Monday, October 31, 2011

Thunks and lazy blackholes: an introduction to GHC at runtime

This article is about a GHC bug I encountered recently, but it's really an excuse to talk about some GHC internals at an intro level. (In turn, an excuse for me to learn about those internals.)

I'll assume you're familiar with the basics of Haskell and lazy evaluation.

The bug

I spoke before of using global locks in Haskell to protect a thread-unsafe C library. Unfortunately a GHC bug prevents this from working. Using unsafePerformIO at the top level of a file can result in IO that happens more than once.

Here is a simple program which illustrates the problem:

import Control.Concurrent
import Control.Monad
import System.IO.Unsafe

ioThunk :: ()
ioThunk = unsafePerformIO $ do
me <- myThreadId
putStrLn ("IO executed by " ++ show me)
{-# NOINLINE ioThunk #-}

main :: IO ()
main = do
replicateM_ 100 (forkIO (print ioThunk))
threadDelay 10000 -- wait for other threads

Let's test this, following the compiler flag recommendations for unsafePerformIO.

$ ghc -V
The Glorious Glasgow Haskell Compilation System, version 7.2.1

$ ghc -rtsopts -threaded -fno-cse -fno-full-laziness dupe.hs
[1 of 1] Compiling Main             ( dupe.hs, dupe.o )
Linking dupe ...

$ while true; do ./dupe +RTS -N | head -n 2; echo ----; done

Within a few seconds I see output like this:

IO executed by ThreadId 35
IO executed by ThreadId 78
IO executed by ThreadId 85
IO executed by ThreadId 48

In the middle run, two threads executed the IO action.

This bug was reported two weeks ago and is already fixed in GHC HEAD. I tested with GHC 7.3.20111026, aka g6f5b798, and the problem seemed to go away.

Unfortunately it will be some time before GHC 7.4 is widely deployed, so I'm thinking about workarounds for my original global locking problem. I'll probably store the lock in a C global variable via StablePtr, or failing that, implement all locking in C. But I'd appreciate any other suggestions.

The remainder of this article is an attempt to explain this GHC bug, and the fix committed by Simon Marlow. It's long because

  • I try not to assume you know anything about how GHC works. I don't know very much, myself.

  • There are various digressions.

Objects at runtime

Code produced by GHC can allocate many kinds of objects. Here are just a few:

  • CONSTR objects represent algebraic data constructors and their associated fields. The value (Just 'x') would be represented by a CONSTR object, holding a pointer to another object representing 'x'.

  • FUN objects represent functions, like the value (\x -> x+1).

  • THUNK objects represent computations which have not yet happened. Suppose we write:

    let x = 2 + 2 in f x x

    This code will construct a THUNK object for x and pass it to the code for f. Some time later, f may force evaluation of its argument, and the thunk will, in turn, invoke (+). When the thunk has finished evaluating, it is overwritten with the evaluation result. (Here, this might be an I# CONSTR holding the number 4.) If f then forces its second argument, which is also x, the work done by (+) is not repeated. This is the essence of lazy evaluation.

  • When a thunk is forced, it's first overwritten with a BLACKHOLE object. This BLACKHOLE is eventually replaced with the evaluation result. Therefore a BLACKHOLE represents a thunk which is currently being evaluated.

    Identifying this case helps the garbage collector, and it also gives GHC its seemingly magical ability to detect some infinite loops. Forcing a BLACKHOLE indicates a computation which cannot proceed until the same computation has finished. The GHC runtime will terminate the program with a <<loop>> exception.

  • We can't truly update thunks in place, because the evaluation result might be larger than the space originally allocated for the thunk. So we write an indirection pointing to the evaluation result. These IND objects will later be removed by the garbage collector.

Static objects

Dynamically-allocated objects make sense for values which are created as your program runs. But the top-level declarations in a Haskell module don't need to be dynamically allocated; they already exist when your program starts up. GHC allocates these static objects in your executable's data section, the same place where C global variables live.

Consider this program:

x = Just 'x'

f (Just _) = \y -> y+1

main = print (f x 3)

Ignoring optimizations, GHC will produce code where:

  • x is a CONSTR_STATIC object.

  • f is a FUN_STATIC object. When called, f will return a dynamically-allocated FUN object representing (\y -> y+1).

  • main is a THUNK_STATIC object. It represents the unevaluated expression formed by applying the function print to the argument (f x 3). A static thunk is also known as a constant applicative form, or a CAF for short. Like any other thunk, a CAF may or may not get evaluated. If evaluated, it will be replaced with a black hole and eventually the evaluation result. In this example, main will be evaluated by the runtime system, in deciding what IO to perform.

