I updated the patch with documentation but forgot about it,
earlier :x
[ruby-core:88616] [Misc #15014]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64535 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Relying on "struct timespec" was too annoying API-wise and
used more stack space. "double" was a bit wacky w.r.t rounding
in the past, so now we'll switch to using a 64-bit type.
Unsigned 64-bit integer is able to give us over nearly 585
years of range with nanoseconds. This range is good enough
for the Linux kernel internal time representation, so it
ought to be good enough for us.
This reduces the stack usage of functions while GVL is held
(and thus subject to marking) on x86-64 Linux (with ppoll):
rb_wait_for_single_fd 120 => 104
do_select 120 => 88
[ruby-core:88582] [Misc #15014]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64533 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Based on r64478, any regular user creating more than 1024 pipes
on Linux will end up with tiny pipes with only a single page
capacity. So avoid wasting user resources and use lighter
eventfd on Linux.
[ruby-core:88563] [Misc #15011]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64527 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Line coverage was based on special instruction "tracecoverage".
Now, instead, it uses the mechanism of trace hook [Feature #14104].
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64509 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
When coverage measurement is enabled, the compiler makes each iseq have
a reference to the counter array of coverage.
Even after coverage measurement is disabled, the reference is kept.
And, if coverage measurement is restarted, a coverage hook will increase
the counter. This is completely meaningless; it brings just overhead.
To remove this meaninglessness, this change removes all the reference
when coverage measuement is stopped.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64504 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Following ko1's lead in r59192, this gets rid of non-obvious
assignments which happen inside macros.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64490 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
According to r52446, it is only necessary for the current item (@i),
not the `@nxt` parameter for list_for_each_safe.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64486 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
It's possible for the ubf_list_head to be populated with dead
threads at fork or the ubf_list_lock to be held, so reinitialize
both at startup.
And while we're at it, use a static initializer at startup
to save a library call and kill some ifdef.
[ruby-core:88578] [Bug #15013]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64485 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
select(2) needs the nfds argument to be one higher than the
largest FD in the sets :x
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64475 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
We do not want to risk switching threads before going to sleep
because it can cause unexpected wakeups and put us in an
unexpected state when used with ConditionVariable.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64464 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Having threads switch before we sleep can cause applications
to misread the state of the thread. Now, we are consistent
with blocking_region_begin behavior and change th->status
AFTER checking interrupts.
Maybe this can fix [Bug #15002]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64449 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Spurious interrupts from SIGCHLD cause Mutex#sleep (via
ConditionVariable#wait) to return early and breaks some use
cases. Since these are outside the programs's control with
MJIT, we will only consider pending interrupts (e.g. those
from Thread#run) and signals which cause a Ruby-level Signal.trap
handler to fire as "spurious" wakeups.
[ruby-core:88537] [Feature #15002]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64444 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Same reasoning as the disarm in rb_sigwait_fd_get, the current
thread is already processing signals, so we do not need
UBF_TIMER to continually kick the process, anymore.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64390 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
On a 64-bit system, this reduces rb_thread_t from 536 to 520 bytes.
Depending on the allocation, this can reduce cacheline access
for checking the abort_on_exception, report_on_exception and
pending_interrupt_queue_checked flags.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64376 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This reverts commit 194a6a2c68 (r64203).
Race conditions which caused the original reversion will be fixed
in the subsequent commit.
[ruby-core:88360] [Misc #14937]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64352 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Saves a syscall and slightly improves vm_thread_condvar1
benchmark slightly (more improvements on the way):
r64170 this patch
vm_thread_condvar1 0.917 1.065
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64185 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
We need to be able to perform periodic ubf_list wakeups when a
thread is sleeping and waiting on signals.
[ruby-core:88088] [Misc #14937] [Bug #5343]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64115 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
We can't always designate a timer thread, so any sleepers must
also perform ubf wakeups. Note: a similar change needs to be
made for rb_thread_fd_select and rb_wait_for_single_fd.
[ruby-core:88088] [Misc #14937] [Bug #5343]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64111 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread_pthread.c relies on ppoll for rb_sigwait_sleep, so ensure
the compatibility wrapper is available for it.
[Bug #14950]
Reported-by: SHIBATA Hiroshi <hsbt@ruby-lang.org>
Reported-by: Greg L <Greg.mpls@gmail.com>
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64110 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
thread_pthread.c relies on ppoll for rb_sigwait_sleep, so ensure
the compatibility wrapper is available for it.
Reported-by: SHIBATA Hiroshi <hsbt@ruby-lang.org>
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64109 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
To reduce resource use and reduce CI failure; remove
timer-thread. Single-threaded Ruby processes (including forked
children) will never see extra thread overhead. This prevents
glibc and jemalloc from going into multi-threaded mode and
initializing locks or causing fragmentation via arena explosion.
