ardour/libs/pbd/pthread_utils.cc

505 lines
13 KiB
C++

/*
* Copyright (C) 2002-2015 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2007-2009 David Robillard <d@drobilla.net>
* Copyright (C) 2015-2018 Robin Gareus <robin@gareus.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <cstring>
#include <set>
#include <stdint.h>
#include <string>
#if !defined PLATFORM_WINDOWS && defined __GLIBC__
#include <climits>
#include <dlfcn.h>
#endif
#include "pbd/failed_constructor.h"
#include "pbd/pthread_utils.h"
#ifdef COMPILER_MSVC
DECLARE_DEFAULT_COMPARISONS (pthread_t) // Needed for 'DECLARE_DEFAULT_COMPARISONS'. Objects in an STL container can be
// searched and sorted. Thus, when instantiating the container, MSVC complains
// if the type of object being contained has no appropriate comparison operators
// defined (specifically, if operators '<' and '==' are undefined). This seems
// to be the case with ptw32 'pthread_t' which is a simple struct.
#endif
#ifdef __APPLE__
#include <mach/mach_time.h>
#include <mach/thread_act.h>
#include <mach/thread_policy.h>
#endif
using namespace std;
typedef std::list<pthread_t> ThreadMap;
static ThreadMap all_threads;
static pthread_mutex_t thread_map_lock = PTHREAD_MUTEX_INITIALIZER;
static Glib::Threads::Private<char> thread_name (free);
namespace PBD
{
PBD::Signal3<void, pthread_t, std::string, uint32_t> ThreadCreatedWithRequestSize;
}
using namespace PBD;
void
PBD::notify_event_loops_about_thread_creation (pthread_t thread, const std::string& emitting_thread_name, int request_count)
{
/* notify threads that may exist in the future (they may also exist
* already, in which case they will catch the
* ThreadCreatedWithRequestSize signal)
*/
EventLoop::pre_register (emitting_thread_name, request_count);
/* notify all existing threads */
ThreadCreatedWithRequestSize (thread, emitting_thread_name, request_count);
}
struct ThreadStartWithName {
void* (*thread_work) (void*);
void* arg;
std::string name;
ThreadStartWithName (void* (*f) (void*), void* a, const std::string& s)
: thread_work (f)
, arg (a)
, name (s)
{}
};
static void*
fake_thread_start (void* arg)
{
ThreadStartWithName* ts = (ThreadStartWithName*)arg;
void* (*thread_work) (void*) = ts->thread_work;
void* thread_arg = ts->arg;
/* name will be deleted by the default handler for GStaticPrivate, when the thread exits */
pthread_set_name (ts->name.c_str ());
/* we don't need this object anymore */
delete ts;
/* actually run the thread's work function */
void* ret = thread_work (thread_arg);
/* cleanup */
pthread_mutex_lock (&thread_map_lock);
for (ThreadMap::iterator i = all_threads.begin (); i != all_threads.end (); ++i) {
if (pthread_equal ((*i), pthread_self ())) {
all_threads.erase (i);
break;
}
}
pthread_mutex_unlock (&thread_map_lock);
/* done */
return ret;
}
int
pthread_create_and_store (string name, pthread_t* thread, void* (*start_routine) (void*), void* arg)
{
pthread_attr_t default_attr;
int ret;
/* set default stack size to sensible default for memlocking */
pthread_attr_init (&default_attr);
pthread_attr_setstacksize (&default_attr, 0x80000); // 512kB
ThreadStartWithName* ts = new ThreadStartWithName (start_routine, arg, name);
if ((ret = pthread_create (thread, &default_attr, fake_thread_start, ts)) == 0) {
pthread_mutex_lock (&thread_map_lock);
all_threads.push_back (*thread);
pthread_mutex_unlock (&thread_map_lock);
}
pthread_attr_destroy (&default_attr);
return ret;
}
void
pthread_set_name (const char* str)
{
/* copy string and delete it when exiting */
thread_name.set (strdup (str)); // leaks
#if !defined PLATFORM_WINDOWS && defined _GNU_SOURCE
/* set public thread name, up to 16 chars */
char ptn[16];
memset (ptn, 0, 16);
strncpy (ptn, str, 15);
pthread_setname_np (pthread_self (), ptn);
#endif
}
const char*
pthread_name ()
{
const char* str = thread_name.get ();
if (str) {
return str;
}
return "unknown";
}
