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construct/ircd/ctx.cc

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29 KiB
C++

// Matrix Construct
//
// Copyright (C) Matrix Construct Developers, Authors & Contributors
// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice is present in all copies. The
// full license for this software is available in the LICENSE file.
#include <RB_INC_X86INTRIN_H
#include <cxxabi.h>
#include <ircd/asio.h>
/// Internal context implementation
///
struct ircd::ctx::ctx
{
using error_code = boost::system::error_code;
static uint64_t id_ctr; // monotonic
uint64_t id; // Unique runtime ID
const char *name; // User given name (optional)
context::flags flags; // User given flags
boost::asio::io_service::strand strand; // mutex/serializer
boost::asio::steady_timer alarm; // acting semaphore (64B)
boost::asio::yield_context *yc; // boost interface
uintptr_t stack_base; // assigned when spawned
size_t stack_max; // User given stack size
int64_t notes; // norm: 0 = asleep; 1 = awake; inc by others; dec by self
continuation *cont; // valid when asleep; invalid when awake
ctx *adjoindre; // context waiting for this to join()
microseconds awake; // monotonic counter
ctx *next; // next node in a ctx::list
ctx *prev; // prev node in a ctx::list
bool started() const { return stack_base != 0; }
bool finished() const { return started() && yc == nullptr; }
bool interruption_point(std::nothrow_t); // Check for interrupt (and clear flag)
void interruption_point(); // throws interrupted
bool wait(); // yield context to ios queue (returns on this resume)
void jump(); // jump to context directly (returns on your resume)
void wake(); // jump to context by queueing with ios (use note())
bool note(); // properly request wake()
void operator()(boost::asio::yield_context, const std::function<void ()>) noexcept;
ctx(const char *const &name = "<noname>",
const size_t &stack_max = DEFAULT_STACK_SIZE,
const context::flags &flags = (context::flags)0,
boost::asio::io_service *const &ios = ircd::ios);
ctx(ctx &&) noexcept = delete;
ctx(const ctx &) = delete;
};
/// Monotonic ctx id counter state. This counter is incremented for each
/// newly created context.
decltype(ircd::ctx::ctx::id_ctr)
ircd::ctx::ctx::id_ctr
{
0
};
ircd::ctx::ctx::ctx(const char *const &name,
const size_t &stack_max,
const context::flags &flags,
boost::asio::io_service *const &ios)
:id{++id_ctr}
,name{name}
,flags{flags}
,strand{*ios}
,alarm{*ios}
,yc{nullptr}
,stack_base{0}
,stack_max{stack_max}
,notes{1}
,cont{nullptr}
,adjoindre{nullptr}
,awake{0us}
,next{nullptr}
,prev{nullptr}
{
}
/// Base frame for a context.
///
/// This function is the first thing executed on the new context's stack
/// and calls the user's function.
void
ircd::ctx::ctx::operator()(boost::asio::yield_context yc,
const std::function<void ()> func)
noexcept try
{
this->yc = &yc;
notes = 1;
stack_base = uintptr_t(__builtin_frame_address(0));
ircd::ctx::current = this;
mark(prof::event::CUR_ENTER);
const unwind atexit([this]
{
mark(prof::event::CUR_LEAVE);
if(adjoindre)
notify(*adjoindre);
ircd::ctx::current = nullptr;
this->yc = nullptr;
if(flags & context::DETACH)
delete this;
});
// Check for a precocious interrupt
if(unlikely(flags & context::INTERRUPTED))
return;
if(likely(bool(func)))
func();
}
catch(const std::exception &e)
{
log::critical
{
"ctx(%p '%s' #%u): unhandled: %s",
current,
name,
id,
e.what()
};
// Preserving the stacktrace from the throw point here is hopeless.
// We can terminate for developer nuisance but we will never know
// where this exception came from and where it is going. Bottom line
// is that #ifdef'ing away this handler or rethrowing isn't as useful as
// handling the exception here with a log message and calling it a day.
return;
}
/// Direct context switch to this context.
///
/// This currently doesn't work yet because the suspension state of this
/// context has to be ready to be jumped to and that isn't implemented yet.
void
ircd::ctx::ctx::jump()
{
assert(this->yc);
assert(current != this); // can't jump to self
auto &yc(*this->yc);
auto &target(*yc.coro_.lock());
// Jump from the currently running context (source) to *this (target)
// with continuation of source after target
{
current->notes = 0; // Unconditionally cleared here
const continuation continuation{current};
target();
}
assert(current != this);
assert(current->notes == 1); // notes = 1; set by continuation dtor on wakeup
interruption_point();
}
/// Yield (suspend) this context until notified.
