From 0c0b89a88ba6544e42cca43913ed65dea64bff3a Mon Sep 17 00:00:00 2001
From: "Mark D. Roth" <roth@google.com>
Date: Wed, 19 Apr 2017 13:28:24 -0700
Subject: [PATCH] Change hash table to use linear probing and add unit test.
 Also add some missing rules in test/core/slice/BUILD.

---
 CMakeLists.txt                                |  32 +++
 Makefile                                      |  36 ++++
 build.yaml                                    |  10 +
 src/core/lib/slice/slice_hash_table.c         |  55 +++--
 src/core/lib/slice/slice_hash_table.h         |   4 +-
 test/core/slice/BUILD                         |  23 +-
 test/core/slice/slice_hash_table_test.c       | 202 ++++++++++++++++++
 .../generated/sources_and_headers.json        |  17 ++
 tools/run_tests/generated/tests.json          |  22 ++
 vsprojects/buildtests_c.sln                   |  27 +++
 .../slice_hash_table_test.vcxproj             | 199 +++++++++++++++++
 .../slice_hash_table_test.vcxproj.filters     |  21 ++
 12 files changed, 616 insertions(+), 32 deletions(-)
 create mode 100644 test/core/slice/slice_hash_table_test.c
 create mode 100644 vsprojects/vcxproj/test/slice_hash_table_test/slice_hash_table_test.vcxproj
 create mode 100644 vsprojects/vcxproj/test/slice_hash_table_test/slice_hash_table_test.vcxproj.filters

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a6a2af65d5..230a3d1ac0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -493,6 +493,7 @@ add_dependencies(buildtests_c sequential_connectivity_test)
 add_dependencies(buildtests_c server_chttp2_test)
 add_dependencies(buildtests_c server_test)
 add_dependencies(buildtests_c slice_buffer_test)
+add_dependencies(buildtests_c slice_hash_table_test)
 add_dependencies(buildtests_c slice_string_helpers_test)
 add_dependencies(buildtests_c slice_test)
 add_dependencies(buildtests_c sockaddr_resolver_test)
@@ -8007,6 +8008,37 @@ target_link_libraries(slice_buffer_test
 endif (gRPC_BUILD_TESTS)
 if (gRPC_BUILD_TESTS)
 
+add_executable(slice_hash_table_test
+  test/core/slice/slice_hash_table_test.c
+)
+
+
+target_include_directories(slice_hash_table_test
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}
+  PRIVATE ${CMAKE_CURRENT_SOURCE_DIR}/include
+  PRIVATE ${BORINGSSL_ROOT_DIR}/include
+  PRIVATE ${PROTOBUF_ROOT_DIR}/src
+  PRIVATE ${BENCHMARK_ROOT_DIR}/include
+  PRIVATE ${ZLIB_ROOT_DIR}
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/zlib
+  PRIVATE ${CARES_BUILD_INCLUDE_DIR}
+  PRIVATE ${CARES_INCLUDE_DIR}
+  PRIVATE ${CARES_PLATFORM_INCLUDE_DIR}
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/cares/cares
+  PRIVATE ${CMAKE_CURRENT_BINARY_DIR}/third_party/gflags/include
+)
+
+target_link_libraries(slice_hash_table_test
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  grpc_test_util
+  grpc
+  gpr_test_util
+  gpr
+)
+
+endif (gRPC_BUILD_TESTS)
+if (gRPC_BUILD_TESTS)
+
 add_executable(slice_string_helpers_test
   test/core/slice/slice_string_helpers_test.c
 )
diff --git a/Makefile b/Makefile
index 8898939af9..a233f712e4 100644
--- a/Makefile
+++ b/Makefile
@@ -1073,6 +1073,7 @@ server_chttp2_test: $(BINDIR)/$(CONFIG)/server_chttp2_test
 server_fuzzer: $(BINDIR)/$(CONFIG)/server_fuzzer
 server_test: $(BINDIR)/$(CONFIG)/server_test
 slice_buffer_test: $(BINDIR)/$(CONFIG)/slice_buffer_test
+slice_hash_table_test: $(BINDIR)/$(CONFIG)/slice_hash_table_test
 slice_string_helpers_test: $(BINDIR)/$(CONFIG)/slice_string_helpers_test