void
pthread_kill_all (int signum)
{
pthread_mutex_lock (&thread_map_lock);
for (ThreadMap::iterator i = all_threads.begin (); i != all_threads.end (); ++i) {
if (!pthread_equal ((*i), pthread_self ())) {
pthread_kill ((*i), signum);
}
}
all_threads.clear ();
pthread_mutex_unlock (&thread_map_lock);
}
void
pthread_cancel_all ()
{
pthread_mutex_lock (&thread_map_lock);
for (ThreadMap::iterator i = all_threads.begin (); i != all_threads.end ();) {
ThreadMap::iterator nxt = i;
++nxt;
if (!pthread_equal ((*i), pthread_self ())) {
pthread_cancel ((*i));
}
i = nxt;
}
all_threads.clear ();
pthread_mutex_unlock (&thread_map_lock);
}
void
pthread_cancel_one (pthread_t thread)
{
pthread_mutex_lock (&thread_map_lock);
for (ThreadMap::iterator i = all_threads.begin (); i != all_threads.end (); ++i) {
if (pthread_equal ((*i), thread)) {
all_threads.erase (i);
break;
}
}
pthread_cancel (thread);
pthread_mutex_unlock (&thread_map_lock);
}
static size_t
pbd_stack_size ()
{
size_t rv = 0;
#if !defined PLATFORM_WINDOWS && defined __GLIBC__
size_t pt_min_stack = 16384;
#ifdef PTHREAD_STACK_MIN
pt_min_stack = PTHREAD_STACK_MIN;
#endif
void* handle = dlopen (NULL, RTLD_LAZY);
/* This function is internal (it has a GLIBC_PRIVATE) version, but
* available via weak symbol, or dlsym, and returns
*
* GLRO(dl_pagesize) + __static_tls_size + PTHREAD_STACK_MIN
*/
size_t (*__pthread_get_minstack) (const pthread_attr_t* attr) =
(size_t (*) (const pthread_attr_t*))dlsym (handle, "__pthread_get_minstack");
if (__pthread_get_minstack != NULL) {
pthread_attr_t attr;
pthread_attr_init (&attr);
rv = __pthread_get_minstack (&attr);
assert (rv >= pt_min_stack);
rv -= pt_min_stack;
pthread_attr_destroy (&attr);
}
dlclose (handle);
#endif
return rv;
}
int
pbd_pthread_create (
const size_t stacksize,
pthread_t* thread,
void* (*start_routine) (void*),
void* arg)
{
int rv;
pthread_attr_t attr;
pthread_attr_init (&attr);
pthread_attr_setstacksize (&attr, stacksize + pbd_stack_size ());
rv = pthread_create (thread, &attr, start_routine, arg);
pthread_attr_destroy (&attr);
return rv;
}
int
pbd_pthread_priority (PBDThreadClass which)
{
/* fall back to use values relative to max */
#ifdef PLATFORM_WINDOWS
switch (which) {
case THREAD_MAIN:
return -1;
case THREAD_MIDI:
return -2;
default:
case THREAD_PROC:
return -2;
}
#else
int base = -20;
const char* p = getenv ("ARDOUR_SCHED_PRI");
if (p && *p) {
base = atoi (p);
if (base > -5 && base < 5) {
base = -20;
}
}
switch (which) {
case THREAD_MAIN:
return base;
case THREAD_MIDI:
return base - 1;
default:
case THREAD_PROC:
return base - 2;
}
#endif
}
int
pbd_absolute_rt_priority (int policy, int priority)
{
/* POSIX requires a spread of at least 32 steps between min..max */
const int p_min = sched_get_priority_min (policy); // Linux: 1
const int p_max = sched_get_priority_max (policy); // Linux: 99
if (priority == 0) {
assert (0);
priority = (p_min + p_max) / 2;
} else if (priority > 0) {
/* value relative to minium */
priority += p_min - 1;
} else {
/* value relative maximum */
priority += p_max + 1;
}
if (priority > p_max) {
priority = p_max;
}
if (priority < p_min) {
priority = p_min;
}
return priority;
}
int
pbd_realtime_pthread_create (
const int policy, int priority, const size_t stacksize,
pthread_t* thread,
void* (*start_routine) (void*),
void* arg)
{
int rv;
pthread_attr_t attr;
struct sched_param parm;
parm.sched_priority = pbd_absolute_rt_priority (policy, priority);
pthread_attr_init (&attr);
pthread_attr_setschedpolicy (&attr, policy);
pthread_attr_setschedparam (&attr, &parm);
pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
pthread_attr_setinheritsched (&attr, PTHREAD_EXPLICIT_SCHED);
pthread_attr_setstacksize (&attr, stacksize + pbd_stack_size ());
rv = pthread_create (thread, &attr, start_routine, arg);
pthread_attr_destroy (&attr);
return rv;
}
int
pbd_set_thread_priority (pthread_t thread, const int policy, int priority)