///
/// This context must be currently running otherwise bad things. Returns false
/// if the context was notified before actually suspending; the note is then
/// considered handled an another attempt to `wait()` can be made. Returns true
/// if the context suspended and was notified. When a context wakes up the
/// note counter is reset.
bool
ircd::ctx::ctx::wait()
{
namespace errc = boost::system::errc;
assert(this->yc);
assert(current == this);
if(--notes > 0)
return false;
const auto interruption{[this]
(ctx *const &interruptor) noexcept
{
wake();
}};
boost::system::error_code ec;
alarm.async_wait(boost::asio::yield_context{to_asio{interruption}}[ec]);
assert(ec == errc::operation_canceled || ec == errc::success);
assert(current == this);
assert(notes == 1); // notes = 1; set by continuation dtor on wakeup
interruption_point();
return true;
}
/// Notifies this context to resume (wake up from waiting).
///
/// Returns true if this note was the first note received by this context
/// while it's been suspended or false if it's already been notified.
bool
ircd::ctx::ctx::note()
{
if(notes++ > 0)
return false;
wake();
return true;
}
/// Wakes a context without a note (internal)
void
ircd::ctx::ctx::wake()
try
{
alarm.cancel();
}
catch(const boost::system::system_error &e)
{
log::error
{
"ctx::wake(%p): %s", this, e.what()
};
}
/// Throws if this context has been flagged for interruption and clears
/// the flag.
void
ircd::ctx::ctx::interruption_point()
{
if(unlikely(interruption_point(std::nothrow)))
throw interrupted("ctx(%p) '%s'", (const void *)this, name);
}
/// Returns true if this context has been flagged for interruption and
/// clears the flag.
bool
ircd::ctx::ctx::interruption_point(std::nothrow_t)
{
// Interruption shouldn't be used for normal operation,
// so please eat this branch misprediction.
if(unlikely(flags & context::INTERRUPTED))
{
mark(prof::event::CUR_INTERRUPT);
flags &= ~context::INTERRUPTED;
return true;
}
else return false;
}
///////////////////////////////////////////////////////////////////////////////
//
// ctx/ctx.h
//
/// Yield to context `ctx`.
///
///
void
ircd::ctx::yield(ctx &ctx)
{
assert(current);
//ctx.jump();
// !!! TODO !!!
// XXX: We can't jump directly to a context if it's waiting on its alarm, and
// we don't know whether it's waiting on its alarm. We can add another flag to
// inform us of that, but most contexts are usually waiting on their alarm anyway.
//
// Perhaps a better way to do this would be to centralize the alarms into a single
// context with the sole job of waiting on a single alarm. Then it can schedule
// things allowing for more direct jumps until all work is complete.
// !!! TODO !!!
notify(ctx);
}
/// Notifies `ctx` to wake up from another std::thread
void
ircd::ctx::notify(ctx &ctx,
threadsafe_t)
{
signal(ctx, [&ctx]
{
notify(ctx);
});
}
/// Notifies `ctx` to wake up. This will enqueue the resumption, not jump
/// directly to `ctx`.
bool
ircd::ctx::notify(ctx &ctx)
{
return ctx.note();
}
/// Executes `func` sometime between executions of `ctx` with thread-safety
/// so `func` and `ctx` are never executed concurrently no matter how many
/// threads the io_service has available to execute events on.
void
ircd::ctx::signal(ctx &ctx,
std::function<void ()> func)
{
ctx.strand.post(std::move(func));
}
/// Marks `ctx` for interruption and enqueues it for resumption to receive the
/// interrupt which will be an exception coming out of the point where the
/// `ctx` was yielding.