 slice_test: $(BINDIR)/$(CONFIG)/slice_test
 sockaddr_resolver_test: $(BINDIR)/$(CONFIG)/sockaddr_resolver_test
@@ -1443,6 +1444,7 @@ buildtests_c: privatelibs_c \
   $(BINDIR)/$(CONFIG)/server_chttp2_test \
   $(BINDIR)/$(CONFIG)/server_test \
   $(BINDIR)/$(CONFIG)/slice_buffer_test \
+  $(BINDIR)/$(CONFIG)/slice_hash_table_test \
   $(BINDIR)/$(CONFIG)/slice_string_helpers_test \
   $(BINDIR)/$(CONFIG)/slice_test \
   $(BINDIR)/$(CONFIG)/sockaddr_resolver_test \
@@ -1915,6 +1917,8 @@ test_c: buildtests_c
 	$(Q) $(BINDIR)/$(CONFIG)/server_test || ( echo test server_test failed ; exit 1 )
 	$(E) "[RUN]     Testing slice_buffer_test"
 	$(Q) $(BINDIR)/$(CONFIG)/slice_buffer_test || ( echo test slice_buffer_test failed ; exit 1 )
+	$(E) "[RUN]     Testing slice_hash_table_test"
+	$(Q) $(BINDIR)/$(CONFIG)/slice_hash_table_test || ( echo test slice_hash_table_test failed ; exit 1 )
 	$(E) "[RUN]     Testing slice_string_helpers_test"
 	$(Q) $(BINDIR)/$(CONFIG)/slice_string_helpers_test || ( echo test slice_string_helpers_test failed ; exit 1 )
 	$(E) "[RUN]     Testing slice_test"
@@ -12349,6 +12353,38 @@ endif
 endif
 
 
+SLICE_HASH_TABLE_TEST_SRC = \
+    test/core/slice/slice_hash_table_test.c \
+
+SLICE_HASH_TABLE_TEST_OBJS = $(addprefix $(OBJDIR)/$(CONFIG)/, $(addsuffix .o, $(basename $(SLICE_HASH_TABLE_TEST_SRC))))
+ifeq ($(NO_SECURE),true)
+
+# You can't build secure targets if you don't have OpenSSL.
+
+$(BINDIR)/$(CONFIG)/slice_hash_table_test: openssl_dep_error
+
+else
+
+
+
+$(BINDIR)/$(CONFIG)/slice_hash_table_test: $(SLICE_HASH_TABLE_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+	$(E) "[LD]      Linking $@"
+	$(Q) mkdir -p `dirname $@`
+	$(Q) $(LD) $(LDFLAGS) $(SLICE_HASH_TABLE_TEST_OBJS) $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a $(LDLIBS) $(LDLIBS_SECURE) -o $(BINDIR)/$(CONFIG)/slice_hash_table_test
+
+endif
+
+$(OBJDIR)/$(CONFIG)/test/core/slice/slice_hash_table_test.o:  $(LIBDIR)/$(CONFIG)/libgrpc_test_util.a $(LIBDIR)/$(CONFIG)/libgrpc.a $(LIBDIR)/$(CONFIG)/libgpr_test_util.a $(LIBDIR)/$(CONFIG)/libgpr.a
+
+deps_slice_hash_table_test: $(SLICE_HASH_TABLE_TEST_OBJS:.o=.dep)
+
+ifneq ($(NO_SECURE),true)
+ifneq ($(NO_DEPS),true)
+-include $(SLICE_HASH_TABLE_TEST_OBJS:.o=.dep)
+endif
+endif
+
+
 SLICE_STRING_HELPERS_TEST_SRC = \
     test/core/slice/slice_string_helpers_test.c \
 
diff --git a/build.yaml b/build.yaml
index f4461e40ef..b40834e16d 100644
--- a/build.yaml
+++ b/build.yaml
@@ -2807,6 +2807,16 @@ targets:
   - grpc
   - gpr_test_util
   - gpr
+- name: slice_hash_table_test
+  build: test
+  language: c
+  src:
+  - test/core/slice/slice_hash_table_test.c
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr_test_util
+  - gpr
 - name: slice_string_helpers_test
   build: test
   language: c
diff --git a/src/core/lib/slice/slice_hash_table.c b/src/core/lib/slice/slice_hash_table.c
index 7a8b79cc33..a33f6069fd 100644
--- a/src/core/lib/slice/slice_hash_table.c
+++ b/src/core/lib/slice/slice_hash_table.c
@@ -44,6 +44,7 @@ struct grpc_slice_hash_table {
   gpr_refcount refs;
   void (*destroy_value)(grpc_exec_ctx *exec_ctx, void *value);
   size_t size;
+  size_t max_num_probes;
   grpc_slice_hash_table_entry* entries;
 };
 
@@ -51,32 +52,22 @@ static bool is_empty(grpc_slice_hash_table_entry* entry) {
   return entry->value == NULL;
 }
 
-// Helper function for insert and get operations that performs quadratic
-// probing (https://en.wikipedia.org/wiki/Quadratic_probing).
