Remove dependency on platform threads library (#7297)

* Refactor internal ThreadPool.h into halide_thread_pool.h tool * Drop dependency of libHalide on threads library * Remove other redundant uses of Threads::Threads * Update CMake documentation.
halide · Jan 20, 2023 · 147ff48 · 147ff48
1 parent 314b2fd
commit 147ff48
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Showing 10 changed files with 32 additions and 19 deletions.
diff --git a/Makefile b/Makefile
@@ -726,7 +726,6 @@ HEADER_FILES = \
   StrictifyFloat.h \
   Substitute.h \
   Target.h \
-  ThreadPool.h \
   Tracing.h \
   TrimNoOps.h \
   Tuple.h \
@@ -2256,6 +2255,7 @@ install: $(LIB_DIR)/libHalide.a $(BIN_DIR)/libHalide.$(SHARED_EXT) $(INCLUDE_DIR
 	cp $(ROOT_DIR)/tools/halide_image_io.h $(PREFIX)/share/halide/tools
 	cp $(ROOT_DIR)/tools/halide_image_info.h $(PREFIX)/share/halide/tools
 	cp $(ROOT_DIR)/tools/halide_malloc_trace.h $(PREFIX)/share/halide/tools
+	cp $(ROOT_DIR)/tools/halide_thread_pool.h $(PREFIX)/share/halide/tools
 ifeq ($(UNAME), Darwin)
 	install_name_tool -id $(PREFIX)/lib/libHalide.$(SHARED_EXT) $(PREFIX)/lib/libHalide.$(SHARED_EXT)
 endif
@@ -2334,6 +2334,7 @@ $(DISTRIB_DIR)/lib/libHalide.$(SHARED_EXT): \
 	cp $(ROOT_DIR)/tools/halide_image_io.h $(DISTRIB_DIR)/tools
 	cp $(ROOT_DIR)/tools/halide_image_info.h $(DISTRIB_DIR)/tools
 	cp $(ROOT_DIR)/tools/halide_malloc_trace.h $(DISTRIB_DIR)/tools
+	cp $(ROOT_DIR)/tools/halide_thread_pool.h $(DISTRIB_DIR)/tools
 	cp $(ROOT_DIR)/tools/halide_trace_config.h $(DISTRIB_DIR)/tools
 	cp $(ROOT_DIR)/README*.md $(DISTRIB_DIR)
 	cp $(BUILD_DIR)/halide_config.* $(DISTRIB_DIR)

diff --git a/README_cmake.md b/README_cmake.md
@@ -769,14 +769,15 @@ Variables set by the package:
 
 Halide defines the following targets that are available to users:
 
-| Imported target      | Description                                                                                                                          |
-|----------------------|--------------------------------------------------------------------------------------------------------------------------------------|
-| `Halide::Halide`     | this is the JIT-mode library to use when using Halide from C++.                                                                      |
-| `Halide::Generator`  | this is the target to use when defining a generator executable. It supplies a `main()` function.                                     |
-| `Halide::Runtime`    | adds include paths to the Halide runtime headers                                                                                     |
-| `Halide::Tools`      | adds include paths to the Halide tools, including the benchmarking utility.                                                          |
-| `Halide::ImageIO`    | adds include paths to the Halide image IO utility and sets up dependencies to PNG / JPEG if they are available.                      |
-| `Halide::RunGenMain` | used with the `REGISTRATION` parameter of `add_halide_library` to create simple runners and benchmarking tools for Halide libraries. |
+| Imported target      | Description                                                                                                                                                                                    |
+|----------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| `Halide::Halide`     | this is the JIT-mode library to use when using Halide from C++.                                                                                                                                |
+| `Halide::Generator`  | this is the target to use when defining a generator executable. It supplies a `main()` function.                                                                                               |
+| `Halide::Runtime`    | adds include paths to the Halide runtime headers                                                                                                                                               |
+| `Halide::Tools`      | adds include paths to the Halide tools, including the benchmarking utility.                                                                                                                    |
+| `Halide::ImageIO`    | adds include paths to the Halide image IO utility. Depends on `PNG::PNG` and `JPEG::JPEG` if they exist or were loaded through the corresponding package components.                           |
+| `Halide::ThreadPool` | adds include paths to the Halide _simple_ thread pool utility library. This is not the same as the runtime's thread pool and is intended only for use by tests. Depends on `Threads::Threads`. |
+| `Halide::RunGenMain` | used with the `REGISTRATION` parameter of `add_halide_library` to create simple runners and benchmarking tools for Halide libraries.                                                           |
 
 The following targets are not guaranteed to be available:
 

diff --git a/cmake/HalideTestHelpers.cmake b/cmake/HalideTestHelpers.cmake
@@ -15,7 +15,7 @@ if (NOT TARGET Halide::Test)
     add_library(Halide_test INTERFACE)
     add_library(Halide::Test ALIAS Halide_test)
 
-    # Obviously, link to the main library
+    # Obviously link to libHalide, but also grant all tests access to the threads library.
     target_link_libraries(Halide_test INTERFACE Halide::Halide Threads::Threads)
 
     # Everyone gets to see the common headers

diff --git a/packaging/CMakeLists.txt b/packaging/CMakeLists.txt
@@ -51,7 +51,7 @@ endforeach ()
 
 target_sources(Halide_RunGenMain INTERFACE $<INSTALL_INTERFACE:${Halide_INSTALL_TOOLSDIR}/RunGenMain.cpp>)
 
-install(TARGETS Halide_Tools Halide_ImageIO Halide_RunGenMain
+install(TARGETS Halide_Tools Halide_ImageIO Halide_RunGenMain Halide_ThreadPool
         EXPORT Halide_Interfaces
         INCLUDES DESTINATION ${Halide_INSTALL_TOOLSDIR})
 