void
ircd::ctx::interrupt(ctx &ctx)
{
if(finished(ctx))
return;
if(interruption(ctx))
return;
ctx.flags |= context::INTERRUPTED;
if(likely(&ctx != current && ctx.cont != nullptr))
ctx.cont->interrupted(current);
}
/// Indicates if `ctx` was ever jumped to
bool
ircd::ctx::started(const ctx &ctx)
{
return ctx.started();
}
/// Indicates if the base frame for `ctx` returned
bool
ircd::ctx::finished(const ctx &ctx)
{
return ctx.finished();
}
/// Indicates if `ctx` was interrupted; does not clear the flag
bool
ircd::ctx::interruption(const ctx &c)
{
return c.flags & context::INTERRUPTED;
}
/// Returns the notification count for `ctx
const int64_t &
ircd::ctx::notes(const ctx &ctx)
{
return ctx.notes;
}
/// Returns the developer's optional name literal for `ctx`
ircd::string_view
ircd::ctx::name(const ctx &ctx)
{
return ctx.name;
}
/// Returns a reference to unique ID for `ctx` (which will go away with `ctx`)
const uint64_t &
ircd::ctx::id(const ctx &ctx)
{
return ctx.id;
}
///////////////////////////////////////////////////////////////////////////////
//
// ctx/this_ctx.h
//
// set by the continuation object and the base frame.
__thread ircd::ctx::ctx *
ircd::ctx::current;
/// Yield the currently running context until `time_point` ignoring notes
void
ircd::ctx::this_ctx::sleep_until(const std::chrono::steady_clock::time_point &tp)
{
while(!wait_until(tp, std::nothrow));
}
/// Yield the currently running context until notified or `time_point`.
///
/// Returns true if this function returned because `time_point` was hit or
/// false because this context was notified.
bool
ircd::ctx::this_ctx::wait_until(const std::chrono::steady_clock::time_point &tp,
const std::nothrow_t &)
{
auto &c(cur());
c.alarm.expires_at(tp);
c.wait(); // now you're yielding with portals
return std::chrono::steady_clock::now() >= tp;
}
/// Yield the currently running context for `duration` or until notified.
///
/// Returns the duration remaining if notified, or <= 0 if suspended for
/// the full duration, or unchanged if no suspend ever took place.
std::chrono::microseconds
ircd::ctx::this_ctx::wait(const std::chrono::microseconds &duration,
const std::nothrow_t &)
{
auto &c(cur());
c.alarm.expires_from_now(duration);
c.wait(); // now you're yielding with portals
const auto ret(c.alarm.expires_from_now());
// return remaining duration.
// this is > 0 if notified
// this is unchanged if a note prevented any wait at all
return std::chrono::duration_cast<std::chrono::microseconds>(ret);
}
/// Yield the currently running context until notified.
void
ircd::ctx::this_ctx::wait()
{
auto &c(cur());
c.alarm.expires_at(std::chrono::steady_clock::time_point::max());
c.wait(); // now you're yielding with portals
}
/// Post the currently running context to the event queue and then suspend to
/// allow other contexts in the queue to run.
///
/// Until we have our own queue the ios queue makes no guarantees if the queue
/// is FIFO or LIFO etc :-/ It is generally bad practice to use this function,
/// as one should make the effort to devise a specific cooperative strategy for
/// how context switching occurs rather than this coarse/brute technique.
void
ircd::ctx::this_ctx::yield()
{
bool done(false);
const auto restore([&done, &me(cur())]
{
done = true;
notify(me);
});
// All spurious notifications are ignored until `done`
ios->post(restore); do
{
wait();
}
while(!done);
}
/// Throws interrupted if the currently running context was interrupted
/// and clears the interrupt flag.
void
ircd::ctx::this_ctx::interruption_point()
{
return cur().interruption_point();
}
/// Returns true if the currently running context was interrupted and clears
/// the interrupt flag.
bool
ircd::ctx::this_ctx::interruption_requested()
{
return interruption(cur());
}
/// Returns unique ID of currently running context
const uint64_t &
ircd::ctx::this_ctx::id()
{
static const uint64_t zero{0};
return current? id(cur()) : zero;
}
/// Returns optional developer-given name for currently running context
ircd::string_view
ircd::ctx::this_ctx::name()
{
static const string_view nada{"*"};
return current? name(cur()) : nada;
}
//
// exception_handler
//
ircd::ctx::this_ctx::exception_handler::exception_handler()
noexcept
:std::exception_ptr{std::current_exception()}
{
assert(bool(*this));
assert(!std::uncaught_exceptions());
__cxa_end_catch();
assert(!std::current_exception());
}
//
// critical_assertion
//
namespace ircd::ctx
{
bool critical_asserted;
}
ircd::ctx::this_ctx::critical_assertion::critical_assertion()
:theirs{critical_asserted}
{
critical_asserted = true;
}
ircd::ctx::this_ctx::critical_assertion::~critical_assertion()
noexcept
{
assert(critical_asserted);
critical_asserted = theirs;
}
///////////////////////////////////////////////////////////////////////////////
//
// ctx/continuation.h
//
//
// continuation
//
ircd::ctx::continuation::continuation(ctx *const &self)
:self{self}
{
mark(prof::event::CUR_YIELD);
assert(!critical_asserted);
assert(self != nullptr);
assert(self->notes <= 1);
// Note: Construct an instance of ctx::exception_handler to enable yielding
// in your catch block.
