ARM/Memory: Correct Exclusive Monitor and Implement Exclusive Memory Writes.

This commit is contained in:
Fernando Sahmkow 2020-03-07 18:59:42 -04:00
parent 535c542d84
commit cd1c38be8d
12 changed files with 325 additions and 24 deletions

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@ -98,6 +98,8 @@ add_library(common STATIC
algorithm.h algorithm.h
alignment.h alignment.h
assert.h assert.h
atomic_ops.cpp
atomic_ops.h
detached_tasks.cpp detached_tasks.cpp
detached_tasks.h detached_tasks.h
bit_field.h bit_field.h

70
src/common/atomic_ops.cpp Normal file
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@ -0,0 +1,70 @@
// Copyright 2020 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <cstring>
#include "common/atomic_ops.h"
#if _MSC_VER
#include <intrin.h>
#endif
namespace Common {
#if _MSC_VER
bool AtomicCompareAndSwap(u8 volatile* pointer, u8 value, u8 expected) {
u8 result = _InterlockedCompareExchange8((char*)pointer, value, expected);
return result == expected;
}
bool AtomicCompareAndSwap(u16 volatile* pointer, u16 value, u16 expected) {
u16 result = _InterlockedCompareExchange16((short*)pointer, value, expected);
return result == expected;
}
bool AtomicCompareAndSwap(u32 volatile* pointer, u32 value, u32 expected) {
u32 result = _InterlockedCompareExchange((long*)pointer, value, expected);
return result == expected;
}
bool AtomicCompareAndSwap(u64 volatile* pointer, u64 value, u64 expected) {
u64 result = _InterlockedCompareExchange64((__int64*)pointer, value, expected);
return result == expected;
}
bool AtomicCompareAndSwap(u64 volatile* pointer, u128 value, u128 expected) {
return _InterlockedCompareExchange128((__int64*)pointer, value[1], value[0], (__int64*)expected.data()) != 0;
}
#else
bool AtomicCompareAndSwap(u8 volatile* pointer, u8 value, u8 expected) {
return __sync_bool_compare_and_swap (pointer, value, expected);
}
bool AtomicCompareAndSwap(u16 volatile* pointer, u16 value, u16 expected) {
return __sync_bool_compare_and_swap (pointer, value, expected);
}
bool AtomicCompareAndSwap(u32 volatile* pointer, u32 value, u32 expected) {
return __sync_bool_compare_and_swap (pointer, value, expected);
}
bool AtomicCompareAndSwap(u64 volatile* pointer, u64 value, u64 expected) {
return __sync_bool_compare_and_swap (pointer, value, expected);
}
bool AtomicCompareAndSwap(u64 volatile* pointer, u128 value, u128 expected) {
unsigned __int128 value_a;
unsigned __int128 expected_a;
std::memcpy(&value_a, value.data(), sizeof(u128));
std::memcpy(&expected_a, expected.data(), sizeof(u128));
return __sync_bool_compare_and_swap ((unsigned __int128*)pointer, value_a, expected_a);
}
#endif
} // namespace Common

17
src/common/atomic_ops.h Normal file
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@ -0,0 +1,17 @@
// Copyright 2020 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include "common/common_types.h"
namespace Common {
bool AtomicCompareAndSwap(u8 volatile * pointer, u8 value, u8 expected);
bool AtomicCompareAndSwap(u16 volatile* pointer, u16 value, u16 expected);
bool AtomicCompareAndSwap(u32 volatile* pointer, u32 value, u32 expected);
bool AtomicCompareAndSwap(u64 volatile* pointer, u64 value, u64 expected);
bool AtomicCompareAndSwap(u64 volatile* pointer, u128 value, u128 expected);
} // namespace Common

