c - Posix Timer periodically skips ahead half of its period -

-

I have a task related to the posx timer (timer_cut), which executes every 20 ms / 50hz. Works fine for most part, except for every 334.5 seconds (approx), the timer starts 10 ms for a circle. The interval for the next 334.5-ish seconds is all 20 ms again.

I've included the relevant code to configure the timer. Gumstix Verdex Pro runs this application with the default version of Gumstix Linux on XL6P. I have also set it with the FIFA scheduling algorithm.

My stomach says this is an integer overflow problem. Maybe there is something else using the same signal?

This problem is not a show stop but I really want to understand why this is happening.

Here's the code to configure the timer: 

  // --------------------- ------- ------------------------------------------- ------- // Create a timer, which sets fire on the specified time and calls the timer event // handler. // // handler: To call the function when the timer expires: Number of microsoft to add timer / MS: Number of milliseconds to add in timer / second: Number of seconds to add to timer. - ------------------------------------------------- - --------------------------- Zero create timer (zero (* handler) (zero), uint32 us, uint32 ms, uint32 seconds) { Struct signification sign; Straight sigevent sigev; Timer_t timer; Straight Eatimerspeak Ewalwal; Straight Eatimerspec Ottawal; Timer_info_t * newTimer = NULL; // start the signal signal if (timer == faucet) signalNum = SIGRTMAX; If (SignalName and Lieutenant; SIGRTMIN) exit, outer ("no available signal, unable to make timers"); Sigemptyset (& amp; cigact.sa_mask); Sigact.sa_flags = SA_SIGINFO; Sigact.sa_sigaction = signalHandler; // Set signals to capture the signal if (signage (signaling, signal, and signet, null) == -1) exit the sound ("signification (failure), timer unable to live"); // Create a POSIX timer to generate sine sign sigev.sigev_notify = SIGEV_SIGNAL; Sigev.sigev_signo = signNum; Sigev.sigev_value.sival_ptr = & timer; Long ret = timer_create (CLOCK_REALTIME, & amp; sigev, & timerid); If (rate == 0) {// stop overflow in the calculation of the NSec below (MS> = 1000) {sec + = (MS / 1000); Ms = ms% 1000; } Itval.it_value.tv_sec = sec; Itval.it_value.tv_nsec = (long) (we * 1000l) + (tall) (ms * 1000 l * 1000 l); // configure it as a recurrence timer Itval.it_interval.tv_sec = itval.it_value.tv_sec; Itval.it_interval.tv_nsec = itval.it_value.tv_nsec; If (timer_settime (timerid, 0, and evalval, and otitle)! = 0) Exit thunder ("time_settime (error)!"); } And with the exit always ("timer_create () error!"); NewTimer = (timer_info_t *) mlok (size file (timer_info_t)); NewTimer-> Timer = timer; NewTimer-> Handler = handler; NewTimer-> SigNum = signNum; NewTimer-> Next = null; // Check to see if this is the first time (timer == faucet) {timer = new timer; Atexit (deleteTimers); } And the last timer-> gt; Next = new timer; Last time = new timer; SignalNum--; }   
 Thanks in advance.   
 
 
 My guess is that you are using 'NTP', and due to the timing of those intervals is. Instead you can try using  CLOCK_MONOTONIC , but it can also be affected accordingly.

Comments

Post a Comment

Popular posts from this blog

mysql - BLOB/TEXT column 'value' used in key specification without a key length -

-
I have developed an extension which works up to 1.6 on Magren (I'm trying Enterprise Edition, And I think the community is the same problem, because it is the same code). In my install script, I see the $ installer-> gt; CreateEntityTables ($ this- & gt; getTable ('alphanum / info')); The installation is done until it is not in the _text unit table. It crashed there! It turns out that when I log in to SQL and run it via PHPmyadmin, then this error is: Blob / Text column 'value' is used without the key 'key' . I saw the code there, and this is what is trying to create an index on the value column: -> addIndex ($ this- & gt; getIdxName ($ eavTableName, array ( 'attribute_id array (' attribute_id ',' value ')) - & gt; addIndex ($ this- & gt; getIdxName ($ eavTableName, array (' entity_type_id ' , 'Value')), array ('entity_type_id', 'value')) If there is no if statement is n...
Read more

c# - Using Vici cool Storage with monodroid -

-
Oh, for the moment I am not sure how it is officially supported, but for the success of the people Using Monodroid Vic Cool Storage I am able to leave and compile assemblies in my project, but while trying to use some classes, the errors of time have to be gathered. Especially when trying to connect like the example for Mono Touch string dbName = path. Cobain (environment. Gatefolder path (environment specialfolder personal), "mydb.db3"); // The following line will be called coolestation, where is the database, // to make it if it does not exist, and call a delegate that creates the necessary tables (only when the database file was newly created //) CSConfig.SetDB (DbName, true, () => {CSDatabase.ExecuteNonQuery ("Subscriber Integer Primary Key Attribute, Name Text (50) No, Number, Date First Text (30)");); There is no difference when I try to use the methods of CSConfig and when I cscfif If I try to pass 3 aggregates to STDB (3) then I get the invalid ...
Read more

python - referencing a variable in another function? -

-
I am an experienced TCL developer and write my own processes to help myself. I call it a proc i callVar, print out the value of the variable in a certain format, so I know that it is variable and what is the value "set foo 1; putVar foo" result 'foo = "1" I want to do the same thing in Python, but I can not find the answer :( In TCL I use the up command because when I pass the name of the variable, then I can see the value at the top. . I understand that an advanced light in the dragon There is no mechanism of r, but with its introspection capability, I would think that this is something trivial, but I am not getting the answer anywhere. It seems that this should work: and expanded: def foo (): y = "Hello World" printwor ("y") foo () y = "Hello World " You can, but you should not do so if your code is correct If is needed , then there is something wrong with your design, and you should probably use the dictionar...
Read more