//
// GNU cxxabi uses a singly-linked forward list (aka the 'exception
// stack') for pending exception activities. Due to this limitation we
// cannot interleave _cxa_begin_catch() and __cxa_end_catch() by yielding
// the ircd::ctx in an exception handler.
assert(!std::uncaught_exceptions());
assert(!std::current_exception());
self->cont = this;
ircd::ctx::current = nullptr;
}
ircd::ctx::continuation::~continuation()
noexcept
{
ircd::ctx::current = self;
self->notes = 1;
mark(prof::event::CUR_CONTINUE);
// self->continuation is not null'ed here; it remains an invalid
// pointer while the context is awake.
}
void
ircd::ctx::continuation::interrupted(ctx *const &interruptor)
noexcept
{
}
ircd::ctx::continuation::operator boost::asio::yield_context &()
{
return *self->yc;
}
ircd::ctx::continuation::operator const boost::asio::yield_context &()
const
{
return *self->yc;
}
//
// to_asio
//
void
ircd::ctx::to_asio::interrupted(ctx *const &interruptor)
noexcept
{
if(handler)
handler(interruptor);
}
///////////////////////////////////////////////////////////////////////////////
//
// ctx/context.h
//
namespace ircd::ctx
{
static void spawn(ctx *const c, context::function func);
}
void
ircd::ctx::spawn(ctx *const c,
context::function func)
{
const boost::coroutines::attributes attrs
{
c->stack_max,
boost::coroutines::stack_unwind
};
auto bound
{
std::bind(&ctx::operator(), c, ph::_1, std::move(func))
};
boost::asio::spawn(c->strand, std::move(bound), attrs);
}
ircd::ctx::context::context(const char *const &name,
const size_t &stack_sz,
const flags &flags,
function func)
:c{std::make_unique<ctx>(name, stack_sz, flags, ircd::ios)}
{
auto spawn
{
std::bind(&ircd::ctx::spawn, c.get(), std::move(func))
};
// The profiler is told about the spawn request here, not inside the closure
// which is probably the same event-slice as event::CUR_ENTER and not as useful.
mark(prof::event::SPAWN);
// When the user passes the DETACH flag we want to release the unique_ptr
// of the ctx if and only if that ctx is committed to freeing itself. Our
// commitment ends at the 180 of this function. If no exception was thrown
// we expect the context to be committed to entry. If the POST flag is
// supplied and it gets lost in the asio queue it will not be entered, and
// will not be able to free itself; that will leak.
const unwind::nominal release
{
[this, &flags]
{
if(flags & context::DETACH)
this->detach();
}
};
if(flags & POST)
{
ios->post(std::move(spawn));
return;
}
// The current context must be reasserted if spawn returns here
auto *const theirs(ircd::ctx::current);
const unwind recurrent([&theirs]
{
ircd::ctx::current = theirs;
});
if(flags & DISPATCH)
ios->dispatch(std::move(spawn));
else
spawn();
}
ircd::ctx::context::context(const char *const &name,
const size_t &stack_size,
function func,
const flags &flags)
:context
{
name, stack_size, flags, std::move(func)
}
{
}
ircd::ctx::context::context(const char *const &name,
const flags &flags,
function func)
:context
{
name, DEFAULT_STACK_SIZE, flags, std::move(func)
}
{
}
ircd::ctx::context::context(const char *const &name,
function func,
const flags &flags)
:context
{
name, DEFAULT_STACK_SIZE, flags, std::move(func)
}
{
}
ircd::ctx::context::context(function func,
const flags &flags)
:context
{
"<noname>", DEFAULT_STACK_SIZE, flags, std::move(func)
}
{
}
ircd::ctx::context::~context()
noexcept
{
if(!c)
return;
// Can't join to bare metal, only from within another context.