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
@@ -152,7 +152,6 @@ set(HEADER_FILES
     StrictifyFloat.h
     Substitute.h
     Target.h
-    ThreadPool.h
     Tracing.h
     TrimNoOps.h
     Tuple.h
@@ -378,7 +377,6 @@ add_library(Halide
             $<TARGET_OBJECTS:Halide_initmod>)
 add_library(Halide::Halide ALIAS Halide)
 
-target_link_libraries(Halide PUBLIC Threads::Threads)
 target_link_libraries(Halide PRIVATE Halide::LLVM)
 target_link_libraries(Halide PUBLIC Halide::LanguageOptions)
 target_compile_definitions(Halide PRIVATE $<$<STREQUAL:$<TARGET_PROPERTY:TYPE>,STATIC_LIBRARY>:Halide_STATIC_DEFINE>)

diff --git a/src/autoschedulers/adams2019/AutoSchedule.cpp b/src/autoschedulers/adams2019/AutoSchedule.cpp
@@ -72,6 +72,8 @@
 #ifdef _WIN32
 #include <io.h>
 #define _isatty isatty;
+#else
+#include <unistd.h>
 #endif
 
 namespace Halide {

diff --git a/test/correctness/CMakeLists.txt b/test/correctness/CMakeLists.txt
@@ -382,9 +382,12 @@ tests(GROUPS correctness multithreaded
       unroll_huge_mux.cpp
       )
 
-# Make sure the test that needs image_io has it
+# Make sure the test that needs Halide::ImageIO has it
 target_link_libraries(correctness_image_io PRIVATE Halide::ImageIO)
 
+# Make sure the test that needs Halide::ThreadPool has it
+target_link_libraries(correctness_gpu_allocation_cache PRIVATE Halide::ThreadPool)
+
 # Tests which use external funcs need to enable exports.
 set_target_properties(correctness_async
                       correctness_atomics

diff --git a/test/correctness/gpu_allocation_cache.cpp b/test/correctness/gpu_allocation_cache.cpp
@@ -1,5 +1,6 @@
 #include "Halide.h"
 #include "halide_benchmark.h"
+#include "halide_thread_pool.h"
 
 using namespace Halide;
 
@@ -136,7 +137,7 @@ int main(int argc, char **argv) {
     // issues. Probably due to using the GL context on the wrong
     // thread.
     if (!target.has_feature(Target::OpenGLCompute)) {
-        Halide::Internal::ThreadPool<void> pool(1);
+        Halide::Tools::ThreadPool<void> pool(1);
         std::vector<std::future<void>> futures;
         futures.emplace_back(pool.async(test1, true));
         futures.emplace_back(pool.async(test1, true));

diff --git a/tools/CMakeLists.txt b/tools/CMakeLists.txt
@@ -35,16 +35,22 @@ target_include_directories(Halide_ImageIO INTERFACE $<BUILD_INTERFACE:${CMAKE_CU
 add_library(Halide_RunGenMain INTERFACE)
 add_library(Halide::RunGenMain ALIAS Halide_RunGenMain)
 target_sources(Halide_RunGenMain INTERFACE $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/RunGenMain.cpp>)
-target_link_libraries(Halide_RunGenMain INTERFACE Halide::Runtime Halide::ImageIO Threads::Threads)
+target_link_libraries(Halide_RunGenMain INTERFACE Halide::Runtime Halide::ImageIO Halide::Tools)
 set_target_properties(Halide_RunGenMain PROPERTIES EXPORT_NAME RunGenMain)
 
 add_library(Halide_Generator INTERFACE)
 add_library(Halide::Generator ALIAS Halide_Generator)
 target_sources(Halide_Generator INTERFACE $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/GenGen.cpp>)
-target_link_libraries(Halide_Generator INTERFACE Halide::Halide Threads::Threads ${CMAKE_DL_LIBS})
+target_link_libraries(Halide_Generator INTERFACE Halide::Halide ${CMAKE_DL_LIBS})
 set_target_properties(Halide_Generator PROPERTIES EXPORT_NAME Generator)
 
 add_library(Halide_Tools INTERFACE)
 add_library(Halide::Tools ALIAS Halide_Tools)
 target_include_directories(Halide_Tools INTERFACE $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>)
 set_target_properties(Halide_Tools PROPERTIES EXPORT_NAME Tools)
+
+add_library(Halide_ThreadPool INTERFACE)
+add_library(Halide::ThreadPool ALIAS Halide_ThreadPool)
+target_link_libraries(Halide_ThreadPool INTERFACE Threads::Threads)
+target_include_directories(Halide_Tools INTERFACE $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>)
+set_target_properties(Halide_ThreadPool PROPERTIES EXPORT_NAME ThreadPool)
diff --git a/src/ThreadPool.h → tools/halide_thread_pool.h b/src/ThreadPool.h → tools/halide_thread_pool.h
@@ -1,6 +1,7 @@
 #ifndef HALIDE_THREAD_POOL_H
 #define HALIDE_THREAD_POOL_H
 
+#include <cassert>
 #include <condition_variable>
 #include <functional>
 #include <future>
@@ -35,7 +36,7 @@
  * *not* intended to be the underlying implementation for Halide runtime threads
  */
 namespace Halide {
-namespace Internal {
+namespace Tools {
 
 template<typename T>
 class ThreadPool {
@@ -154,7 +155,7 @@ inline void ThreadPool<void>::Job::run_unlocked(std::unique_lock<std::mutex> &un
     result.set_value();
 }
 
-}  // namespace Internal
+}  // namespace Tools
 }  // namespace Halide
 
 #endif  // HALIDE_THREAD_POOL_H