[ECOS] about timeslice and same priority thread switch.

[ECOS] about timeslice and same priority thread switch.

[yyl]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 541 bytes --]




Hi, after finished building the ecos1.3.1 on Redhat 
linux6.1(target is pc x86),I use gdb stub and the example twothreads.c to 
test.
From the doc ument and the code of 
kernel, I think the threads of same priority should switch by 
timeslice .But after comment the sentence in twothreads.c as 
followed:
          
cyg_thread_delay(200);
I find no switch.Who can tell me why? I think the switch of 
thread invoked by dsr of real time clock interrupt.Is that right?
  Thanks a lot.
 

Re: [ECOS] about timeslice and same priority thread switch.

[Jonathan Larmour]

> yyl wrote:
> 
> Hi, after finished building the ecos1.3.1 on Redhat linux6.1(target is pc
> x86),I use gdb stub and the example twothreads.c to test.
> From the document and the code of kernel,I think the threads of same
> priority should switch by timeslice.But after comment the sentence in
> twothreads.c as followed:
>           cyg_thread_delay(200);
> I find no switch.Who can tell me why?

So you are saying that by changing the code to the following, it stops
working?

  printf("Beginning execution; thread data is %d\n", message);
 
/*  cyg_thread_delay(200); */
 
  for (;;) {
    delay = 200 + (rand() % 50);
 
    /* note: printf() must be protected by a
       call to cyg_mutex_lock() */
    cyg_mutex_lock(&cliblock); {
      printf("Thread %d: and now a delay of %d clock ticks\n",
             message, delay);
    }
    cyg_mutex_unlock(&cliblock);
    cyg_thread_delay(delay);
  }

Are you sure you didn't change anything in your configuration from the
default that you didn't mean to?

> I think the switch of thread
> invoked by dsr of real time clock interrupt.Is that right?

Yes. See Cyg_RealTimeClock::dsr() in kernel/VERSION/src/common/clock.cxx

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault

Re: [ECOS] about timeslice and same priority thread switch.

[yyl]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 3655 bytes --]




 
----- Original Message ----- 
From: Jonathan Larmour < jlarmour@redhat.co.uk >
To: yyl < ylyuan@csrd.org >
Cc: ecos < ecos-discuss@sourceware.cygnus.com >
Sent: Wednesday, May 31, 2000 5:47 AM
Subject: Re: [ECOS] about timeslice and same priority 
thread switch.

> > yyl wrote: > > > > Hi, 
after finished building the ecos1.3.1 on Redhat linux6.1(target is pc > 
> x86),I use gdb stub and the example twothreads.c to test. > > From 
the document and the code of kernel,I think the threads of same > > 
priority should switch by timeslice.But after comment the sentence in > 
> twothreads.c as followed: > 
>           
cyg_thread_delay(200); > > I find no switch.Who can tell me 
why? > > So you are saying that by changing the code to the 
following, it stops > working?
        It 
working.I mean the threads execute in the turn which they resume,but not switch 
by timeslice,ie,only the first thread finished ,the second thread can start.The 
code I modified as followed(I comment two sentences):
      /*        
cyg_thread_delay(200);  */
             
for (i=0;i<=100;i + +) 
{            delay = 
200 + (rand() % 50 )
          /* 
note: printf() must be protected by 
a                
 call to cyg_mutex_lock() 
*/              
cyg_mutex_lock(&cliblock); 
{             
printf("Thread %d: and now a delay of %d clock 
ticks\n",                  
 message, 
delay);              
 }             
cyg_mutex_unlock(&cliblock);            
/*  cyg_thread_delay(delay); */
 
 the result of the run:
          
Entering twothreads' cyg_user_start() function
          
Thread 0 and now a delay of 233 clock ticks
          ...
          
...
          
Thread 0 and now a delay of 225 clock ticks
          
Thread 1 and now a delay of 226 clock ticks
          
...
          
...
          
Thread 1 and now a delay of 238 clock ticks
         

I think the result should be:
          

          
Entering twothreads' cyg_user_start() function
          
Thread 0 and now a delay of 233 clock ticks
          ...
          Thread 1 and now a 
delay of 226 clock ticks
          ...
          Thread 0 and now a 
delay of 233 clock tick
          ...
          Thread 1 and 
now a delay of 238 clock ticks
          ...
     
          

          I didn't 
change anything in the configuration from the default .
          Last I don't 
express clearly.I'm very sorry.
          Thank you 
very much!
 
 

Re: [ECOS] about timeslice and same priority thread switch.

