ladybird/Kernel/FutexQueue.cpp

166 lines
5.7 KiB
C++
Raw Normal View History

/*
* Copyright (c) 2020, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
Meta: Split debug defines into multiple headers. The following script was used to make these changes: #!/bin/bash set -e tmp=$(mktemp -d) echo "tmp=$tmp" find Kernel \( -name '*.cpp' -o -name '*.h' \) | sort > $tmp/Kernel.files find . \( -path ./Toolchain -prune -o -path ./Build -prune -o -path ./Kernel -prune \) -o \( -name '*.cpp' -o -name '*.h' \) -print | sort > $tmp/EverythingExceptKernel.files cat $tmp/Kernel.files | xargs grep -Eho '[A-Z0-9_]+_DEBUG' | sort | uniq > $tmp/Kernel.macros cat $tmp/EverythingExceptKernel.files | xargs grep -Eho '[A-Z0-9_]+_DEBUG' | sort | uniq > $tmp/EverythingExceptKernel.macros comm -23 $tmp/Kernel.macros $tmp/EverythingExceptKernel.macros > $tmp/Kernel.unique comm -1 $tmp/Kernel.macros $tmp/EverythingExceptKernel.macros > $tmp/EverythingExceptKernel.unique cat $tmp/Kernel.unique | awk '{ print "#cmakedefine01 "$1 }' > $tmp/Kernel.header cat $tmp/EverythingExceptKernel.unique | awk '{ print "#cmakedefine01 "$1 }' > $tmp/EverythingExceptKernel.header for macro in $(cat $tmp/Kernel.unique) do cat $tmp/Kernel.files | xargs grep -l $macro >> $tmp/Kernel.new-includes ||: done cat $tmp/Kernel.new-includes | sort > $tmp/Kernel.new-includes.sorted for macro in $(cat $tmp/EverythingExceptKernel.unique) do cat $tmp/Kernel.files | xargs grep -l $macro >> $tmp/Kernel.old-includes ||: done cat $tmp/Kernel.old-includes | sort > $tmp/Kernel.old-includes.sorted comm -23 $tmp/Kernel.new-includes.sorted $tmp/Kernel.old-includes.sorted > $tmp/Kernel.includes.new comm -13 $tmp/Kernel.new-includes.sorted $tmp/Kernel.old-includes.sorted > $tmp/Kernel.includes.old comm -12 $tmp/Kernel.new-includes.sorted $tmp/Kernel.old-includes.sorted > $tmp/Kernel.includes.mixed for file in $(cat $tmp/Kernel.includes.new) do sed -i -E 's/#include <AK\/Debug\.h>/#include <Kernel\/Debug\.h>/' $file done for file in $(cat $tmp/Kernel.includes.mixed) do echo "mixed include in $file, requires manual editing." done
2021-01-25 18:07:10 +03:00
#include <Kernel/Debug.h>
#include <Kernel/FutexQueue.h>
#include <Kernel/Thread.h>
namespace Kernel {
FutexQueue::FutexQueue()
{
}
FutexQueue::~FutexQueue()
{
}
bool FutexQueue::should_add_blocker(Thread::Blocker& b, void*)
{
VERIFY(m_lock.is_locked());
VERIFY(b.blocker_type() == Thread::Blocker::Type::Futex);
2021-01-23 17:30:51 +03:00
VERIFY(m_imminent_waits > 0);
m_imminent_waits--;
if (m_was_removed) {
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: should not block thread {}: was removed", this, b.thread());
return false;
}
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: should block thread {}", this, b.thread());
2021-01-23 17:30:51 +03:00
return true;
}
u32 FutexQueue::wake_n_requeue(u32 wake_count, const Function<FutexQueue*()>& get_target_queue, u32 requeue_count, bool& is_empty, bool& is_empty_target)
{
is_empty_target = false;
SpinlockLocker lock(m_lock);
2021-01-23 17:30:51 +03:00
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: wake_n_requeue({}, {})", this, wake_count, requeue_count);
2021-01-23 17:30:51 +03:00
u32 did_wake = 0, did_requeue = 0;
unblock_all_blockers_whose_conditions_are_met_locked([&](Thread::Blocker& b, void*, bool& stop_iterating) {
VERIFY(b.blocker_type() == Thread::Blocker::Type::Futex);
auto& blocker = static_cast<Thread::FutexBlocker&>(b);
2021-01-23 17:30:51 +03:00
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: wake_n_requeue unblocking {}", this, blocker.thread());
VERIFY(did_wake < wake_count);
