23.2.2.18 Threads In Python

Python scripts can access information about, and manipulate inferior threads controlled by GDB, via objects of the gdb.InferiorThread class.

The following thread-related functions are available in the gdb module:

Function
gdb.selected_thread ()
This function returns the thread object for the selected thread. If there is no selected thread, this will return None.

To get the list of threads for an inferior, use the Inferior.threads() method. See Inferiors In Python.

A gdb.InferiorThread object has the following attributes:

Variable: InferiorThread.name

The name of the thread. If the user specified a name using thread name, then this returns that name. Otherwise, if an OS-supplied name is available, then it is returned. Otherwise, this returns None.

This attribute can be assigned to. The new value must be a string object, which sets the new name, or None, which removes any user-specified thread name.

Variable
InferiorThread.num
The per-inferior number of the thread, as assigned by GDB.
Variable
InferiorThread.global_num
The global ID of the thread, as assigned by GDB. You can use this to make Python breakpoints thread-specific, for example (see The Breakpoint.thread attribute).
Variable
InferiorThread.ptid
ID of the thread, as assigned by the operating system. This attribute is a tuple containing three integers. The first is the Process ID (PID); the second is the Lightweight Process ID (LWPID), and the third is the Thread ID (TID). Either the LWPID or TID may be 0, which indicates that the operating system does not use that identifier.
Variable
InferiorThread.inferior
The inferior this thread belongs to. This attribute is represented as a gdb.Inferior object. This attribute is not writable.

A gdb.InferiorThread object has the following methods:

Function
InferiorThread.is_valid ()
Returns True if the gdb.InferiorThread object is valid, False if not. A gdb.InferiorThread object will become invalid if the thread exits, or the inferior that the thread belongs is deleted. All other gdb.InferiorThread methods will throw an exception if it is invalid at the time the method is called.
Function
InferiorThread.switch ()
This changes GDB’s currently selected thread to the one represented by this object.
Function
InferiorThread.is_stopped ()
Return a Boolean indicating whether the thread is stopped.
Function
InferiorThread.is_running ()
Return a Boolean indicating whether the thread is running.
Function
InferiorThread.is_exited ()
Return a Boolean indicating whether the thread is exited.
Function
InferiorThread.handle ()
Return the thread object’s handle, represented as a Python bytes object. A gdb.Value representation of the handle may be constructed via gdb.Value(bufobj, type) where bufobj is the Python bytes representation of the handle and type is a gdb.Type for the handle type.