Merge pull request #24431 from ZhenLian/zhen_dynamic_file_reloading_4

Add an API to get Timestamp of a File with stat(2) in gpr

BUILD

@@ -534,6 +534,8 @@ grpc_cc_library(
         "src/core/lib/gprpp/global_config_env.cc",
         "src/core/lib/gprpp/host_port.cc",
         "src/core/lib/gprpp/mpscq.cc",
+        "src/core/lib/gprpp/stat_posix.cc",
+        "src/core/lib/gprpp/stat_windows.cc",
         "src/core/lib/gprpp/thd_posix.cc",
         "src/core/lib/gprpp/thd_windows.cc",
         "src/core/lib/profiling/basic_timers.cc",
@@ -567,6 +569,7 @@ grpc_cc_library(
         "src/core/lib/gprpp/map.h",
         "src/core/lib/gprpp/memory.h",
         "src/core/lib/gprpp/mpscq.h",
+        "src/core/lib/gprpp/stat.h",
         "src/core/lib/gprpp/sync.h",
         "src/core/lib/gprpp/thd.h",
         "src/core/lib/profiling/timers.h",
@@ -574,6 +577,7 @@ grpc_cc_library(
     external_deps = [
         "absl/base",
         "absl/memory",
+        "absl/status",
         "absl/strings",
         "absl/strings:str_format",
         "absl/synchronization",

BUILD.gn

@@ -161,6 +161,9 @@ config("grpc_config") {
         "src/core/lib/gprpp/memory.h",
         "src/core/lib/gprpp/mpscq.cc",
         "src/core/lib/gprpp/mpscq.h",
+        "src/core/lib/gprpp/stat.h",
+        "src/core/lib/gprpp/stat_posix.cc",
+        "src/core/lib/gprpp/stat_windows.cc",
         "src/core/lib/gprpp/sync.h",
         "src/core/lib/gprpp/thd.h",
         "src/core/lib/gprpp/thd_posix.cc",
@@ -174,6 +177,7 @@ config("grpc_config") {
         ":absl/synchronization:synchronization",
         ":absl/strings:strings",
         ":absl/strings:str_format",
+        ":absl/status:status",
         ":absl/memory:memory",
         ":absl/base:base",
     ]

CMakeLists.txt

@@ -896,6 +896,7 @@ if(gRPC_BUILD_TESTS)
   add_dependencies(buildtests_cxx settings_timeout_test)
   add_dependencies(buildtests_cxx shutdown_test)
   add_dependencies(buildtests_cxx simple_request_bad_client_test)
+  add_dependencies(buildtests_cxx stat_test)
   add_dependencies(buildtests_cxx static_metadata_test)
   add_dependencies(buildtests_cxx stats_test)
   add_dependencies(buildtests_cxx status_metadata_test)
@@ -1311,6 +1312,8 @@ add_library(gpr
   src/core/lib/gprpp/global_config_env.cc
   src/core/lib/gprpp/host_port.cc
   src/core/lib/gprpp/mpscq.cc
+  src/core/lib/gprpp/stat_posix.cc
+  src/core/lib/gprpp/stat_windows.cc
   src/core/lib/gprpp/thd_posix.cc
   src/core/lib/gprpp/thd_windows.cc
   src/core/lib/profiling/basic_timers.cc
@@ -1351,6 +1354,7 @@ target_link_libraries(gpr
   absl::synchronization
   absl::strings
   absl::str_format
+  absl::status
   absl::memory
   absl::base
 )
@@ -14240,6 +14244,45 @@ target_link_libraries(simple_request_bad_client_test
 )
 
