Add new test case and amended assertion to repro issue #467

Rework large_inserts_bugs_stress test to generate assertion failure.

This commit slightly enhances do_inserts_n_threads() in this
test case to cajole an assertion seen from BTree split code, or
thereabouts:

OS-pid=1839020, Thread-ID=5, Assertion failed at src/trunk.c:5521:trunk_split_leaf(): "(num_leaves + trunk_num_pivot_keys(spl, parent) <= spl->cfg.max_pivot_keys)". num_leaves=6, trunk_num_pivot_keys()=9, cfg.max_pivot_keys=14

The changes are:
- Provide options to use same / diff start-key for each thread.
- Increase TEST_KEY_SIZE to 30 and TEST_VALUE_SIZE to 256 bytes.
- Provide an option to either generate sequential values or to
  use fully-packed values for each key. The latter seems to be
  the condition that triggers this assertion.

Many diff variations of test cases are provided in this one large
framework. See large_inserts_bugs_stress_test --list for names of
individual test cases.

Makefile

@@ -39,7 +39,7 @@ TESTSRC := $(COMMON_TESTSRC) $(FUNCTIONAL_TESTSRC) $(UNIT_TESTSRC)
 #    run as fast as it can.
 #  - Skip tests that are to be invoked with specialized command-line arguments.
 # These skipped tests which will have to be run stand-alone.
-FAST_UNIT_TESTSRC := $(shell find $(UNIT_TESTSDIR) -name "*.c" | egrep -v -e"splinter_test|config_parse_test")
+FAST_UNIT_TESTSRC := $(shell find $(UNIT_TESTSDIR) -name "*.c" | egrep -v -e"splinter_test|config_parse_test|large_inserts_bugs_stress")
 
 EXAMPLES_SRC := $(shell find $(EXAMPLES_DIR) -name "*.c")
 
@@ -428,6 +428,10 @@ $(BINDIR)/$(UNITDIR)/task_system_test: $(UTIL_SYS)
                                        $(OBJDIR)/$(FUNCTIONAL_TESTSDIR)/test_async.o \
                                        $(LIBDIR)/libsplinterdb.so
 
+$(BINDIR)/$(UNITDIR)/large_inserts_bugs_stress_test: $(UTIL_SYS)                                   \
+                                                     $(OBJDIR)/$(TESTS_DIR)/config.o \
+                                                     $(LIBDIR)/libsplinterdb.so
+
 ########################################
 # Convenience mini unit-test targets
 unit/util_test:                    $(BINDIR)/$(UNITDIR)/util_test

src/trunk.c

@@ -5426,8 +5426,13 @@ trunk_split_leaf(trunk_handle *spl,
    key_buffer_init_from_key(
       &scratch->pivot[num_leaves], spl->heap_id, trunk_max_key(spl, leaf));
 
-   platform_assert(num_leaves + trunk_num_pivot_keys(spl, parent)
-                   <= spl->cfg.max_pivot_keys);
+   platform_assert((num_leaves + trunk_num_pivot_keys(spl, parent)
+                    <= spl->cfg.max_pivot_keys),
+                   "num_leaves=%u, trunk_num_pivot_keys()=%u"
+                   ", cfg.max_pivot_keys=%lu\n",
+                   num_leaves,
+                   trunk_num_pivot_keys(spl, parent),
+                   spl->cfg.max_pivot_keys);
 
    /*
     * 3. Clear old bundles from leaf and put all branches in a new bundle

tests/config.c

@@ -35,6 +35,7 @@
 // Configs that are usually changed by different tests
 #define TEST_CONFIG_DEFAULT_SEED        0
 #define TEST_CONFIG_DEFAULT_NUM_INSERTS 0
+#define TEST_CONFIG_DEFAULT_NUM_THREADS 8
 
 // clang-format off
 void
@@ -65,6 +66,7 @@ config_set_defaults(master_config *cfg)
       .max_key_size                 = TEST_CONFIG_DEFAULT_KEY_SIZE,
       .message_size             = TEST_CONFIG_DEFAULT_MESSAGE_SIZE,
       .num_inserts              = TEST_CONFIG_DEFAULT_NUM_INSERTS,
+      .num_threads              = TEST_CONFIG_DEFAULT_NUM_THREADS,
       .seed                     = TEST_CONFIG_DEFAULT_SEED,
    };
 }
@@ -276,6 +278,7 @@ config_parse(master_config *cfg, const uint8 num_config, int argc, char *argv[])
          // Test-execution configuration parameters
          config_set_uint64("seed", cfg, seed) {}
          config_set_uint64("num-inserts", cfg, num_inserts) {}
+         config_set_uint64("num-threads", cfg, num_threads) {}
 
          config_set_else
          {

tests/config.h

@@ -88,6 +88,7 @@ typedef struct master_config {
    // Test-execution configuration parameters
    uint64 seed;
    uint64 num_inserts;
+   uint64 num_threads;
 } master_config;