-static size_t grpc_slice_hash_table_find_index(
-    const grpc_slice_hash_table* table, const grpc_slice key, bool find_empty) {
-  size_t hash = grpc_slice_hash(key);
-  for (size_t i = 0; i < table->size; ++i) {
-    const size_t idx = (hash + i * i) % table->size;
-    if (is_empty(&table->entries[idx])) {
-      return find_empty ? idx : table->size;
-    }
-    if (grpc_slice_eq(table->entries[idx].key, key)) {
-      return idx;
-    }
-  }
-  return table->size;  // Not found.
-}
-
 static void grpc_slice_hash_table_add(grpc_slice_hash_table* table,
                                       grpc_slice key, void* value) {
   GPR_ASSERT(value != NULL);
-  const size_t idx =
-      grpc_slice_hash_table_find_index(table, key, true /* find_empty */);
-  GPR_ASSERT(idx != table->size);  // Table should never be full.
-  grpc_slice_hash_table_entry* entry = &table->entries[idx];
-  entry->key = key;
-  entry->value = value;
+  const size_t hash = grpc_slice_hash(key);
+  for (size_t offset = 0; offset < table->size; ++offset) {
+    const size_t idx = (hash + offset) % table->size;
+    if (is_empty(&table->entries[idx])) {
+      table->entries[idx].key = key;
+      table->entries[idx].value = value;
+      // Keep track of the maximum number of probes needed, since this
+      // provides an upper bound for lookups.
+      if (offset > table->max_num_probes) table->max_num_probes = offset;
+      return;
+    }
+  }
+  GPR_ASSERT(false);  // Table should never be full.
 }
 
 grpc_slice_hash_table* grpc_slice_hash_table_create(
@@ -85,8 +76,7 @@ grpc_slice_hash_table* grpc_slice_hash_table_create(
   grpc_slice_hash_table* table = gpr_zalloc(sizeof(*table));
   gpr_ref_init(&table->refs, 1);
   table->destroy_value = destroy_value;
-  // Quadratic probing gets best performance when the table is no more
-  // than half full.
+  // Keep load factor low to improve performance of lookups.
   table->size = num_entries * 2;
   const size_t entry_size = sizeof(grpc_slice_hash_table_entry) * table->size;
   table->entries = gpr_zalloc(entry_size);
@@ -119,8 +109,15 @@ void grpc_slice_hash_table_unref(grpc_exec_ctx* exec_ctx,
 
 void* grpc_slice_hash_table_get(const grpc_slice_hash_table* table,
                                 const grpc_slice key) {
-  const size_t idx =
-      grpc_slice_hash_table_find_index(table, key, false /* find_empty */);
-  if (idx == table->size) return NULL;  // Not found.
-  return table->entries[idx].value;
+  const size_t hash = grpc_slice_hash(key);
+  // We cap the number of probes at the max number recorded when
+  // populating the table.
+  for (size_t offset = 0; offset <= table->max_num_probes; ++offset) {
+    const size_t idx = (hash + offset) % table->size;
+    if (is_empty(&table->entries[idx])) break;
+    if (grpc_slice_eq(table->entries[idx].key, key)) {
+      return table->entries[idx].value;
+    }
+  }
+  return NULL;  // Not found.
 }
diff --git a/src/core/lib/slice/slice_hash_table.h b/src/core/lib/slice/slice_hash_table.h
index 81e92b6e21..1e61c5eb11 100644
--- a/src/core/lib/slice/slice_hash_table.h
+++ b/src/core/lib/slice/slice_hash_table.h
@@ -37,8 +37,8 @@
 /** Hash table implementation.