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@ -66,6 +66,22 @@ public:
memory.Write64(vaddr + 8, value[1]); memory.Write64(vaddr + 8, value[1]);
} }
bool MemoryWriteExclusive8(u64 vaddr, std::uint8_t value, std::uint8_t expected) override {
return parent.system.Memory().WriteExclusive8(vaddr, value, expected);
}
bool MemoryWriteExclusive16(u64 vaddr, std::uint16_t value, std::uint16_t expected) override {
return parent.system.Memory().WriteExclusive16(vaddr, value, expected);
}
bool MemoryWriteExclusive32(u64 vaddr, std::uint32_t value, std::uint32_t expected) override {
return parent.system.Memory().WriteExclusive32(vaddr, value, expected);
}
bool MemoryWriteExclusive64(u64 vaddr, std::uint64_t value, std::uint64_t expected) override {
return parent.system.Memory().WriteExclusive64(vaddr, value, expected);
}
bool MemoryWriteExclusive128(u64 vaddr, Vector value, Vector expected) override {
return parent.system.Memory().WriteExclusive128(vaddr, value, expected);
}
void InterpreterFallback(u64 pc, std::size_t num_instructions) override { void InterpreterFallback(u64 pc, std::size_t num_instructions) override {
LOG_INFO(Core_ARM, "Unicorn fallback @ 0x{:X} for {} instructions (instr = {:08X})", pc, LOG_INFO(Core_ARM, "Unicorn fallback @ 0x{:X} for {} instructions (instr = {:08X})", pc,
num_instructions, MemoryReadCode(pc)); num_instructions, MemoryReadCode(pc));
@ -284,9 +300,29 @@ DynarmicExclusiveMonitor::DynarmicExclusiveMonitor(Memory::Memory& memory, std::
DynarmicExclusiveMonitor::~DynarmicExclusiveMonitor() = default; DynarmicExclusiveMonitor::~DynarmicExclusiveMonitor() = default;
void DynarmicExclusiveMonitor::SetExclusive(std::size_t core_index, VAddr addr) { void DynarmicExclusiveMonitor::SetExclusive8(std::size_t core_index, VAddr addr) {
// Size doesn't actually matter. monitor.Mark<u8>(core_index, addr, 1, [&]() -> u8 { return memory.Read8(addr); });
monitor.Mark(core_index, addr, 16); }
void DynarmicExclusiveMonitor::SetExclusive16(std::size_t core_index, VAddr addr) {
monitor.Mark<u16>(core_index, addr, 2, [&]() -> u16 { return memory.Read16(addr); });
}
void DynarmicExclusiveMonitor::SetExclusive32(std::size_t core_index, VAddr addr) {
monitor.Mark<u32>(core_index, addr, 4, [&]() -> u32 { return memory.Read32(addr); });
}
void DynarmicExclusiveMonitor::SetExclusive64(std::size_t core_index, VAddr addr) {
monitor.Mark<u64>(core_index, addr, 8, [&]() -> u64 { return memory.Read64(addr); });
}
void DynarmicExclusiveMonitor::SetExclusive128(std::size_t core_index, VAddr addr) {
monitor.Mark<u128>(core_index, addr, 16, [&]() -> u128 {
