fixes #5771 merge the single txnid optimization to main. single threaded write...

fixes #5771 merge the single txnid optimization to main. single threaded write performance is up 20-50% in mysql and multithreaded performance is largely unchanged.


git-svn-id: file:///svn/toku/tokudb@51108 c7de825b-a66e-492c-adef-691d508d4ae1

locktree/concurrent_tree.cc

@@ -29,6 +29,7 @@ void concurrent_tree::locked_keyrange::prepare(concurrent_tree *tree) {
     treenode *const root = &tree->m_root;
     m_tree = tree;
     m_subtree = root;
+    m_range = keyrange::get_infinite_range();
     root->mutex_lock();
 }
 
@@ -83,12 +84,6 @@ void concurrent_tree::locked_keyrange::remove(const keyrange &range) {
     }
 }
 
-uint64_t concurrent_tree::locked_keyrange::remove_all(uint64_t *mem_released) {
-    // in practice, remove_all is only okay on the root node, because you 
-    // want to remove all of the elements in the tree, not some subtree.
-    //
-    // so we lazily enforce that you are removing from a non-empty root.
-    invariant(m_subtree->is_root());
-    invariant(!m_subtree->is_empty());
-    return m_subtree->recursive_remove(mem_released);
+void concurrent_tree::locked_keyrange::remove_all(void) {
+    m_subtree->recursive_remove();
 }

locktree/concurrent_tree.h

@@ -36,11 +36,14 @@ class concurrent_tree {
         // effect: prepare to acquire a locked keyrange over the given
         //         concurrent_tree, preventing other threads from preparing
         //         until this thread either does acquire() or release().
-        // rationale: this provides the user with a serialization point
-        //            for descending / modifying the the tree.
+        // note: operations performed on a prepared keyrange are equivalent
+        //         to ones performed on an acquired keyrange over -inf, +inf.
+        // rationale: this provides the user with a serialization point for descending 
+        //            or modifying the the tree. it also proives a convenient way of
+        //            doing serializable operations on the tree.
         // There are two valid sequences of calls:
-        //  - prepare, acquire, release
-        //  - prepare, release
+        //  - prepare, acquire, [operations], release
+        //  - prepare, [operations],release
         void prepare(concurrent_tree *tree);
 
         // requires: the locked keyrange was prepare()'d
@@ -68,12 +71,9 @@ class concurrent_tree {
         // rationale: caller is responsible for only removing existing ranges
         void remove(const keyrange &range);
 
-        // effect: removes everything within this locked keyrange
-        // requires: the locked keyrange is over -inf, +inf
-        // returns: the number of nodes removed
-        // returns: *mem_released updated to the cumulative size of all keyranges destroyed
-        // rationale: we'd like a fast O(n) way of removing everything from the tree
-        uint64_t remove_all(uint64_t *mem_released);
+        // effect: removes all of the keys represented by this locked keyrange
+        // rationale: we'd like a fast way to empty out a tree
+        void remove_all(void);
 
     private:
         // the concurrent tree this locked keyrange is for

locktree/manager.cc

@@ -196,6 +196,11 @@ void locktree::manager::release_lt(locktree *lt) {
     }
 }
 
+// test-only version of lock escalation
+void locktree::manager::run_escalation_for_test(void) {
+    run_escalation();
+}
+
 // effect: escalate's the locks in each locktree
 // requires: manager's mutex is held
 void locktree::manager::run_escalation(void) {

locktree/range_buffer.cc

@@ -116,6 +116,7 @@ void range_buffer::create(void) {
     m_buf = nullptr;
     m_buf_size = 0;
     m_buf_current = 0;
+    m_num_ranges = 0;
 }
 
 void range_buffer::append(const DBT *left_key, const DBT *right_key) {
@@ -125,6 +126,19 @@ void range_buffer::append(const DBT *left_key, const DBT *right_key) {
     } else {
         append_range(left_key, right_key);
     }
+    m_num_ranges++;
+}
+
+bool range_buffer::is_empty(void) const {
+    return m_buf == nullptr;
+}
+
+uint64_t range_buffer::get_num_bytes(void) const {
+    return m_buf_current;
+}
+
+int range_buffer::get_num_ranges(void) const {
+    return m_num_ranges;
 }
 
 void range_buffer::destroy(void) {

locktree/range_buffer.h

@@ -98,12 +98,22 @@ class range_buffer {
     // if the keys are equal, then only one copy is stored.
     void append(const DBT *left_key, const DBT *right_key);
 