 
+endif()
+if(gRPC_BUILD_TESTS)
+
+add_executable(stat_test
+  test/core/gprpp/stat_test.cc
+  third_party/googletest/googletest/src/gtest-all.cc
+  third_party/googletest/googlemock/src/gmock-all.cc
+)
+
+target_include_directories(stat_test
+  PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/include
+    ${_gRPC_ADDRESS_SORTING_INCLUDE_DIR}
+    ${_gRPC_RE2_INCLUDE_DIR}
+    ${_gRPC_SSL_INCLUDE_DIR}
+    ${_gRPC_UPB_GENERATED_DIR}
+    ${_gRPC_UPB_GRPC_GENERATED_DIR}
+    ${_gRPC_UPB_INCLUDE_DIR}
+    ${_gRPC_ZLIB_INCLUDE_DIR}
+    third_party/googletest/googletest/include
+    third_party/googletest/googletest
+    third_party/googletest/googlemock/include
+    third_party/googletest/googlemock
+    ${_gRPC_PROTO_GENS_DIR}
+)
+
+target_link_libraries(stat_test
+  ${_gRPC_PROTOBUF_LIBRARIES}
+  ${_gRPC_ALLTARGETS_LIBRARIES}
+  grpc_test_util
+  grpc
+  gpr
+  address_sorting
+  upb
+  ${_gRPC_GFLAGS_LIBRARIES}
+)
+
+
 endif()
 if(gRPC_BUILD_TESTS)
 
@@ -16102,7 +16145,7 @@ generate_pkgconfig(
   "gRPC platform support library"
   "${gRPC_CORE_VERSION}"
   ""
-  "-lgpr -labsl_str_format_internal -labsl_bad_optional_access -labsl_synchronization -labsl_graphcycles_internal -labsl_symbolize -labsl_demangle_internal -labsl_stacktrace -labsl_debugging_internal -labsl_malloc_internal -labsl_time -labsl_time_zone -labsl_civil_time -labsl_strings -labsl_strings_internal -labsl_throw_delegate -labsl_int128 -labsl_base -labsl_spinlock_wait -labsl_raw_logging_internal -labsl_log_severity"
+  "-lgpr -labsl_status -labsl_cord -labsl_str_format_internal -labsl_bad_optional_access -labsl_synchronization -labsl_graphcycles_internal -labsl_symbolize -labsl_demangle_internal -labsl_stacktrace -labsl_debugging_internal -labsl_malloc_internal -labsl_time -labsl_time_zone -labsl_civil_time -labsl_strings -labsl_strings_internal -labsl_throw_delegate -labsl_int128 -labsl_base -labsl_spinlock_wait -labsl_raw_logging_internal -labsl_log_severity"
   ""
   "gpr.pc")
 

Makefile

@@ -1746,6 +1746,8 @@ LIBGPR_SRC = \
     src/core/lib/gprpp/global_config_env.cc \
     src/core/lib/gprpp/host_port.cc \
     src/core/lib/gprpp/mpscq.cc \
+    src/core/lib/gprpp/stat_posix.cc \
+    src/core/lib/gprpp/stat_windows.cc \
     src/core/lib/gprpp/thd_posix.cc \
     src/core/lib/gprpp/thd_windows.cc \
     src/core/lib/profiling/basic_timers.cc \

build_autogenerated.yaml

@@ -305,6 +305,7 @@ libs:
   - src/core/lib/gprpp/map.h
   - src/core/lib/gprpp/memory.h
   - src/core/lib/gprpp/mpscq.h
+  - src/core/lib/gprpp/stat.h
   - src/core/lib/gprpp/sync.h
   - src/core/lib/gprpp/thd.h
   - src/core/lib/profiling/timers.h
@@ -346,6 +347,8 @@ libs:
   - src/core/lib/gprpp/global_config_env.cc
   - src/core/lib/gprpp/host_port.cc
   - src/core/lib/gprpp/mpscq.cc
+  - src/core/lib/gprpp/stat_posix.cc
+  - src/core/lib/gprpp/stat_windows.cc
   - src/core/lib/gprpp/thd_posix.cc
   - src/core/lib/gprpp/thd_windows.cc
   - src/core/lib/profiling/basic_timers.cc
@@ -355,6 +358,7 @@ libs:
   - absl/synchronization:synchronization
   - absl/strings:strings
   - absl/strings:str_format
+  - absl/status:status
   - absl/memory:memory
   - absl/base:base
   secure: false
@@ -7326,6 +7330,20 @@ targets:
   corpus_dirs:
   - test/core/security/corpus/ssl_server_corpus
   maxlen: 2048
+- name: stat_test
+  gtest: true
+  build: test
+  language: c++
+  headers: []
+  src:
+  - test/core/gprpp/stat_test.cc
+  deps:
+  - grpc_test_util
+  - grpc
+  - gpr
+  - address_sorting
+  - upb
+  uses_polling: false
 - name: static_metadata_test
   gtest: true
   build: test