[Jonathan Larmour]

> yyl wrote:
>      It working.I mean the threads execute in the turn which they
> resume,but not switch by timeslice,ie,only the first thread finished ,the
> second thread can start.The code I modified as followed(I comment two
> sentences):
>      /*        cyg_thread_delay(200);  */
>              for (i=0;i<=100;i + +) {
>           delay = 200 + (rand() % 50 )
>          /* note: printf() must be protected by a
>                call to cyg_mutex_lock() */
>             cyg_mutex_lock(&cliblock); {
>            printf("Thread %d: and now a delay of %d clock ticks\n",
>                  message, delay);
>              }
>            cyg_mutex_unlock(&cliblock);
>            /* cyg_thread_delay(delay); */
> 
>  the result of the run:
>           Entering twothreads' cyg_user_start() function
>           Thread 0 and now a delay of 233 clock ticks
>           ...
>           ...
>           Thread 0 and now a delay of 225 clock ticks
>           Thread 1 and now a delay of 226 clock ticks
>           ...
>           ...
>           Thread 1 and now a delay of 238 clock ticks
> 
> I think the result should be:
> 
>           Entering twothreads' cyg_user_start() function
>           Thread 0 and now a delay of 233 clock ticks
>           ...
>           Thread 1 and now a delay of 226 clock ticks
>           ...
>           Thread 0 and now a delay of 233 clock tick
>           ...
>           Thread 1 and now a delay of 238 clock ticks
>           ...

Ah, that happens because in each `for' loop, the majority of the execution
time is spent in the printf function. printf is notoriously expensive. As a
result, most of the time that a timeslice occurs, the mutex `cliblock' is
locked, so the newly woken up thread cannot run; so it goes back to sleep
again.

Simply comment out the mutex lock and unlock calls in twothreads.c and you
will see that things begin to behave slightly more sensibly. The mutex is
completely unnecessary if the configuration option
CYGSEM_LIBC_STDIO_THREAD_SAFE_STREAMS is enabled, which controls the
existence of a mutex deeper inside libc stdio.

Note that if you disable that configuration option as well, then the
threads should then strictly alternate as you expected; however it also
means there is a chance of them corrupting common data inside libc stdio
since they can then interrupt each other at any point.

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault

[ECOS] Configuration tool problem

[Alessandro Pinto]

Thank you a lot for your help yesterday, I compiled the gcc and all was ok.
Now I need to create a the ecos RTOS to use the library and link it.
When I try to run the configuration tool, the compilation results in the
follow error:

arm-elf-gcc -c  -I//C/ecoslib/prova_install/include -I//C/PROGRA~1/REDHAT~1/
eCos/packages/hal/arm/arch/v1_3_1 -I//C/PROGRA~1/REDHAT~1/eCos/packages/hal/
arm/arch/v1_3_1/src -I//C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_
1/tests -I. -I//C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/ -
mcpu=arm7tdmi -Wall -Wpointer-arith -Wstrict-prototypes -Winline -Wundef -Wo
verloaded-virtual -g -O2 -ffunction-sections -fdata-sections -fno-rtti -fno-
exceptions -fvtable-gc -finit-priority -Wp,-MD,src/context.tmp -o
src/hal_arm_arch_context.o
file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S
file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S:
Assembler messages:
file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S:1
14: Error: undefined symbol CPSR_IRQ_DISABLE in operation
file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S:1
14: Error: undefined symbol CPSR_FIQ_DISABLE in operation
file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S:8
5: Error: Internal_relocation (type 187) not fixed up (OFFSET_IMM)
file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S:1
16: Error: Internal_relocation (type 187) not fixed up (OFFSET_IMM)
make[1]: *** [src/context.o.d] Error 1
make[1]: Leaving directory `/c/ecoslib/prova_build/hal/arm/arch/v1_3_1'
make: *** [build] Error 2

Can you help me?

Bye

AP

[ECOS] Re: Configuration tool problem

[Jonathan Larmour]

Alessandro Pinto wrote:
> 
> Thank you a lot for your help yesterday, I compiled the gcc and all was ok.
> Now I need to create a the ecos RTOS to use the library and link it.
> When I try to run the configuration tool, the compilation results in the
> follow error:
> 
> file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S
> file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S:
> Assembler messages:
> file://C/PROGRA~1/REDHAT~1/eCos/packages/hal/arm/arch/v1_3_1/src/context.S:1
> 14: Error: undefined symbol CPSR_IRQ_DISABLE in operation
[snip rest]

Can you try deleting the file hal/arm/arch/v1_3_1/arm.inc in your build
tree and trying the make again (which will recreate arm.inc). If it still
doesn't work, please send us the arm.inc file.