Black holes and revelations

That's all fine for a single-threaded Haskell runtime, but GHC supports running many Haskell threads across multiple OS threads. This introduces some additional complications. For example, one thread might force a thunk which is currently being evaluated by another thread. The thread will find a BLACKHOLE, but terminating the program would be incorrect. Instead the BLACKHOLE puts the current Haskell thread to sleep, and wakes it up when the evaluation result is ready.

If two threads force the same thunk at the same time, they will both perform the deferred computation. We could avoid this wasted effort by writing and checking for black holes using expensive atomic memory operations. But this is a poor tradeoff; we slow down every evaluation in order to prevent a rare race condition.

As a compiler for a language with pure evaluation, GHC has the luxury of tolerating some duplicated computation. Evaluating an expression twice can't change a program's behavior. And most thunks are cheap to evaluate, hardly worth the effort of avoiding duplication. So GHC follows a "lazy black-holing" strategy.12 Threads write black holes only when they enter the garbage collector. If a thread discovers that one of its thunks has already been claimed, it will abandon the duplicated work-in-progress. This scheme avoids large wasted computations without paying the price on small computations. You can find the gritty details within the function threadPaused, in rts/ThreadPaused.c.


You may remember that we started, all those many words ago, with a program that uses unsafePerformIO. This breaks the pure-evaluation property of Haskell. Repeated evaluation will affect semantics! Might lazy black-holing be the culprit in the original bug?

Naturally, the GHC developers thought about this case. Here's the implementation of unsafePerformIO:

unsafePerformIO m = unsafeDupablePerformIO (noDuplicate >> m)

noDuplicate = IO $ \s -> case noDuplicate# s of s' -> (# s', () #)

unsafeDupablePerformIO (IO m) = lazy (case m realWorld# of (# _, r #) -> r)

The core behavior is implemented by unsafeDupablePerformIO, using GHC's internal representation of IO actions (which is beyond the scope of this article, to the extent I even have a scope in mind). As the name suggests, unsafeDupablePerformIO provides no guarantee against duplicate execution. The more familiar unsafePerformIO builds this guarantee by first invoking the noDuplicate# primitive operation.

The implementation of noDuplicate#, written in GHC's Cmm intermediate language, handles a few tricky considerations. But it's basically a call to the function threadPaused, which we saw is responsible for lazy black-holing. In other words, thunks built from unsafePerformIO perform eager black-holing.

Since threadPaused has to walk the evaluation stack, unsafeDupablePerformIO might be much faster than unsafePerformIO. In practice, this will matter when performing a great number of very quick IO actions, like peeking a single byte from memory. In this case it is safe to duplicate IO, provided the buffer is unchanging. Let's measure the performance difference.

import GHC.IO
import Foreign hiding (unsafePerformIO)
import System.Random
import Criterion.Main

main = do
let sz = 1024*1024
buf <- mallocBytes sz
let get i = peekByteOff buf i :: IO Word8
peek_d i = unsafeDupablePerformIO (get i)
peek_n i = unsafePerformIO (get i)
idxes = take 1024 $ randomRs (0, sz-1) (mkStdGen 49)
evaluate (sum idxes) -- force idxes ahead of time
[ bench "dup" $ nf (map peek_d) idxes
, bench "noDup" $ nf (map peek_n) idxes ]

And the results:

$ ghc -rtsopts -threaded -O2 peek.hs && ./peek +RTS -N

benchmarking dup
mean: 76.42962 us, lb 75.11134 us, ub 78.18593 us, ci 0.950
std dev: 7.764123 us, lb 6.300310 us, ub 9.790345 us, ci 0.950

benchmarking noDup
mean: 142.1720 us, lb 139.7312 us, ub 145.4300 us, ci 0.950
std dev: 14.43673 us, lb 11.40254 us, ub 17.86663 us, ci 0.950

So performance-critical idempotent actions can benefit from unsafeDupablePerformIO. But most code should use the safer unsafePerformIO, as our bug reproducer does. And the noDuplicate# machinery for unsafePerformIO makes sense, so what's causing our bug?

The bug, finally

After all those details and diversions, let's go back to the fix for GHC bug #5558. The action is mostly in rts/sm/Storage.c. This file is part of GHC's storage manager, which provides services such as garbage collection.

Recall that our problematic code looked like this:

ioThunk :: ()
ioThunk = unsafePerformIO $ do ...

