GDB/MI Thread Commands - Debugging with GDB
Description: Debugging with GDB

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### 27.11 gdb/mi Thread Commands

#### The `-thread-info` Command

##### Synopsis

          -thread-info [ thread-id ]

Reports information about either a specific thread, if the thread-id parameter is present, or about all threads. When printing information about all threads, also reports the current thread.

##### gdb Command

The ‘`info thread`’ command prints the same information about all threads.

##### Result

The result is a list of threads. The following attributes are defined for a given thread:

‘`current`’
  This field exists only for the current thread. It has the value ‘`*`’.
‘`id`’
  The identifier that gdb uses to refer to the thread.
‘`target-id`’
  The identifier that the target uses to refer to the thread.
‘`details`’
  Extra information about the thread, in a target-specific format. This field is optional.
‘`name`’
  The name of the thread. If the user specified a name using the `thread name` command, then this name is given. Otherwise, if gdb can extract the thread name from the target, then that name is given. If gdb cannot find the thread name, then this field is omitted.
‘`frame`’
  The stack frame currently executing in the thread.
‘`state`’
  The thread's state. The ‘`state`’ field may have the following values:
  `stopped`
    The thread is stopped. Frame information is available for stopped threads.
  `running`
    The thread is running. There's no frame information for running threads.
‘`core`’
  If gdb can find the CPU core on which this thread is running, then this field is the core identifier. This field is optional.

##### Example

         -thread-info
         ^done,threads=[
         {id="2",target-id="Thread 0xb7e14b90 (LWP 21257)",
            frame={level="0",addr="0xffffe410",func="__kernel_vsyscall",
                    args=[]},state="running"},
         {id="1",target-id="Thread 0xb7e156b0 (LWP 21254)",
            frame={level="0",addr="0x0804891f",func="foo",
                    args=[{name="i",value="10"}],
                    file="/tmp/a.c",fullname="/tmp/a.c",line="158"},
                    state="running"}],
         current-thread-id="1"
         (gdb)

#### The `-thread-list-ids` Command

##### Synopsis

          -thread-list-ids

Produces a list of the currently known gdb thread ids. At the end of the list it also prints the total number of such threads.

This command is retained for historical reasons, the `-thread-info` command should be used instead.

##### gdb Command

Part of ‘`info threads`’ supplies the same information.

##### Example

         (gdb)
         -thread-list-ids
         ^done,thread-ids={thread-id="3",thread-id="2",thread-id="1"},
         current-thread-id="1",number-of-threads="3"
         (gdb)

#### The `-thread-select` Command

##### Synopsis

          -thread-select threadnum

Make threadnum the current thread. It prints the number of the new current thread, and the topmost frame for that thread.

This command is deprecated in favor of explicitly using the ‘`--thread`’ option to each command.

##### gdb Command

The corresponding gdb command is ‘`thread`’.

##### Example

         (gdb)
         -exec-next
         ^running
         (gdb)
         *stopped,reason="end-stepping-range",thread-id="2",line="187",
         file="../../../devo/gdb/testsuite/gdb.threads/linux-dp.c"
         (gdb)
         -thread-list-ids
         ^done,
         thread-ids={thread-id="3",thread-id="2",thread-id="1"},
         number-of-threads="3"
         (gdb)
         -thread-select 3
         ^done,new-thread-id="3",
         frame={level="0",func="vprintf",
         args=[{name="format",value="0x8048e9c \"%*s%c %d %c\\n\""},
         {name="arg",value="0x2"}],file="vprintf.c",line="31"}
         (gdb)