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Kernel: Rewrite ThreadBlocker

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This gets rid of a very old bug where kernel panics when thread is being
woken up and unblocked at the same time on different cores. This
required adding a new lock to SchedulerQueue::Node and adding a cap to
how many threads a threadblocker can simultaneously block. I don't think
I ever block more than five threads on the same ThreadBlocker so this
should be fine.
This commit is contained in:
Bananymous
2025-07-02 00:17:42 +03:00
parent 41e1819072
commit 92e4078287
5 changed files with 85 additions and 70 deletions
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kernel/kernel/Scheduler.cpp
+18 -9
View File
@@ -4,6 +4,7 @@
#include <kernel/Lock/Mutex.h>
#include <kernel/Process.h>
#include <kernel/Scheduler.h>
#include <kernel/SchedulerQueueNode.h>
#include <kernel/Thread.h>
#include <kernel/Timer/Timer.h>
@@ -307,8 +308,11 @@ namespace Kernel
while (!m_block_queue.empty() && current_ns >= m_block_queue.front()->wake_time_ns)
{
auto* node = m_block_queue.pop_front();
if (node->blocker)
node->blocker->remove_blocked_thread(node);
{
SpinLockGuard _(node->blocker_lock);
if (node->blocker)
node->blocker->remove_blocked_thread(node);
}
node->blocked = false;
update_most_loaded_node_queue(node, &m_run_queue);
m_run_queue.add_thread_to_back(node);
@@ -336,8 +340,11 @@ namespace Kernel
return;
if (node != m_current)
m_block_queue.remove_node(node);
if (node->blocker)
node->blocker->remove_blocked_thread(node);
{
SpinLockGuard _(node->blocker_lock);
if (node->blocker)
node->blocker->remove_blocked_thread(node);
}
node->blocked = false;
if (node != m_current)
m_run_queue.add_thread_to_back(node);
@@ -618,8 +625,13 @@ namespace Kernel
m_current->blocked = true;
m_current->wake_time_ns = wake_time_ns;
if (blocker)
blocker->add_thread_to_block_queue(m_current);
{
SpinLockGuard _(m_current->blocker_lock);
if (blocker)
blocker->add_thread_to_block_queue(m_current);
}
update_most_loaded_node_queue(m_current, &m_block_queue);
uint32_t lock_depth = 0;
@@ -642,10 +654,7 @@ namespace Kernel
void Scheduler::unblock_thread(Thread* thread)
{
auto state = Processor::get_interrupt_state();
Processor::set_interrupt_state(InterruptState::Disabled);
unblock_thread(thread->m_scheduler_node);
Processor::set_interrupt_state(state);
}
Thread& Scheduler::current_thread()