This is an application of the function ($) to the argument unsafePerformIO. So it's a static thunk, a CAF. Here's the old description of how CAF evaluation works, from Storage.c:

The entry code for every CAF does the following:

  • builds a BLACKHOLE in the heap
  • pushes an update frame pointing to the BLACKHOLE
  • calls newCaf, below
  • updates the CAF with a static indirection to the BLACKHOLE

Why do we build an BLACKHOLE in the heap rather than just updating the thunk directly? It's so that we only need one kind of update frame - otherwise we'd need a static version of the update frame too.

So here's the problem. Normal thunks get blackholed in place, and a thread detects duplicated evaluation by noticing that one of its thunks-in-progress became a BLACKHOLE. But static thunks — CAFs — are blackholed by indirection. Two threads might perform the above procedure concurrently, producing two different heap-allocated BLACKHOLEs, and they'd never notice.

As Simon Marlow put it:

Note [atomic CAF entry]

With THREADED_RTS, newCaf() is required to be atomic (see #5558). This is because if two threads happened to enter the same CAF simultaneously, they would create two distinct CAF_BLACKHOLEs, and so the normal threadPaused() machinery for detecting duplicate evaluation will not detect this. Hence in lockCAF() below, we atomically lock the CAF with WHITEHOLE before updating it with IND_STATIC, and return zero if another thread locked the CAF first. In the event that we lost the race, CAF entry code will re-enter the CAF and block on the other thread's CAF_BLACKHOLE.

I can't explain precisely what a WHITEHOLE means, but they're used for spin locks or wait-free synchronization in various places. For example, the MVar primitives are synchronized by the lockClosure spinlock routine, which uses WHITEHOLEs.

The fix

Here's the corrected CAF evaluation procedure:

The entry code for every CAF does the following:

  • builds a CAF_BLACKHOLE in the heap
  • calls newCaf, which atomically updates the CAF with IND_STATIC pointing to the CAF_BLACKHOLE
  • if newCaf returns zero, it re-enters the CAF (see Note [atomic CAF entry])
  • pushes an update frame pointing to the CAF_BLACKHOLE

newCAF is made atomic by introducing a new helper function, lockCAF, which is reproduced here for your viewing pleasure:

STATIC_INLINE StgWord lockCAF (StgClosure *caf, StgClosure *bh)
const StgInfoTable *orig_info;

orig_info = caf->;

const StgInfoTable *cur_info;

if (orig_info == &stg_IND_STATIC_info ||
orig_info == &stg_WHITEHOLE_info) {
// already claimed by another thread; re-enter the CAF
return 0;

cur_info = (const StgInfoTable *)

if (cur_info != orig_info) {
// already claimed by another thread; re-enter the CAF
return 0;

// successfully claimed by us; overwrite with IND_STATIC

// For the benefit of revertCAFs(), save the original info pointer
((StgIndStatic *)caf)->saved_info = orig_info;

((StgIndStatic*)caf)->indirectee = bh;

return 1;

We grab the CAF's info table pointer, which tells us what kind of object it is. If it's not already claimed by another thread, we write a WHITEHOLE — but only if the CAF hasn't changed in the meantime. This step is an atomic compare-and-swap, implemented by architecture-specific code. The function cas is specified by this pseudocode:

cas(p,o,n) {
atomically {
r = *p;
if (r == o) { *p = n };
return r;

Here's the implementation for x86, using GCC extended inline assembly:

cas(StgVolatilePtr p, StgWord o, StgWord n)
__asm__ __volatile__ (
"lock\ncmpxchg %3,%1"
:"=a"(o), "=m" (*(volatile unsigned int *)p)
:"0" (o), "r" (n));
return o;

There are some interesting variations between architectures. SPARC and x86 use single instructions, while PowerPC and ARMv6 have longer sequences. Old ARM processors require a global spinlock, which sounds painful. Who's running Haskell on ARMv5 chips?

*deep breath*

Thanks for reading / skimming this far! I learned a lot by writing this article, and I hope you enjoyed reading it. I'm sure I said something wrong somewhere, so please do not hesitate to correct me in the comments.

  1. Tim Harris, Simon Marlow, and Simon Peyton Jones. Haskell on a shared-memory multiprocessor. In Haskell '05: Proceedings of the 2005 ACM SIGPLAN workshop on Haskell, pages 49–61.

  2. Simon Marlow, Simon Peyton Jones, and Satnam Singh. Runtime Support for Multicore Haskell. In ICFP'09.


  1. > Who's running Haskell on ARMv5 chips?

