Frédéric DesbiensandClaude Opus 5
fe40079353
The SMP suite has been failing on threadx_thread_priority_change since 30 June.
The test reports SUCCESS and the process then never exits, so ctest kills it at
the thousand second timeout, twice, and the log carries nothing past the result
line. Instrumenting the harness teardown produced the state at the hang:
last stage reached: test_control_return: control thread resume returned
_tx_thread_preempt_disable: 0
core 0: current=thread 0 execute=thread 0
thread test control thread state=0 priority=0 threshold=0 core_control=1
thread thread 0 state=1 priority=0 threshold=0 inherit=0
Core 0 is held by a thread in state 1, TX_COMPLETED, while the control thread
sits in state 0, TX_READY, at priority 0. The Linux SMP scheduler fills a core
only when _tx_thread_current_ptr for it is null, and clears that pointer only
for a thread carrying a deferred preemption, which thread 0 is not. So core 0
can never be handed on, and with TX_THREAD_SMP_ONLY_CORE_0_DEFAULT and
TX_SMP_NOT_POSSIBLE the control thread has nowhere else to go. The scheduler
re-reads the same state every two milliseconds for as long as it is allowed to.
What put thread 0 at priority 0 is the last thing this test does:
thread_0.tx_thread_inherit_priority = 0;
_tx_thread_smp_simple_priority_change(&thread_0, 16);
with the stated intent of reaching the branch where the new priority is below
the inheritance priority. Zero cannot reach that branch, because 16 is not less
than 0. The other branch runs instead, and that branch assigns the inheritance
priority as the thread's priority while the code after it links the thread into
the list for the new priority regardless. Thread 0 therefore came away claiming
priority 0 while living in the priority 16 list.
Both halves of that hurt. Priority 0 ties with the control thread, so resuming
the control thread raised no preemption and left the execute pointer alone. The
mismatch between the recorded priority and the list the thread is linked into
then means that completing thread 0 removes it from a list it was never in,
leaving core 0 pointing at it for good.
Give the inheritance priority a value above the new one, which is what the
branch the comment names actually requires, and put it back to
TX_MAX_PRIORITIES afterwards so nothing downstream reasons about an
inheritance that is not there. Hold protection across the call as well: this is
an internal routine that expects it, and it was being called in the open.
Measured before and after by printing the thread's state at the point the test
reports success. With the inheritance priority at 0 it is priority 0 threshold
0, matching the hang above, on every run. With it above the new priority it is
priority 16 threshold 16, which agrees with the list the thread is linked into,
and resuming the control thread preempts core 0 the ordinary way.
All five SMP configurations pass 110 of 110 at the parallelism CI uses.
The comparison in _tx_thread_smp_simple_priority_change deserves a second look
on its own account. When its else branch runs, the thread's recorded priority
and the list it is linked into disagree by construction. Only this test is
known to reach that branch, by supplying an inheritance priority that cannot
arise in ordinary operation, so nothing here claims a defect in shipped paths.
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
Eclipse ThreadX RTOS
This advanced real-time operating system (RTOS) is designed specifically for deeply embedded applications. Among the multiple benefits it provides are advanced scheduling facilities, message passing, interrupt management, and messaging services. Eclipse ThreadX RTOS has many advanced features, including picokernel architecture, preemption threshold, event chaining, and a rich set of system services.
Here are the key features and modules of ThreadX:
Getting Started
Eclipse ThreadX has been integrated to the semiconductor's SDKs and development environment. You can develop using the tools of choice from STMicroelectronics, NXP, Renesas and Microchip.
We also provide getting started guide and samples using development boards from semiconductors you can build and test with.
See Overview of Eclipse ThreadX RTOS for the high-level overview.
Repository Structure and Usage
Directory layout
.
├── cmake # CMakelist files for building the project
├── common # Core ThreadX files
├── common_modules # Core ThreadX module files
├── common_smp # Core ThreadX SMP files
├── docs # Documentation supplements
├── ports # Architecture and compiler specific files. See below for directory breakdown
│ ├── cortex_m7
│ │ ├── iar # Example IAR compiler sample project
│ │ │ ├── example build # IAR workspace and sample project files
│ │ │ ├── inc # tx_port.h for this architecture
│ │ │ └── src # Source files for this architecture
│ │ ├── ac6 # Example ac6/Keil sample project
│ │ ├── gnu # Example gnu sample project
│ │ └── ...
│ └── ...
├── ports_modules # Architecture and compiler specific files for threadX modules
├── ports_smp # Architecture and compiler specific files for threadX SMP
├── samples # demo_threadx.c
└── utility # Test cases and utilities
Branches & Releases
The master branch has the most recent code with all new features and bug fixes. It does not represent the latest General Availability (GA) release of the library. Each official release (preview or GA) will be tagged to mark the commit and push it into the Github releases tab, e.g. v6.2-rel.
When you see xx-xx-xxxx, 6.x or x.x in function header, this means the file is not officially released yet. They will be updated in the next release. See example below.
