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Improve the isolation level (read committed) by using non-temporal store #6

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Improve the isolation level (read committed) by using non-temporal store #6

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14 changes: 13 additions & 1 deletion lbtree-src/lbtree.cc
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Original file line number Diff line number Diff line change
Expand Up @@ -732,10 +732,15 @@ void lbtree::insert (key_type key, void *ptr)
if (slot<3) {
// 1.3.1 write word 0
meta.v.bitmap= bitmap;

#ifdef NONTEMP
lp->setWord0_temporal(&meta);
#else
lp->setWord0(&meta);

// 1.3.2 flush
clwb(lp); sfence();
#endif

return;
}
Expand All @@ -760,8 +765,12 @@ void lbtree::insert (key_type key, void *ptr)

// 1.4.3 change meta and flush line 0
meta.v.bitmap= bitmap;
#ifdef NONTEMP
lp->setBothWords_temporal(&meta);
#else
lp->setBothWords(&meta);
clwb(lp); sfence();
#endif

return;
}
Expand Down Expand Up @@ -1138,9 +1147,12 @@ void lbtree::del (key_type key)

meta.v.lock= 0; // clear lock in temp meta
meta.v.bitmap &= ~(1<<ppos[0]); // mark the bitmap to delete the entry
#ifdef NONTEMP
lp->setWord0_temporal(&meta);
#else
lp->setWord0(&meta);
clwb(lp); sfence();

#endif
return;

} // end of more than one key
Expand Down
19 changes: 19 additions & 0 deletions lbtree-src/lbtree.h
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Original file line number Diff line number Diff line change
Expand Up @@ -36,6 +36,9 @@

#define LEAF_KEY_NUM (14)

// use non-temporal store for correct isolation
#define NONTEMP 1

/* ---------------------------------------------------------------------- */
/**
* Pointer8B defines a class that can be assigned to either bnode or bleaf.
Expand Down Expand Up @@ -136,6 +139,12 @@ typedef union bleafMeta {
} v;
} bleafMeta;

void movnt64(uint64_t *dest, uint64_t const src, bool front, bool back) {
if (front) sfence();
_mm_stream_si64((long long int *)dest, (long long int) src);
if (back) sfence();
}

/**
* bleaf: leaf node
*
Expand Down Expand Up @@ -170,6 +179,16 @@ class bleaf {
my_meta->word8B[0]= m->word8B[0];
}

void setWord0_temporal(bleafMeta *m){
bleafMeta * my_meta= (bleafMeta *)this;
movnt64((uint64_t*)&my_meta->word8B[0], m->word8B[0], false, true);
}

void setBothWords_temporal(bleafMeta *m) {
bleafMeta * my_meta= (bleafMeta *)this;
my_meta->word8B[1]= m->word8B[1];
movnt64((uint64_t*)&my_meta->word8B[0], m->word8B[0], false, true);
}
}; // bleaf

/* ---------------------------------------------------------------------- */
Expand Down