  *
  * This implementation uses open addressing
- * (https://en.wikipedia.org/wiki/Open_addressing) with quadratic
- * probing (https://en.wikipedia.org/wiki/Quadratic_probing).
+ * (https://en.wikipedia.org/wiki/Open_addressing) with linear
+ * probing (https://en.wikipedia.org/wiki/Linear_probing).
  *
  * The keys are \a grpc_slice objects.  The values are arbitrary pointers
  * with a common destroy function.
diff --git a/test/core/slice/BUILD b/test/core/slice/BUILD
index 4d64d0a818..18cf6f60af 100644
--- a/test/core/slice/BUILD
+++ b/test/core/slice/BUILD
@@ -47,12 +47,33 @@ cc_test(
 )
 
 cc_test(
-    name = "slice_buffer_test",
+    name = "slice_test",
+    srcs = ["slice_test.c"],
+    deps = ["//:grpc", "//test/core/util:grpc_test_util", "//:gpr", "//test/core/util:gpr_test_util"],
+    copts = ['-std=c99']
+)
+
+cc_test(
+    name = "slice_string_helpers_test",
     srcs = ["slice_string_helpers_test.c"],
     deps = ["//:grpc", "//test/core/util:grpc_test_util", "//:gpr", "//test/core/util:gpr_test_util"],
     copts = ['-std=c99']
 )
 
+cc_test(
+    name = "slice_buffer_test",
+    srcs = ["slice_buffer_test.c"],
+    deps = ["//:grpc", "//test/core/util:grpc_test_util", "//:gpr", "//test/core/util:gpr_test_util"],
+    copts = ['-std=c99']
+)
+
+cc_test(
+    name = "slice_hash_table_test",
+    srcs = ["slice_hash_table_test.c"],
+    deps = ["//:grpc", "//test/core/util:grpc_test_util", "//:gpr", "//test/core/util:gpr_test_util"],
+    copts = ['-std=c99']
+)
+
 cc_test(
     name = "b64_test",
     srcs = ["b64_test.c"],
diff --git a/test/core/slice/slice_hash_table_test.c b/test/core/slice/slice_hash_table_test.c
new file mode 100644
index 0000000000..24a4354b8b
--- /dev/null
+++ b/test/core/slice/slice_hash_table_test.c
@@ -0,0 +1,202 @@
+/*
+ *
+ * Copyright 2017, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "src/core/lib/slice/slice_hash_table.h"
+
+#include <string.h>
+
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+
+#include "src/core/lib/slice/slice_internal.h"
+#include "test/core/util/test_config.h"
+
+typedef struct {
+  char* key;
+  char* value;
+} test_entry;
+
+static void populate_entries(const test_entry* input, size_t num_entries,
+                             grpc_slice_hash_table_entry* output) {
+  for (size_t i = 0; i < num_entries; ++i) {
+    output[i].key = grpc_slice_from_copied_string(gpr_strdup(input[i].key));
+    output[i].value = gpr_strdup(input[i].value);
+  }
+}
+
+static void check_values(const test_entry* input, size_t num_entries,
+                         grpc_slice_hash_table* table) {
+  for (size_t i = 0; i < num_entries; ++i) {
+    grpc_slice key = grpc_slice_from_static_string(input[i].key);
+    char* actual = grpc_slice_hash_table_get(table, key);
+    GPR_ASSERT(actual != NULL);
+    GPR_ASSERT(strcmp(actual, input[i].value) == 0);
+    grpc_slice_unref(key);
+  }
+}
+
+static void check_non_existent_value(const char* key_string,
+                                     grpc_slice_hash_table* table) {
+  grpc_slice key = grpc_slice_from_static_string(key_string);
+  GPR_ASSERT(grpc_slice_hash_table_get(table, key) == NULL);
+  grpc_slice_unref(key);
+}
+
+static void destroy_string(grpc_exec_ctx* exec_ctx, void* value) {
+  gpr_free(value);
+}
+
+static void test_slice_hash_table() {
+  const test_entry test_entries[] = {
