added CMake option USE_PI_MUTEX

Signed-off-by: Martin Mayer <[email protected]>

CMakeLists.txt

@@ -37,6 +37,16 @@ if(WIN32)
   target_compile_definitions(${PROJECT_NAME}
     PRIVATE "RCPPUTILS_BUILDING_LIBRARY")
 endif()
+
+option(USE_PI_MUTEX "Enables priority inheritance mutexes." ON)
+if(USE_PI_MUTEX)
+  if(WIN32 OR APPLE)
+    message("Mutexes with priority inheritance are not supported on your system. Using std mutexes.")
+  else()
+    target_compile_definitions(${PROJECT_NAME} PUBLIC "RCPPUTILS_USE_PIMUTEX")
+  endif()
+endif()
+
 ament_target_dependencies(${PROJECT_NAME} rcutils)
 
 # Export old-style CMake variables

Doxyfile

@@ -23,6 +23,7 @@ EXPAND_ONLY_PREDEF     = YES
 PREDEFINED             += __declspec(x)=
 PREDEFINED             += RCPPUTILS_PUBLIC=
 PREDEFINED             += RCPPUTILS_PUBLIC_TYPE=
+PREDEFINED             += RCPPUTILS_USE_PIMUTEX
 
 # Tag files that do not exist will produce a warning and cross-project linking will not work.
 TAGFILES += "../../../doxygen_tag_files/cppreference-doxygen-web.tag.xml=http://en.cppreference.com/w/"

README.md

@@ -17,6 +17,7 @@ This package currently contains:
 * String helpers
 * File system helpers
 * Type traits helpers
+* Mutex classes that support thread priority inheritance
 * Class that dynamically loads, unloads and get symbols from shared libraries at run-time.
 
 Features are described in more detail at [docs/FEATURES.md](docs/FEATURES.md)

include/rcpputils/mutex.hpp

@@ -1,4 +1,4 @@
-// Copyright 2020 Open Source Robotics Foundation, Inc.
+// Copyright 2023 Open Source Robotics Foundation, Inc.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -21,11 +21,18 @@
 
 namespace rcpputils
 {
+#ifndef RCPPUTILS_USE_PIMUTEX
+
+// Fallback code path
+using PIMutex = std::mutex;
+using RecursivePIMutex = std::recursive_mutex;
+
+#else
 
 /**
  * Mutex with priority inheritance on systems that support it.
  * This class derives from std::mutex to be fully compatible with standard C++.
- * This implementation is a workaround that is needed until the C++ standard library offers the same mutex functionality.
+ * This implementation is needed because the C++ standard library doesn't support priority inheritance.
   **/
 class PIMutex : public std::mutex
 {
@@ -42,7 +49,7 @@ class PIMutex : public std::mutex
 /**
  * Recursive mutex with priority inheritance on systems that support it.
  * This class derives from std::recursive_mutex to be fully compatible with standard C++.
- * This implementation is a workaround that is needed until the C++ standard library offers the same mutex functionality.
+ * This implementation is needed because the C++ standard library doesn't support priority inheritance.
  **/
 class RecursivePIMutex : public std::recursive_mutex
 {
@@ -56,6 +63,6 @@ class RecursivePIMutex : public std::recursive_mutex
   ~RecursivePIMutex();
 };
 
+#endif  // RCPPUTILS_USE_PIMUTEX
 }  // namespace rcpputils
-
 #endif  // RCPPUTILS__MUTEX_HPP_

src/mutex.cpp

@@ -1,4 +1,4 @@
-// Copyright 2020 Open Source Robotics Foundation, Inc.
+// Copyright 2023 Open Source Robotics Foundation, Inc.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -14,14 +14,13 @@
 
 #include "rcpputils/mutex.hpp"
 
-#ifndef _WIN32
+#ifdef RCPPUTILS_USE_PIMUTEX
+
 #include <pthread.h>
-#endif
 
 namespace rcpputils
 {
 
-#ifndef _WIN32
 PIMutex::PIMutex()
 {
   // Destroy the underlying mutex
@@ -60,15 +59,6 @@ RecursivePIMutex::RecursivePIMutex()
   // The attribute object isn't needed any more
   pthread_mutexattr_destroy(&attr);
 }
-#else
-PIMutex::PIMutex()
-{
-}
-
-RecursivePIMutex::RecursivePIMutex()
-{
-}
-#endif  // _WIN32
 
 PIMutex::~PIMutex()
 {
@@ -77,4 +67,6 @@ PIMutex::~PIMutex()
 RecursivePIMutex::~RecursivePIMutex()
 {
 }
+
 }  // namespace rcpputils
+#endif  // RCPPUTILS_USE_PIMUTEX

test/test_mutex.cpp

@@ -1,4 +1,4 @@
-// Copyright 2019 Open Source Robotics Foundation, Inc.
+// Copyright 2023 Open Source Robotics Foundation, Inc.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -19,10 +19,14 @@
 
 #include "rcpputils/mutex.hpp"
 
-#ifdef __linux__
+#ifdef RCPPUTILS_USE_PIMUTEX
 #include <pthread.h>
 #include "rcutils/types/rcutils_ret.h"
-#endif  // __linux__
+#ifdef __QNXNTO__
+  #include <sys/neutrino.h>
+  #include <sys/syspage.h>
+#endif  // __QNXNTO__
+#endif  // RCPPUTILS_USE_PIMUTEX
 
 using namespace std::chrono_literals;
 
@@ -99,7 +103,7 @@ TEST(test_mutex, pimutex_lockthread) {
   test_thread.join();
 }
 
-#ifdef __linux__
+#ifdef RCPPUTILS_USE_PIMUTEX
 //
 // The test cases pimutex_priority_inversion & rpimutex_priority_inversion provoke
 // a thread priority inversion. To do so they need to configure the cpu priority,
@@ -160,14 +164,27 @@ rcutils_ret_t configure_native_realtime_thread(
     RCUTILS_RET_OK ? 1 : 0);
   success &= (pthread_setschedparam(native_handle, SCHED_FIFO, &params) == 0);
 
+#ifdef __QNXNTO__
+  // run_mask is a bit mask to set which cpu a thread runs on
+  // where each bit corresponds to a cpu core
+  int64_t run_mask = cpu_bitmask;
+
+  // change thread affinity of thread associated with native_handle
+  success &= (ThreadCtlExt(
+      0, native_handle, _NTO_TCTL_RUNMASK,
+      reinterpret_cast<void *>(run_mask)) != -1);
+#else  // __QNXNTO__
   cpu_set_t cpuset;
   CPU_ZERO(&cpuset);
   for (unsigned int i = 0; i < sizeof(cpu_bitmask) * 8; i++) {
     if ( (cpu_bitmask & (1 << i)) != 0) {
       CPU_SET(i, &cpuset);
     }
   }
+
+  // change thread affinity of thread associated with native_handle
   success &= (pthread_setaffinity_np(native_handle, sizeof(cpu_set_t), &cpuset) == 0);
+#endif  // __QNXNTO__
 
   return success ? RCUTILS_RET_OK : RCUTILS_RET_ERROR;
 }
@@ -285,4 +302,4 @@ TEST(test_mutex, rpimutex_priority_inversion) {
   priority_inheritance_test<rcpputils::RecursivePIMutex>();
 }
 
-#endif  // __linux__
+#endif  // RCPPUTILS_USE_PIMUTEX