u128 result;
result[0] = memory.Read64(addr);
result[1] = memory.Read64(addr + 8);
return result;
});
} }
void DynarmicExclusiveMonitor::ClearExclusive() { void DynarmicExclusiveMonitor::ClearExclusive() {
@ -294,28 +330,32 @@ void DynarmicExclusiveMonitor::ClearExclusive() {
} }
bool DynarmicExclusiveMonitor::ExclusiveWrite8(std::size_t core_index, VAddr vaddr, u8 value) { bool DynarmicExclusiveMonitor::ExclusiveWrite8(std::size_t core_index, VAddr vaddr, u8 value) {
return monitor.DoExclusiveOperation(core_index, vaddr, 1, [&] { memory.Write8(vaddr, value); }); return monitor.DoExclusiveOperation<u8>(core_index, vaddr, 1, [&](u8 expected) -> bool {
return memory.WriteExclusive8(vaddr, value, expected);
});
} }
bool DynarmicExclusiveMonitor::ExclusiveWrite16(std::size_t core_index, VAddr vaddr, u16 value) { bool DynarmicExclusiveMonitor::ExclusiveWrite16(std::size_t core_index, VAddr vaddr, u16 value) {
return monitor.DoExclusiveOperation(core_index, vaddr, 2, return monitor.DoExclusiveOperation<u16>(core_index, vaddr, 2, [&](u16 expected) -> bool {
[&] { memory.Write16(vaddr, value); }); return memory.WriteExclusive16(vaddr, value, expected);
});
} }
bool DynarmicExclusiveMonitor::ExclusiveWrite32(std::size_t core_index, VAddr vaddr, u32 value) { bool DynarmicExclusiveMonitor::ExclusiveWrite32(std::size_t core_index, VAddr vaddr, u32 value) {
return monitor.DoExclusiveOperation(core_index, vaddr, 4, return monitor.DoExclusiveOperation<u32>(core_index, vaddr, 4, [&](u32 expected) -> bool {
[&] { memory.Write32(vaddr, value); }); return memory.WriteExclusive32(vaddr, value, expected);
});
} }
bool DynarmicExclusiveMonitor::ExclusiveWrite64(std::size_t core_index, VAddr vaddr, u64 value) { bool DynarmicExclusiveMonitor::ExclusiveWrite64(std::size_t core_index, VAddr vaddr, u64 value) {
return monitor.DoExclusiveOperation(core_index, vaddr, 8, return monitor.DoExclusiveOperation<u64>(core_index, vaddr, 8, [&](u64 expected) -> bool {
[&] { memory.Write64(vaddr, value); }); return memory.WriteExclusive64(vaddr, value, expected);
});
} }
bool DynarmicExclusiveMonitor::ExclusiveWrite128(std::size_t core_index, VAddr vaddr, u128 value) { bool DynarmicExclusiveMonitor::ExclusiveWrite128(std::size_t core_index, VAddr vaddr, u128 value) {
return monitor.DoExclusiveOperation(core_index, vaddr, 16, [&] { return monitor.DoExclusiveOperation<u128>(core_index, vaddr, 16, [&](u128 expected) -> bool {
memory.Write64(vaddr + 0, value[0]); return memory.WriteExclusive128(vaddr, value, expected);
memory.Write64(vaddr + 8, value[1]);
}); });
} }