    Debian does:
    $ uname -a
    Linux abel 2.6.32 #4 Thu Sep 29 18:52:43 UTC 2011 armv5tel GNU/Linux

    But it is causing problems:

  2. I don't know GHC internals, and found this enlightening and interesting. Thanks :)

  3. (Split into a new comment at the blog software's insistence.)

    I ended up with the following hierarchy of what things are safe to perform unsafely in what ways. I would appreciate any experienced GHC hackers telling me if I'm wrong about it.

    unsafePerformIO x: x must be externally observably pure: you must not be able to tell when or how many times x was evaluated from within a pure function.

    unsafeDupablePerformIO x: x must be externally pure, period: you must not be able to tell when or how many times x was evaluated from anywhere. Or, at least, it must not make a difference. I'm not sure if there's a one-to-one correspondence, but another way of putting it might be that the result of x must not have identity.

    unsafeInlinePerformIO x: x must be internally as well as externally pure; it must not be the composition of impure parts into a pure whole, because the GHC optimizer will take it, decompose it, and scatter its component parts over a wide area.

  4. ...and now it's gone and lost the first half. Should I post it again? I guess I should make a blog post out of this, but I don't have a blog... maybe some day.

  5. @illissius
    I have a more operational take on it (I am not an experienced GHC hacker):

    unsafeDupablePerformIO: the input must be idempotent, because we may run it twice.

    unsafeInlinePerformIO: the operation gets entirely inlined, so optimization passes may decide to float various bits and pieces out from under the call, including constant-sized allocations and other bad things.

  6. @Antoine

    The bit about idempotency was exactly what the first half of my comment was about, and why I think it's wrong. For some reason it disappeared when I posted the second half. Anyway, here it is again...

    I really liked this post. Thanks.

    I was thinking about, asking about, and discussing unsafeDupablePerformIO on IRC a month or many months ago. My problem was that I didn't quite understand why it needed to exist -- or rather, why unsafeNotDupablePerformIO needed to exist. My initial thinking was that unsafeDupablePerformIO is safe for idempotent IO actions, while unsafePerformIO is safe even for non-idempotent ones. But as I thought about it, I realized this couldn't be right. 'Write $x into address $y in memory' is idempotent: doing it multiple times won't change the result. But does unsafeDupablePerformIO at least guarantee that any duplicate performances will all happen before the evaluation is considered 'done', and before the next thing happens? Otherwise, $x will be written into $y at some random point in time, which might be bad. It became obvious that it couldn't be so: some IO actions return results, and obviously it can't be returning more than one of them, so presumably it's going to use the first one it gets. And the other copies are going to silently execute in the background somewhere at some unknown time and have their results discarded. (IRC corrected me that this wasn't quite right, actually: what does happen is that more than one thread might request the result of a computation at the same time, and end up computing it independently along with any side effects, and each will use the result of its own computation.) But either way, idempotency clearly wasn't the right precondition for being safe to unsafeDupablePerformIO.

    I realized that my hypothetical idempotent IO action wasn't safe to unsafeNotDupablePerformIO, either. Why would you unsafelyPerformIO something without a result, but with a side effect, after all? That's very wrong by definition. You generally want the opposite: a useful result without side effects. If you have side effects, referential transparency breaks, and unsafePerformIO is unsafe. The reason why unsafePerformIO exists is because side effecting computations can be composed into pure ones.

    But if the IO action passed to unsafePerformIO must, by definition, be externally pure, in order to be correct, then why is evaluating it multiple times a problem? In other words, once you allow for a computation to be performed at an unpredictable time due to laziness, what further constraints does it provoke if you must also allow for it to be performed multiple times? What possible input could there be for which unsafePerformIO is safe and unsafeDupablePerformIO is not? After a productive discussion on IRC it became clear that the important word is 'observable'. All agreed that if you were to implement, say, immutable reference cells using IORefs in the background (though this would have little practical value) that using unsafeDupablePerformIO to implement the read, copy-and-write, etc. operations would have no observably ill effects... from within a pure function. The big difference-making thing turns out to be stuff that's not observable from a pure function, but *is* observable from the IO monad. You can't tell from a pure function whether evaluations of copyAndWrite from two separate threads got the same object as result or two equivalent objects, but if you start mucking with the bare IORefs in the IO monad and expect it to be the former, you might get burned. (As a more blatant example, you could have a hidden reference field which gets secretly updated by externally-pure functions but which is only accessible from IO.)

  7. There is a slight factual inaccuracy in this article: it is stated that lazy black holing only occurs when threads enter the garbage collector; however, in modern GHC, lazy blackholing occurs whenever a thread returns to the scheduler (e.g. including if it was preempted). This allows us to avoid having to walk all the thread stacks to black hole at once when a GC occurs.