+    {"key_0", "value_0"},
+    {"key_1", "value_1"},
+    {"key_2", "value_2"},
+    {"key_3", "value_3"},
+    {"key_4", "value_4"},
+    {"key_5", "value_5"},
+    {"key_6", "value_6"},
+    {"key_7", "value_7"},
+    {"key_8", "value_8"},
+    {"key_9", "value_9"},
+    {"key_10", "value_10"},
+    {"key_11", "value_11"},
+    {"key_12", "value_12"},
+    {"key_13", "value_13"},
+    {"key_14", "value_14"},
+    {"key_15", "value_15"},
+    {"key_16", "value_16"},
+    {"key_17", "value_17"},
+    {"key_18", "value_18"},
+    {"key_19", "value_19"},
+    {"key_20", "value_20"},
+    {"key_21", "value_21"},
+    {"key_22", "value_22"},
+    {"key_23", "value_23"},
+    {"key_24", "value_24"},
+    {"key_25", "value_25"},
+    {"key_26", "value_26"},
+    {"key_27", "value_27"},
+    {"key_28", "value_28"},
+    {"key_29", "value_29"},
+    {"key_30", "value_30"},
+    {"key_31", "value_31"},
+    {"key_32", "value_32"},
+    {"key_33", "value_33"},
+    {"key_34", "value_34"},
+    {"key_35", "value_35"},
+    {"key_36", "value_36"},
+    {"key_37", "value_37"},
+    {"key_38", "value_38"},
+    {"key_39", "value_39"},
+    {"key_40", "value_40"},
+    {"key_41", "value_41"},
+    {"key_42", "value_42"},
+    {"key_43", "value_43"},
+    {"key_44", "value_44"},
+    {"key_45", "value_45"},
+    {"key_46", "value_46"},
+    {"key_47", "value_47"},
+    {"key_48", "value_48"},
+    {"key_49", "value_49"},
+    {"key_50", "value_50"},
+    {"key_51", "value_51"},
+    {"key_52", "value_52"},
+    {"key_53", "value_53"},
+    {"key_54", "value_54"},
+    {"key_55", "value_55"},
+    {"key_56", "value_56"},
+    {"key_57", "value_57"},
+    {"key_58", "value_58"},
+    {"key_59", "value_59"},
+    {"key_60", "value_60"},
+    {"key_61", "value_61"},
+    {"key_62", "value_62"},
+    {"key_63", "value_63"},
+    {"key_64", "value_64"},
+    {"key_65", "value_65"},
+    {"key_66", "value_66"},
+    {"key_67", "value_67"},
+    {"key_68", "value_68"},
+    {"key_69", "value_69"},
+    {"key_70", "value_70"},
+    {"key_71", "value_71"},
+    {"key_72", "value_72"},
+    {"key_73", "value_73"},
+    {"key_74", "value_74"},
+    {"key_75", "value_75"},
+    {"key_76", "value_76"},
+    {"key_77", "value_77"},
+    {"key_78", "value_78"},
+    {"key_79", "value_79"},
+    {"key_80", "value_80"},
+    {"key_81", "value_81"},
+    {"key_82", "value_82"},
+    {"key_83", "value_83"},
+    {"key_84", "value_84"},
+    {"key_85", "value_85"},
+    {"key_86", "value_86"},
+    {"key_87", "value_87"},
+    {"key_88", "value_88"},
+    {"key_89", "value_89"},
+    {"key_90", "value_90"},
+    {"key_91", "value_91"},
+    {"key_92", "value_92"},
+    {"key_93", "value_93"},
+    {"key_94", "value_94"},
+    {"key_95", "value_95"},
+    {"key_96", "value_96"},
+    {"key_97", "value_97"},
+    {"key_98", "value_98"},
+    {"key_99", "value_99"},
+  };
+  const size_t num_entries = GPR_ARRAY_SIZE(test_entries);
+  // Construct table.
+  grpc_slice_hash_table_entry entries[num_entries];
+  populate_entries(test_entries, num_entries, entries);
+  grpc_slice_hash_table* table =
+      grpc_slice_hash_table_create(num_entries, entries, destroy_string);
+  // Check contents of table.
+  check_values(test_entries, num_entries, table);
+  check_non_existent_value("XX", table);
+  // Clean up.