if (blocker.unblock()) {
if (++did_wake >= wake_count)
stop_iterating = true;
return true;
}
return false;
});
is_empty = is_empty_and_no_imminent_waits_locked();
if (requeue_count > 0) {
auto blockers_to_requeue = do_take_blockers(requeue_count);
if (!blockers_to_requeue.is_empty()) {
if (auto* target_futex_queue = get_target_queue()) {
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: wake_n_requeue requeueing {} blockers to {}", this, blockers_to_requeue.size(), target_futex_queue);
2021-01-23 17:30:51 +03:00
// While still holding m_lock, notify each blocker
for (auto& info : blockers_to_requeue) {
VERIFY(info.blocker->blocker_type() == Thread::Blocker::Type::Futex);
auto& blocker = *static_cast<Thread::FutexBlocker*>(info.blocker);
blocker.begin_requeue();
}
lock.unlock();
did_requeue = blockers_to_requeue.size();
SpinlockLocker target_lock(target_futex_queue->m_lock);
// Now that we have the lock of the target, append the blockers
// and notify them that they completed the move
for (auto& info : blockers_to_requeue) {
VERIFY(info.blocker->blocker_type() == Thread::Blocker::Type::Futex);
auto& blocker = *static_cast<Thread::FutexBlocker*>(info.blocker);
blocker.finish_requeue(*target_futex_queue);
}
target_futex_queue->do_append_blockers(move(blockers_to_requeue));
is_empty_target = target_futex_queue->is_empty_and_no_imminent_waits_locked();
} else {
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: wake_n_requeue could not get target queue to requeue {} blockers", this, blockers_to_requeue.size());
do_append_blockers(move(blockers_to_requeue));
}
}
}
return did_wake + did_requeue;
}
u32 FutexQueue::wake_n(u32 wake_count, const Optional<u32>& bitset, bool& is_empty)
{
if (wake_count == 0) {
is_empty = false;
2021-01-22 19:42:36 +03:00
return 0; // should we assert instead?
}
SpinlockLocker lock(m_lock);
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: wake_n({})", this, wake_count);
u32 did_wake = 0;
unblock_all_blockers_whose_conditions_are_met_locked([&](Thread::Blocker& b, void*, bool& stop_iterating) {
VERIFY(b.blocker_type() == Thread::Blocker::Type::Futex);
auto& blocker = static_cast<Thread::FutexBlocker&>(b);
2021-01-23 17:30:51 +03:00
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: wake_n unblocking {}", this, blocker.thread());
VERIFY(did_wake < wake_count);
if (bitset.has_value() ? blocker.unblock_bitset(bitset.value()) : blocker.unblock()) {
if (++did_wake >= wake_count)
stop_iterating = true;
return true;
}
return false;
});
is_empty = is_empty_and_no_imminent_waits_locked();
return did_wake;
}
u32 FutexQueue::wake_all(bool& is_empty)
{
SpinlockLocker lock(m_lock);
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: wake_all", this);
u32 did_wake = 0;
unblock_all_blockers_whose_conditions_are_met_locked([&](Thread::Blocker& b, void*, bool&) {
VERIFY(b.blocker_type() == Thread::Blocker::Type::Futex);
auto& blocker = static_cast<Thread::FutexBlocker&>(b);
dbgln_if(FUTEXQUEUE_DEBUG, "FutexQueue @ {}: wake_all unblocking {}", this, blocker.thread());
if (blocker.unblock(true)) {
did_wake++;
return true;
}
return false;
});
is_empty = is_empty_and_no_imminent_waits_locked();
return did_wake;
}
bool FutexQueue::is_empty_and_no_imminent_waits_locked()
{
return m_imminent_waits == 0 && is_empty_locked();
}
bool FutexQueue::queue_imminent_wait()
{
SpinlockLocker lock(m_lock);
if (m_was_removed)
return false;
m_imminent_waits++;
return true;
}
bool FutexQueue::try_remove()
{
SpinlockLocker lock(m_lock);
if (m_was_removed)
return false;
if (!is_empty_and_no_imminent_waits_locked())
return false;
m_was_removed = true;
return true;
}
}