+    // is this range buffer empty?
+    bool is_empty(void) const;
+
+    // how many bytes are stored in this range buffer?
+    uint64_t get_num_bytes(void) const;
+
+    // how many ranges are stored in this range buffer?
+    int get_num_ranges(void) const;
+
     void destroy(void);
 
 private:
     char *m_buf;
     size_t m_buf_size;
     size_t m_buf_current;
+    int m_num_ranges;
 
     void append_range(const DBT *left_key, const DBT *right_key);
 

locktree/tests/concurrent_tree_lkr_remove_all.cc

@@ -18,13 +18,6 @@ void concurrent_tree_unit_test::test_lkr_remove_all(void) {
     const uint64_t min = 0;
     const uint64_t max = 20;
 
-    // determine how much memory should be released
-    keyrange example_keyrange;
-    example_keyrange.create(get_dbt(0), get_dbt(0));
-    const uint64_t num_elements = max + 1;
-    const uint64_t expected_mem_released = 
-        example_keyrange.get_memory_size() * num_elements;
-
     // remove_all should work regardless of how the
     // data was inserted into the tree, so we test it
     // on a tree whose elements were populated starting
@@ -44,10 +37,7 @@ void concurrent_tree_unit_test::test_lkr_remove_all(void) {
 
         // remove_all() from the locked keyrange and assert that
         // the number of elements and memory removed is correct.
-        uint64_t mem_released = 0;
-        uint64_t num_removed = lkr.remove_all(&mem_released);
-        invariant(num_removed == num_elements);
-        invariant(mem_released == expected_mem_released);
+        lkr.remove_all();
 
         invariant(lkr.m_subtree->is_empty());
         invariant(tree.is_empty());

locktree/tests/lock_request_start_pending.cc

@@ -51,7 +51,7 @@ void lock_request_unit_test::test_start_pending(void) {
     invariant(compare_dbts(nullptr, &request.m_right_key_copy, one) == 0);
 
     // release the range lock for txnid b
-    lt->remove_overlapping_locks_for_txnid(txnid_b, zero, two);
+    locktree_unit_test::locktree_test_release_lock(lt, txnid_b, zero, two);
 
     // now retry the lock requests.
     // it should transition the request to successfully complete.
@@ -60,7 +60,7 @@ void lock_request_unit_test::test_start_pending(void) {
     invariant(request.m_state == lock_request::state::COMPLETE);
     invariant(request.m_complete_r == 0);
 
-    lt->remove_overlapping_locks_for_txnid(txnid_a, one, one);
+    locktree_unit_test::locktree_test_release_lock(lt, txnid_a, one, one);
 
     request.destroy();
     mgr.release_lt(lt);

locktree/tests/lock_request_unit_test.h

@@ -8,6 +8,7 @@
 #define TOKU_LOCK_REQUEST_UNIT_TEST_H
 
 #include "test.h"
+#include "locktree_unit_test.h"
 
 #include "lock_request.h"
 
@@ -37,7 +38,7 @@ class lock_request_unit_test {
     // lt->release_locks(), not individually using lt->remove_overlapping_locks_for_txnid).
     void release_lock_and_retry_requests(locktree *lt,
             TXNID txnid, const DBT *left_key, const DBT * right_key) {
-        lt->remove_overlapping_locks_for_txnid(txnid, left_key, right_key);
+        locktree_unit_test::locktree_test_release_lock(lt, txnid, left_key, right_key);
         lock_request::retry_all_lock_requests(lt);
     }
 };

locktree/tests/locktree_conflicts.cc

@@ -77,10 +77,9 @@ void locktree_unit_test::test_conflicts(void) {
 #undef ACQUIRE_LOCK
         }
 
-        invariant(num_row_locks(lt) == 2);
         lt->remove_overlapping_locks_for_txnid(txnid_a, one, one);
         lt->remove_overlapping_locks_for_txnid(txnid_a, three, four);
-        invariant(num_row_locks(lt) == 0);
+        invariant(no_row_locks(lt));
     }
 
     mgr.release_lt(lt);

locktree/tests/locktree_overlapping_relock.cc

@@ -29,6 +29,16 @@ void locktree_unit_test::test_overlapping_relock(void) {
     int r;
     TXNID txnid_a = 1001;
 