if(current)
{
interrupt();
join();
}
// because *this uses unique_ptr's, if we dtor the ircd::ctx from
// right here and ircd::ctx hasn't been entered yet because the user
// passed the POST flag, the ctx::spawn() is still sitting in the ios
// queue.
if(c && !started(*c))
{
c->flags |= context::DETACH;
c.release();
}
}
void
ircd::ctx::context::join()
{
if(joined())
return;
mark(prof::event::JOIN);
assert(bool(c));
assert(!c->adjoindre);
c->adjoindre = &cur(); // Set the target context to notify this context when it finishes
wait();
mark(prof::event::JOINED);
}
ircd::ctx::ctx *
ircd::ctx::context::detach()
{
assert(bool(c));
c->flags |= DETACH;
return c.release();
}
///////////////////////////////////////////////////////////////////////////////
//
// ctx_pool.h
//
ircd::ctx::pool::pool(const char *const &name,
const size_t &stack_size,
const size_t &size)
:name{name}
,stack_size{stack_size}
,running{0}
,working{0}
{
add(size);
}
ircd::ctx::pool::~pool()
noexcept
{
del(size());
}
void
ircd::ctx::pool::operator()(closure closure)
{
queue.push_back(std::move(closure));
dock.notify_one();
}
void
ircd::ctx::pool::del(const size_t &num)
{
const ssize_t requested(size() - num);
const size_t target(std::max(requested, ssize_t(0)));
while(ctxs.size() > target)
ctxs.pop_back();
}
void
ircd::ctx::pool::add(const size_t &num)
{
for(size_t i(0); i < num; ++i)
ctxs.emplace_back(name, stack_size, context::POST, std::bind(&pool::main, this));
}
void
ircd::ctx::pool::join()
{
del(size());
}
void
ircd::ctx::pool::interrupt()
{
for(auto &context : ctxs)
context.interrupt();
}
void
ircd::ctx::pool::main()
noexcept try
{
++running;
const unwind avail([this]
{
--running;
});
while(1)
next();
}
catch(const interrupted &e)
{
/*
log::debug
{
"pool(%p) ctx(%p): %s", this, &cur(), e.what()
};
*/
}
void
ircd::ctx::pool::next()
try
{
dock.wait([this]
{
return !queue.empty();
});
++working;
const unwind avail([this]
{
--working;
});
const auto func(std::move(queue.front()));
queue.pop_front();
func();
}
catch(const interrupted &e)
{
throw;
}
catch(const std::exception &e)
{
log::critical
{
"pool(%p) ctx(%p '%s' #%u): unhandled: %s",
this,
current,
ircd::ctx::name(cur()),
ircd::ctx::id(cur()),
e.what()
};
}
void
ircd::ctx::debug_stats(const pool &pool)
{
log::debug
{
"pool '%s' (stack size: %zu) total: %zu avail: %zu queued: %zu active: %zu pending: %zu",
pool.name,
pool.stack_size,
pool.size(),
pool.avail(),
pool.queued(),
pool.active(),
pool.pending()
};
}
///////////////////////////////////////////////////////////////////////////////
//
// ctx_prof.h
//
namespace ircd::ctx::prof
{
time_point cur_slice_start; // Time slice state
uint64_t cur_slice_rdtsc; // Time slice state
void check_stack();
void check_slice();
void slice_start();
void handle_cur_continue();
void handle_cur_yield();
void handle_cur_leave();
void handle_cur_enter();
}
struct ircd::ctx::prof::settings ircd::ctx::prof::settings
{
0.33, // stack_usage_warning at 1/3 engineering tolerance
0.50, // stack_usage_assertion at 1/2 engineering tolerance
50ms, // slice_warning at 1/20 slices per second
0us, // slice_interrupt unused until project more mature...
0us, // slice_assertion unused; warning sufficient for now...
