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[BUG FIX] FAIR algorithm #4

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[BUG FIX] FAIR algorithm #4

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faca189
[BUG FIX] The bug of FAIR algorithm is fixed.
SeKwonLee Feb 28, 2019
a5def6c
Fixing FAIR algorithm bug of leaf node split
SeKwonLee Mar 14, 2019
fe79323
Adding new test code to run without input file
SeKwonLee Mar 14, 2019
db74fa8
[BUG FIX] FAIR algorithm of leafnode split
SeKwonLee Mar 14, 2019
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38 changes: 21 additions & 17 deletions concurrent/src/btree.h
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Original file line number Diff line number Diff line change
Expand Up @@ -113,7 +113,9 @@ class header{
uint8_t switch_counter; // 1 bytes
uint8_t is_deleted; // 1 bytes
int16_t last_index; // 2 bytes
std::mutex *mtx; // 8 bytes
std::mutex *mtx; // 8 bytes
entry_key_t highest; // 8 bytes
uint64_t dummy[1]; // 24 bytes

friend class page;
friend class btree;
Expand Down Expand Up @@ -154,7 +156,7 @@ const int count_in_line = CACHE_LINE_SIZE / sizeof(entry);

class page{
private:
header hdr; // header in persistent memory, 16 bytes
header hdr; // header in persistent memory, 64 bytes
entry records[cardinality]; // slots in persistent memory, 16 bytes * n

public:
Expand All @@ -167,7 +169,7 @@ class page{

// this is called when tree grows
page(page* left, entry_key_t key, page* right, uint32_t level = 0) {
hdr.leftmost_ptr = left;
hdr.leftmost_ptr = left;
hdr.level = level;
records[0].key = key;
records[0].ptr = (char*) right;
Expand Down Expand Up @@ -212,15 +214,15 @@ class page{

inline bool remove_key(entry_key_t key) {
// Set the switch_counter
if(IS_FORWARD(hdr.switch_counter))
if(IS_FORWARD(hdr.switch_counter))
++hdr.switch_counter;

bool shift = false;
int i;
for(i = 0; records[i].ptr != NULL; ++i) {
if(!shift && records[i].key == key) {
records[i].ptr = (i == 0) ?
(char *)hdr.leftmost_ptr : records[i - 1].ptr;
records[i].ptr = (i == 0) ?
(char *)hdr.leftmost_ptr : records[i - 1].ptr;
shift = true;
}

Expand All @@ -231,8 +233,8 @@ class page{
// flush
uint64_t records_ptr = (uint64_t)(&records[i]);
int remainder = records_ptr % CACHE_LINE_SIZE;
bool do_flush = (remainder == 0) ||
((((int)(remainder + sizeof(entry)) / CACHE_LINE_SIZE) == 1) &&
bool do_flush = (remainder == 0) ||
((((int)(remainder + sizeof(entry)) / CACHE_LINE_SIZE) == 1) &&
((remainder + sizeof(entry)) % CACHE_LINE_SIZE) != 0);
if(do_flush) {
clflush((char *)records_ptr, CACHE_LINE_SIZE);
Expand All @@ -259,7 +261,7 @@ class page{
/*
* Although we implemented the rebalancing of B+-Tree, it is currently blocked for the performance.
* Please refer to the follow.
* Chi, P., Lee, W. C., & Xie, Y. (2014, August).
* Chi, P., Lee, W. C., & Xie, Y. (2014, August).
* Making B+-tree efficient in PCM-based main memory. In Proceedings of the 2014
* international symposium on Low power electronics and design (pp. 69-74). ACM.
*/
Expand Down Expand Up @@ -589,13 +591,13 @@ class page{
// If this node has a sibling node,
if(hdr.sibling_ptr && (hdr.sibling_ptr != invalid_sibling)) {
// Compare this key with the first key of the sibling
if(key > hdr.sibling_ptr->records[0].key) {
if(with_lock) {
hdr.mtx->unlock(); // Unlock the write lock
if(key >= hdr.sibling_ptr->hdr.highest) { // internal node
if(with_lock) {
hdr.mtx->unlock(); // Unlock the write lock
}
return hdr.sibling_ptr->store(bt, NULL, key, right,
true, with_lock, invalid_sibling);
}
return hdr.sibling_ptr->store(bt, NULL, key, right,
true, with_lock, invalid_sibling);
}
}

register int num_entries = count();
Expand Down Expand Up @@ -623,12 +625,14 @@ class page{
for(int i=m; i<num_entries; ++i){
sibling->insert_key(records[i].key, records[i].ptr, &sibling_cnt, false);
}
sibling->hdr.highest = records[m].key;
}
else{ // internal node
for(int i=m+1;i<num_entries;++i){
sibling->insert_key(records[i].key, records[i].ptr, &sibling_cnt, false);
}
sibling->hdr.leftmost_ptr = (page*) records[m].ptr;
sibling->hdr.highest = records[m].key;
}

sibling->hdr.sibling_ptr = hdr.sibling_ptr;
Expand Down Expand Up @@ -830,7 +834,7 @@ class page{
return ret;
}

if((t = (char *)hdr.sibling_ptr) && key >= ((page *)t)->records[0].key)
if((t = (char *)hdr.sibling_ptr) && key >= ((page *)t)->hdr.highest)
return t;

return NULL;
Expand Down Expand Up @@ -883,7 +887,7 @@ class page{
} while(hdr.switch_counter != previous_switch_counter);

if((t = (char *)hdr.sibling_ptr) != NULL) {
if(key >= ((page *)t)->records[0].key)
if(key >= ((page *)t)->hdr.highest)
return t;
}

Expand Down