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _tx_initialize_low_level Cortex-M23/GNU */
/* 6.x */
/* AUTHOR */
/* */
/* Scott Larson, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function is responsible for any low-level processor */
/* initialization, including setting up interrupt vectors, setting */
/* up a periodic timer interrupt source, saving the system stack */
/* pointer for use in ISR processing later, and finding the first */
/* available RAM memory address for tx_application_define. */
/* */
/* INPUT */
/* */
/* None */
/* */
/* OUTPUT */
/* */
/* None */
/* */
/* CALLS */
/* */
/* None */
/* */
/* CALLED BY */
/* */
/* _tx_initialize_kernel_enter ThreadX entry function */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 09-30-2020 Scott Larson Initial Version 6.1 */
/* xx-xx-xxxx Scott Larson Include tx_user.h, */
/* resulting in version 6.x */
/* */
/**************************************************************************/
Supported Architecture Ports
ThreadX
arc_em cortex_a12 cortex_m0 cortex_r4
arc_hs cortex_a15 cortex_m23 cortex_r5
arm11 cortex_a17 cortex_m3 cortex_r7
arm9 cortex_a34 cortex_m33
c667x cortex_a35 cortex_m4
linux cortex_a5 cortex_m55
risc-v32 cortex_a53 cortex_m7
rxv1 cortex_a55 cortex_m85
rxv2 cortex_a57
rxv3 cortex_a5x
win32 cortex_a65
xtensa cortex_a65ae
cortex_a7
cortex_a72
cortex_a73
cortex_a75
cortex_a76
cortex_a76ae
cortex_a77
cortex_a8
cortex_a9
ThreadX Modules
Eclipse ThreadX Modules component provides an infrastructure for applications to dynamically load modules that are built separately from the resident portion of the application.
cortex_a35
cortex_a35_smp
cortex_a7
cortex_m0+
cortex_m23
cortex_m3
cortex_m33
cortex_m4
cortex_m7
cortex_r4
rxv2
ThreadX SMP
Eclipse ThreadX SMP is a high-performance real-time SMP kernel designed specifically for embedded applications.
arc_hs_smp
cortex_a34_smp
cortex_a35_smp
cortex_a53_smp
cortex_a55_smp
cortex_a57_smp
cortex_a5x_smp
cortex_a5_smp
cortex_a65ae_smp
cortex_a65_smp
cortex_a72_smp
cortex_a73_smp
cortex_a75_smp
cortex_a76ae_smp
cortex_a76_smp
cortex_a77_smp
cortex_a78_smp
cortex_a7_smp
cortex_a9_smp
linux
Adaptation layer for ThreadX
ThreadX is an advanced real-time operating system (RTOS) designed specifically for deeply embedded applications. To help ease application migration to ThreadX RTOS, Eclipse ThreadX provides adaption layers for various legacy RTOS APIs (FreeRTOS, POSIX, OSEK, etc.).
Component dependencies
The main components of ThreadX RTOS are each provided in their own repository, but there are dependencies between them, as shown in the following graph. This is important to understand when setting up your builds.
You will have to take the dependency graph above into account when building anything other than ThreadX itself.
Building and using the library
Instruction for building the ThreadX as static library using Arm GNU Toolchain and CMake. If you are using toolchain and IDE from semiconductor, you might follow its own instructions to use ThreadX RTOS components as explained in the Getting Started section.
-
Install the following tools:
- CMake version 3.0 or later
- Arm GNU Toolchain for arm-none-eabi
- Ninja
-
Cloning the repo
$ git clone https://github.com/eclipse-threadx/threadx.git -
Define the features and addons you need in
tx_user.hand build together with the component source code. You can refer totx_user_sample.has an example. -
Building as a static library
Each component of ThreadX RTOS comes with a composable CMake-based build system that supports many different MCUs and host systems. Integrating any of these components into your device app code is as simple as adding a git submodule and then including it in your build using the CMake
add_subdirectory().While the typical usage pattern is to include ThreadX into your device code source tree to be built & linked with your code, you can compile this project as a standalone static library to confirm your build is set up correctly.
An example of building the library for Cortex-M4:
$ cmake -Bbuild -GNinja -DCMAKE_TOOLCHAIN_FILE=cmake/cortex_m4.cmake . $ cmake --build ./build
Licensing
License terms for using Eclipse ThreadX are defined in the LICENSE.txt file of this repo. Please refer to this file for all definitive licensing information for all content, incl. the history of this repo.
Resources
The following are references to additional ThreadX RTOS resources:
- Product introduction: https://github.com/eclipse-threadx/rtos-docs
- Product issues and bugs, or feature requests: https://github.com/eclipse-threadx/threadx/issues
- TraceX Installer: https://aka.ms/azrtos-tracex-installer
You can also check previous questions or ask new ones on StackOverflow using the threadx-rtos and threadx tags.
Security
Eclipse ThreadX provides OEMs with components to secure communication and to create code and data isolation using underlying MCU/MPU hardware protection mechanisms. It is ultimately the responsibility of the device builder to ensure the device fully meets the evolving security requirements associated with its specific use case.
Contribution
Please follow the instructions provided in the CONTRIBUTING.md for the corresponding repository.