+    // because of the single txnid optimization, there is no consolidation
+    // of read or write ranges until there is at least two txnids in
+    // the locktree. so here we add some arbitrary txnid to get a point
+    // lock [100, 100] so that the test below can expect to actually 
+    // do something. at the end of the test, we release 100, 100.
+    const TXNID the_other_txnid = 9999;
+    const DBT *hundred = get_dbt(100);
+    r = lt->acquire_write_lock(the_other_txnid, hundred, hundred, nullptr);
+    invariant(r == 0);
+
     for (int test_run = 0; test_run < 2; test_run++) {
         // test_run == 0 means test with read lock
         // test_run == 1 means test with write lock
@@ -40,19 +50,22 @@ void locktree_unit_test::test_overlapping_relock(void) {
         // ensure only [1,2] exists in the tree
         r = ACQUIRE_LOCK(txnid_a, one, one, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 1);
         r = ACQUIRE_LOCK(txnid_a, two, two, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 2);
         r = ACQUIRE_LOCK(txnid_a, one, two, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 1);
 
         struct verify_fn_obj {
+            bool saw_the_other;
             TXNID expected_txnid;
             keyrange *expected_range;
             comparator *cmp;
             bool fn(const keyrange &range, TXNID txnid) {
+                if (txnid == the_other_txnid) {
+                    invariant(!saw_the_other);
+                    saw_the_other = true;
+                    return true;
+                }
                 invariant(txnid == expected_txnid);
                 keyrange::comparison c = range.compare(cmp, *expected_range);
                 invariant(c == keyrange::comparison::EQUALS);
@@ -61,55 +74,52 @@ void locktree_unit_test::test_overlapping_relock(void) {
         } verify_fn;
         verify_fn.cmp = lt->m_cmp;
 
+#define do_verify() \
+        do { verify_fn.saw_the_other = false; locktree_iterate<verify_fn_obj>(lt, &verify_fn); } while (0)
+
         keyrange range;
         range.create(one, two);
         verify_fn.expected_txnid = txnid_a;
         verify_fn.expected_range = &range;
-        locktree_iterate<verify_fn_obj>(lt, &verify_fn);
+        do_verify();
 
         // unlocking [1,1] should remove the only range,
         // the other unlocks shoudl do nothing.
-        invariant(num_row_locks(lt) == 1);
         lt->remove_overlapping_locks_for_txnid(txnid_a, one, one);
-        invariant(num_row_locks(lt) == 0);
         lt->remove_overlapping_locks_for_txnid(txnid_a, two, two);
-        invariant(num_row_locks(lt) == 0);
         lt->remove_overlapping_locks_for_txnid(txnid_a, one, two);
-        invariant(num_row_locks(lt) == 0);
 
         // try overlapping from the right
         r = ACQUIRE_LOCK(txnid_a, one, three, nullptr);
-        invariant(num_row_locks(lt) == 1);
         r = ACQUIRE_LOCK(txnid_a, two, five, nullptr);
-        invariant(num_row_locks(lt) == 1);
         verify_fn.expected_txnid = txnid_a;
         range.create(one, five);
         verify_fn.expected_range = &range;
-        locktree_iterate<verify_fn_obj>(lt, &verify_fn);
+        do_verify();
 
         // now overlap from the left
         r = ACQUIRE_LOCK(txnid_a, zero, four, nullptr);
-        invariant(num_row_locks(lt) == 1);
         verify_fn.expected_txnid = txnid_a;
         range.create(zero, five);
         verify_fn.expected_range = &range;
-        locktree_iterate<verify_fn_obj>(lt, &verify_fn);
+        do_verify();
 
         // now relock in a range that is already dominated
         r = ACQUIRE_LOCK(txnid_a, five, five, nullptr);
-        invariant(num_row_locks(lt) == 1);
         verify_fn.expected_txnid = txnid_a;
         range.create(zero, five);
         verify_fn.expected_range = &range;
-        locktree_iterate<verify_fn_obj>(lt, &verify_fn);
+        do_verify();
 
         // release one of the locks we acquired. this should clean up the whole range.
         lt->remove_overlapping_locks_for_txnid(txnid_a, zero, four);
-        invariant(num_row_locks(lt) == 0);
 
