On 02/10/14 11:16, Dr. David Alan Gilbert wrote:
> * Laszlo Ersek (ler...@redhat.com) wrote:
>> a few irrelevant comments below:
>>
>> On 01/30/14 11:20, Dr. David Alan Gilbert (git) wrote:
>>> From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
>>>
>>> Add flag storage to qemu-thread-* to store the namethreads flag
>>>
>>> Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
>>> ---
>>> include/qemu/thread.h | 1 +
>>> qemu-options.hx | 7 +++++--
>>> util/qemu-thread-posix.c | 7 +++++++
>>> util/qemu-thread-win32.c | 8 ++++++++
>>> vl.c | 9 +++++++++
>>> 5 files changed, 30 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/include/qemu/thread.h b/include/qemu/thread.h
>>> index 3e32c65..bf1e110 100644
>>> --- a/include/qemu/thread.h
>>> +++ b/include/qemu/thread.h
>>> @@ -59,5 +59,6 @@ void *qemu_thread_join(QemuThread *thread);
>>> void qemu_thread_get_self(QemuThread *thread);
>>> bool qemu_thread_is_self(QemuThread *thread);
>>> void qemu_thread_exit(void *retval);
>>> +void qemu_thread_naming(bool enable);
>>>
>>> #endif
>>> diff --git a/qemu-options.hx b/qemu-options.hx
>>> index 56e5fdf..068da2d 100644
>>> --- a/qemu-options.hx
>>> +++ b/qemu-options.hx
>>> @@ -328,9 +328,11 @@ possible drivers and properties, use @code{-device
>>> help} and
>>> ETEXI
>>>
>>> DEF("name", HAS_ARG, QEMU_OPTION_name,
>>> - "-name string1[,process=string2]\n"
>>> + "-name string1[,process=string2][,debug-threads=on|off]\n"
>>> " set the name of the guest\n"
>>> - " string1 sets the window title and string2 the process
>>> name (on Linux)\n",
>>> + " string1 sets the window title and string2 the process
>>> name (on Linux)\n"
>>> + " When debug-threads is enabled, individual threads are
>>> given a separate name (on Linux)\n"
>>> + " NOTE: The thread names are for debugging and not a
>>> stable API.\n",
>>> QEMU_ARCH_ALL)
>>> STEXI
>>> @item -name @var{name}
>>> @@ -339,6 +341,7 @@ Sets the @var{name} of the guest.
>>> This name will be displayed in the SDL window caption.
>>> The @var{name} will also be used for the VNC server.
>>> Also optionally set the top visible process name in Linux.
>>> +Naming of individual threads can also be enabled on Linux to aid debugging.
>>> ETEXI
>>>
>>> DEF("uuid", HAS_ARG, QEMU_OPTION_uuid,
>>> diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
>>> index 37dd298..0fa6c81 100644
>>> --- a/util/qemu-thread-posix.c
>>> +++ b/util/qemu-thread-posix.c
>>> @@ -27,6 +27,13 @@
>>> #include "qemu/thread.h"
>>> #include "qemu/atomic.h"
>>>
>>> +static bool name_threads;
>>> +
>>> +void qemu_thread_naming(bool enable)
>>> +{
>>> + name_threads = enable;
>>> +}
>>> +
>>> static void error_exit(int err, const char *msg)
>>> {
>>> fprintf(stderr, "qemu: %s: %s\n", msg, strerror(err));
>>> diff --git a/util/qemu-thread-win32.c b/util/qemu-thread-win32.c
>>> index 27a5217..e42cb77 100644
>>> --- a/util/qemu-thread-win32.c
>>> +++ b/util/qemu-thread-win32.c
>>> @@ -16,6 +16,14 @@
>>> #include <assert.h>
>>> #include <limits.h>
>>>
>>> +static bool name_threads;
>>> +
>>> +void qemu_thread_naming(bool enable)
>>> +{
>>> + /* But note we don't actually name them on Windows yet */
>>> + name_threads = enable;
>>> +}
>>> +
>>> static void error_exit(int err, const char *msg)
>>> {
>>> char *pstr;
>>> diff --git a/vl.c b/vl.c
>>> index 5f993e4..77d6d9e 100644
>>> --- a/vl.c
>>> +++ b/vl.c
>>> @@ -547,6 +547,12 @@ static QemuOptsList qemu_name_opts = {
>>> .name = "process",
>>> .type = QEMU_OPT_STRING,
>>> .help = "Sets the name of the QEMU process, as shown in top
>>> etc",
>>> + }, {
>>> + .name = "debug-threads",
>>> + .type = QEMU_OPT_BOOL,
>>> + .help = "When enabled, name the individual threads; defaults
>>> off.\n"
>>
>> (1) same question about newlines applies
>
> I'd assumed this landed in -help output and that looked OK.
>
>> (2) the default setting is usually advertised in qemu-options.hx, not here
>
> OK
>
>> (3) the meaning of "default" is relative to the case when the option is
>> specified and the option argument is not, *not* relative to when the
>> option is missing. Cf.
>>
>> (a) -name debug-threads
>> (b) -name debug-threads=on
>> (c) [nothing]
>>
>> The default as explained by the help text (in qemu-options.hx),
>> independently of option argument type, is usually the difference between
>> (a) and (b), not (a) and (c), nor between (b) and (c).
>>
>> Here, due to the way boolean options are parsed in parse_option_bool(),
>> (a) is identical to (b), so the default is "on". (See -msg timestamp in
>> qemu-options.hx, it's similar.)
>>
>> I *think*. But I could never really form a decisive understanding of the
>> tradition here, so feel free to ignore it.
>
> If 'default' is (a) then what is the word for (c) ? What I was really
> trying to express was that if you don't pass the option at all it's
> not going to name the threads.
I see. I couldn't name an example where (c) is explicitly referred to.
Thanks
Laszlo