The GVL is implements its own wait-queue as a ccan/list to
permit controlling wakeup order. Timeslice under contention is
handled by a designated timer thread (similar to choosing a
"patrol_thread" for current deadlock checking).
There is only one self-pipe, now, as wakeups for timeslice are
done independently using condition variables. This reduces FD
pressure slightly.
Signal handling is handled directly by a Ruby Thread (instead
of timer-thread) by exposing signal self-pipe to callers of
rb_thread_fd_select, native_sleep, rb_wait_for_single_fd, etc...
Acquiring, using, and releasing the self-pipe is exposed via 4
new internal functions:
1) rb_sigwait_fd_get - exclusively acquire timer_thread_pipe.normal[0]
2) rb_sigwait_fd_sleep - sleep and wait for signal (and no other FDs)
3) rb_sigwait_fd_put - release acquired result from rb_sigwait_fd_get
4) rb_sigwait_fd_migrate - migrate signal handling to another thread
after calling rb_sigwait_fd_put.
rb_sigwait_fd_migrate is necessary for waitpid callers because
only one thread can wait on self-pipe at a time, otherwise a
deadlock will occur if threads fight over the self-pipe.
TRAP_INTERRUPT_MASK is now set for the main thread directly in
signal handler via rb_thread_wakeup_timer_thread.
Originally, I wanted to use POSIX timers
(timer_create/timer_settime) for this. Unfortunately, this
proved unfeasible as Mutex#sleep resumes on spurious wakeups and
test/thread/test_cv.rb::test_condvar_timed_wait failed. Using
pthread_sigmask to mask out SIGVTALRM fixed that test, but
test/fiddle/test_function.rb::test_nogvl_poll proved there'd be
some unavoidable (and frequent) incompatibilities from that
approach.
Finally, this allows us to drop thread_destruct_lock and
interrupt current ec directly.
We don't need to rely on vm->thread_destruct_lock or a coherent
vm->running_thread on any platform. Separate timer-thread for
time slice and signal handling is relegated to thread_win32.c,
now.
[ruby-core:88088] [Misc #14937]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64107 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
If we keep ubf set after unregistering, there is a window for
other threads (including timer thread) to put this thread back
on the ubf_list right away. Entering ubf_list unexpectedly
after GVL acquisition may cause spurious wakeup and trigger
unexpected behavior.
Finally, clear ubf before acquiring GVL, to since ubf is useless
during GVL acquisition anyways and we don't want to waste cycles
in other threads calling ubf for useless work.
[ruby-core:88141] [Bug #14945]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64083 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
There's no need to resize each rb_fdset_t to match the size of
the biggest one. This can allow some small memory savings if
watching several sets of FDs simultaneously.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64017 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
When do_select is interrupted and raise happens from
RUBY_VM_CHECK_INTS_BLOCKING, the original FD sets we copied
do not get freed, leading to a memory leak. Wrap up all the
FD sets into a Ruby object to ensure the GC can release an
allocations made for rb_fdset_t.
This leak existed since Ruby 2.0.0 (r36430)
[Bug #14929]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@64007 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
pthread_atfork is not idempotent and repeatedly calling it
causes it to register the same hook repeatedly; leading to
unbound memory growth.
Ruby already has a (confusing-named) internal API for to call
in the forked child process: rb_thread_atfork
Call the MJIT child_after_fork hook inside that to prevent
unbound growth with the following loop:
loop do
RubyVM::MJIT.pause
RubyVM::MJIT.resume
end
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63884 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Round up non-zero <1ms timeouts to 1ms and use INT_MAX instead
of infinite (-1) for extremely large timeouts. All of our
ppoll/select callers are able to handle spurious wakeups,
anyways.
This avoids excessive CPU usage and busy waits with short
timeouts to rb_wait_for_single_fd.
CPU usage with the following script is significantly reduced
for systems with "#undef HAVE_PPOLL":
require 'io/wait'
r, w = IO.pipe
Thread.new { loop { r.wait_readable(0.000001) } }.join(5)
exit!(0)
Low-resolution in poll(2) still sucks, though...
Note: I don't see the value in making a similar change to
time_timeval of a <1us sleep is attempted because of GVL
release and syscall latency.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63867 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Rename it to "ruby_ppoll" so it looks more obvious in debuggers.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63866 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Reading win32/win32.c waitpid implementation, maybe waitpid(-1, ...)
on that platform will never conflict with mjit use of waitpid.