 #undef ACQUIRE_LOCK
     }
 
+    // remove the other txnid's lock now
+    lt->remove_overlapping_locks_for_txnid(the_other_txnid, hundred, hundred);
+
     mgr.release_lt(lt);
     mgr.destroy();
 }

locktree/tests/locktree_simple_lock.cc

@@ -36,60 +36,35 @@ void locktree_unit_test::test_simple_lock(void) {
         // four txns, four points
         r = ACQUIRE_LOCK(txnid_a, one, one, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 1);
         r = ACQUIRE_LOCK(txnid_b, two, two, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 2);
         r = ACQUIRE_LOCK(txnid_c, three, three, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 3);
         r = ACQUIRE_LOCK(txnid_d, four, four, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 4);
-        lt->remove_overlapping_locks_for_txnid(txnid_a, one, one);
-        invariant(num_row_locks(lt) == 3);
-        lt->remove_overlapping_locks_for_txnid(txnid_b, two, two);
-        invariant(num_row_locks(lt) == 2);
-        lt->remove_overlapping_locks_for_txnid(txnid_c, three, three);
-        invariant(num_row_locks(lt) == 1);
-        lt->remove_overlapping_locks_for_txnid(txnid_d, four, four);
-        invariant(num_row_locks(lt) == 0);
+        locktree_test_release_lock(lt, txnid_a, one, one);
+        locktree_test_release_lock(lt, txnid_b, two, two);
+        locktree_test_release_lock(lt, txnid_c, three, three);
+        locktree_test_release_lock(lt, txnid_d, four, four);
+        invariant(no_row_locks(lt));
 
         // two txns, two ranges
         r = ACQUIRE_LOCK(txnid_c, one, two, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 1);
         r = ACQUIRE_LOCK(txnid_b, three, four, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 2);
-        lt->remove_overlapping_locks_for_txnid(txnid_c, one, two);
-        invariant(num_row_locks(lt) == 1);
-        lt->remove_overlapping_locks_for_txnid(txnid_b, three, four);
-        invariant(num_row_locks(lt) == 0);
-
-        // one txn, one range, one point
-        r = ACQUIRE_LOCK(txnid_a, two, three, nullptr);
-        invariant(r == 0);
-        invariant(num_row_locks(lt) == 1);
-        r = ACQUIRE_LOCK(txnid_a, four, four, nullptr);
-        invariant(r == 0);
-        invariant(num_row_locks(lt) == 2);
-        lt->remove_overlapping_locks_for_txnid(txnid_a, two, three);
-        invariant(num_row_locks(lt) == 1);
-        lt->remove_overlapping_locks_for_txnid(txnid_a, four, four);
-        invariant(num_row_locks(lt) == 0);
+        locktree_test_release_lock(lt, txnid_c, one, two);
+        locktree_test_release_lock(lt, txnid_b, three, four);
+        invariant(no_row_locks(lt));
 
         // two txns, one range, one point
         r = ACQUIRE_LOCK(txnid_c, three, four, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 1);
         r = ACQUIRE_LOCK(txnid_d, one, one, nullptr);
         invariant(r == 0);
-        invariant(num_row_locks(lt) == 2);
-        lt->remove_overlapping_locks_for_txnid(txnid_c, three, four);
-        invariant(num_row_locks(lt) == 1);
-        lt->remove_overlapping_locks_for_txnid(txnid_d, one, one);
-        invariant(num_row_locks(lt) == 0);
+        locktree_test_release_lock(lt, txnid_c, three, four);
+        locktree_test_release_lock(lt, txnid_d, one, one);
+        invariant(no_row_locks(lt));
 
 #undef ACQUIRE_LOCK
     }
@@ -124,7 +99,7 @@ void locktree_unit_test::test_simple_lock(void) {
 
     for (int64_t i = 0; i < num_locks; i++) {
         k.data = (void *) &keys[i];
-        lt->remove_overlapping_locks_for_txnid(txnid_a, &k, &k);
+        locktree_test_release_lock(lt, txnid_a, &k, &k);
     }
 
     toku_free(keys);

locktree/tests/locktree_single_txnid_optimization.cc

@@ -58,20 +58,10 @@ void locktree_unit_test::test_single_txnid_optimization(void) {
         lock_and_append_point_for_txnid_a(zero);
         maybe_point_locks_for_txnid_b(2);
 
-        // txnid b does not take a lock on iteration 3
-        if (where != 3) {
-            invariant(num_row_locks(lt) == 4);
-        } else {
-            invariant(num_row_locks(lt) == 3);
-        }
-
-
         lt->release_locks(txnid_a, &buffer);
 