};
#ifdef RB_DEBUG
void
ircd::ctx::prof::mark(const event &e)
{
switch(e)
{
case event::CUR_ENTER: handle_cur_enter(); break;
case event::CUR_LEAVE: handle_cur_leave(); break;
case event::CUR_YIELD: handle_cur_yield(); break;
case event::CUR_CONTINUE: handle_cur_continue(); break;
default: break;
}
}
#else
void
ircd::ctx::prof::mark(const event &e)
{
}
#endif
void
ircd::ctx::prof::handle_cur_enter()
{
slice_start();
}
void
ircd::ctx::prof::handle_cur_leave()
{
check_slice();
}
void
ircd::ctx::prof::handle_cur_yield()
{
check_stack();
check_slice();
}
void
ircd::ctx::prof::handle_cur_continue()
{
slice_start();
}
void
ircd::ctx::prof::slice_start()
{
cur_slice_rdtsc = __rdtsc();
cur_slice_start = steady_clock::now();
}
void
ircd::ctx::prof::check_slice()
{
const uint64_t now_rdtsc(__rdtsc());
const uint64_t rdtsc_usage(now_rdtsc - cur_slice_rdtsc);
const auto now_sc(steady_clock::now());
const auto time_usage(now_sc - cur_slice_start);
auto &c(cur());
c.awake += duration_cast<microseconds>(time_usage);
if(unlikely(settings.slice_warning > 0us && time_usage >= settings.slice_warning))
{
log::dwarning
{
"context timeslice exceeded '%s' #%lu total: %06ld$us last: %lu$ns %lu$tsc",
name(c),
id(c),
c.awake.count(),
duration_cast<nanoseconds>(time_usage).count(),
rdtsc_usage
};
assert(settings.slice_assertion == 0us || time_usage < settings.slice_assertion);
}
if(unlikely(settings.slice_interrupt > 0us && time_usage >= settings.slice_interrupt))
throw interrupted
{
"Time slice exceeded '%s' #%lu (last: %06ld microseconds)",
name(c),
id(c),
duration_cast<microseconds>(time_usage).count()
};
}
void
ircd::ctx::prof::check_stack()
{
auto &c(cur());
const double &stack_max(c.stack_max);
const auto stack_usage(stack_usage_here(c));
if(unlikely(stack_usage > stack_max * settings.stack_usage_warning))
{
log::dwarning
{
"context stack usage ctx '%s' #%lu used %zu of %zu bytes",
name(c),
id(c),
stack_usage,
c.stack_max
};
assert(stack_usage < c.stack_max * settings.stack_usage_assertion);
}
}
size_t
ircd::ctx::stack_usage_here()
{
assert(current);
return stack_usage_here(*current);
}
size_t
ircd::ctx::stack_usage_here(const ctx &ctx)
{
return ctx.stack_base - uintptr_t(__builtin_frame_address(0));
}
///////////////////////////////////////////////////////////////////////////////
//
// ctx_ole.h
//
namespace ircd::ctx::ole
{
using closure = std::function<void () noexcept>;
std::mutex mutex;
std::condition_variable cond;
std::deque<closure> queue;
bool interruption;
std::thread *thread;
closure pop();
void worker() noexcept;
void push(closure &&);
}
ircd::ctx::ole::init::init()
{
assert(!thread);
interruption = false;
}
ircd::ctx::ole::init::~init()
noexcept
{
if(!thread)
return;
mutex.lock();
interruption = true;
cond.notify_one();
mutex.unlock();
thread->join();
delete thread;
thread = nullptr;
}
void
ircd::ctx::ole::offload(const std::function<void ()> &func)
{
bool done(false);
auto *const context(current);
const auto kick([&context, &done]
{
done = true;
notify(*context);
});
std::exception_ptr eptr;
auto closure([&func, &eptr, &context, &kick]
() noexcept
{
try
{
func();
}
catch(...)
