Set the worker thread name on Windows

This patch is a bit different from the rest of the series, in that it
is a change to gdb's behavior on the host.  It changes gdb's thread
pool to try to set the thread name on Windows, if SetThreadDescription
is available.

This is part of PR win32/29050.

This patch isn't likely to be useful to many people in the short term,
because the Windows port of the libstdc++ thread code is not upstream.
(AdaCore uses it, and sent it upstream, but it did not land, I don't
know why.)  However, if that patch does ever go in, or presumably if
you build using some other C++ runtime library, then this will be
useful.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29050
This commit is contained in:
Tom Tromey 2022-04-13 08:12:52 -06:00
parent 42a5971407
commit 1ea519ec19

View File

@ -46,14 +46,15 @@
difference. */
ATTRIBUTE_UNUSED static void
set_thread_name (int (*set_name) (pthread_t, const char *, void *),
const char *name)
do_set_thread_name (int (*set_name) (pthread_t, const char *, void *),
const char *name)
{
set_name (pthread_self (), "%s", const_cast<char *> (name));
}
ATTRIBUTE_UNUSED static void
set_thread_name (int (*set_name) (pthread_t, const char *), const char *name)
do_set_thread_name (int (*set_name) (pthread_t, const char *),
const char *name)
{
set_name (pthread_self (), name);
}
@ -61,12 +62,69 @@ set_thread_name (int (*set_name) (pthread_t, const char *), const char *name)
/* The macOS man page says that pthread_setname_np returns "void", but
the headers actually declare it returning "int". */
ATTRIBUTE_UNUSED static void
set_thread_name (int (*set_name) (const char *), const char *name)
do_set_thread_name (int (*set_name) (const char *), const char *name)
{
set_name (name);
}
#endif /* USE_PTHREAD_SETNAME_NP */
static void
set_thread_name (const char *name)
{
do_set_thread_name (pthread_setname_np, name);
}
#elif defined (USE_WIN32API)
#include <windows.h>
typedef HRESULT WINAPI (SetThreadDescription_ftype) (HANDLE, PCWSTR);
static SetThreadDescription_ftype *dyn_SetThreadDescription;
static bool initialized;
static void
init_windows ()
{
initialized = true;
HMODULE hm = LoadLibrary (TEXT ("kernel32.dll"));
if (hm)
dyn_SetThreadDescription
= (SetThreadDescription_ftype *) GetProcAddress (hm,
"SetThreadDescription");
/* On some versions of Windows, this function is only available in
KernelBase.dll, not kernel32.dll. */
if (dyn_SetThreadDescription == nullptr)
{
hm = LoadLibrary (TEXT ("KernelBase.dll"));
if (hm)
dyn_SetThreadDescription
= (SetThreadDescription_ftype *) GetProcAddress (hm,
"SetThreadDescription");
}
}
static void
do_set_thread_name (const wchar_t *name)
{
if (!initialized)
init_windows ();
if (dyn_SetThreadDescription != nullptr)
dyn_SetThreadDescription (GetCurrentThread (), name);
}
#define set_thread_name(NAME) do_set_thread_name (L ## NAME)
#else /* USE_WIN32API */
static void
set_thread_name (const char *name)
{
}
#endif
#endif /* CXX_STD_THREAD */
namespace gdb
@ -159,11 +217,9 @@ thread_pool::do_post_task (std::packaged_task<void ()> &&func)
void
thread_pool::thread_function ()
{
#ifdef USE_PTHREAD_SETNAME_NP
/* This must be done here, because on macOS one can only set the
name of the current thread. */
set_thread_name (pthread_setname_np, "gdb worker");
#endif
set_thread_name ("gdb worker");
/* Ensure that SIGSEGV is delivered to an alternate signal
stack. */