[t:5106] closes #5106 Replaced txn omt (in FT) with integer

git-svn-id: file:///svn/toku/tokudb@44754 c7de825b-a66e-492c-adef-691d508d4ae1

ft/ft-internal.h

@@ -445,14 +445,14 @@ struct ft {
     TXNID txnid_that_created_or_locked_when_empty;
     TXNID txnid_that_suppressed_recovery_logs;
 
-    // Logically the reference count is zero if live_ft_handles is empty, txns is empty, and pinned_by_checkpoint is false.
+    // Logically the reference count is zero if live_ft_handles is empty, txns is 0, and pinned_by_checkpoint is false.
 
     // ft_ref_lock protects modifying live_ft_handles, txns, and pinned_by_checkpoint.
     toku_mutex_t ft_ref_lock;     
     struct toku_list live_ft_handles;
-    // transactions that are using this header.  you should only be able
-    // to modify this if you have a valid handle in the list of live brts
-    OMT txns;
+    // Number of transactions that are using this FT.  you should only be able
+    // to modify this if you have a valid handle in live_ft_handles
+    uint32_t num_txns;
     // A checkpoint is running.  If true, then keep this header around for checkpoint, like a transaction
     bool pinned_by_checkpoint;
 

ft/ft-serialize.c

@@ -158,8 +158,6 @@ deserialize_ft_versioned(int fd, struct rbuf *rb, FT *ftp, uint32_t version)
     ft->panic = 0;
     ft->panic_string = 0;
     toku_list_init(&ft->live_ft_handles);
-    r = toku_omt_create(&ft->txns);
-    assert_zero(r);
 
     //version MUST be in network order on disk regardless of disk order
     ft->layout_version_read_from_disk = rbuf_network_int(rb);

ft/ft.c

@@ -41,7 +41,6 @@ ft_destroy(FT ft) {
     if (ft->cmp_descriptor.dbt.data) toku_free(ft->cmp_descriptor.dbt.data);
     toku_ft_destroy_treelock(ft);
     toku_ft_destroy_reflock(ft);
-    toku_omt_destroy(&ft->txns);
     toku_free(ft->h);
 }
 
@@ -385,8 +384,6 @@ ft_init(FT ft, FT_OPTIONS options, CACHEFILE cf) {
     ft->layout_version_read_from_disk = FT_LAYOUT_VERSION;             // fake, prevent unnecessary upgrade logic
 
     toku_list_init(&ft->live_ft_handles);
-    int r = toku_omt_create(&ft->txns);
-    assert_zero(r);
 
     ft->compare_fun = options->compare_fun;
     ft->update_fun = options->update_fun;
@@ -397,6 +394,7 @@ ft_init(FT ft, FT_OPTIONS options, CACHEFILE cf) {
     ft->cf = cf;
     ft->in_memory_stats = ZEROSTATS;
 
+    int r;
     r = setup_initial_ft_root_node(ft, ft->h->root_blocknum);
     if (r != 0) {
         goto exit;
@@ -550,9 +548,8 @@ toku_ft_note_ft_handle_open(FT ft, FT_HANDLE live) {
 static int
 ft_get_reference_count(FT ft) {
     u_int32_t pinned_by_checkpoint = ft->pinned_by_checkpoint ? 1 : 0;
-    u_int32_t num_txns = toku_omt_size(ft->txns);
     int num_handles = toku_list_num_elements_est(&ft->live_ft_handles);
-    return pinned_by_checkpoint + num_txns + num_handles;
+    return pinned_by_checkpoint + ft->num_txns + num_handles;
 }
 
 // a ft is needed in memory iff its reference count is non-zero
@@ -842,40 +839,23 @@ cleanup:
     return r;
 }
 
-//Heaviside function to find a TOKUTXN by TOKUTXN (used to find the index)
-static int find_xid (OMTVALUE v, void *txnv) {
-    TOKUTXN txn = v;
-    TOKUTXN txnfind = txnv;
-    if (txn->txnid64<txnfind->txnid64) return -1;
-    if (txn->txnid64>txnfind->txnid64) return +1;
-    return 0;
-}
-
 // Insert reference to transaction into ft
 void
-toku_ft_add_txn_ref(FT ft, TOKUTXN txn) {
+toku_ft_add_txn_ref(FT ft) {
     toku_ft_grab_reflock(ft);
-    uint32_t idx;
-    int r = toku_omt_insert(ft->txns, txn, find_xid, txn, &idx);
-    assert(r==0);
+    ++ft->num_txns;
     toku_ft_release_reflock(ft);
 }
 
 static void
-remove_txn_ref_callback(FT ft, void *context) {
-    TOKUTXN txn = context;
-    OMTVALUE txnv_again=NULL;
-    u_int32_t index;
-    int r = toku_omt_find_zero(ft->txns, find_xid, txn, &txnv_again, &index);
-    assert(r==0);
-    assert(txnv_again == txn);
-    r = toku_omt_delete_at(ft->txns, index);
-    assert(r==0);
+remove_txn_ref_callback(FT ft, void *UU(context)) {
+    invariant(ft->num_txns > 0);
+    --ft->num_txns;
 }
 
 void
-toku_ft_remove_txn_ref(FT ft, TOKUTXN txn) {
-    toku_ft_remove_reference(ft, false, ZERO_LSN, remove_txn_ref_callback, txn);
+toku_ft_remove_txn_ref(FT ft) {
+    toku_ft_remove_reference(ft, false, ZERO_LSN, remove_txn_ref_callback, NULL);
 }
 
 void toku_calculate_root_offset_pointer (

ft/ft.h

@@ -70,10 +70,8 @@ void toku_reset_root_xid_that_created(FT h, TXNID new_root_xid_that_created);
 // This redefines which xid created the dictionary.
 
 
-void
-toku_ft_add_txn_ref(FT h, TOKUTXN txn);
-void
-toku_ft_remove_txn_ref(FT h, TOKUTXN txn);
+void toku_ft_add_txn_ref(FT h);
+void toku_ft_remove_txn_ref(FT h);
 
 void toku_calculate_root_offset_pointer ( FT h, CACHEKEY* root_key, u_int32_t *roothash);
 void toku_ft_set_new_root_blocknum(FT h, CACHEKEY new_root_key); 

ft/rollback.c

@@ -154,7 +154,7 @@ void toku_txn_maybe_note_ft (TOKUTXN txn, FT ft) {
     assert_zero(r);
     // TODO(leif): if there's anything that locks the reflock and then
     // the txn lock, this may deadlock, because it grabs the reflock.
-    toku_ft_add_txn_ref(ft, txn);
+    toku_ft_add_txn_ref(ft);
 exit:
     toku_txn_unlock(txn);
 }

ft/txn.c

@@ -414,7 +414,7 @@ static int remove_txn (OMTVALUE hv, u_int32_t UU(idx), void *txnv)
     if (txn->txnid64==h->txnid_that_suppressed_recovery_logs) {
         h->txnid_that_suppressed_recovery_logs = TXNID_NONE;
     }
-    toku_ft_remove_txn_ref(h, txn);
+    toku_ft_remove_txn_ref(h);
 
     return 0;
 }