config.m4

@@ -376,6 +376,8 @@ if test "$PHP_GRPC" != "no"; then
     src/core/lib/gprpp/global_config_env.cc \
     src/core/lib/gprpp/host_port.cc \
     src/core/lib/gprpp/mpscq.cc \
+    src/core/lib/gprpp/stat_posix.cc \
+    src/core/lib/gprpp/stat_windows.cc \
     src/core/lib/gprpp/thd_posix.cc \
     src/core/lib/gprpp/thd_windows.cc \
     src/core/lib/http/format_request.cc \

config.w32

@@ -343,6 +343,8 @@ if (PHP_GRPC != "no") {
     "src\\core\\lib\\gprpp\\global_config_env.cc " +
     "src\\core\\lib\\gprpp\\host_port.cc " +
     "src\\core\\lib\\gprpp\\mpscq.cc " +
+    "src\\core\\lib\\gprpp\\stat_posix.cc " +
+    "src\\core\\lib\\gprpp\\stat_windows.cc " +
     "src\\core\\lib\\gprpp\\thd_posix.cc " +
     "src\\core\\lib\\gprpp\\thd_windows.cc " +
     "src\\core\\lib\\http\\format_request.cc " +

gRPC-C++.podspec

@@ -507,6 +507,7 @@ Pod::Spec.new do |s|
                       'src/core/lib/gprpp/orphanable.h',
                       'src/core/lib/gprpp/ref_counted.h',
                       'src/core/lib/gprpp/ref_counted_ptr.h',
+                      'src/core/lib/gprpp/stat.h',
                       'src/core/lib/gprpp/sync.h',
                       'src/core/lib/gprpp/thd.h',
                       'src/core/lib/http/format_request.h',
@@ -1107,6 +1108,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/gprpp/orphanable.h',
                               'src/core/lib/gprpp/ref_counted.h',
                               'src/core/lib/gprpp/ref_counted_ptr.h',
+                              'src/core/lib/gprpp/stat.h',
                               'src/core/lib/gprpp/sync.h',
                               'src/core/lib/gprpp/thd.h',
                               'src/core/lib/http/format_request.h',

gRPC-Core.podspec

@@ -834,6 +834,9 @@ Pod::Spec.new do |s|
                       'src/core/lib/gprpp/orphanable.h',
                       'src/core/lib/gprpp/ref_counted.h',
                       'src/core/lib/gprpp/ref_counted_ptr.h',
+                      'src/core/lib/gprpp/stat.h',
+                      'src/core/lib/gprpp/stat_posix.cc',
+                      'src/core/lib/gprpp/stat_windows.cc',
                       'src/core/lib/gprpp/sync.h',
                       'src/core/lib/gprpp/thd.h',
                       'src/core/lib/gprpp/thd_posix.cc',
@@ -1631,6 +1634,7 @@ Pod::Spec.new do |s|
                               'src/core/lib/gprpp/orphanable.h',
                               'src/core/lib/gprpp/ref_counted.h',
                               'src/core/lib/gprpp/ref_counted_ptr.h',
+                              'src/core/lib/gprpp/stat.h',
                               'src/core/lib/gprpp/sync.h',
                               'src/core/lib/gprpp/thd.h',
                               'src/core/lib/http/format_request.h',

grpc.gemspec

@@ -752,6 +752,9 @@ Gem::Specification.new do |s|
   s.files += %w( src/core/lib/gprpp/orphanable.h )
   s.files += %w( src/core/lib/gprpp/ref_counted.h )
   s.files += %w( src/core/lib/gprpp/ref_counted_ptr.h )
+  s.files += %w( src/core/lib/gprpp/stat.h )
+  s.files += %w( src/core/lib/gprpp/stat_posix.cc )
+  s.files += %w( src/core/lib/gprpp/stat_windows.cc )
   s.files += %w( src/core/lib/gprpp/sync.h )
   s.files += %w( src/core/lib/gprpp/thd.h )
   s.files += %w( src/core/lib/gprpp/thd_posix.cc )

