pthreads | Threading for PHP - Share Nothing , Do Everything | Android library

I am working on a project where we have used pthread_create to create several child threads. The thread creation logic is not in my control as its implemented by some other part of project.

Each thread perform some operation which takes more than 30 seconds to complete. Under normal condition the program works perfectly fine. But the problem occurs at the time of termination of the program. I need to exit from main as quickly as possible when I receive the SIGINT signal.

When I call exit() or return from main, the exit handlers and global objects' destructors are called. And I believe these operations are having a race condition with the running threads. And I believe there are many race conditions, which is making hard to solve all of theses. The way I see it there are two solutions.

1. call _exit() and forget all de-allocation of resources
2. When SIGINT is there, close/kill all threads and then call exit() from main thread, which will release resources.

I think 1st option will work, but I do not want to abruptly terminate the process. So I want to know if it is possible to terminate all child threads as quickly as possible so that exit handler & destructor can perform required clean-up task and terminate the program.

I have gone through this post, let me know if you know other ways: POSIX API call to list all the pthreads running in a process

Also, let me know if there is any other solution to this problem

I posted a similar question to this one a few weeks ago where I had trouble finding the data race in my N-queens program using pthreads in C. Why is my multithreaded C program not working on macOS, but completely fine on Linux?

I got a few suggestions in the comments sections of the post and I really tried my best to make corrections based on them. I sat with the suggestions a few days, changed some parts but the data race persisted and I just cannot understand why. There are counters inside critical sections for the number of productions and consumptions. I feel completely blind when looking through the code and analyzing it, I'm aware that consumptions are too many but the synchronization around that code fragment should with my knowledge be correct, but obviously something's not right. External input would be greatly appreciated.

This is the code I'm using and I'm not sure how to reduce its size to still reproduce the issue. I compile it with gcc (clang-1205.0.22.11) on macOS Monterey (12.1) using a MacBook Pro 2020 x86_64 architecture.

compile: gcc -o 8q 8q.c*
run: ./8q , NxN chess board, N queens to place
parameters: ./8q 2 4 Enough to highlight the problem (should yield 2 solutions, but every other run yields 3+ solutions, i.e duplicate solutions exist
note: running the program with ./8q 2 4 should give 2 solutions, 1820 productions and 1820 consumptions.

I'm trying to add rotation metadata to the video recorded from RTSP stream. All works fine until I try to run recording with segment format. My command looks like this:

I am a beginner in C programming. In the following code, we have two pthreads. I want one of them to be delayed at the user's choice after the two pthreads are synchronized. I want this delay to be as accurate as possible. In the following code I have done this but the exact amount of delay does not occur.

But I also have another question, and that is how can I force a pthread to run a certain part of the program from start to finish without interruption.

Thank you in advance.

code:

I'm trying to run the following code:

I'm starting from scratch and am following the main steps below:

1. Build and install a cross-compiler toolchain (host Linux, target Win64):

Get this MXE version, only changing plugins/gcc6/gcc6-overlay.mk with:

I am trying to configure CMake to compile my C++ project using the C++20 standard, but it keeps compiling in C++17. My compiler settings in CMakeLists.txt are as follows:

The Question

I have a docker image that builds fine on my local machine (Ubuntu 20.04) but fails on a shared Linode when compiling dlib. And I have absolutely no clue why this is happening.

Anybody knows or has any idea what to do? I assume it has something to do with the underlying hardware but what do I know...

Further Background

• Docker and Docker Compose version are the same on both systems
• all requirements for building dlib are met (proven by my successfull local build)
• I have an image based on nvidia/cuda:11.0.3-cudnn8-runtime-ubuntu20.04
• As I think the missing GPU on the Linode has something to do with it I tried to compile dlib without GPU support with several methods. None worked
• In the end the image exposes a Django API that does a bunch of Machine Learning stuff (using e.g. spacy or face-recognition).

The error message

I recently observed that the CMake Tools Extension in VS Code runs this command to generate the build file for a project I'm working on:

/usr/bin/cmake --no-warn-unused-cli -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=TRUE -DCMAKE_BUILD_TYPE:STRING=Debug -H/home/tirthankar/projects/physicc/Light/Editor -B/home/tirthankar/projects/physicc/Light/build -G Ninja

The part I am confused about is the -H/home/tirthankar/projects/physicc/Light/Editor part. I searched the CMake Docs for this behavior, but all I could find for the -H was this:

CMake Docs saying that -H is for printing the help docs to the terminal

So the question is, what does -H do in CMake? Is it a standard feature? Is it a deprecated feature? Did the CMake Tools Extension make a mistake?

For reference, here is the entire output: