The code of resizable hash table has been updated so that it doesn't
need to compute the hash twice since 2019. Here are some related
commits:
2ea492bbab9d ("datatruct/hash: Don't recompute hashes in hashtab_add()")
2a7f20d234e7 ("datastruct/hash: Don't recompute hashes in hashtab_del()")
...
So, the patch removes the outdated content.
Signed-off-by: Alan Huang <mmpgouride@xxxxxxxxx>
Reviewed-by: Akira Yokosawa <akiyks@xxxxxxxxx>
---
datastruct/datastruct.tex | 29 +++--------------------------
1 file changed, 3 insertions(+), 26 deletions(-)
diff --git a/datastruct/datastruct.tex b/datastruct/datastruct.tex
index 8c2bfc16..0242ccc7 100644
--- a/datastruct/datastruct.tex
+++ b/datastruct/datastruct.tex
@@ -2017,32 +2017,10 @@ which could allow the compiler to inline the resulting fixed functions,
eliminating not only the overhead of the call instruction, but the
argument marshalling as well.
-In addition, the resizable hash table is designed to fit an API
-that segregates bucket selection from concurrency control.
-Although this allows a single torture test to exercise all the hash-table
-implementations in this chapter, it also means that many operations
-must compute the hash and interact with possible resize operations twice
-rather than just once.
-In a performance-conscious environment, the \co{hashtab_lock_mod()}
-function would also return a reference to the bucket selected, eliminating
-the subsequent call to \co{ht_get_bucket()}.
-
-\QuickQuizSeries{%
-\QuickQuizB{
- Couldn't the \path{hashtorture.h} code be modified to accommodate
- a version of \co{hashtab_lock_mod()} that subsumes the
- \co{ht_get_bucket()} functionality?
-}\QuickQuizAnswerB{
- It probably could, and doing so would benefit all of the
- per-bucket-locked hash tables presented in this chapter.
- Making this modification is left as an exercise for the
- reader.
-}\QuickQuizEndB
-%
-\QuickQuizE{
+\QuickQuiz{
How much do these specializations really save?
Are they really worth it?
-}\QuickQuizAnswerE{
+}\QuickQuizAnswer{
The answer to the first question is left as an exercise to
the reader.
Try specializing the resizable hash table and see how much
@@ -2051,8 +2029,7 @@ the subsequent call to \co{ht_get_bucket()}.
instead be answered with respect to a specific use case.
Some use cases are extremely sensitive to performance and
scalability, while others are less so.
-}\QuickQuizEndE
-}
+}\QuickQuizEnd
All that aside, one of the great benefits of modern hardware compared
to that available when I first started learning to program back in
--
2.34.1
