build: Update CMake to use system threads

With the help of Gabriel Ferreira and Tommaso Pecorella.

build-support/core-config-template.h

@@ -15,7 +15,6 @@
 #cmakedefine01 HAVE_STDLIB_H
 #cmakedefine01 HAVE_GETENV
 #cmakedefine01 HAVE_SIGNAL_H
-#cmakedefine01 HAVE_PTHREAD_H
 #cmakedefine   HAVE_RT
 
 #endif //NS3_CORE_CONFIG_H

build-support/custom-modules/ns3-configtable.cmake

@@ -25,7 +25,6 @@
 # Tap Bridge                    : enabled
 # Tap FdNetDevice               : enabled
 # Tests                         : not enabled (defaults to disabled)
-# Threading Primitives          : enabled
 # Use sudo to set suid bit      : not enabled (option --enable-sudo not selected)
 # XmlIo                         : enabled
 #

build-support/custom-modules/ns3-module-macros.cmake

@@ -110,7 +110,10 @@ function(build_lib)
   endif()
 
   # Split ns and non-ns libraries to manage their propagation properly
-  set(non_ns_libraries_to_link)
+  set(non_ns_libraries_to_link
+      ${CMAKE_THREAD_LIBS_INIT}
+  )
+
   set(ns_libraries_to_link)
 
   foreach(library ${BLIB_LIBRARIES_TO_LINK})

build-support/macros-and-definitions.cmake

@@ -688,13 +688,8 @@ macro(process_options)
 
   set(THREADS_PREFER_PTHREAD_FLAG)
   find_package(Threads QUIET)
-  if(${CMAKE_USE_PTHREADS_INIT})
-    include_directories(${THREADS_PTHREADS_INCLUDE_DIR})
-    set(HAVE_PTHREAD_H TRUE) # for core-config.h
-    set(THREADS_ENABLED TRUE)
-    set(THREADS_FOUND TRUE)
-  else()
-    message(FATAL_ERROR Pthreads are required by ns-3)
+  if(NOT ${Threads_FOUND})
+    message(FATAL_ERROR Threads are required by ns-3)
   endif()
 
   set(Python3_LIBRARIES)

doc/tutorial/source/getting-started.rst

@@ -563,8 +563,6 @@ output that looks similar to the following:
   -- Looking for C++ include signal.h - found
   -- Looking for C++ include netpacket/packet.h
   -- Looking for C++ include netpacket/packet.h - found
-  -- Looking for C++ include semaphore.h
-  -- Looking for C++ include semaphore.h - found
   -- Looking for getenv
   -- Looking for getenv - found
   -- Processing src/antenna
@@ -653,7 +651,6 @@ output that looks similar to the following:
   Tap Bridge                    : ON
   Tap FdNetDevice               : ON
   Tests                         : ON
-  Threading Primitives          : ON
   
   
   Modules configured to be built:

src/core/CMakeLists.txt

@@ -120,26 +120,6 @@ elseif(
   )
 endif()
 
-set(thread_sources
-    model/system-thread.cc
-    model/unix-fd-reader.cc
-    model/unix-system-condition.cc
-    model/unix-system-mutex.cc
-)
-set(thread_headers
-    model/system-condition.h
-    model/system-mutex.h
-    model/system-thread.h
-    model/unix-fd-reader.h
-)
-set(libraries_to_link
-    ${libraries_to_link}
-    pthread
-)
-set(thread_test_sources
-    test/threaded-test-suite.cc
-)
-
 if(${ENABLE_EXAMPLES})
   set(example_as_test_sources
       model/example-as-test.cc
@@ -169,7 +149,6 @@ set(source_files
     ${rt_sources}
     ${osclock_sources}
     ${int64x64_sources}
-    ${thread_sources}
     ${example_as_test_sources}
     ${embedded_version_sources}
     helper/csv-reader.cc
@@ -234,13 +213,13 @@ set(source_files
     model/system-wall-clock-timestamp.cc
     model/length.cc
     model/trickle-timer.cc
+    model/unix-fd-reader.cc
 )
 
 # Define core lib headers
 set(header_files
     ${rt_headers}
     ${int64x64_headers}
-    ${thread_headers}
     ${example_as_test_headers}
     ${embedded_version_headers}
     helper/csv-reader.h
@@ -334,6 +313,7 @@ set(header_files
     model/type-name.h
     model/type-traits.h
     model/uinteger.h
+    model/unix-fd-reader.h
     model/unused.h
     model/valgrind.h
     model/vector.h
@@ -343,7 +323,6 @@ set(header_files
 set(test_sources
     ${example_as_test_suite}
     ${gsl_test_sources}
-    ${thread_test_sources}
     test/attribute-container-test-suite.cc
     test/attribute-test-suite.cc
     test/build-profile-test-suite.cc
@@ -363,6 +342,7 @@ set(test_sources
     test/ptr-test-suite.cc
     test/sample-test-suite.cc
     test/simulator-test-suite.cc
+    test/threaded-test-suite.cc
     test/time-test-suite.cc
     test/timer-test-suite.cc
     test/traced-callback-test-suite.cc

src/fd-net-device/CMakeLists.txt

@@ -6,11 +6,6 @@ option(
 
 set(module_enabled_features) # modulegen_customizations consumes this list
 
-mark_as_advanced(ENABLE_THREADING)
-set(ENABLE_THREADING
-    ${HAVE_PTHREAD_H}
-)
-
 check_include_file_cxx(
   net/ethernet.h
   HAVE_NET_ETHERNET_H

test.py

@@ -61,7 +61,6 @@ interesting_config_items = [
     "NS3_ENABLED_CONTRIBUTED_MODULES",
     "NS3_MODULE_PATH",
     "ENABLE_REAL_TIME",
-    "ENABLE_THREADING",
     "ENABLE_EXAMPLES",
     "ENABLE_TESTS",
     "EXAMPLE_DIRECTORIES",
@@ -77,7 +76,6 @@ interesting_config_items = [
 ]
 
 ENABLE_REAL_TIME = False
-ENABLE_THREADING = False
 ENABLE_EXAMPLES = True
 ENABLE_TESTS = True
 NSCLICK = False