fix merge deadlock; port to fixed stasis buffer manager api; enable new buffer manager by default

git-svn-id: svn+ssh://svn.corp.yahoo.com/yahoo/yrl/labs/pnuts/code/logstore@2330 8dad8b1f-cf64-0410-95b6-bcf113ffbcfe

datapage.cpp

@@ -114,7 +114,7 @@ void DataPage<TUPLE>::initialize_page(pageid_t pageid) {
     //initialize header
     p->pageType = DATA_PAGE;
     
-    //clear page (arranges for null-padding)
+    //clear page (arranges for null-padding)  XXX null pad more carefully and use sentinel value instead?
     memset(p->memAddr, 0, PAGE_SIZE);
 
     //we're the last page for now.
@@ -162,7 +162,10 @@ size_t DataPage<TUPLE>::read_bytes(byte * buf, off_t offset, ssize_t remaining)
 		chunk.size = 0; // eof
 	} else {
 		Page *p = alloc_ ? alloc_->load_page(xid_, chunk.page) : loadPage(xid_, chunk.page);
-		assert(p->pageType == DATA_PAGE);
+                if(p->pageType != DATA_PAGE) {
+                  fprintf(stderr, "Page type %d, id %lld lsn %lld\n", (int)p->pageType, (long long)p->id, (long long)p->LSN);
+                  assert(p->pageType == DATA_PAGE);
+                }
 		if((chunk.page + 1 == page_count_ + first_page_)
 		  && (*is_another_page_ptr(p))) {
 			page_count_++;

diskTreeComponent.cpp

@@ -398,7 +398,7 @@ recordid diskTreeComponent::internalNodes::appendInternalNode(int xid, Page *p,
     if(ret.size != INVALID_SLOT) {
       stasis_record_alloc_done(xid, p, ret);
       writeNodeRecord(xid,p,ret,key,key_len,val_page);
-      stasis_page_lsn_write(xid, p, internal_node_alloc->get_lsn(xid));
+      stasis_page_lsn_write(xid, p, internal_node_alloc->get_lsn(xid)); // XXX remove this (writeNodeRecord calls it for us)
     }
     unlock(p->rwlatch);
   } else {

logstore.cpp

@@ -37,7 +37,8 @@ logtable<TUPLE>::logtable(pageid_t max_c0_size, pageid_t internal_region_size, p
     // This bool is purely for external code.
     this->accepting_new_requests = true;
     this->shutting_down_ = false;
-    flushing = false;
+    c0_flushing = false;
+    c1_flushing = false;
     this->merge_mgr = 0;
     tmerger = new tuplemerger(&replace_merger);
 
@@ -85,8 +86,8 @@ void logtable<TUPLE>::init_stasis() {
   DataPage<datatuple>::register_stasis_page_impl();
   //stasis_buffer_manager_size = 768 * 1024; // 4GB = 2^10 pages:
   // XXX Workaround Stasis' (still broken) default concurrent buffer manager
-  stasis_buffer_manager_factory = stasis_buffer_manager_hash_factory;
-  stasis_buffer_manager_hint_writes_are_sequential = 0;
+//  stasis_buffer_manager_factory = stasis_buffer_manager_hash_factory;
+  stasis_buffer_manager_hint_writes_are_sequential = 1;
   Tinit();
 
 }
@@ -159,7 +160,7 @@ void logtable<TUPLE>::flushTable()
     start = tv_to_double(start_tv);
 
 
-    flushing = true;
+    c0_flushing = true;
     bool blocked = false;
 
     int expmcount = merge_count;
@@ -201,7 +202,7 @@ void logtable<TUPLE>::flushTable()
     } else {
       DEBUG("signaled c0-c1 merge\n");
     }
-    flushing = false;
+    c0_flushing = false;
 }
 
 template<class TUPLE>

logstore.h

@@ -124,7 +124,8 @@ public:
       if(!shutting_down_) {
         shutting_down_ = true;
         flushTable();
-        flushing = true;
+        c0_flushing = true;
+        c1_flushing = true;
       }
       rwlc_unlock(header_mut);
       // XXX must need to do other things! (join the threads?)
@@ -144,7 +145,8 @@ private:
     bool c0_is_merging;
 
 public:
-    bool flushing;
+    bool c0_flushing;
+    bool c1_flushing; // this needs to be set to true at shutdown, or when the c0-c1 merger is waiting for c1-c2 to finish its merge
 
     //DATA PAGE SETTINGS
     pageid_t internal_region_size; // in number of pages

merger.cpp

@@ -103,7 +103,7 @@ void * merge_scheduler::memMergeThread() {
 
         // needs to be past the rwlc_unlock...
         memTreeComponent<datatuple>::batchedRevalidatingIterator *itrB =
-            new memTreeComponent<datatuple>::batchedRevalidatingIterator(ltable_->get_tree_c0(), ltable_->merge_mgr, ltable_->max_c0_size, &ltable_->flushing, 100, &ltable_->rb_mut);
+            new memTreeComponent<datatuple>::batchedRevalidatingIterator(ltable_->get_tree_c0(), ltable_->merge_mgr, ltable_->max_c0_size, &ltable_->c0_flushing, 100, &ltable_->rb_mut);
 
         //: do the merge
         DEBUG("mmt:\tMerging:\n");
@@ -171,7 +171,9 @@ void * merge_scheduler::memMergeThread() {
 
             // XXX need to report backpressure here!
             while(ltable_->get_tree_c1_mergeable()) {
+                ltable_->c1_flushing = true;
                 rwlc_cond_wait(&ltable_->c1_needed, ltable_->header_mut);
+                ltable_->c1_flushing = false;
             }
 
             xid = Tbegin();
@@ -254,7 +256,7 @@ void * merge_scheduler::diskMergeThread()
         // 4: do the merge.
         //create the iterators
         diskTreeComponent::iterator *itrA = ltable_->get_tree_c2()->open_iterator();
-        diskTreeComponent::iterator *itrB = ltable_->get_tree_c1_mergeable()->open_iterator(ltable_->merge_mgr, 0.05, &ltable_->shutting_down_);
+        diskTreeComponent::iterator *itrB = ltable_->get_tree_c1_mergeable()->open_iterator(ltable_->merge_mgr, 0.05, &ltable_->c1_flushing);
 
         //create a new tree
         diskTreeComponent * c2_prime = new diskTreeComponent(xid, ltable_->internal_region_size, ltable_->datapage_region_size, ltable_->datapage_size, stats, (uint64_t)(ltable_->max_c0_size * *ltable_->R() + stats->base_size)/ 1000);

regionAllocator.h

@@ -121,6 +121,7 @@ public:
 
 
   lsn_t get_lsn(int xid) {
+    // XXX we shouldn't need to have this logic in here anymore...
     lsn_t xid_lsn = stasis_transaction_table_get((stasis_transaction_table_t*)stasis_runtime_transaction_table(), xid)->prevLSN;
     lsn_t log_lsn = ((stasis_log_t*)stasis_log())->next_available_lsn((stasis_log_t*)stasis_log());
     lsn_t ret = xid_lsn == INVALID_LSN ? log_lsn-1 : xid_lsn;