         // txnid b does not take a lock on iteration 3
         if (where != 3) {
-            invariant(num_row_locks(lt) == 1);
-
             struct verify_fn_obj {
                 TXNID expected_txnid;
                 keyrange *expected_range;

locktree/tests/locktree_unit_test.h

@@ -56,20 +56,19 @@ class locktree_unit_test {
         ltr.release();
     }
 
-    static size_t num_row_locks(const locktree *lt) {
-        struct count_fn_obj {
-            size_t count;
-            bool fn(const keyrange &range, TXNID txnid) {
-                (void) range;
-                (void) txnid;
-                count++;
-                return true;
+    static bool no_row_locks(const locktree *lt) {
+        return lt->m_rangetree->is_empty() && lt->m_sto_buffer.is_empty();
     }
-        } count_fn;
-        count_fn.count = 0;
-        locktree_iterate<count_fn_obj>(lt, &count_fn);
-        return count_fn.count;
+
+    static void locktree_test_release_lock(locktree *lt, TXNID txnid, const DBT *left_key, const DBT *right_key) {
+        range_buffer buffer;
+        buffer.create();
+        buffer.append(left_key, right_key);
+        lt->release_locks(txnid, &buffer);
+        buffer.destroy();
     }
+
+    friend class lock_request_unit_test;
 };
 
 } /* namespace toku */

locktree/treenode.cc

@@ -266,31 +266,23 @@ treenode *treenode::remove_root_of_subtree() {
     return this;
 }
 
-uint64_t treenode::recursive_remove(uint64_t *mem_released) {
-    // remove left and right subtrees
-    uint64_t nodes_removed = 0;
-
+void treenode::recursive_remove(void) {
     treenode *left = m_left_child.ptr;
     if (left) {
-        nodes_removed += left->recursive_remove(mem_released);
+        left->recursive_remove();
     }
     m_left_child.set(nullptr);
 
     treenode *right = m_right_child.ptr;
     if (right) {
-        nodes_removed += right->recursive_remove(mem_released);
+        right->recursive_remove();
     }
     m_right_child.set(nullptr);
 
-    // note the amount of memory to-be released by this node
-    if (mem_released) {
-        *mem_released += m_range.get_memory_size();
-    }
     // we do not take locks on the way down, so we know non-root nodes
     // are unlocked here and the caller is required to pass a locked
     // root, so this free is correct.
     treenode::free(this);
-    return nodes_removed + 1;
 }
 
 treenode *treenode::remove(const keyrange &range) {

locktree/treenode.h

@@ -86,10 +86,7 @@ class treenode {
 
     // effect: removes this node and all of its children, recursively
     // requires: every node at and below this node is unlocked
-    // returns: the number of nodes removed
-    // returns: *mem_released is the total amount of keyrange memory released.
-    //          mem_released does not account for treenode insertion overhead.
-    uint64_t recursive_remove(uint64_t *mem_released);
+    void recursive_remove(void);
 
 private:
 

src/tests/CMakeLists.txt

@@ -343,7 +343,9 @@ if(BUILD_TESTING OR BUILD_SRC_TESTS)
     # libtokudb.so.
     # We link the test with util directly so that the test code itself can use
     # some of those things (i.e. kibbutz in the threaded tests).
-    target_link_libraries(${base}.tdb util ${LIBTOKUDB} ${LIBTOKUPORTABILITY})
+    # We link the locktree so that threaded stress tests can call some
+    # functions (ie: lock escalation) directly. 
+    target_link_libraries(${base}.tdb util locktree ${LIBTOKUDB} ${LIBTOKUPORTABILITY})
     set_property(TARGET ${base}.tdb APPEND PROPERTY
       COMPILE_DEFINITIONS "ENVDIR=\"dir.${bin}\";USE_TDB;IS_TDB=1;TOKUDB=1")
     set_property(DIRECTORY APPEND PROPERTY ADDITIONAL_MAKE_CLEAN_FILES "dir.${bin}")
@@ -378,7 +380,7 @@ if(BUILD_TESTING OR BUILD_SRC_TESTS)
 
   function(add_custom_executable prefix binary source)
     add_executable(${prefix}_${binary} ${source})
-    target_link_libraries(${prefix}_${binary} util ${LIBTOKUDB} ${LIBTOKUPORTABILITY})
+    target_link_libraries(${prefix}_${binary} util locktree ${LIBTOKUDB} ${LIBTOKUPORTABILITY})
     set_target_properties(${prefix}_${binary} PROPERTIES
       COMPILE_DEFINITIONS "ENVDIR=\"dir.${prefix}_${source}.tdb\";USE_TDB;IS_TDB=1;TOKUDB=1")
     set_property(DIRECTORY APPEND PROPERTY ADDITIONAL_MAKE_CLEAN_FILES "dir.${prefix}_${source}.tdb")

src/tests/test_stress0.cc

@@ -40,9 +40,18 @@ stress_table(DB_ENV *env, DB **dbp, struct cli_args *cli_args) {
     myargs[0].operation_extra = &soe[0];
     myargs[0].operation = scan_op;
 