+  grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT;
+  grpc_slice_hash_table_unref(&exec_ctx, table);
+  grpc_exec_ctx_finish(&exec_ctx);
+}
+
+int main(int argc, char **argv) {
+  grpc_test_init(argc, argv);
+  test_slice_hash_table();
+  return 0;
+}
diff --git a/tools/run_tests/generated/sources_and_headers.json b/tools/run_tests/generated/sources_and_headers.json
index aa4869e1c8..9635dbec83 100644
--- a/tools/run_tests/generated/sources_and_headers.json
+++ b/tools/run_tests/generated/sources_and_headers.json
@@ -1978,6 +1978,23 @@
     "third_party": false, 
     "type": "target"
   }, 
+  {
+    "deps": [
+      "gpr", 
+      "gpr_test_util", 
+      "grpc", 
+      "grpc_test_util"
+    ], 
+    "headers": [], 
+    "is_filegroup": false, 
+    "language": "c", 
+    "name": "slice_hash_table_test", 
+    "src": [
+      "test/core/slice/slice_hash_table_test.c"
+    ], 
+    "third_party": false, 
+    "type": "target"
+  }, 
   {
     "deps": [
       "gpr", 
diff --git a/tools/run_tests/generated/tests.json b/tools/run_tests/generated/tests.json
index 6338ea7012..eb8fb20d7d 100644
--- a/tools/run_tests/generated/tests.json
+++ b/tools/run_tests/generated/tests.json
@@ -2071,6 +2071,28 @@
       "windows"
     ]
   }, 
+  {
+    "args": [], 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "gtest": false, 
+    "language": "c", 
+    "name": "slice_hash_table_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ]
+  }, 
   {
     "args": [], 
     "ci_platforms": [
diff --git a/vsprojects/buildtests_c.sln b/vsprojects/buildtests_c.sln
index 6ae8bfa74d..539f474f9e 100644
--- a/vsprojects/buildtests_c.sln
+++ b/vsprojects/buildtests_c.sln
@@ -1440,6 +1440,17 @@ Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "slice_buffer_test", "vcxpro
 		{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792} = {B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}
 	EndProjectSection
 EndProject
+Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "slice_hash_table_test", "vcxproj\test\slice_hash_table_test\slice_hash_table_test.vcxproj", "{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}"
+	ProjectSection(myProperties) = preProject
+        	lib = "False"
+	EndProjectSection
+	ProjectSection(ProjectDependencies) = postProject
+		{17BCAFC0-5FDC-4C94-AEB9-95F3E220614B} = {17BCAFC0-5FDC-4C94-AEB9-95F3E220614B}
+		{29D16885-7228-4C31-81ED-5F9187C7F2A9} = {29D16885-7228-4C31-81ED-5F9187C7F2A9}
+		{EAB0A629-17A9-44DB-B5FF-E91A721FE037} = {EAB0A629-17A9-44DB-B5FF-E91A721FE037}
+		{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792} = {B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}
+	EndProjectSection
+EndProject
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "slice_string_helpers_test", "vcxproj\test\slice_string_helpers_test\slice_string_helpers_test.vcxproj", "{419167BB-C3F5-DDEA-403A-394D1902DE65}"
 	ProjectSection(myProperties) = preProject
         	lib = "False"
@@ -3823,6 +3834,22 @@ Global
 		{F0FA4A41-5695-580A-DCDA-EC719CB041B0}.Release-DLL|Win32.Build.0 = Release|Win32
 		{F0FA4A41-5695-580A-DCDA-EC719CB041B0}.Release-DLL|x64.ActiveCfg = Release|x64
 		{F0FA4A41-5695-580A-DCDA-EC719CB041B0}.Release-DLL|x64.Build.0 = Release|x64
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Debug|Win32.ActiveCfg = Debug|Win32
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Debug|x64.ActiveCfg = Debug|x64
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Release|Win32.ActiveCfg = Release|Win32
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Release|x64.ActiveCfg = Release|x64
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Debug|Win32.Build.0 = Debug|Win32
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Debug|x64.Build.0 = Debug|x64
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Release|Win32.Build.0 = Release|Win32
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Release|x64.Build.0 = Release|x64
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Debug-DLL|Win32.ActiveCfg = Debug|Win32
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Debug-DLL|Win32.Build.0 = Debug|Win32
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Debug-DLL|x64.ActiveCfg = Debug|x64
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Debug-DLL|x64.Build.0 = Debug|x64