  8. Nice article, thanks for the information. It's very complete information. I will bookmark for next reference
    jaring futsal | jaring golf | jaring pengaman proyek |
    jaring pengaman bangunan | jaring pengaman gedung

  9. People know what it's like to face the challenge of cleaning a messy bedroom. Sometimes, it can feel like you're about to climb Mount Everest when all you're really doing is putting some clothes and books away. Luckily, it doesn't have to be as hard as scaling the tallest peak. Follow these simple steps to make cleaning your room a walk in the park rather than a mountain climbing race. شركة مكافحة حشرات بجدة شركة مكافحة النمل الابيض بجدة شركة كشف تسربات المياه بجدة شركة تسليك مجارى بجدة شركة مكافحة حشرات بالاحساء شركة مكافحة النمل الابيض بالاحساء شركة كشف تسربات المياه بالاحساء

  10. People know what it's like to face the challenge of cleaning a messy bedroom. Sometimes, it can feel like you're about to climb Mount Everest when all you're really doing is putting some clothes and books away. Luckily, it doesn't have to be as hard as scaling the tallest peak. Follow these simple steps to make cleaning your room a walk in the park rather than a mountain climbing race. شركة مكافحة حشرات بجدة شركة مكافحة النمل الابيض بجدة شركة كشف تسربات المياه بجدة شركة تسليك مجارى بجدة شركة مكافحة حشرات بالاحساء شركة مكافحة النمل الابيض بالاحساء شركة كشف تسربات المياه بالاحساء

  11. Plan out when you will take a break. Taking a break to eat, drink, and kick up your heels is often a good idea. However, don’t let yourself become too distracted during your break! Plan out a chosen amount of time that you will take a break for. It is best to take a break after you have completed an entire task rather than in the middle of it. One example could be that you plan to take a break after you have cleaned out under your bed and before you start organizing the smaller things in your room.
    • Don't take a break if the time of your break comes around and you feel as though you're on a roll. Use that feeling of being on a roll to get even more done!
    شركة تنظيف خزانات بالرياض شركة عزل خزانات بالرياض شركة عزل اسطح بالرياض شركة نقل عفش بالرياض شركة نقل اثاث بالرياض شركة تسليك مجارى بالرياض

  12. It is a beautiful post as always. Thank you so much for sharing this information.
    digital marketing services in delhi

  13. In the last few months we've seen a lot of Health Care Reform rules and regulations being introduced by the Health and Human Services Department. Every time that happens, the media gets hold of it and all kinds of articles are written in the Wall Street Journal, the New York Times, and the TV network news programs talk about it. All the analysts start talking about the pros and cons, and what it means to businesses and individuals. Health is God

  14. I think this is a real great article post.Really looking forward to read more. Visit at
    Crazy Video Hub

  15. Nutra Trials defines personal characteristics of different health products including skincare, weight loss, muscle and male enhancement. The study presented here is briefly described for reader convenience and to deliver them assurance with health standards. The best possible answers are given here regarding the selection of an ideal supplement or cream or serum that possibly remains to be safe for health and do not cause any side effects.

  16. It is a great job, I like your posts and wish you all the best. and I hope you continue this job well.
    NutraT line

  17. Very useful post and I think it is rather easy to see from the other comments as well that this post is well written and useful. I bookmarked this blog a while ago because of the useful content and I am never being disappointed. Keep up the good work..
    kim kardashian sex tape
    porn sex video hd
    mia khalifa sex video
    sunny leone sexy movie

  18. Hello, I am thomus jons thank you for this informative post. That is a great job. Wish you more success.Thank you so much and for you all the best. Takes Down

  19. Times For Health is Online Health & Wellness Program! This post is really really nice and so informative. Thanks for the nice post share with us!

  20. TecSmash is your ultimate source of Technology news and Make Money Online product reviews. We research and review all Tech, MMO, Biz Opp and IM products.TecSmash

  21. Income is the number one destination to find genuine make money online programs and services Income designers

  22. Best softwares for Internet Marketers and legitimate make money online opportunities cxyrc

  23. Supplements For Fitness For example, Xenical acts as a fat blocker. It is known to reduce up to 25% of weight if used correctly. The pill is considered adequate even for long-term weight loss.

  24. We are here to give you a complete review on the Parallel Profit project by Steve Clayton and Aidan Booth. If you are someone from the field you would already be familiar with these two names, for those of who are new. Parallel Profits Review

  25. Pilpedia is supplying 100 percent original and accurate information at each moment of time around our site and merchandise, and the intent is to improve the usage of good and pure health supplement. For More Info please visit Pilpedia online store.

