line to keep module names from being loaded on the target.
 * The module name strings are placed in the .const section. Setting this
 * parameter to false will save space in the .const section.  Error and
 * Assert messages will contain an "unknown module" prefix instead
 * of the actual module name.
Defaults.common$.namedModule = false;
 */

/*
 * Minimize exit handler array in System.  The System module includes
 * an array of functions that are registered with System_atexit() to be
 * called by System_exit().
 */
System.maxAtexitHandlers = 4;       

/* 
 * Uncomment this line to disable the Error print function.  
 * We lose error information when this is disabled since the errors are
 * not printed.  Disabling the raiseHook will save some code space if
 * your app is not using System_printf() since the Error_print() function
 * calls System_printf().
Error.raiseHook = null;
 */

/* 
 * Uncomment this line to keep Error, Assert, and Log strings from being
 * loaded on the target.  These strings are placed in the .const section.
 * Setting this parameter to false will save space in the .const section.
 * Error, Assert and Log message will print raw ids and args instead of
 * a formatted message.
Text.isLoaded = false;
 */

/*
 * Uncomment this line to disable the output of characters by SysMin
 * when the program exits.  SysMin writes characters to a circular buffer.
 * This buffer can be viewed using the SysMin Output view in ROV.
SysMin.flushAtExit = false;
 */

//var heapSection = new Program.SectionSpec();
//heapSection.loadSegment = "DDR3_HI";
//heapSection.type = "NOINIT";
//heapSection.type = "NOLOAD";

/* Create heap as global variable so it can be used in C code and set it as the default */
//var heapMemParams = new HeapMem.Params();
//heapMemParams.size = 128*1024*1024;
//heapMemParams.sectionName = "heapSection";
//Program.global.noInitHeap = HeapMem.create(heapMemParams);
//Memory.defaultHeapInstance = Program.global.noinitHeap;

//Program.sectMap[".heapSection"] = "DDR3_HI";

//HeapMem.common$.instanceSection = ".heapStatic";
//Program.sectMap[".heapStatic"] = new Program.SectionSpec();
//Program.sectMap[".heapStatic"].loadSegment = "DDR3_HI";
//Program.sectMap[".heapStatic"].runSegment = "DDR3_HI";
//Program.sectMap[".heapStatic"].type = "NOINIT";
//Program.sectMap[".heapStatic"].type = "NOLOAD";

/*
 * Build a custom SYS/BIOS library from sources.
 */
BIOS.libType = BIOS.LibType_Custom;

/* Circular buffer size for System_printf() */
SysMin.bufSize = 0x200;

/* 
 * Create and install logger for the whole system
 */
var loggerBufParams = new LoggerBuf.Params();
loggerBufParams.numEntries = 16;
var logger0 = LoggerBuf.create(loggerBufParams);
Defaults.common$.logger = logger0;
Main.common$.diags_INFO = Diags.ALWAYS_ON;

System.SupportProxy = SysMin;
Defaults.common$.diags_ASSERT = Diags.ALWAYS_ON;
Defaults.common$.diags_INTERNAL = Diags.ALWAYS_ON;

/* 
 * Cache and MMU setup
 */

// Enable the cache
Cache.enableCache = true;

// Enable the MMU (Required for L1/L2 data caching) and configure the memory areas
Mmu.enableMMU = true;

// Force peripheral section to be NON cacheable
var Peripheral_Attrs = {
    type : Mmu.FirstLevelDesc_SECTION, // SECTION descriptor
    tex: 0,
    bufferable : false, // bufferable
    cacheable : false, // cacheable
    shareable : false, // shareable
    noexecute : true, // not executable
};

// Set the descriptor for each entry in the address range
for (var i=0x44000000; i < 0x80000000; i = i + 0x00100000) {
    // Each 'SECTION' descriptor entry spans a 1MB address range
    Mmu.setFirstLevelDescMeta(i, i, Peripheral_Attrs);
}

// descriptor attribute structure
var DDR3_Attrs = {
    type: Mmu.FirstLevelDesc_SECTION,  // SECTION descriptor
    tex: 0x1,
    bufferable: true,                  // bufferable
    cacheable: true,                   // cacheable
};

// Set the descriptor for each entry in the address range
for (var i=0x80000000; i < 0xc0000000; i = i + 0x00100000) {
    // Each 'SECTION' descriptor entry spans a 1MB address range
    Mmu.setFirstLevelDescMeta(i, i, DDR3_Attrs);
}

/*
 * The BIOS module will create the default heap for the system.
 * Specify the size of this default heap.
 */
BIOS.heapSize = 128*1024*1024;	//128M

Idle.idleFxns[0] = "&idle_function";

BIOS.cpuFreq.lo = 1000000000;
Task.idleTaskStackSize = 8*1024*1024;	//8M
Task.defaultStackSize = 4*1024;

/* System stack size (used by sISRs and Swis) */
Program.stack = 1*1024*1024;	//1M

Program.sectMap[".c_int00"] = new Program.SectionSpec(); 
Program.sectMap[".c_int00"].loadAddress = 0x80000000; 
Program.sectMap[".c_int00"].runAddress = 0x80000000;

Hi Todd so it gets to the leave in the idle loop and then when you step or run into that you get the exit so it doesn't hit the leave in the task and doesn't get to the while(1).

Hi Sean,

Sorry, I did not quite understand your description. Let's put labels on the break-points.

You should hit the breakpoints in this order if you are running between breakpoints. Which breakpoint are you not hitting?

Todd

Hi Todd,

I am not hitting 3 or 4 as it exits inside the leave call at 2 in the idle loop.

Sean