grpc.gyp

@@ -383,6 +383,7 @@
         'absl/synchronization:synchronization',
         'absl/strings:strings',
         'absl/strings:str_format',
+        'absl/status:status',
         'absl/memory:memory',
         'absl/base:base',
       ],
@@ -424,6 +425,8 @@
         'src/core/lib/gprpp/global_config_env.cc',
         'src/core/lib/gprpp/host_port.cc',
         'src/core/lib/gprpp/mpscq.cc',
+        'src/core/lib/gprpp/stat_posix.cc',
+        'src/core/lib/gprpp/stat_windows.cc',
         'src/core/lib/gprpp/thd_posix.cc',
         'src/core/lib/gprpp/thd_windows.cc',
         'src/core/lib/profiling/basic_timers.cc',

include/grpc/impl/codegen/port_platform.h

@@ -100,6 +100,7 @@
 #define GPR_WINDOWS_TMPFILE
 #define GPR_WINDOWS_LOG
 #define GPR_WINDOWS_CRASH_HANDLER 1
+#define GPR_WINDOWS_STAT
 #define GPR_WINDOWS_STRING
 #define GPR_WINDOWS_TIME
 #endif
@@ -126,6 +127,7 @@
 #define GPR_STDCPP_TLS 1
 #define GPR_POSIX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_ANDROID_LOG 1
 #define GPR_POSIX_STRING 1
 #define GPR_POSIX_SUBPROCESS 1
@@ -154,6 +156,7 @@
 #define GPR_SUPPORT_CHANNELS_FROM_FD 1
 #define GPR_LINUX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_POSIX_STRING 1
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
@@ -216,6 +219,7 @@
 #define GPR_POSIX_LOG 1
 #define GPR_POSIX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_POSIX_STRING 1
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
@@ -242,6 +246,7 @@
 #define GPR_POSIX_LOG 1
 #define GPR_POSIX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_POSIX_STRING 1
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
@@ -266,6 +271,7 @@
 #define GPR_POSIX_LOG 1
 #define GPR_POSIX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_POSIX_STRING 1
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
@@ -287,6 +293,7 @@
 #define GPR_POSIX_LOG 1
 #define GPR_POSIX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_POSIX_STRING 1
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
@@ -310,6 +317,7 @@
 #define GPR_POSIX_LOG 1
 #define GPR_POSIX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_POSIX_STRING 1
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
@@ -339,6 +347,7 @@
 #define GPR_POSIX_LOG 1
 #define GPR_POSIX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_POSIX_STRING 1
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
@@ -365,6 +374,7 @@
 #define GPR_POSIX_SYNC 1
 #define GPR_POSIX_ENV 1
 #define GPR_POSIX_TMPFILE 1
+#define GPR_POSIX_STAT 1
 #define GPR_POSIX_SUBPROCESS 1
 #define GPR_POSIX_SYNC 1
 #define GPR_POSIX_STRING 1

package.xml

@@ -732,6 +732,9 @@
     <file baseinstalldir="/" name="src/core/lib/gprpp/orphanable.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/ref_counted.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/ref_counted_ptr.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/stat.h" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/stat_posix.cc" role="src" />
+    <file baseinstalldir="/" name="src/core/lib/gprpp/stat_windows.cc" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/sync.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/thd.h" role="src" />
     <file baseinstalldir="/" name="src/core/lib/gprpp/thd_posix.cc" role="src" />

src/core/lib/gprpp/README.md

@@ -6,7 +6,3 @@ for other open source projects written in C++.
 