  26. Vital Keto : L'argent change tout. Je présume que vous savez que c'est nécessaire afin de se spécialiser dans la perte de poids et, malheureusement, je suis juste plutôt confus maintenant. Cela ne réfute pas la perte de poids. Ce matin, je mangeais un repas à mon favori Fast-Food joint.

    Visitez-nous : Vital Keto

    Vous pouvez également visiter :

  27. Keto CLarity
    Despite that, they give you weight lose for a second-rate price. Weight lose has not made a significant impact. Trust me on this, that will occur one way or another. You would be stunned how many problems you will avoid with weight loss. I'm determined to help you with it. Weight loss is quite praiseworthy. It isn't ingenious at this time.

  28. Keto 180 Shark Tank : These nutrients are essential to dissolve fats and cholesterol. A diet that contains monounsaturated fats instead of saturated fats is conducive for heart health. All of us would love to go to an inexpensive health club, that is nearby, not overcrowded and equipped with numerous coaching equipment. Here’s a fast 5 minute mental exercise you can begin doing currently to help you start changing the manner you crave food.

  29. Keto X Factor
    Checkout any medical website and you will notice that stomach fat on men, especially using a waist 40" or above, is directly related heart disease, Type II diabetes, liver and kidney problems, insulin resistance, and erectile dysfunction. Is there anything remotely appealing about any sexual health drawbacks? Why run the risk if you can follow a successful program to obtain rid of weight, abolish fat, and build lean muscle group?


  30. Thermofight X

    Fat burner may be a rather well-practiced fat burner strategy. Sometimes I get the feeling like I'm running a variety of type of a race. It's nonstop. Bear in mind, that should be done. How annoying… Take this to heart, "What's the frequency, Kenneth?" Permit me offer you a great many beneficial information. When you suspect regarding your weight lose you should keep this in mind. Here are the facts you should understand regarding weight loss. It very found out when fat burner substituted with weight loss formula. Nonetheless, here is my advice to you.


  31. Legends Keto Most ladies use weight reduction pills so as to dispose of paunch fats. However, isn't this Fat Loss Pills are over the top expensive realizing that you need to keep up them for such a significant lot? Besides, weight reduction pills are not beneficial to utilize as a result of the negative reactions that you may involvement in your fat misfortune. Such negative symptoms will just bring medical issues that will make your eating routine arrangement increasingly costly to fix its unfortunate impacts in your body. Then again, some utilization machines and costly weight sets to smooth their paunches. However, they are extravagant. It will cost you a ton of cash, reality. That is the reason, it is in every case best to utilize the most ideal approaches to lose tummy fats through the fat misfortune tips that I will share you.

  32. Don't Waste Time! 5 Facts Until You Reach Your Adtrics Academy -

  33. 9 Ways Sluggish Economy Changed My Outlook On Forex Duality -

  34. Rapid Slim Keto is a doctor-formulated diet pill, designed for the fast-paced lives of women. The pill was created to be discreet and easy to take. It’s a liquid gel caplet that uses LiQuick Fix technology. Kindly Visit on

  35. Livlean Formula is the current nourishing product that might function efficiently to reinforce some of the physique processes. This quick and effective product functions to make certain that the users perceive the reinforcement that they require. You should also have it mind that this formula has been verified. However, to attain some gains the results may differ from one person to the other, thus consumers are advised to stick on the regimen to encounter perfect outcomes. Visit On

  36. Quick Results Keto The keto diet is loaded with tempting guarantees — you'll shed pounds quick, any mind haze will vanish, and you'll have more vitality than you recognize how to manage. Yet, imagine a scenario in which you've been following the high-fat, low-carb plan for a long time and you're feeling lousy, or the weight simply isn't liquefying off.Kindly Visit on Quick Results Keto

  37. Ultra Diet Patch is a weight reduction and body act support item. It is simpler to use when contrasted with numerous other weight reduction supplements. You ought to be exceptionally mindful of its utilization. Ultra Diet Patch is a one of a kind item. Visit On

  38. Keto X Factor is one of the most intense weight loss products for excess fat and excess calories. This supplement effectively helps to overcome emotional eating disorders and behavior by pulling the digestive tract and cravings. It detoxifies the body to clean it of all hard and negative particles.
    Kindly Visit on Keto X Factor reviews