+    // make the lock escalation thread.
+    // it should sleep somewhere between 10 and 20
+    // seconds between each escalation.
+    struct lock_escalation_op_extra eoe;
+    eoe.min_sleep_time_micros = 10UL * (1000 * 1000);
+    eoe.max_sleep_time_micros = 20UL * (1000 * 1000);
+    myargs[1].operation_extra = &eoe;
+    myargs[1].operation = lock_escalation_op;
+
     // make the threads that update the db
     struct update_op_args uoe = get_update_op_args(cli_args, NULL);
-    for (int i = 1; i < 1 + cli_args->num_update_threads; ++i) {
+    for (int i = 2; i < 2 + cli_args->num_update_threads; ++i) {
         myargs[i].operation_extra = &uoe;
         myargs[i].operation = update_op;
         myargs[i].do_prepare = false;
@@ -50,7 +59,7 @@ stress_table(DB_ENV *env, DB **dbp, struct cli_args *cli_args) {
         // doing sequential updates. the rest of the threads
         // will take point write locks on update as usual.
         // this ensures both ranges and points are stressed.
-        myargs[i].prelock_updates = i < 4 ? true : false;
+        myargs[i].prelock_updates = i < 5 ? true : false;
     }
 
     run_workers(myargs, num_threads, cli_args->num_seconds, false, cli_args);

src/tests/threaded_stress_test_helpers.h

@@ -34,6 +34,8 @@
 #include <util/rwlock.h>
 #include <util/kibbutz.h>
 
+#include <src/ydb-internal.h>
+
 #include <ft/ybt.h>
 
 using namespace toku;
@@ -888,6 +890,27 @@ static int UU() verify_op(DB_TXN* UU(txn), ARG UU(arg), void* UU(operation_extra
     return r;
 }
 
+struct lock_escalation_op_extra {
+    // sleep somewhere between these times before running escalation.
+    // this will add some chaos into the mix.
+    uint64_t min_sleep_time_micros;
+    uint64_t max_sleep_time_micros;
+};
+
+static int UU() lock_escalation_op(DB_TXN *UU(txn), ARG arg, void* operation_extra, void *UU(stats_extra)) {
+    struct lock_escalation_op_extra *CAST_FROM_VOIDP(extra, operation_extra);
+    if (extra->max_sleep_time_micros > 0) {
+        invariant(extra->max_sleep_time_micros >= extra->min_sleep_time_micros);
+        uint64_t extra_sleep_time = (extra->max_sleep_time_micros - extra->min_sleep_time_micros) + 1;
+        uint64_t sleep_time = extra->min_sleep_time_micros + (myrandom_r(arg->random_data) % extra_sleep_time);
+        usleep(sleep_time);
+    }
+    if (!arg->cli->nolocktree) {
+        toku_env_run_lock_escalation_for_test(arg->env);
+    }
+    return 0;
+}
+
 static int UU() scan_op(DB_TXN *txn, ARG UU(arg), void* operation_extra, void *UU(stats_extra)) {
     struct scan_op_extra* CAST_FROM_VOIDP(extra, operation_extra);
     for (int i = 0; run_test && i < arg->cli->num_DBs; i++) {

src/ydb-internal.h

@@ -95,6 +95,12 @@ struct __toku_db_env_internal {
     int tmpdir_lockfd;
 };
 
+// test-only environment function for running lock escalation
+static inline void toku_env_run_lock_escalation_for_test(DB_ENV *env) {
+    toku::locktree::manager *mgr = &env->i->ltm;
+    mgr->run_escalation_for_test();
+}
+
 // Common error handling macros and panic detection
 #define MAYBE_RETURN_ERROR(cond, status) if (cond) return status;
 #define HANDLE_PANICKED_ENV(env) if (toku_env_is_panicked(env)) { sleep(1); return EINVAL; }