 Note that this is one of the few places in src/core where we allow
 the use of portability macros.
-
-Note that this is the only place in src/core where we allow
-use of the C++ standard library (i.e., anything in the `std::`
-namespace). 

src/core/lib/gprpp/stat.h

@@ -0,0 +1,38 @@
+//
+// Copyright 2020 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#ifndef GRPC_CORE_LIB_GPRPP_STAT_H
+#define GRPC_CORE_LIB_GPRPP_STAT_H
+
+#include <grpc/support/port_platform.h>
+
+#include <stdio.h>
+#include <time.h>
+
+#include "absl/status/status.h"
+#include "absl/strings/string_view.h"
+
+namespace grpc_core {
+
+// Gets the last-modified timestamp of a file or a directory.
+// On success, the correct timestamp will be filled with an StatusCode::kOk
+// returned. Otherwise, timestamp will be untouched and an
+// StatusCode::kInternal will be returned.
+absl::Status GetFileModificationTime(const char* filename, time_t* timestamp);
+
+}  // namespace grpc_core
+
+#endif  // GRPC_CORE_LIB_GPRPP_STAT_H

src/core/lib/gprpp/stat_posix.cc

@@ -0,0 +1,49 @@
+//
+// Copyright 2020 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_POSIX_STAT
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <grpc/support/log.h>
+
+#include "src/core/lib/gprpp/stat.h"
+
+namespace grpc_core {
+
+absl::Status GetFileModificationTime(const char* filename, time_t* timestamp) {
+  GPR_ASSERT(filename != nullptr);
+  GPR_ASSERT(timestamp != nullptr);
+  struct stat buf;
+  if (stat(filename, &buf) != 0) {
+    const char* error_msg = strerror(errno);
+    gpr_log(GPR_ERROR, "stat failed for filename %s with error %s.", filename,
+            error_msg);
+    return absl::Status(absl::StatusCode::kInternal, error_msg);
+  }
+  // Last file/directory modification time.
+  *timestamp = buf.st_mtime;
+  return absl::OkStatus();
+}
+
+}  // namespace grpc_core
+
+#endif  // GPR_POSIX_STAT

src/core/lib/gprpp/stat_windows.cc

@@ -0,0 +1,48 @@
+//
+// Copyright 2020 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include <grpc/support/port_platform.h>
+
+#ifdef GPR_WINDOWS_STAT
+
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <grpc/support/log.h>
+
+#include "src/core/lib/gprpp/stat.h"
+
+namespace grpc_core {
+
+absl::Status GetFileModificationTime(const char* filename, time_t* timestamp) {
+  GPR_ASSERT(filename != nullptr);
+  GPR_ASSERT(timestamp != nullptr);
+  struct _stat buf;
+  if (_stat(filename, &buf) != 0) {
+    const char* error_msg = strerror(errno);
+    gpr_log(GPR_ERROR, "_stat failed for filename %s with error %s.", filename,
+            error_msg);
+    return absl::Status(absl::StatusCode::kInternal, error_msg);
+  }
+  // Last file/directory modification time.
+  *timestamp = buf.st_mtime;
+  return absl::OkStatus();
+}
+
+}  // namespace grpc_core
+
+#endif  // GPR_WINDOWS_STAT

src/python/grpcio/grpc_core_dependencies.py

@@ -352,6 +352,8 @@ CORE_SOURCE_FILES = [
     'src/core/lib/gprpp/global_config_env.cc',
     'src/core/lib/gprpp/host_port.cc',
     'src/core/lib/gprpp/mpscq.cc',
+    'src/core/lib/gprpp/stat_posix.cc',
+    'src/core/lib/gprpp/stat_windows.cc',
     'src/core/lib/gprpp/thd_posix.cc',
     'src/core/lib/gprpp/thd_windows.cc',
     'src/core/lib/http/format_request.cc',

test/core/gprpp/BUILD

@@ -159,3 +159,18 @@ grpc_cc_test(
         "//test/core/util:grpc_test_util",
     ],
 )
+
+grpc_cc_test(
+    name = "stat_test",
+    srcs = ["stat_test.cc"],
+    external_deps = [
+        "gtest",
+    ],
+    language = "C++",
+    uses_polling = False,
+    deps = [
+        "//:gpr",
+        "//:grpc",
+        "//test/core/util:grpc_test_util",
+    ],
+)