In any case, I've added WAITPID_USE_SIGCHLD macro to vm_core.h
so it can be easy for Linux/BSD users to test (hopefully!)
win32-compatible code.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63855 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
The change is unstable on Windows. Please re-commit it when it correctly
supports Windows.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63852 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Use a global SIGCHLD handler to guard all callers of rb_waitpid.
To work safely with multi-threaded programs, we introduce a
VM-wide waitpid_lock to be acquired BEFORE fork/vfork spawns the
process. This is to be combined with the new ruby_waitpid_locked
function used by mjit.c in a non-Ruby thread.
Ruby-level SIGCHLD handlers registered with Signal.trap(:CHLD)
continues to work as before and there should be no regressions
in any existing use cases.
Splitting the wait queues for PID > 0 and groups (PID <= 0)
ensures we favor PID > 0 callers.
The disabling of SIGCHLD in rb_f_system is longer necessary,
as we use deferred signal handling and no longer make ANY
blocking waitpid syscalls in other threads which could "beat"
the waitpid call made by rb_f_system.
We prevent SIGCHLD from firing in normal Ruby Threads and only
enable it in the timer-thread, to prevent spurious wakeups
from in test/-ext-/gvl/test_last_thread.rb with MJIT enabled.
I've tried to guard as much of the code for RUBY_SIGCHLD==0
using C "if" statements rather than CPP "#if" so to reduce
the likelyhood of portability problems as the compiler will
see more code.
We also work to suppress false-positives from
Process.wait(-1, Process::WNOHANG) to quiets warnings from
spec/ruby/core/process/wait2_spec.rb with MJIT enabled.
Lastly, we must implement rb_grantpt for ext/pty. We need a
MJIT-compatible way of supporting grantpt(3) which may spawn
the `pt_chown' binary and call waitpid(2) on it.
[ruby-core:87605] [Ruby trunk Bug#14867]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63758 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
No point in wasting cycles updating the timespec when not
checking on spurious wakeups.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63719 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
I can't seem to reproduce the maybe-uninitialized warning on
gcc 7 or 8 on Debian sid (7.3.0-16 / 8-20180425-1 r259628),
so the guard from r62305 is dropped.
* thread.c (timeout_prepare): hoist out from do_select
(do_select): ditto
(rb_wait_for_single_fd): use timeout_prepare
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63672 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Same thing as https://bugs.ruby-lang.org/issues/14798
My easily-confused mind gets function call ordering confused
easily:
sleep_forever(..., TRUE, FALSE);
sleep_forever(..., FALSE, TRUE);
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63647 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
We must not leak EINTR to users in case a signal hits a
ppoll/select caller right when (or just before) the timeout
expires. In other words, the timeout should take precedence
over the -1 result from ppoll or select.
We also try one more time in case of EINTR with a zero timeout,
since technically the syscall finished before timing out if
it returns EINTR.
Regression appeared in r62457
("thread.c (update_timespec): use timespec_update_expire",
commit e6bf0128ad)
and is not in any stable release of Ruby.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63462 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This allows native_sleep to use less stack (80 -> 64 bytes on
x86-64) for GVL_UNLOCK_BEGIN/END. For future APIs, we will pass
`ec` or `th` around anyways, so the BLOCKING_REGION change
should be beneficial in the future.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63448 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
FreeBSD 11.0+ supports ppoll, so we may use it after accounting
for portability differences in how it treats POLLOUT vs POLLHUP
events as mutually exclusive (as documented in the FreeBSD
poll(2) manpage).
For waiting on high-numbered single FDs, this should put
FreeBSD on equal footing with Linux and should allow cheaper
FD readiness checking with sleepy GC in the future.
* thread.c (USE_POLL, POLLERR_SET): define for FreeBSD 11.0+
(rb_wait_for_single_fd): return all requested events on POLLERR_SET
io.c (USE_POLL): define for FreeBSD 11.0+
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63427 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
While we cannot use LIST_HEAD since r63312, we can at
least use list_head_init to make our code more readable.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63314 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Address of a variable whose storage duration is `auto` is _not_ a
compile time constant, according to ISO 9899 section 6.4.
LIST_HEAD takes such thing. You can't use it to declare local
variables.
Interestingly, address of a static variable _is_ a compile time
constant. So a declaration like `static LIST_HEAD..` is
completely legal even in C90.