  39. Delta Prime is a supplement which was manufactured with the main aim of ensuring that there are constant supply and production of testosterone in the user’s body. The Manufacturer of this product are confident and they claim that it is capable of increasing energy levels, thus, men can carry out activities with much ease.This product’s formulation consists of a traditional blend of herbs which also makes it quite safe to be used for a long period without causing any side effects. Visit On

  40. There are tons of free ready-made themes available in WordPress directory. If you're writing relevant content, Google will ‘get it' and start to rank you for related terms,” Bird says. These programs allow you to choose from pre-made themes, and some allow you to customize elements such as CSS. Nearly one-third of all mobile searches are location-based queries, such as restaurants near me.” And even if the near me” is not added, Google's algorithm now automatically prioritizes local options if you just search restaurants.” SERPs are teeing up small businesses to be successful with local SEO, so it's paramount that they capitalize on the opportunity.

    Instead of focusing on number 1 in Google, your focus should be to appear in as many Google properties as possible, to give your business as much opportunity as possible to appear for as many searches as possible that are relevant to your business. This is perhaps one of the most overlooked ranking factors of our era. Basically, it's about ranking higher in the search engine results for keywords related to your site. Unfortunately, the default WP installation does not come with appropriate SEO tools for the current age So, bloggers have to head over to the WP plugin directory to try and figure out which SEO tools are best for their website.

  41. Our vision is that individuals discover best quality wellbeing items they need; that the wellbeing items are protected and affodable for them. Fitdiettrendss (

  42. we are in the matter of aiding for visitor post...

  43. A very effective and inexpensive solution to get rid of nasty skin lesions on the body, such as skin tags Skintology MD. This is a reliable way to remove the skin panels and moles you have. This cream is suitable for all skin types. Whether greasy or normal, dry or sensitive, it affects all skin types. It works really fast and better than other expensive methods as surgery.

  44. Insta Keto may be a natural dieting supplement that is designed in such a means that you will be in a position to attain ketosis process. It elevates the metabolic rate within the body by promoting healthy ketosis to manage carbs conversion into fats and build it utilised as energy boosters for the body.

  45. Ultra Fast Keto Boost For Weight Loss This formulation is created of natural ingredients, so that square measure the foremost crucial compounds. That ease to offer the organic compound within the body, thereby increasing the quantity of BHB. By the regular use of this supplement, the human body is performed within the acetonemia technique. It can help to rework undesirable carbohydrates into energy. With this supplement, you will have the ability to burn fat faster than ever before. Visit On

  46. Super Fast Keto Boost is an advanced weight loss formula that can help you burn fat more effectively than ever. It is formulated in such a way that it can help your body reach a state of ketosis faster. The active component in Super Fast Keto Boost is a fat-burning ketone called BHB (beta-hydroxybutyrate). This ketone is one of the first substrates that helps your body to enter a state of ketosis faster. Visit On

  47. Customers familiar with IGGM know that every year they will have a big discount to give back to old customers. There have been a lot of POE Currency soon, and as a player, you can't miss it. Last year, they will not only launch a single product offer but also offer a package offer, which makes many players feel very convenient and hopes to launch this year.

    The next thing I want to say is the discount on POE Items. According to my understanding, the discount for their website will be 6% Off! The most important thing is that IGGM always adheres to the concept of quality and price development, and the transaction process is safe, reliable, stable and cheap. Their website is dedicated to improving the player's service through honesty, friendliness, and strives to satisfy each customer.


    Yang Merupakan Agen Bandarq, Domino 99, Dan Bandar Poker Online Terpercaya di asia hadir untuk anda semua dengan permainan permainan menarik dan bonus menarik untuk anda semua

    Bonus yang diberikan NagaQQ :
    * Bonus rollingan 0.5%,setiap senin di bagikannya
    * Bonus Refferal 10% + 10%,seumur hidup
    * Bonus Jackpot, yang dapat anda dapatkan dengan mudah
    * Minimal Depo 15.000
    * Minimal WD 20.000

    Memegang Gelar atau title sebagai QQ Online Terbaik di masanya

    Games Yang di Hadirkan NagaQQ :
    * Poker Online
    * BandarQ
    * Domino99
    * Bandar Poker
    * Bandar66
    * Sakong
    * Capsa Susun
    * AduQ
    * Perang Bacarrat (New Game)

    Tersedia Deposit Via pulsa :
    Telkomsel & XL

    Info Lebih lanjut Kunjungi :
    Website : NAGAQQ
    Facebook : NagaQQ Official
    Kontakk : Info NagaQQ
    linktree : Agen Judi Online
    WHATSAPP : +855977509035
    Line : Cs_nagaQQ
    TELEGRAM : +855967014811

    agen bandarq terbaik
    Winner NagaQQ
    Daftar NagaQQ
    Agen Poker Online

  49. Hellio gomovies It is a great job, I love your posts and wish you all the very best. And I hope you continue doing this job well.