test/core/gprpp/stat_test.cc

@@ -0,0 +1,74 @@
+//
+// Copyright 2020 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#include <stdio.h>
+#include <string.h>
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <grpc/grpc.h>
+#include <grpc/slice.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+
+#include "src/core/lib/gpr/string.h"
+#include "src/core/lib/gpr/tmpfile.h"
+#include "src/core/lib/gprpp/stat.h"
+#include "src/core/lib/iomgr/load_file.h"
+#include "test/core/util/test_config.h"
+
+namespace grpc_core {
+namespace testing {
+namespace {
+
+TEST(STAT, GetTimestampOnTmpFile) {
+  // Create a temporary empty file.
+  FILE* tmp = nullptr;
+  char* tmp_name;
+  tmp = gpr_tmpfile("prefix", &tmp_name);
+  ASSERT_NE(tmp_name, nullptr);
+  ASSERT_NE(tmp, nullptr);
+  fclose(tmp);
+  // Check the last modified date is correctly set.
+  time_t timestamp = 0;
+  absl::Status status =
+      grpc_core::GetFileModificationTime(tmp_name, &timestamp);
+  EXPECT_EQ(status.code(), absl::StatusCode::kOk);
+  EXPECT_GT(timestamp, 0);
+  // Clean up.
+  remove(tmp_name);
+  gpr_free(tmp_name);
+}
+
+TEST(STAT, GetTimestampOnFailure) {
+  time_t timestamp = 0;
+  absl::Status status =
+      grpc_core::GetFileModificationTime("/DOES_NOT_EXIST", &timestamp);
+  EXPECT_EQ(status.code(), absl::StatusCode::kInternal);
+  // Check the last modified date is not set.
+  EXPECT_EQ(timestamp, 0);
+}
+
+}  // namespace
+}  // namespace testing
+}  // namespace grpc_core
+
+int main(int argc, char** argv) {
+  grpc::testing::TestEnvironment env(argc, argv);
+  ::testing::InitGoogleTest(&argc, argv);
+  return RUN_ALL_TESTS();
+}

tools/doxygen/Doxyfile.c++.internal

@@ -1684,6 +1684,9 @@ src/core/lib/gprpp/mpscq.h \
 src/core/lib/gprpp/orphanable.h \
 src/core/lib/gprpp/ref_counted.h \
 src/core/lib/gprpp/ref_counted_ptr.h \
+src/core/lib/gprpp/stat.h \
+src/core/lib/gprpp/stat_posix.cc \
+src/core/lib/gprpp/stat_windows.cc \
 src/core/lib/gprpp/sync.h \
 src/core/lib/gprpp/thd.h \
 src/core/lib/gprpp/thd_posix.cc \

tools/doxygen/Doxyfile.core.internal

@@ -1525,6 +1525,9 @@ src/core/lib/gprpp/mpscq.h \
 src/core/lib/gprpp/orphanable.h \
 src/core/lib/gprpp/ref_counted.h \
 src/core/lib/gprpp/ref_counted_ptr.h \
+src/core/lib/gprpp/stat.h \
+src/core/lib/gprpp/stat_posix.cc \
+src/core/lib/gprpp/stat_windows.cc \
 src/core/lib/gprpp/sync.h \
 src/core/lib/gprpp/thd.h \
 src/core/lib/gprpp/thd_posix.cc \

tools/run_tests/generated/tests.json

@@ -5667,6 +5667,30 @@
     ], 
     "uses_polling": true
   }, 
+  {
+    "args": [], 
+    "benchmark": false, 
+    "ci_platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "cpu_cost": 1.0, 
+    "exclude_configs": [], 
+    "exclude_iomgrs": [], 
+    "flaky": false, 
+    "gtest": true, 
+    "language": "c++", 
+    "name": "stat_test", 
+    "platforms": [
+      "linux", 
+      "mac", 
+      "posix", 
+      "windows"
+    ], 
+    "uses_polling": false
+  }, 
   {
     "args": [], 
     "benchmark": false,