In C99 and newer, this is not a constraint violation.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63312 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
It is unsafe to release GVL and call rb_notify_fd_close after
close(2) on any given FD. FDs (file descriptor) may be recycled
in other threads immediately after close() to point to a different
file description. Note the distinction between "file description"
and "file descriptor".
th-1 | th-2
-------------------------------+---------------------------------------
io_close_fptr |
rb_notify_fd_close(fd) |
fptr_finalize_flush |
close(fd) |
rb_thread_schedule |
| fd reused (via pipe/open/socket/etc)
rb_notify_fd_close(fd) |
| sees "stream closed" exception
| for DIFFERENT file description
* thread.c (rb_thread_io_blocking_region): adjust comment for list_del
* thread.c (rb_notify_fd_close): give busy list to caller
* thread.c (rb_thread_fd_close): loop on busy list
* io.c (io_close_fptr): do not call rb_thread_fd_close on invalid FD
* io.c (io_reopen): use rb_thread_fd_close
Fixes: r57422 ("io.c: close before wait")
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63216 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Instead of maintaining linked-lists to store all
rb_queue/rb_szqueue/rb_condvar structs; store only a fork_gen
serial number to simplify management of these items.
This reduces initialization costs and avoids the up-front cost
of resetting all Queue/SizedQueue/ConditionVariable objects at
fork while saving 8 bytes per-structure on 64-bit. There are no
savings on 32-bit.
* thread.c (rb_thread_atfork_internal): remove rb_thread_sync_reset_all call
* thread_sync.c (rb_thread_sync_reset_all): remove
* thread_sync.c (queue_live): remove
* thread_sync.c (queue_free): remove
* thread_sync.c (struct rb_queue): s/live/fork_gen/
* thread_sync.c (queue_data_type): use default free
* thread_sync.c (queue_alloc): remove list_add
* thread_sync.c (queue_fork_check): new function
* thread_sync.c (queue_ptr): call queue_fork_check
* thread_sync.c (szqueue_free): remove
* thread_sync.c (szqueue_data_type): use default free
* thread_sync.c (szqueue_alloc): remove list_add
* thread_sync.c (szqueue_ptr): check fork_gen via queue_fork_check
* thread_sync.c (struct rb_condvar): s/live/fork_gen/
* thread_sync.c (condvar_free): remove
* thread_sync.c (cv_data_type): use default free
* thread_sync.c (condvar_ptr): check fork_gen
* thread_sync.c (condvar_alloc): remove list_add
[ruby-core:86316] [Bug #14634]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63215 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Instead of allocating and registering the altstack in different
places, do it together to reduce code and improve readability.
When thread cache is enabled, storing altstack in rb_thread_t
is wasteful and we may reuse altstack in the same pthread.
This also lets us clearly allow use of xmalloc to allow GC to
recover from ENOMEM.
[ruby-core:85621] [Feature #14487]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63213 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
This is fairly non-intrusive bugfix to prevent children
from trying to reach into thread stacks of the parent.
I will probably reuse this idea and redo r62934, too
(same bug).
* vm_core.h (typedef struct rb_vm_struct): add fork_gen counter
* thread.c (rb_thread_atfork_internal): increment fork_gen
* variable.c (struct autoload_data_i): store fork_gen
* variable.c (check_autoload_data): remove (replaced with get_...)
* variable.c (get_autoload_data): check fork_gen when retrieving
* variable.c (check_autoload_required): use get_autoload_data
* variable.c (rb_autoloading_value): ditto
* variable.c (rb_autoload_p): ditto
* variable.c (current_autoload_data): ditto
* variable.c (autoload_reset): reset fork_gen, adjust indent
* variable.c (rb_autoload_load): set fork_gen when setting state
* test/ruby/test_autoload.rb (test_autoload_fork): new test
[ruby-core:86410] [Bug #14634]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63210 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* cont.c (root_fiber_alloc): call `ConvertThreadToFiber()` here.
`rb_fiber_t` for root_fiber is allocated before running Threads.
Fiber objects wrapping this rb_fiber_t for root_fiber are created
when root Fiber object is required explicitly (for example, Fiber
switching and so on). We can put calling `ConvertThreadToFiber()`.
In other words, we can pending `ConvertThreadToFiber()`
until Fiber objects are created.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63090 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* cont.c (rb_threadptr_root_fiber_setup): divide into two functions:
* rb_threadptr_root_fiber_setup_by_parent(): called by the parent thread.
* rb_threadptr_root_fiber_setup_by_child(): called by the created thread.
`rb_threadptr_root_fiber_setup()` is called by the parent thread and
set fib->fib_handle by ConvertThreadToFiber() on the parent thread on
Windows enveironment.
This means that root_fib->fib_handle of child thread is initialized
with parent thread's Fiber handle. Furthermore, second call of
`ConvertThreadToFiber()` for the same thread fails.
This patch solves this weird situateion. However, maybe we can make more
clean code.
* thread.c (thread_start_func_2): call
`rb_threadptr_root_fiber_setup_by_child()` at thread initialize routine.
* vm.c (th_init): call `rb_threadptr_root_fiber_setup_by_parent()`.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63073 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
normal
mame
naruse
shyouhei
ko1