Replace port_posix with port_stdcxx.

The porting layer implements threading primitives: atomic pointers,
condition variables, mutexes, thread-safe initialization. These are all
specified in C++11, so the reference open source port implementation can
become platform-independent.

The porting layer will remain in place to allow the use of other
implementations with more features, such as the built-in deadlock
detection in abseil's Mutex.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=193245934

1 files changed, 16 insertions, 48 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5588120..4bf3df3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -79,33 +79,10 @@ if(BUILD_SHARED_LIBS)
   add_compile_options(-fvisibility=hidden)
 endif(BUILD_SHARED_LIBS)
 
-# POSIX code is specified separately so we can leave it out in the future.
-add_library(leveldb_port_posix OBJECT "")
-target_sources(leveldb_port_posix
-  PRIVATE
-    "${PROJECT_SOURCE_DIR}/port/port_posix.cc"
-
-  PUBLIC
-    # The headers below are dependencies for leveldb, but aren't needed by users
-    # that link to the installed version of leveldb and rely on its public API.
-    $<BUILD_INTERFACE:${PROJECT_BINARY_DIR}/${LEVELDB_PORT_CONFIG_DIR}/port_config.h>
-    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/port/atomic_pointer.h>
-    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/port/port_posix.h>
-    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/port/port.h>
-)
-if (NOT HAVE_CXX17_HAS_INCLUDE)
-  target_compile_definitions(leveldb_port_posix
-    PRIVATE
-      LEVELDB_HAS_PORT_CONFIG_H=1
-  )
-endif(NOT HAVE_CXX17_HAS_INCLUDE)
-if(BUILD_SHARED_LIBS)
-  set_property(TARGET leveldb_port_posix PROPERTY POSITION_INDEPENDENT_CODE ON)
-endif(BUILD_SHARED_LIBS)
-
 add_library(leveldb "")
 target_sources(leveldb
   PRIVATE
+    "${PROJECT_BINARY_DIR}/${LEVELDB_PORT_CONFIG_DIR}/port_config.h"
     "${PROJECT_SOURCE_DIR}/db/builder.cc"
     "${PROJECT_SOURCE_DIR}/db/builder.h"
     "${PROJECT_SOURCE_DIR}/db/c.cc"
@@ -136,6 +113,8 @@ target_sources(leveldb
     "${PROJECT_SOURCE_DIR}/db/version_set.h"
     "${PROJECT_SOURCE_DIR}/db/write_batch_internal.h"
     "${PROJECT_SOURCE_DIR}/db/write_batch.cc"
+    "${PROJECT_SOURCE_DIR}/port/atomic_pointer.h"
+    "${PROJECT_SOURCE_DIR}/port/port_stdcxx.h"
     "${PROJECT_SOURCE_DIR}/port/port.h"
     "${PROJECT_SOURCE_DIR}/port/thread_annotations.h"
     "${PROJECT_SOURCE_DIR}/table/block_builder.cc"
@@ -163,7 +142,6 @@ target_sources(leveldb
     "${PROJECT_SOURCE_DIR}/util/comparator.cc"
     "${PROJECT_SOURCE_DIR}/util/crc32c.cc"
     "${PROJECT_SOURCE_DIR}/util/crc32c.h"
-    "${PROJECT_SOURCE_DIR}/util/env_posix.cc"
     "${PROJECT_SOURCE_DIR}/util/env.cc"
     "${PROJECT_SOURCE_DIR}/util/filter_policy.cc"
     "${PROJECT_SOURCE_DIR}/util/hash.cc"
@@ -172,10 +150,8 @@ target_sources(leveldb
     "${PROJECT_SOURCE_DIR}/util/logging.h"
     "${PROJECT_SOURCE_DIR}/util/mutexlock.h"
     "${PROJECT_SOURCE_DIR}/util/options.cc"
-    "${PROJECT_SOURCE_DIR}/util/posix_logger.h"
     "${PROJECT_SOURCE_DIR}/util/random.h"
     "${PROJECT_SOURCE_DIR}/util/status.cc"
-    $<TARGET_OBJECTS:leveldb_port_posix>
 
   # Only CMake 3.3+ supports PUBLIC sources in targets exported by "install".
   $<$<VERSION_GREATER:CMAKE_VERSION,3.2>:PUBLIC>
@@ -195,12 +171,21 @@ target_sources(leveldb
     "${LEVELDB_PUBLIC_INCLUDE_DIR}/table.h"
     "${LEVELDB_PUBLIC_INCLUDE_DIR}/write_batch.h"
 )
+
+# POSIX code is specified separately so we can leave it out in the future.
+target_sources(leveldb
+  PRIVATE
+    "${PROJECT_SOURCE_DIR}/util/env_posix.cc"
+    "${PROJECT_SOURCE_DIR}/util/posix_logger.h"
+)
+
 # MemEnv is not part of the interface and could be pulled to a separate library.
 target_sources(leveldb
   PRIVATE
     "${PROJECT_SOURCE_DIR}/helpers/memenv/memenv.cc"
     "${PROJECT_SOURCE_DIR}/helpers/memenv/memenv.h"
 )
+
 target_include_directories(leveldb
   PUBLIC
     $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
@@ -234,11 +219,6 @@ if(HAVE_CLANG_THREAD_SAFETY)
       -Werror -Wthread-safety)
 endif(HAVE_CLANG_THREAD_SAFETY)
 
-# TODO(costan): This is only needed for port_posix.
-set(THREADS_PREFER_PTHREAD_FLAG ON)
-find_package(Threads REQUIRED)
-target_link_libraries(leveldb Threads::Threads)
-
 if(HAVE_CRC32C)
   target_link_libraries(leveldb crc32c)
 endif(HAVE_CRC32C)
@@ -249,6 +229,10 @@ if(HAVE_TCMALLOC)
   target_link_libraries(leveldb tcmalloc)
 endif(HAVE_TCMALLOC)
 
+# Needed by port_stdcxx.h
+find_package(Threads REQUIRED)
+target_link_libraries(leveldb Threads::Threads)
+
 add_executable(leveldbutil
   "${PROJECT_SOURCE_DIR}/db/leveldbutil.cc"
 )
@@ -271,14 +255,6 @@ if(LEVELDB_BUILD_TESTS)
 
         "${test_file}"
     )
-    if(BUILD_SHARED_LIBS)
-      # Port functions aren't exposed in the shared library build.
-      target_sources("${test_target_name}"
-        PRIVATE
-          $<TARGET_OBJECTS:leveldb_port_posix>
-      )
-    endif(BUILD_SHARED_LIBS)
-
     target_link_libraries("${test_target_name}" leveldb)
     target_compile_definitions("${test_target_name}"
       PRIVATE
@@ -351,14 +327,6 @@ if(LEVELDB_BUILD_BENCHMARKS)
 
         "${bench_file}"
     )
-    if(BUILD_SHARED_LIBS)
-      # Port functions aren't exposed in the shared library build.
-      target_sources("${bench_target_name}"
-        PRIVATE
-          $<TARGET_OBJECTS:leveldb_port_posix>
-      )
-    endif(BUILD_SHARED_LIBS)
-
     target_link_libraries("${bench_target_name}" leveldb)
     target_compile_definitions("${bench_target_name}"
       PRIVATE