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault

[ECOS] Re: Configuration tool problem

[Alessandro Pinto]

The ecos build now is OK and I tried to compile some file automatic
generated by VCC and all is OK.

But I'm brave and I'm thinking to use an ARM instuction set simulator. This
simulator need the RTOS library but the ones generated by the configuration
tool (libtarget.a) doesn't work.
There is the possibilities to compile the library for another compiler (in
this case armcc by arm) ?

THANKS

AP
------------------------------------------------------------------
Alessandro Pinto
Mobile: (+39)(0)3395366531
Address: Via L. Viani, 12
00125 Roma, Italy
http://web.tiscalinet.it/alessandro_pinto/index.htm
------------------------------------------------------------------

[ECOS] Re: Configuration tool problem

[Jonathan Larmour]

Alessandro Pinto wrote:
> 
> The ecos build now is OK and I tried to compile some file automatic
> generated by VCC and all is OK.
> 
> But I'm brave and I'm thinking to use an ARM instuction set simulator. This
> simulator need the RTOS library but the ones generated by the configuration
> tool (libtarget.a) doesn't work.
> There is the possibilities to compile the library for another compiler (in
> this case armcc by arm) ?

eCos uses features only found in GNU cc, so unfortunately that isn't an
option worth pursuing.

I believe the right way to go about running eCos with the ARMulator is to
do a port of eCos to it. The reason is because eCos does not interwork with
Angel on the boards, using the ROM monitor interface for I/O etc. To port
eCos, the platform HAL would have to provide low-level communication with
RDI/RDP.

I don't know in detail how much work would be involved with that. We don't
currently have plans to do it ourselves, so a contributed port would be
welcome.

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault

Re: [ECOS] about timeslice and same priority thread switch.

[zhang]

 
> Ah, that happens because in each `for' loop, the majority of the execution
> time is spent in the printf function. printf is notoriously expensive. As a
> result, most of the time that a timeslice occurs, the mutex `cliblock' is
> locked, so the newly woken up thread cannot run; so it goes back to sleep
> again.
> 
> Simply comment out the mutex lock and unlock calls in twothreads.c and you
> will see that things begin to behave slightly more sensibly. The mutex is
> completely unnecessary if the configuration option
> CYGSEM_LIBC_STDIO_THREAD_SAFE_STREAMS is enabled, which controls the
> existence of a mutex deeper inside libc stdio.
> 
> Note that if you disable that configuration option as well, then the
> threads should then strictly alternate as you expected; however it also
> means there is a chance of them corrupting common data inside libc stdio
> since they can then interrupt each other at any point.
> 
> Jifl

Hi,sorry to bother you again ,as you explained ,we change the value of CYGSEM_LIBC_STDIO_THREAD_SAFE_STREAMS from 1 to 0 in the file of ecos.ecc ,then we build the thread.c and run it ,but the result is the same ,
so ,we want to know whether we miss something to do or do not catch your real meaning. 

Moreover we also have some question on your explain.As your say , the majority of the execution time is spent in the printf function, it seems that the printf is the real cause of the unablity of thread switch ,however if we build another source file of two thread switch ,with one thread having lower priority and the other having higher ,the result is that they can switch .We are puzzled because this time  the  source file also contain   printf, if the printf expense too much time as you said ,even if another thread have a higher priority ,the thread switch  may not be realized either.So we are not sure ,will any body hints me ?

Thanks a lot !!

Re: [ECOS] about timeslice and same priority thread switch.

[Jonathan Larmour]

zhang wrote:
> Hi,sorry to bother you again ,as you explained ,we change the value of
> CYGSEM_LIBC_STDIO_THREAD_SAFE_STREAMS from 1 to 0 in the file of ecos.ecc
> ,then we build the thread.c and run it ,but the result is the same ,
> so ,we want to know whether we miss something to do or do not catch your
> real meaning.

Did you also comment out the mutex lock/unlock lines? Otherwise disabling
that option will have no effect.

But it turns out I missed out that there is yet another mutex lock buried
deep in the serial code (called from serial_write() specifically). So even
with the above option disabled, *and* the mutexes removed, it is still
possible for the threads to not strictly alternate on a timeslice, because
one of them is holding that mutex. But it will be a lot closer. Try it and
see.

> Moreover we also have some question on your explain.As your say , the 
> majority of the execution time is spent in the printf function, it seems
> that the printf is the real cause of the unablity of thread switch
> ,however if we build another source file of two thread switch ,with one
> thread having lower priority and the other having higher ,the result is
> that they can switch .We are puzzled because this time  the  source file
> also contain   printf, if the printf expense too much time as you said
> ,even if another thread have a higher priority ,the thread switch  may not
> be realized either.So we are not sure ,will any body hints me ?