{
eptr = std::current_exception();
}
// To wake the context on the IRCd thread we give it the kick
signal(*context, kick);
});
push(std::move(closure)); do
{
wait();
}
while(!done);
if(eptr)
std::rethrow_exception(eptr);
}
void
ircd::ctx::ole::push(closure &&func)
{
if(unlikely(!thread))
thread = new std::thread(&worker);
const std::lock_guard<decltype(mutex)> lock(mutex);
queue.emplace_back(std::move(func));
cond.notify_one();
}
void
ircd::ctx::ole::worker()
noexcept try
{
while(1)
{
const auto func(pop());
func();
}
}
catch(const interrupted &)
{
return;
}
ircd::ctx::ole::closure
ircd::ctx::ole::pop()
{
std::unique_lock<decltype(mutex)> lock(mutex);
cond.wait(lock, []
{
if(!queue.empty())
return true;
if(unlikely(interruption))
throw interrupted();
return false;
});
auto c(std::move(queue.front()));
queue.pop_front();
return std::move(c);
}
///////////////////////////////////////////////////////////////////////////////
//
// ctx_list.h
//
void
ircd::ctx::list::remove(ctx *const &c)
{
assert(c);
if(c == head)
{
pop_front();
return;
}
if(c == tail)
{
pop_back();
return;
}
assert(c->next && c->prev);
c->next->prev = c->prev;
c->prev->next = c->next;
c->next = nullptr;
c->prev = nullptr;
}
ircd::ctx::ctx *
ircd::ctx::list::pop_back()
{
const auto tail
{
this->tail
};
if(!tail)
return tail;
assert(!tail->next);
if(!tail->prev)
{
this->head = nullptr;
this->tail = nullptr;
} else {
assert(tail->prev->next == tail);
tail->prev->next = nullptr;
this->tail = tail->prev;
}
tail->prev = nullptr;
tail->next = nullptr;
return tail;
}
ircd::ctx::ctx *
ircd::ctx::list::pop_front()
{
const auto head
{
this->head
};
if(!head)
return head;
assert(!head->prev);
if(!head->next)
{
this->head = nullptr;
this->tail = nullptr;
} else {
assert(head->next->prev == head);
head->next->prev = nullptr;
this->head = head->next;
}
head->prev = nullptr;
head->next = nullptr;
return head;
}
void
ircd::ctx::list::push_front(ctx *const &c)
{
assert(c->next == nullptr);
assert(c->prev == nullptr);
if(!head)
{
head = c;
tail = c;
return;
}
assert(head->prev == nullptr);
head->prev = c;
c->next = head;
head = c;
}
void
ircd::ctx::list::push_back(ctx *const &c)
{
assert(c->next == nullptr);
assert(c->prev == nullptr);
if(!tail)
{
assert(!head);
head = c;
tail = c;
return;
}
assert(tail->next == nullptr);
tail->next = c;
c->prev = tail;
tail = c;
}
void
ircd::ctx::list::rfor_each(const std::function<void (ctx &)> &closure)
{
for(ctx *tail{this->tail}; tail; tail = prev(tail))
closure(*tail);
}
void
ircd::ctx::list::rfor_each(const std::function<void (const ctx &)> &closure)
const
{
for(const ctx *tail{this->tail}; tail; tail = prev(tail))
closure(*tail);
}
void
ircd::ctx::list::for_each(const std::function<void (ctx &)> &closure)
{
for(ctx *head{this->head}; head; head = next(head))
closure(*head);
}
void
ircd::ctx::list::for_each(const std::function<void (const ctx &)> &closure)
const
{
for(const ctx *head{this->head}; head; head = next(head))
closure(*head);
}
bool
ircd::ctx::list::runtil(const std::function<bool (ctx &)> &closure)
{
for(ctx *tail{this->tail}; tail; tail = prev(tail))
if(!closure(*tail))
return false;
return true;
}
bool
ircd::ctx::list::runtil(const std::function<bool (const ctx &)> &closure)
const
{
for(const ctx *tail{this->tail}; tail; tail = prev(tail))
if(!closure(*tail))
return false;
return true;
}
bool
ircd::ctx::list::until(const std::function<bool (ctx &)> &closure)
{
for(ctx *head{this->head}; head; head = next(head))
if(!closure(*head))
return false;
return true;
}
bool
ircd::ctx::list::until(const std::function<bool (const ctx &)> &closure)
const
{
for(const ctx *head{this->head}; head; head = next(head))
if(!closure(*head))
return false;
return true;
}
ircd::ctx::ctx *
ircd::ctx::list::prev(ctx *const &c)
{
assert(c);
return c->prev;
}
ircd::ctx::ctx *
ircd::ctx::list::next(ctx *const &c)
{
assert(c);
return c->next;
}
const ircd::ctx::ctx *
ircd::ctx::list::prev(const ctx *const &c)
{
assert(c);
return c->prev;
}
const ircd::ctx::ctx *
ircd::ctx::list::next(const ctx *const &c)
{
assert(c);
return c->next;
}
///////////////////////////////////////////////////////////////////////////////
//
// ircd/ios.h
//
void
ircd::post(std::function<void ()> function)
{
ircd::ios->post(std::move(function));
}
void
ircd::dispatch(std::function<void ()> function)
{
ircd::ios->dispatch(std::move(function));
}