mirror of
https://github.com/LadybirdBrowser/ladybird.git
synced 2024-11-27 01:50:24 +00:00
7cf0c7cc0d
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
359 lines
14 KiB
C++
359 lines
14 KiB
C++
/*
|
|
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this
|
|
* list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <AK/TemporaryChange.h>
|
|
#include <Kernel/Debug.h>
|
|
#include <Kernel/KSyms.h>
|
|
#include <Kernel/Lock.h>
|
|
#include <Kernel/Thread.h>
|
|
|
|
namespace Kernel {
|
|
|
|
#if LOCK_DEBUG
|
|
void Lock::lock(Mode mode)
|
|
{
|
|
lock("unknown", 0, mode);
|
|
}
|
|
|
|
void Lock::lock(const char* file, int line, Mode mode)
|
|
#else
|
|
void Lock::lock(Mode mode)
|
|
#endif
|
|
{
|
|
// NOTE: This may be called from an interrupt handler (not an IRQ handler)
|
|
// and also from within critical sections!
|
|
ASSERT(!Processor::current().in_irq());
|
|
ASSERT(mode != Mode::Unlocked);
|
|
auto current_thread = Thread::current();
|
|
ScopedCritical critical; // in case we're not in a critical section already
|
|
for (;;) {
|
|
if (m_lock.exchange(true, AK::memory_order_acq_rel) != false) {
|
|
// I don't know *who* is using "m_lock", so just yield.
|
|
Scheduler::yield_from_critical();
|
|
continue;
|
|
}
|
|
|
|
// FIXME: Do not add new readers if writers are queued.
|
|
Mode current_mode = m_mode;
|
|
switch (current_mode) {
|
|
case Mode::Unlocked: {
|
|
dbgln<LOCK_TRACE_DEBUG>("Lock::lock @ ({}) {}: acquire {}, currently unlocked", this, m_name, mode_to_string(mode));
|
|
m_mode = mode;
|
|
ASSERT(!m_holder);
|
|
ASSERT(m_shared_holders.is_empty());
|
|
if (mode == Mode::Exclusive) {
|
|
m_holder = current_thread;
|
|
} else {
|
|
ASSERT(mode == Mode::Shared);
|
|
m_shared_holders.set(current_thread, 1);
|
|
}
|
|
ASSERT(m_times_locked == 0);
|
|
m_times_locked++;
|
|
#if LOCK_DEBUG
|
|
current_thread->holding_lock(*this, 1, file, line);
|
|
#endif
|
|
m_queue.should_block(true);
|
|
m_lock.store(false, AK::memory_order_release);
|
|
return;
|
|
}
|
|
case Mode::Exclusive: {
|
|
ASSERT(m_holder);
|
|
if (m_holder != current_thread)
|
|
break;
|
|
ASSERT(m_shared_holders.is_empty());
|
|
|
|
if constexpr (LOCK_TRACE_DEBUG) {
|
|
if (mode == Mode::Exclusive)
|
|
dbgln("Lock::lock @ {} ({}): acquire {}, currently exclusive, holding: {}", this, m_name, mode_to_string(mode), m_times_locked);
|
|
else
|
|
dbgln("Lock::lock @ {} ({}): acquire exclusive (requested {}), currently exclusive, holding: {}", this, m_name, mode_to_string(mode), m_times_locked);
|
|
}
|
|
|
|
ASSERT(mode == Mode::Exclusive || mode == Mode::Shared);
|
|
ASSERT(m_times_locked > 0);
|
|
m_times_locked++;
|
|
#if LOCK_DEBUG
|
|
current_thread->holding_lock(*this, 1, file, line);
|
|
#endif
|
|
m_lock.store(false, AK::memory_order_release);
|
|
return;
|
|
}
|
|
case Mode::Shared: {
|
|
ASSERT(!m_holder);
|
|
if (mode != Mode::Shared)
|
|
break;
|
|
|
|
dbgln<LOCK_TRACE_DEBUG>("Lock::lock @ {} ({}): acquire {}, currently shared, locks held {}", this, m_name, mode_to_string(mode), m_times_locked);
|
|
|
|
ASSERT(m_times_locked > 0);
|
|
m_times_locked++;
|
|
ASSERT(!m_shared_holders.is_empty());
|
|
auto it = m_shared_holders.find(current_thread);
|
|
if (it != m_shared_holders.end())
|
|
it->value++;
|
|
else
|
|
m_shared_holders.set(current_thread, 1);
|
|
#if LOCK_DEBUG
|
|
current_thread->holding_lock(*this, 1, file, line);
|
|
#endif
|
|
m_lock.store(false, AK::memory_order_release);
|
|
return;
|
|
}
|
|
default:
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
m_lock.store(false, AK::memory_order_release);
|
|
dbgln<LOCK_TRACE_DEBUG>("Lock::lock @ {} ({}) waiting...", this, m_name);
|
|
m_queue.wait_on({}, m_name);
|
|
dbgln<LOCK_TRACE_DEBUG>("Lock::lock @ {} ({}) waited", this, m_name);
|
|
}
|
|
}
|
|
|
|
void Lock::unlock()
|
|
{
|
|
// NOTE: This may be called from an interrupt handler (not an IRQ handler)
|
|
// and also from within critical sections!
|
|
ASSERT(!Processor::current().in_irq());
|
|
auto current_thread = Thread::current();
|
|
ScopedCritical critical; // in case we're not in a critical section already
|
|
for (;;) {
|
|
if (m_lock.exchange(true, AK::memory_order_acq_rel) == false) {
|
|
Mode current_mode = m_mode;
|
|
if constexpr (LOCK_TRACE_DEBUG) {
|
|
if (current_mode == Mode::Shared)
|
|
dbgln("Lock::unlock @ {} ({}): release {}, locks held: {}", this, m_name, mode_to_string(current_mode), m_times_locked);
|
|
else
|
|
dbgln("Lock::unlock @ {} ({}): release {}, holding: {}", this, m_name, mode_to_string(current_mode), m_times_locked);
|
|
}
|
|
|
|
ASSERT(current_mode != Mode::Unlocked);
|
|
|
|
ASSERT(m_times_locked > 0);
|
|
m_times_locked--;
|
|
|
|
switch (current_mode) {
|
|
case Mode::Exclusive:
|
|
ASSERT(m_holder == current_thread);
|
|
ASSERT(m_shared_holders.is_empty());
|
|
if (m_times_locked == 0)
|
|
m_holder = nullptr;
|
|
break;
|
|
case Mode::Shared: {
|
|
ASSERT(!m_holder);
|
|
auto it = m_shared_holders.find(current_thread);
|
|
ASSERT(it != m_shared_holders.end());
|
|
if (it->value > 1) {
|
|
it->value--;
|
|
} else {
|
|
ASSERT(it->value > 0);
|
|
m_shared_holders.remove(it);
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
|
|
bool unlocked_last = (m_times_locked == 0);
|
|
if (unlocked_last) {
|
|
ASSERT(current_mode == Mode::Exclusive ? !m_holder : m_shared_holders.is_empty());
|
|
m_mode = Mode::Unlocked;
|
|
m_queue.should_block(false);
|
|
}
|
|
|
|
#if LOCK_DEBUG
|
|
current_thread->holding_lock(*this, -1);
|
|
#endif
|
|
|
|
m_lock.store(false, AK::memory_order_release);
|
|
if (unlocked_last) {
|
|
u32 did_wake = m_queue.wake_one();
|
|
dbgln<LOCK_TRACE_DEBUG>("Lock::unlock @ {} ({}) wake one ({})", this, m_name, did_wake);
|
|
}
|
|
return;
|
|
}
|
|
// I don't know *who* is using "m_lock", so just yield.
|
|
Scheduler::yield_from_critical();
|
|
}
|
|
}
|
|
|
|
auto Lock::force_unlock_if_locked(u32& lock_count_to_restore) -> Mode
|
|
{
|
|
// NOTE: This may be called from an interrupt handler (not an IRQ handler)
|
|
// and also from within critical sections!
|
|
ASSERT(!Processor::current().in_irq());
|
|
auto current_thread = Thread::current();
|
|
ScopedCritical critical; // in case we're not in a critical section already
|
|
for (;;) {
|
|
if (m_lock.exchange(true, AK::memory_order_acq_rel) == false) {
|
|
Mode previous_mode;
|
|
auto current_mode = m_mode.load(AK::MemoryOrder::memory_order_relaxed);
|
|
switch (current_mode) {
|
|
case Mode::Exclusive: {
|
|
if (m_holder != current_thread) {
|
|
m_lock.store(false, AK::MemoryOrder::memory_order_release);
|
|
lock_count_to_restore = 0;
|
|
return Mode::Unlocked;
|
|
}
|
|
|
|
dbgln<LOCK_RESTORE_DEBUG>("Lock::force_unlock_if_locked @ {}: unlocking exclusive with lock count: {}", this, m_times_locked);
|
|
#if LOCK_DEBUG
|
|
m_holder->holding_lock(*this, -(int)lock_count_to_restore);
|
|
#endif
|
|
m_holder = nullptr;
|
|
ASSERT(m_times_locked > 0);
|
|
lock_count_to_restore = m_times_locked;
|
|
m_times_locked = 0;
|
|
m_mode = Mode::Unlocked;
|
|
m_queue.should_block(false);
|
|
m_lock.store(false, AK::memory_order_release);
|
|
previous_mode = Mode::Exclusive;
|
|
break;
|
|
}
|
|
case Mode::Shared: {
|
|
ASSERT(!m_holder);
|
|
auto it = m_shared_holders.find(current_thread);
|
|
if (it == m_shared_holders.end()) {
|
|
m_lock.store(false, AK::MemoryOrder::memory_order_release);
|
|
lock_count_to_restore = 0;
|
|
return Mode::Unlocked;
|
|
}
|
|
|
|
dbgln<LOCK_RESTORE_DEBUG>("Lock::force_unlock_if_locked @ {}: unlocking exclusive with lock count: {}, total locks: {}",
|
|
this, it->value, m_times_locked);
|
|
|
|
ASSERT(it->value > 0);
|
|
lock_count_to_restore = it->value;
|
|
ASSERT(lock_count_to_restore > 0);
|
|
#if LOCK_DEBUG
|
|
m_holder->holding_lock(*this, -(int)lock_count_to_restore);
|
|
#endif
|
|
m_shared_holders.remove(it);
|
|
ASSERT(m_times_locked >= lock_count_to_restore);
|
|
m_times_locked -= lock_count_to_restore;
|
|
if (m_times_locked == 0) {
|
|
m_mode = Mode::Unlocked;
|
|
m_queue.should_block(false);
|
|
}
|
|
m_lock.store(false, AK::memory_order_release);
|
|
previous_mode = Mode::Shared;
|
|
break;
|
|
}
|
|
case Mode::Unlocked: {
|
|
m_lock.store(false, AK::memory_order_relaxed);
|
|
lock_count_to_restore = 0;
|
|
previous_mode = Mode::Unlocked;
|
|
break;
|
|
}
|
|
default:
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
m_queue.wake_one();
|
|
return previous_mode;
|
|
}
|
|
// I don't know *who* is using "m_lock", so just yield.
|
|
Scheduler::yield_from_critical();
|
|
}
|
|
}
|
|
|
|
#if LOCK_DEBUG
|
|
void Lock::restore_lock(Mode mode, u32 lock_count)
|
|
{
|
|
return restore_lock("unknown", 0, mode, lock_count);
|
|
}
|
|
|
|
void Lock::restore_lock(const char* file, int line, Mode mode, u32 lock_count)
|
|
#else
|
|
void Lock::restore_lock(Mode mode, u32 lock_count)
|
|
#endif
|
|
{
|
|
ASSERT(mode != Mode::Unlocked);
|
|
ASSERT(lock_count > 0);
|
|
ASSERT(!Processor::current().in_irq());
|
|
auto current_thread = Thread::current();
|
|
ScopedCritical critical; // in case we're not in a critical section already
|
|
for (;;) {
|
|
if (m_lock.exchange(true, AK::memory_order_acq_rel) == false) {
|
|
switch (mode) {
|
|
case Mode::Exclusive: {
|
|
auto expected_mode = Mode::Unlocked;
|
|
if (!m_mode.compare_exchange_strong(expected_mode, Mode::Exclusive))
|
|
break;
|
|
|
|
dbgln<LOCK_RESTORE_DEBUG>("Lock::restore_lock @ {}: restoring {} with lock count {}, was unlocked", this, mode_to_string(mode), lock_count);
|
|
|
|
ASSERT(m_times_locked == 0);
|
|
m_times_locked = lock_count;
|
|
ASSERT(!m_holder);
|
|
ASSERT(m_shared_holders.is_empty());
|
|
m_holder = current_thread;
|
|
m_queue.should_block(true);
|
|
m_lock.store(false, AK::memory_order_release);
|
|
#if LOCK_DEBUG
|
|
m_holder->holding_lock(*this, (int)lock_count, file, line);
|
|
#endif
|
|
return;
|
|
}
|
|
case Mode::Shared: {
|
|
auto expected_mode = Mode::Unlocked;
|
|
if (!m_mode.compare_exchange_strong(expected_mode, Mode::Shared) && expected_mode != Mode::Shared)
|
|
break;
|
|
|
|
dbgln<LOCK_RESTORE_DEBUG>("Lock::restore_lock @ {}: restoring {} with lock count {}, was {}",
|
|
this, mode_to_string(mode), lock_count, mode_to_string(expected_mode));
|
|
|
|
ASSERT(expected_mode == Mode::Shared || m_times_locked == 0);
|
|
m_times_locked += lock_count;
|
|
ASSERT(!m_holder);
|
|
ASSERT((expected_mode == Mode::Unlocked) == m_shared_holders.is_empty());
|
|
auto set_result = m_shared_holders.set(current_thread, lock_count);
|
|
// There may be other shared lock holders already, but we should not have an entry yet
|
|
ASSERT(set_result == AK::HashSetResult::InsertedNewEntry);
|
|
m_queue.should_block(true);
|
|
m_lock.store(false, AK::memory_order_release);
|
|
#if LOCK_DEBUG
|
|
m_holder->holding_lock(*this, (int)lock_count, file, line);
|
|
#endif
|
|
return;
|
|
}
|
|
default:
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
|
|
m_lock.store(false, AK::memory_order_relaxed);
|
|
}
|
|
// I don't know *who* is using "m_lock", so just yield.
|
|
Scheduler::yield_from_critical();
|
|
}
|
|
}
|
|
|
|
void Lock::clear_waiters()
|
|
{
|
|
ASSERT(m_mode != Mode::Shared);
|
|
m_queue.wake_all();
|
|
}
|
|
|
|
}
|