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Release-DLL|Win32.ActiveCfg = Release|Win32
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Release-DLL|Win32.Build.0 = Release|Win32
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Release-DLL|x64.ActiveCfg = Release|x64
+		{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}.Release-DLL|x64.Build.0 = Release|x64
 		{419167BB-C3F5-DDEA-403A-394D1902DE65}.Debug|Win32.ActiveCfg = Debug|Win32
 		{419167BB-C3F5-DDEA-403A-394D1902DE65}.Debug|x64.ActiveCfg = Debug|x64
 		{419167BB-C3F5-DDEA-403A-394D1902DE65}.Release|Win32.ActiveCfg = Release|Win32
diff --git a/vsprojects/vcxproj/test/slice_hash_table_test/slice_hash_table_test.vcxproj b/vsprojects/vcxproj/test/slice_hash_table_test/slice_hash_table_test.vcxproj
new file mode 100644
index 0000000000..0fccfdcaa5
--- /dev/null
+++ b/vsprojects/vcxproj/test/slice_hash_table_test/slice_hash_table_test.vcxproj
@@ -0,0 +1,199 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\1.0.204.1.props')" />
+  <ItemGroup Label="ProjectConfigurations">
+    <ProjectConfiguration Include="Debug|Win32">
+      <Configuration>Debug</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Debug|x64">
+      <Configuration>Debug</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|Win32">
+      <Configuration>Release</Configuration>
+      <Platform>Win32</Platform>
+    </ProjectConfiguration>
+    <ProjectConfiguration Include="Release|x64">
+      <Configuration>Release</Configuration>
+      <Platform>x64</Platform>
+    </ProjectConfiguration>
+  </ItemGroup>
+  <PropertyGroup Label="Globals">
+    <ProjectGuid>{B3BC3481-FCD3-BA52-C975-E65CDB1CE9A9}</ProjectGuid>
+    <IgnoreWarnIntDirInTempDetected>true</IgnoreWarnIntDirInTempDetected>
+    <IntDir>$(SolutionDir)IntDir\$(MSBuildProjectName)\</IntDir>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '10.0'" Label="Configuration">
+    <PlatformToolset>v100</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '11.0'" Label="Configuration">
+    <PlatformToolset>v110</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '12.0'" Label="Configuration">
+    <PlatformToolset>v120</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(VisualStudioVersion)' == '14.0'" Label="Configuration">
+    <PlatformToolset>v140</PlatformToolset>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>true</UseDebugLibraries>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'" Label="Configuration">
+    <ConfigurationType>Application</ConfigurationType>
+    <UseDebugLibraries>false</UseDebugLibraries>
+    <WholeProgramOptimization>true</WholeProgramOptimization>
+    <CharacterSet>Unicode</CharacterSet>
+  </PropertyGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
+  <ImportGroup Label="ExtensionSettings">
+  </ImportGroup>
+  <ImportGroup Label="PropertySheets">
+    <Import Project="$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props" Condition="exists('$(UserRootDir)\Microsoft.Cpp.$(Platform).user.props')" Label="LocalAppDataPlatform" />
+    <Import Project="$(SolutionDir)\..\vsprojects\global.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\openssl.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\winsock.props" />
+    <Import Project="$(SolutionDir)\..\vsprojects\zlib.props" />
+  </ImportGroup>
+  <PropertyGroup Label="UserMacros" />
+  <PropertyGroup Condition="'$(Configuration)'=='Debug'">
+    <TargetName>slice_hash_table_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Debug</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Debug</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)'=='Release'">
+    <TargetName>slice_hash_table_test</TargetName>
+    <Linkage-grpc_dependencies_zlib>static</Linkage-grpc_dependencies_zlib>
+    <Configuration-grpc_dependencies_zlib>Release</Configuration-grpc_dependencies_zlib>
+    <Linkage-grpc_dependencies_openssl>static</Linkage-grpc_dependencies_openssl>
+    <Configuration-grpc_dependencies_openssl>Release</Configuration-grpc_dependencies_openssl>
+  </PropertyGroup>
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>Disabled</Optimization>
+      <PreprocessorDefinitions>WIN32;_DEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreadedDebug</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+