  50. التعليم عملية تيسير التعلم أي اكتساب المعرفة والمهارات والمبادئ والمعتقدات والعادات. من وسائل التعليم هناك رواية القصص والنقاش والتدريس والتدريب والبحث العلمي الموجَّه. التعليم كثيرا ما يجري تحت إرشاد معلمين حلول، إلا أن المتعلمين من الممكن أن يعلموا أنفسهم كذلك. يمكن حدوث التعليم في وضع نظامي أو وضع غير نظامي وأية تجربة واجباتي لها تأثير تكويني على طريقة التفكير أو الشعور أو التصرف يمكن اعتبارها تعليمية. منهجية التعليم يشار إليها بصطلح علم التربية أو علم التعليم.
    التعليم الابتدائي الشامل هو واحد من ثماني أهداف إنمائية ألفية عالمية، والتي أُحرِز تقدم نحوها في العقد الماضي لكن بقي هناك عوائق في هذا المجال. يُعد تأمين التمويل الخيري من المانحين المحتملين أحد المشكلات المستمرة بشكل خاص. أشار الباحثون في pg,g ما وراء البحار (أو دي آي) إلى أن العقبات الرئيسية أمام تمويل التعليم تشمل تضارب أولويات المانحين وهيكلية المساعدات غير الناضجة والافتقار إلى الأدلة والمناصرة لهذه القضية. بالإضافة إلى ذلك، حددت منظمة الشفافية الدولية الفساد في قطاع التعليم باعتباره حجر عثرة أمام تحقيق التعليم الابتدائي الشامل في أفريقيا. علاوة على ذلك، فإن الطلب في العالم النامي على تحسين الوصول إلى التعليم ليس مرتفعًا كما توقع الأجانب. تتردد الحكومات الأصلية في تحمّل التكاليف المستمرة المعنية بالتعليم. هناك أيضًا ضغوط اقتصادية من بعض الآباء والأمهات، الذين يفضلون أن يكسب أطفالهم المال على المدى القصير بدلاً من العمل من أجل تحقيق فوائد التعليم على المدى الطويل.

  51. Packers and Movers Bangalore - Reliable and Verified Household Shifting Service Providers Give Reasonable ###Packers and Movers Charges. Cheap and Best Office Relocation Compare Quotation for Assurance for Local and Domestic House Shifting and Get estimates today to save upto 20%, ***Read Customer Reviews - @ Packers And Movers Bangalore

  52. Packers and Movers Chennai Give Safe and Reliable ***Household Shifting Services in Chennai with Reasonable ###Packers and Movers Price Quotation. We Provide Household Shifting, Office Relocation, ✔✔✔ Local and Domestic Transportation Services, Affordable and Reliable Shifting Service Charges @ Packers And Movers Chennai

  53. Packers and Movers Bangalore as a Services providing company can make all the difference to your ###Home Relocation experience. Bangalore based Company which offers versatile solutions, Right team that easily reduce the stress associated with a ✔✔✔Household Shifting, ***Vehicle Transportation. we help things run smoothly and reduce breakages and offer you seamless, Affordable, Reliable Shifting Services, Compare Shifting Charges. @ Packers And Movers Bangalore

  54. At the end of all time, will the human world extend out of a different world? For example, the world of code, the world of Shiny Pokemon, the world of gods and so on. It would be great if there were functions that explained everything.

  55. Your post is great, very useful for us.

  56. HPBOSE: Himachal Pradesh Board of School Education, Dharamshala.Himachal Pradesh 7th Class Books Here in this post you will get HP board 5th class books in the pdf format. We will provide you all subjects books like Hindi, English, Maths, EVS etc.

  57. Dynamic Health Care products offer Sea moss which are spiny sea vegetable that’s primarily harvested for use in health supplements and as a thickening ingredient in commercial foods.
    If you’ve heard about sea moss supplements, you may wonder how you could use them and whether there are other ways to consume sea moss. For more information on our products you can visit our website by clicking the link Dyanmic Health Care Products

    sea moss near me
    How to make sea moss gel
    How to use sea moss gel
    How long does sea moss gel last
    Purple sea moss
    sea moss and bladderwrack
    Where to buy sea moss
    Sea moss capsules
    Where to buy sea moss