{
struct sched_param param;
memset (&param, 0, sizeof (param));
param.sched_priority = pbd_absolute_rt_priority (policy, priority);
return pthread_setschedparam (thread, SCHED_FIFO, &param);
}
bool
pbd_mach_set_realtime_policy (pthread_t thread_id, double period_ns, bool main)
{
#ifdef __APPLE__
/* https://opensource.apple.com/source/xnu/xnu-4570.61.1/osfmk/mach/thread_policy.h.auto.html
* https://opensource.apple.com/source/xnu/xnu-4570.61.1/:sposfmk/kern/sched.h.auto.html
*/
kern_return_t res;
/* Ask for fixed priority */
thread_extended_policy_data_t tep;
tep.timeshare = false;
res = thread_policy_set (pthread_mach_thread_np (thread_id),
THREAD_EXTENDED_POLICY,
(thread_policy_t)&tep,
THREAD_EXTENDED_POLICY_COUNT);
#ifndef NDEBUG
printf ("Mach Thread(%p) set timeshare: %d OK: %d\n", thread_id, tep.timeshare, res == KERN_SUCCESS);
#endif
/* relative value of the computation compared to the other threads in the task. */
thread_precedence_policy_data_t tpp;
tpp.importance = main ? 63 : 62; // MAXPRI_USER = 63
res = thread_policy_set (pthread_mach_thread_np (thread_id),
THREAD_PRECEDENCE_POLICY,
(thread_policy_t)&tpp,
THREAD_PRECEDENCE_POLICY_COUNT);
#ifndef NDEBUG
printf ("Mach Thread(%p) set precedence: %d OK: %d\n", thread_id, tpp.importance, res == KERN_SUCCESS);
#endif
/* Realtime constraints */
double ticks_per_ns = 1.;
mach_timebase_info_data_t timebase;
if (KERN_SUCCESS == mach_timebase_info (&timebase)) {
ticks_per_ns = (double)timebase.denom / (double)timebase.numer;
}
thread_time_constraint_policy_data_t tcp;
#ifndef NDEBUG
mach_msg_type_number_t msgt = 4;
boolean_t dflt = false;
kern_return_t rv = thread_policy_get (pthread_mach_thread_np (thread_id),
THREAD_TIME_CONSTRAINT_POLICY,
(thread_policy_t)&tcp,
&msgt, &dflt);
printf ("Mach Thread(%p) get: period=%d comp=%d constraint=%d preemt=%d OK: %d\n", thread_id, tcp.period, tcp.computation, tcp.constraint, tcp.preemptible, rv == KERN_SUCCESS);
#endif
const double period_clk = period_ns * ticks_per_ns;
tcp.period = period_clk;
tcp.computation = period_clk * .9;
tcp.constraint = period_clk * .95;
tcp.preemptible = true;
#ifndef NDEBUG
printf ("period_ns=%f period_clk=%f timebase.num=%d timebase_den=%d ticks_per_ns=%f\n", period_ns, period_clk, timebase.numer, timebase.denom, ticks_per_ns);
printf ("Mach Thread(%p) request: period=%d comp=%d constraint=%d preemt=%d\n", thread_id, tcp.period, tcp.computation, tcp.constraint, tcp.preemptible);
#endif
res = thread_policy_set (pthread_mach_thread_np (thread_id),
THREAD_TIME_CONSTRAINT_POLICY,
(thread_policy_t)&tcp,
THREAD_TIME_CONSTRAINT_POLICY_COUNT);
#ifndef NDEBUG
printf ("Mach Thread(%p) set: period=%d comp=%d constraint=%d preemt=%d OK: %d\n", thread_id, tcp.period, tcp.computation, tcp.constraint, tcp.preemptible, res == KERN_SUCCESS);
#endif
return res != KERN_SUCCESS;
#endif
return false; // OK
}
PBD::Thread*
PBD::Thread::create (boost::function<void ()> const& slot, std::string const& name)
{
try {
return new PBD::Thread (slot, name);
} catch (...) {
return 0;
}
}
PBD::Thread*
PBD::Thread::self ()
{
return new PBD::Thread ();
}
PBD::Thread::Thread ()
: _name ("Main")
, _joinable (false)
{
_t = pthread_self ();
}
PBD::Thread::Thread (boost::function<void ()> const& slot, std::string const& name)
: _name (name)
, _slot (slot)
, _joinable (true)
{
pthread_attr_t thread_attributes;
pthread_attr_init (&thread_attributes);
if (pthread_create (&_t, &thread_attributes, _run, this)) {
throw failed_constructor ();
}
}
void*
PBD::Thread::_run (void* arg) {
PBD::Thread* self = static_cast<PBD::Thread *>(arg);
if (!self->_name.empty ()) {
pthread_set_name (self->_name.c_str ());
}
self->_slot ();
pthread_exit (0);
return 0;
}
void
PBD::Thread::join ()
{
if (_joinable) {
pthread_join (_t, NULL);
}
}
bool
PBD::Thread::caller_is_self () const
{
return pthread_equal (_t, pthread_self ()) != 0;
}