+    <ItemDefinitionGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
+    <ClCompile>
+      <PrecompiledHeader>NotUsing</PrecompiledHeader>
+      <WarningLevel>Level3</WarningLevel>
+      <Optimization>MaxSpeed</Optimization>
+      <PreprocessorDefinitions>WIN32;NDEBUG;_LIB;%(PreprocessorDefinitions)</PreprocessorDefinitions>
+      <FunctionLevelLinking>true</FunctionLevelLinking>
+      <IntrinsicFunctions>true</IntrinsicFunctions>
+      <SDLCheck>true</SDLCheck>
+      <RuntimeLibrary>MultiThreaded</RuntimeLibrary>
+      <TreatWarningAsError>true</TreatWarningAsError>
+      <DebugInformationFormat Condition="$(Jenkins)">None</DebugInformationFormat>
+      <MinimalRebuild Condition="$(Jenkins)">false</MinimalRebuild>
+    </ClCompile>
+    <Link>
+      <SubSystem>Console</SubSystem>
+      <GenerateDebugInformation Condition="!$(Jenkins)">true</GenerateDebugInformation>
+      <GenerateDebugInformation Condition="$(Jenkins)">false</GenerateDebugInformation>
+      <EnableCOMDATFolding>true</EnableCOMDATFolding>
+      <OptimizeReferences>true</OptimizeReferences>
+    </Link>
+  </ItemDefinitionGroup>
+
+  <ItemGroup>
+    <ClCompile Include="$(SolutionDir)\..\test\core\slice\slice_hash_table_test.c">
+    </ClCompile>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\grpc_test_util\grpc_test_util.vcxproj">
+      <Project>{17BCAFC0-5FDC-4C94-AEB9-95F3E220614B}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\grpc\grpc.vcxproj">
+      <Project>{29D16885-7228-4C31-81ED-5F9187C7F2A9}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\gpr_test_util\gpr_test_util.vcxproj">
+      <Project>{EAB0A629-17A9-44DB-B5FF-E91A721FE037}</Project>
+    </ProjectReference>
+    <ProjectReference Include="$(SolutionDir)\..\vsprojects\vcxproj\.\gpr\gpr.vcxproj">
+      <Project>{B23D3D1A-9438-4EDA-BEB6-9A0A03D17792}</Project>
+    </ProjectReference>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+  </ItemGroup>
+  <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
+  <ImportGroup Label="ExtensionTargets">
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies\grpc.dependencies.zlib.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies\grpc.dependencies.zlib.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies\grpc.dependencies.openssl.targets')" />
+  <Import Project="$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets" Condition="Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies\grpc.dependencies.openssl.targets')" />
+  </ImportGroup>
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Enable NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.redist.1.2.8.10\build\native\grpc.dependencies.zlib.redist.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.zlib.1.2.8.10\build\native\grpc.dependencies.zlib.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.redist.1.0.204.1\build\native\grpc.dependencies.openssl.redist.targets')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.props')" />
+    <Error Condition="!Exists('$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets')" Text="$([System.String]::Format('$(ErrorText)', '$(SolutionDir)\..\vsprojects\packages\grpc.dependencies.openssl.1.0.204.1\build\native\grpc.dependencies.openssl.targets')" />
+  </Target>
+</Project>
+
diff --git a/vsprojects/vcxproj/test/slice_hash_table_test/slice_hash_table_test.vcxproj.filters b/vsprojects/vcxproj/test/slice_hash_table_test/slice_hash_table_test.vcxproj.filters
new file mode 100644
index 0000000000..1973852678
--- /dev/null
+++ b/vsprojects/vcxproj/test/slice_hash_table_test/slice_hash_table_test.vcxproj.filters
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <ItemGroup>
+    <ClCompile Include="$(SolutionDir)\..\test\core\slice\slice_hash_table_test.c">
+      <Filter>test\core\slice</Filter>
+    </ClCompile>
+  </ItemGroup>
+
+  <ItemGroup>
+    <Filter Include="test">
+      <UniqueIdentifier>{e11f5007-84da-0229-9118-2a2bb17f956c}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="test\core">
+      <UniqueIdentifier>{a11f4770-5e13-eb1a-a848-8667dde98812}</UniqueIdentifier>
+    </Filter>
+    <Filter Include="test\core\slice">
+      <UniqueIdentifier>{fb1262a8-0a70-bc85-579a-6ebfffbf25b5}</UniqueIdentifier>
+    </Filter>
+  </ItemGroup>
+</Project>
+
-- 
GitLab