How do I see all threads in gdb?
How do I see all threads 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 debug a thread?
By Freezing and Thawing threads (suspending and resuming), we can have control of the threads running during the debugging process….
- Insert a Breakpoint in the code.
- Run our application (press F5).
- Click on the Debug menu and choose the windows option then select Threads as shown in the following image.
How do I add a thread to gdb?
Just run a program with s few threads, run gdb and before running attach PROCESS_PID run strace in another console. You must see ptrace (PTRACE_ATTACH) for each thread. Show activity on this post. ptrace PTRACE_ATTACH sends SIGSTOP to the process which suspends the whole process i.e. all threads.
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.
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.
What is backtrace in gdb?
A backtrace is a summary of how your program got where it is. It shows one line per frame, for many frames, starting with the currently executing frame (frame zero), followed by its caller (frame one), and on up the stack.
What is LWP in GDB?
LWP is an acronym and stands for Light Weight Process. It is in effect the thread ID of each newly spawned thread.
What is LWP in gdb?
What does the list command do in GDB?
“list -” lists the ten lines before a previous ten-line listing. One argument specifies a line, and ten lines are listed around that line. Two arguments with comma between specify starting and ending lines to list.
Which command list all break points?
The rbreak command can be used to set breakpoints in all the functions in a program, like this: (gdb) rbreak . Print a table of all breakpoints, watchpoints, and catchpoints set and not deleted, with the following columns for each breakpoint: Breakpoint Numbers.
What is Libthread_db?
libthread_db is a library that provides support for monitoring and manipulating threads-related aspects of a multithreaded program. There are at least two processes involved, the controlling process and one or more target processes.
How do I backtrace for all threads?
To display the backtrace for several or all of the threads, use the command thread apply (see thread apply). For example, if you type thread apply all backtrace , GDB will display the backtrace for all the threads; this is handy when you debug a core dump of a multi-threaded program.
How do I get optimized value in gdb?
To view the “optimized-out” value of a variable during debugging, you need to turn off gcccompiler optimization, either on a per-variable basis, or program-wide. If you are interested in a particular variable in gdb, you can delare the variable as “volatile” and recompile the code.
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.
What is frame in gdb?
The frame contains the arguments given to the function, the function’s local variables, and the address at which the function is executing. When your program is started, the stack has only one frame, that of the function main . This is called the initial frame or the outermost frame.
What does list do in GDB?
What is the B command in GDB?
b – Puts a breakpoint at the current line.
How do I break a specific line in GDB?
To do this, just type “break [functionname]”. gdb will stop your program just before that function is called. Breakpoints stay set when your program ends, so you do not have to reset them unless you quit gdb and restart it. Examining data When your program is stopped you can examine or set the value of any variable.
What does backtrace do in GDB?
A backtrace is a summary of how your program got where it is. It shows one line per frame, for many frames, starting with the currently executing frame (frame zero), followed by its caller (frame one), and on up the stack. Print a backtrace of the entire stack: one line per frame for all frames in the stack.