It depends on the exact code you are using, but my guess is that in this
case the threads are not being timesliced. Instead they are being scheduled
strictly according to their priorities, with the possibility of there also
being mutex priority inheritance.

Without seeing the code you are using I can't be sure.

Jifl
-- 
Red Hat, 35 Cambridge Place, Cambridge, UK. CB2 1NS  Tel: +44 (1223) 728762
"Plan to be spontaneous tomorrow."  ||  These opinions are all my own fault

RE: [ECOS] Configuration tool problem

[Trenton D. Adams]

Same here, my user tools path is c:\cygwin\bin

> -----Original Message-----
> From: ecos-discuss-owner@sources.redhat.com 
> [ mailto:ecos-discuss-owner@sources.redhat.com ] On Behalf Of 
> Julian Smart
> Sent: October 26, 2001 8:47 AM
> To: Andreas Savvides; ecos-discuss@sources.redhat.com; 
> Andreas Savvides; ecos-discuss@sources.redhat.com
> Subject: Re: [ECOS] Configuration tool problem
> 
> 
> At 04:31 PM 10/25/01 -0700, Andreas Savvides wrote:
> >Hi,
> >
> >I am trying to setup the eCos tools on Windows 2000 but I am 
> getting stuck
> >on how to set the user tools path in the configuration tool. 
> I have tried
> >installing both the 2.0.4 and 2.0.3 version of the config 
> tool but I get
> >the same error:
> >
> >C:\cygwin\usr\bin does not appear to contain the user tools.
> >
> >I do not understand this problem since the specified directory DOES
> >contain the user tools. Is there any way to resolve this? Any
> >suggestions are appreciated.
> 
> There may be a bug but also check if ls.exe really is in this 
> location (I'm 
> sure you did already). In the latest Cygwin installation I 
> have, ls.exe is 
> in the top-level bin and not under usr. Actually 2.04 is 
> pretty old now 
> (July/August) and the bug does ring a bell from way back, so 
> I'll get a new 
> one uploaded soon -- one that also deals with recent Cygwin 
> path convention 
> changes and the binary/text mode mount issue. If you need it 
> quickly, I can 
> email it to you.
> 
> Thanks,
> 
> Julian
> --
> Red Hat UK Ltd, Unit 200 Rustat House, 62 Clifton Road, 
> Cambridge, UK. CB1 
> 7EG Tel: +44 (1223) 271063
> 

Re: [ECOS] Configuration tool problem

[Julian Smart]

At 04:31 PM 10/25/01 -0700, Andreas Savvides wrote:
>Hi,
>
>I am trying to setup the eCos tools on Windows 2000 but I am getting stuck
>on how to set the user tools path in the configuration tool. I have tried
>installing both the 2.0.4 and 2.0.3 version of the config tool but I get
>the same error:
>
>C:\cygwin\usr\bin does not appear to contain the user tools.
>
>I do not understand this problem since the specified directory DOES
>contain the user tools. Is there any way to resolve this? Any
>suggestions are appreciated.

There may be a bug but also check if ls.exe really is in this location (I'm 
sure you did already). In the latest Cygwin installation I have, ls.exe is 
in the top-level bin and not under usr. Actually 2.04 is pretty old now 
(July/August) and the bug does ring a bell from way back, so I'll get a new 
one uploaded soon -- one that also deals with recent Cygwin path convention 
changes and the binary/text mode mount issue. If you need it quickly, I can 
email it to you.

Thanks,

Julian
--
Red Hat UK Ltd, Unit 200 Rustat House, 62 Clifton Road, Cambridge, UK. CB1 
7EG Tel: +44 (1223) 271063

[ECOS] Configuration tool problem

[Andreas Savvides]

Hi,

I am trying to setup the eCos tools on Windows 2000 but I am getting stuck
on how to set the user tools path in the configuration tool. I have tried
installing both the 2.0.4 and 2.0.3 version of the config tool but I get
the same error:

C:\cygwin\usr\bin does not appear to contain the user tools.

I do not understand this problem since the specified directory DOES
contain the user tools. Is there any way to resolve this? Any
suggestions are appreciated.


Thanks,
Andreas Savvides

Re: [ECOS] Configuration Tool problem

[Bart Veer]

>>>>> "Xavier" == Xavier Wang <xavierwang@ms19.url.com.tw> writes:

    Xavier> I downloaded the new source code of eCos form the
    Xavier> anonymous CVS database. The eCos Configuration Tool is
    Xavier> v1.3.1. When I performed Build/Repository... to point the
    Xavier> repository to the downloaded version of eCos, the
    Xavier> following messages showed:

    Xavier> <<<<<<

    Xavier> Error loading the hardware template 'pid':

    Xavier> Package CYGPKG_IO_SERIAL_GENERIC_16X5X, 1 error
    Xavier> occured while reading in the CDL data.

