How do I get thread info in GDB?

How do I get thread info in GDB?

Use the “info threads” command to see the IDs of currently known threads. The GDB thread debugging facility allows you to observe all threads while your program runs–but whenever GDB takes control, one thread in particular is always the focus of debugging. This thread is called the current thread.

How do I connect to gdbserver?

20.3. 2 Connecting to gdbserver

  1. Run GDB on the host system.
  2. Make sure you have the necessary symbol files (see Host and target files). Load symbols for your application using the file command before you connect.
  3. Connect to your target (see Connecting to a Remote Target).

What is __ Lll_lock_wait?

__lll_lock_wait() is usually because you’re trying to lock a mutex that is already locked by another thread – so if it’s working on other machines, it looks a bit like a race condition resulting in a deadlock.

How do I list breakpoints in gdb?

You can see these breakpoints with the GDB maintenance command `maint info breakpoints’ . Using the same format as `info breakpoints’ , display both the breakpoints you’ve set explicitly, and those GDB is using for internal purposes. Internal breakpoints are shown with negative breakpoint numbers.

How do I suspend a thread in gdb?

To apply a command to a particular thread issue something like thread apply threadnum command. E.g. thread apply 4 bt will apply backtrace command to a thread number 4. thread apply all continue continues all paused threads.

How do I get GDB on my Mac?

As with GCC, the easiest way to install GDB is through Homebrew. In a Terminal window, run the command brew install gdb , and wait for it to complete. (As usual, it may ask for your password.) Now, we need to code-sign the GDB executable, so it will be allowed to control other processes, as necessary for a debugger.

Where is GDB config file?

On non-macOS hosts the locations searched are:

  1. The file gdb/gdbearlyinit within the directory pointed to by the environment variable XDG_CONFIG_HOME , if it is defined.
  2. The file . config/gdb/gdbearlyinit within the directory pointed to by the environment variable HOME , if it is defined.
  3. The file .

What is Pthread_mutex?

A pthread mutex is a structure of type pthread_mutex_t that implement a behavior based on the Pthread mutexes. An MI mutex is a structure built into the machine that implement a similar sort of serialization construct. The maximum number of recursive locks by the owning thread is 32,767.

How do you debug a mutex deadlock?

Debugging Mutex

  1. Run your program using GDB. $ gdb program.
  2. When the program freezes, stop it using Ctrl-C. ^C.
  3. Do a backtrace to see where we’re deadlocked. (gdb) backtrace.
  4. Switch to the frame. (gdb) frame 4.
  5. Determine which thread currently holds the lock we’re attempting to obtain.
  6. Switch to the owning thread.

What are threads in GDB?

The GDB thread debugging facility allows you to observe all threads while your program runs–but whenever GDB takes control, one thread in particular is always the focus of debugging. This thread is called the current thread. Debugging commands show program information from the perspective of the current thread.

Why it is difficult to debug multi threaded programs?

Parallel processing using many threads can greatly improve program performance, but it may also make debugging more difficult because you’re tracking many threads. Multithreading can introduce new types of potential bugs.

How do you debug a thread problem?

Debug the multithreaded app

  1. In the source code editor, look for one of the following code snippets: C# Copy.
  2. Left-click in the left gutter of the Thread.
  3. On the Debug menu, select Start Debugging (F5).
  4. In the source code editor, locate the line that contains the breakpoint.

What does Ctrl C do in GDB?

Normally when you run a program through GDB you can press Ctrl+C to interrupt it, e.g. if it gets stuck in an infinite loop and you want to get a backtrace.