soft and program: comp.programming.threads - 7 new messages in 4 topics

comp.programming.threads
http://groups.google.com/group/comp.programming.threads?hl=en

comp.programming.threads@googlegroups.com

Today's topics:

* AMD Advanced Synchronization Facility: HTM - 1 messages, 1 author
http://groups.google.com/group/comp.programming.threads/t/c1c6c6327aed79b6?hl=en
* Advertisement for 2D Game Developers Central - 1 messages, 1 author
http://groups.google.com/group/comp.programming.threads/t/a0486dfa09cbcc18?hl=en
* Thread within a thread - 2 messages, 1 author
http://groups.google.com/group/comp.programming.threads/t/94f39a94cfc85076?hl=en
* Marketing Professional Seeking Apprentice! - 3 messages, 2 authors
http://groups.google.com/group/comp.programming.threads/t/cc6b98f147c5d71c?hl=en

==============================================================================
TOPIC: AMD Advanced Synchronization Facility: HTM
http://groups.google.com/group/comp.programming.threads/t/c1c6c6327aed79b6?hl=en
==============================================================================

== 1 of 1 ==
Date: Sat, May 30 2009 8:12 am
From: EricP

EricP wrote:
>
> It depends on what one thinks of blocking events vs wait loops.
> One must remember that with ASF, the act of reading a memory
> location during an update causes an Abort.
> So contenders must go away and do something else for a while.
>
> If going with a wait loop approach, I decided in the end that
> using an atomic up-down counter to allocate delay time slots was
> the best approach.

In a nut shell, this is just a global counter to reserve time
delay slots and prevent contention. What we want to avoid is
an Abort loop where A locks some lines, B aborts A,
C aborts B, A aborts C, etc.

A locker is susceptible to contention during its Update Time (UT)
which is from the point where it does its first locked write
and begins to acquire exclusive ownership over the cache lines
until it COMMITs its changes. UT is primarily the time it
takes to move the cache lines from remote L2 to our local L2.

As I mentioned previously, the maximum UT window seems to be
quite variable across systems, from 50ns to 400ns so the code
would need to be able to learn how big a delay was required
for each contender.

The example below serializes contention, gives approximate
FIFO order, a linear delay for each contender,
and automatic timer adjustment.

Eric

// Up-down counter for allocating delay slots.
volatile LONG g_DelaySlotNum;

// Delay duration for each delay slot, automatically adjusted
volatile LONG g_DelayTicks = 100;

void DlinkSafePushAfter (DlinkPT priorP, DlinkPT newP)
{
LONG slotNum, count, curTicks, newTicks, slotTicks = 0;
DlinkPT nextP;

for (;;)
{
SPECULATE
{ nextP = LOCK MOV priorP->FlinkP;
LOCK PREFETCHW nextP;
LOCK PREFETCHW newP;
LOCK MOV newP->FlinkP = priorP->FlinkP;
LOCK MOV priorP->FlinkP = newP;
LOCK MOV newP->BlinkP = priorP;
LOCK MOV newP->FlinkP = nextP;
LOCK MOV nextP->BlinkP = newP;
COMMIT;
break;
}
catch (int reason)
{
// The abort could be spurious, like an interrupt,
// or due to collision, or uncorrectable.
if (reason & ASF_ABORTCODE_CONTENTION)
{
// Serialize access by waiting a little.
// Assign a unique delay slot to each wait.
// We don't know how big a delay slot should be so
// adjust the size up by 50% until we stop colliding.
if (slotTicks == 0)
{ // First collision, use current slot size
slotTicks = g_DelayTicks;
}
else
{ // Subsequent collision. Increase slot size by 50%
// but only if no one else has just done so.
// Otherwise use their updated value.
newTicks = slotTicks + (slotTicks >> 1);
curTicks = InterlockedCompareExchange
(&g_DelayTicks, newTicks, slotTicks);
if (curTicks == slotTicks)
slotTicks = newTicks; // Use our new slot size
else
slotTicks = curTicks; // Use others slot size
}

// Reserve a delay slot and wait a while
slotNum = InterlockedIncrement (&g_DelaySlotNum);
for(count = slotNum*slotTicks; count > 0; count--)
{ Pause;
}
InterlockedDecrement (&g_DelaySlotNum);
}
else
{
FatalExit (0);
}
}
}
}

==============================================================================
TOPIC: Advertisement for 2D Game Developers Central
http://groups.google.com/group/comp.programming.threads/t/a0486dfa09cbcc18?hl=en
==============================================================================

== 1 of 1 ==
Date: Sun, May 31 2009 5:07 am
From: NerdierNerds Advertiser

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----------------------------------------
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----------------------------------------

==============================================================================
TOPIC: Thread within a thread
http://groups.google.com/group/comp.programming.threads/t/94f39a94cfc85076?hl=en
==============================================================================

== 1 of 2 ==
Date: Sun, May 31 2009 5:17 am
From: "Chris M. Thomasson"

> That method should cut down on subsequent corrections...
> But, when your excited, mistakes can and _will_ be made. Luckily he cares
> enough to actually post corrections and document shortcomings...
>
> ;^/
> [...]

BTW, `errno' is the reporter of errors in `sem_wait()'...

BARF..... BARF...

Do type code into newsreader!

== 2 of 2 ==
Date: Sun, May 31 2009 5:19 am
From: "Chris M. Thomasson"

"Chris M. Thomasson" <no@spam.invalid> wrote in message
news:GzuUl.94031$9w4.34661@newsfe08.iad...
>> That method should cut down on subsequent corrections...
>> But, when your excited, mistakes can and _will_ be made. Luckily he cares
>> enough to actually post corrections and document shortcomings...
>>
>> ;^/
>> [...]
>
> BTW, `errno' is the reporter of errors in `sem_wait()'...
>
>
> BARF..... BARF...
>
>
> Do type code into newsreader!

LOL!!!!!!!

Do NOT type code into newsreader!

WOW!!!

==============================================================================
TOPIC: Marketing Professional Seeking Apprentice!
http://groups.google.com/group/comp.programming.threads/t/cc6b98f147c5d71c?hl=en
==============================================================================

== 1 of 3 ==
Date: Sun, May 31 2009 5:34 am
From: David Schwartz

On May 29, 10:31 am, Brandon Noe <hidetor...@gmail.com> wrote:
> Sitting there wondering how your going to pay your bills? Tired of
> living paycheck to paycheck? Then boy do I have the answer for you!
> Self-made Millionaire is revealing his Wealth making blueprint to a

Let me guess -- get a whole bunch of people to pay you $49 for a
wealth-making blueprint?

== 2 of 3 ==
Date: Sun, May 31 2009 5:41 am
From: "Chris M. Thomasson"

"David Schwartz" <davids@webmaster.com> wrote in message
news:febc1cdb-26ba-4a52-99b3-52339fe5ec4f@k8g2000yqn.googlegroups.com...
On May 29, 10:31 am, Brandon Noe <hidetor...@gmail.com> wrote:
> > Sitting there wondering how your going to pay your bills? Tired of
> > living paycheck to paycheck? Then boy do I have the answer for you!
> > Self-made Millionaire is revealing his Wealth making blueprint to a

> Let me guess -- get a whole bunch of people to pay you $49 for a
> wealth-making blueprint?

Perhaps $49.99?

Weeeee!

== 3 of 3 ==
Date: Sun, May 31 2009 5:48 am
From: "Chris M. Thomasson"

"Chris M. Thomasson" <no@spam.invalid> wrote in message
news:PVuUl.94033$9w4.81060@newsfe08.iad...
> "David Schwartz" <davids@webmaster.com> wrote in message
> news:febc1cdb-26ba-4a52-99b3-52339fe5ec4f@k8g2000yqn.googlegroups.com...
> On May 29, 10:31 am, Brandon Noe <hidetor...@gmail.com> wrote:
>> > Sitting there wondering how your going to pay your bills? Tired of
>> > living paycheck to paycheck? Then boy do I have the answer for you!
>> > Self-made Millionaire is revealing his Wealth making blueprint to a
>
>> Let me guess -- get a whole bunch of people to pay you $49 for a
>> wealth-making blueprint?
>
> Perhaps $49.99?
>
>
>
> Weeeee!