    Xavier> Parse message:

    Xavier> D:/RedHat/cvs/ecos/packages/devs/serial/generic/16x5x/current/cdl/ser_generic_16x5x.cdl,
    Xavier> package CYGPKG_IO_SERIAL_GENERIC_16X5X
    Xavier>     Property include_files, missing arguments.

    >>>>>>> 

    Xavier> I suspected that the old Configuration Tool couldn't
    Xavier> recognize the new stuff in the source code. I then
    Xavier> downloaded the Configuration Tool 1.3.1.2. It could
    Xavier> redirect the repository to the new source code of eCos
    Xavier> now.

Correct, CDL support for an empty include_files list was added after
1.3.1. Hence the need for an updated configuration tool.

    Xavier> But it hanged when I perform Build/Library or Tools/Shell.
    Xavier> It seems that it cannot invoke Bash to work.

    Xavier> My platform is Windows 98 SE. Is it the problem? But the
    Xavier> Configuration Tool v1.3.1 works well under 98 SE.

    Xavier> Any help will be appreciated.

AFAIK there have been no changes in this area. The only suggestion I
have is to experiment with the Tools->Paths->UserTools dialog, which
can be used to specify the search path for things like bash.

Bart

Re: [ECOS] Configuration Tool problem

[Julian Smart]

H Xavier,

It could be a Windows 98-related problem, unfortunately; we don't currently 
test the configuration tool (or eCos distribution) under Windows 98, since 
there has been no client demand as yet. If you can find a WinNT machine to 
try it on, and it works OK there, then it might narrow it down to a problem 
with Win98. Meanwhile perhaps someone else might have a better idea whether 
or not there's a problem with the CDL code itself.

Regards,

Julian

At 11:11 AM 1/3/01 +0800, Xavier Wang wrote:

>Hi,
>
>I downloaded the new source code of eCos form the anonymous
>CVS database. The eCos Configuration Tool is v1.3.1. When I
>performed Build/Repository... to point the repository to the
>downloaded version of eCos, the following messages showed:
>
><<<<<<
>
>Error loading the hardware template 'pid':
>
>Package CYGPKG_IO_SERIAL_GENERIC_16X5X, 1 error
>occured while reading in the CDL data.
>
>Parse message:
>
>D:/RedHat/cvs/ecos/packages/devs/serial/generic/16x5x/current/cdl/ser_gener 
>ic_16x5x.cdl,
>package CYGPKG_IO_SERIAL_GENERIC_16X5X
>     Property include_files, missing arguments.
>
> >>>>>>
>
>I suspected that the old Configuration Tool couldn't recognize the
>new stuff in the source code. I then downloaded the Configuration
>Tool 1.3.1.2. It could redirect the repository to the new source code
>of eCos now. But it hanged when I perform Build/Library or
>Tools/Shell. It seems that it cannot invoke Bash to work.
>
>My platform is Windows 98 SE. Is it the problem? But the
>Configuration Tool v1.3.1 works well under 98 SE.
>
>Any help will be appreciated.
>
>--
>Xavier

--
Red Hat UK Ltd, Unit 200 Rustat House, 62 Clifton Road, Cambridge, UK. CB1 
7EG Tel: +44 (1223) 271063

[ECOS] Configuration Tool problem

[Xavier Wang]

Hi,

I downloaded the new source code of eCos form the anonymous
CVS database. The eCos Configuration Tool is v1.3.1. When I
performed Build/Repository... to point the repository to the
downloaded version of eCos, the following messages showed:

<<<<<<

Error loading the hardware template 'pid':

Package CYGPKG_IO_SERIAL_GENERIC_16X5X, 1 error
occured while reading in the CDL data.

Parse message:

D:/RedHat/cvs/ecos/packages/devs/serial/generic/16x5x/current/cdl/ser_generic_16x5x.cdl,
package CYGPKG_IO_SERIAL_GENERIC_16X5X
    Property include_files, missing arguments.

>>>>>>

I suspected that the old Configuration Tool couldn't recognize the
new stuff in the source code. I then downloaded the Configuration
Tool 1.3.1.2. It could redirect the repository to the new source code
of eCos now. But it hanged when I perform Build/Library or
Tools/Shell. It seems that it cannot invoke Bash to work.

My platform is Windows 98 SE. Is it the problem? But the
Configuration Tool v1.3.1 works well under 98 SE.

Any help will be appreciated.

--
Xavier