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b30081b49a
Namely, unblock_all_blockers_whose_conditions_are_met(). The old name made it sound like things were getting unblocked no matter what, but that's not actually the case. What this actually does is iterate through the set of blockers, unblocking those whose conditions are met. So give it a (very) verbose name that errs on the side of descriptiveness.
100 lines
3.4 KiB
C++
100 lines
3.4 KiB
C++
/*
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* Copyright (c) 2020, the SerenityOS developers.
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <Kernel/Debug.h>
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#include <Kernel/Thread.h>
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#include <Kernel/WaitQueue.h>
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namespace Kernel {
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bool WaitQueue::should_add_blocker(Thread::Blocker& b, void* data)
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{
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VERIFY(data != nullptr); // Thread that is requesting to be blocked
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VERIFY(m_lock.is_locked());
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VERIFY(b.blocker_type() == Thread::Blocker::Type::Queue);
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if (m_wake_requested || !m_should_block) {
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m_wake_requested = false;
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: do not block thread {}, {}", this, data, m_should_block ? "wake was pending" : "not blocking");
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return false;
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}
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: should block thread {}", this, data);
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return true;
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}
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u32 WaitQueue::wake_one()
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{
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u32 did_wake = 0;
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SpinlockLocker lock(m_lock);
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_one", this);
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bool did_unblock_one = unblock_all_blockers_whose_conditions_are_met_locked([&](Thread::Blocker& b, void* data, bool& stop_iterating) {
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VERIFY(data);
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VERIFY(b.blocker_type() == Thread::Blocker::Type::Queue);
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auto& blocker = static_cast<Thread::QueueBlocker&>(b);
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_one unblocking {}", this, data);
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if (blocker.unblock()) {
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stop_iterating = true;
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did_wake = 1;
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return true;
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}
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return false;
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});
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m_wake_requested = !did_unblock_one;
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_one woke {} threads", this, did_wake);
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return did_wake;
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}
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u32 WaitQueue::wake_n(u32 wake_count)
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{
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if (wake_count == 0)
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return 0; // should we assert instead?
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SpinlockLocker lock(m_lock);
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_n({})", this, wake_count);
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u32 did_wake = 0;
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bool did_unblock_some = unblock_all_blockers_whose_conditions_are_met_locked([&](Thread::Blocker& b, void* data, bool& stop_iterating) {
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VERIFY(data);
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VERIFY(b.blocker_type() == Thread::Blocker::Type::Queue);
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auto& blocker = static_cast<Thread::QueueBlocker&>(b);
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_n unblocking {}", this, data);
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VERIFY(did_wake < wake_count);
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if (blocker.unblock()) {
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if (++did_wake >= wake_count)
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stop_iterating = true;
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return true;
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}
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return false;
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});
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m_wake_requested = !did_unblock_some;
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_n({}) woke {} threads", this, wake_count, did_wake);
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return did_wake;
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}
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u32 WaitQueue::wake_all()
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{
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SpinlockLocker lock(m_lock);
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_all", this);
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u32 did_wake = 0;
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bool did_unblock_any = unblock_all_blockers_whose_conditions_are_met_locked([&](Thread::Blocker& b, void* data, bool&) {
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VERIFY(data);
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VERIFY(b.blocker_type() == Thread::Blocker::Type::Queue);
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auto& blocker = static_cast<Thread::QueueBlocker&>(b);
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_all unblocking {}", this, data);
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if (blocker.unblock()) {
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did_wake++;
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return true;
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}
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return false;
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});
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m_wake_requested = !did_unblock_any;
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dbgln_if(WAITQUEUE_DEBUG, "WaitQueue @ {}: wake_all woke {} threads", this, did_wake);
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return did_wake;
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}
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}
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