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@ -82,7 +82,11 @@ public:
explicit DynarmicExclusiveMonitor(Memory::Memory& memory, std::size_t core_count); explicit DynarmicExclusiveMonitor(Memory::Memory& memory, std::size_t core_count);
~DynarmicExclusiveMonitor() override; ~DynarmicExclusiveMonitor() override;
void SetExclusive(std::size_t core_index, VAddr addr) override; void SetExclusive8(std::size_t core_index, VAddr addr) override;
void SetExclusive16(std::size_t core_index, VAddr addr) override;
void SetExclusive32(std::size_t core_index, VAddr addr) override;
void SetExclusive64(std::size_t core_index, VAddr addr) override;
void SetExclusive128(std::size_t core_index, VAddr addr) override;
void ClearExclusive() override; void ClearExclusive() override;
bool ExclusiveWrite8(std::size_t core_index, VAddr vaddr, u8 value) override; bool ExclusiveWrite8(std::size_t core_index, VAddr vaddr, u8 value) override;

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@ -18,7 +18,11 @@ class ExclusiveMonitor {
public: public:
virtual ~ExclusiveMonitor(); virtual ~ExclusiveMonitor();
virtual void SetExclusive(std::size_t core_index, VAddr addr) = 0; virtual void SetExclusive8(std::size_t core_index, VAddr addr) = 0;
virtual void SetExclusive16(std::size_t core_index, VAddr addr) = 0;
virtual void SetExclusive32(std::size_t core_index, VAddr addr) = 0;
virtual void SetExclusive64(std::size_t core_index, VAddr addr) = 0;
virtual void SetExclusive128(std::size_t core_index, VAddr addr) = 0;
virtual void ClearExclusive() = 0; virtual void ClearExclusive() = 0;
virtual bool ExclusiveWrite8(std::size_t core_index, VAddr vaddr, u8 value) = 0; virtual bool ExclusiveWrite8(std::size_t core_index, VAddr vaddr, u8 value) = 0;

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@ -90,7 +90,7 @@ ResultCode AddressArbiter::IncrementAndSignalToAddressIfEqual(VAddr address, s32
auto& monitor = system.Monitor(); auto& monitor = system.Monitor();
u32 current_value; u32 current_value;
do { do {
monitor.SetExclusive(current_core, address); monitor.SetExclusive32(current_core, address);
current_value = memory.Read32(address); current_value = memory.Read32(address);
if (current_value != value) { if (current_value != value) {
@ -120,7 +120,7 @@ ResultCode AddressArbiter::ModifyByWaitingCountAndSignalToAddressIfEqual(VAddr a
auto& monitor = system.Monitor(); auto& monitor = system.Monitor();
s32 updated_value; s32 updated_value;
do { do {
monitor.SetExclusive(current_core, address); monitor.SetExclusive32(current_core, address);
updated_value = memory.Read32(address); updated_value = memory.Read32(address);
if (updated_value != value) { if (updated_value != value) {
@ -191,7 +191,7 @@ ResultCode AddressArbiter::WaitForAddressIfLessThan(VAddr address, s32 value, s6
const std::size_t current_core = system.CurrentCoreIndex(); const std::size_t current_core = system.CurrentCoreIndex();
auto& monitor = system.Monitor(); auto& monitor = system.Monitor();
do { do {
monitor.SetExclusive(current_core, address); monitor.SetExclusive32(current_core, address);
current_value = static_cast<s32>(memory.Read32(address)); current_value = static_cast<s32>(memory.Read32(address));
if (should_decrement) { if (should_decrement) {
decrement_value = current_value - 1; decrement_value = current_value - 1;

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@ -10,6 +10,7 @@
#include "common/logging/log.h" #include "common/logging/log.h"
#include "core/core.h" #include "core/core.h"
#include "core/arm/exclusive_monitor.h" #include "core/arm/exclusive_monitor.h"
#include "core/core.h"
#include "core/hle/kernel/errors.h" #include "core/hle/kernel/errors.h"
#include "core/hle/kernel/handle_table.h" #include "core/hle/kernel/handle_table.h"
#include "core/hle/kernel/kernel.h" #include "core/hle/kernel/kernel.h"
@ -138,7 +139,7 @@ std::pair<ResultCode, std::shared_ptr<Thread>> Mutex::Unlock(std::shared_ptr<Thr
const std::size_t current_core = system.CurrentCoreIndex(); const std::size_t current_core = system.CurrentCoreIndex();
if (new_owner == nullptr) { if (new_owner == nullptr) {
do { do {
monitor.SetExclusive(current_core, address); monitor.SetExclusive32(current_core, address);
} while (!monitor.ExclusiveWrite32(current_core, address, 0)); } while (!monitor.ExclusiveWrite32(current_core, address, 0));
return {RESULT_SUCCESS, nullptr}; return {RESULT_SUCCESS, nullptr};
} }
@ -154,7 +155,7 @@ std::pair<ResultCode, std::shared_ptr<Thread>> Mutex::Unlock(std::shared_ptr<Thr
new_owner->ResumeFromWait(); new_owner->ResumeFromWait();
do { do {
monitor.SetExclusive(current_core, address); monitor.SetExclusive32(current_core, address);
} while (!monitor.ExclusiveWrite32(current_core, address, mutex_value)); } while (!monitor.ExclusiveWrite32(current_core, address, mutex_value));
return {RESULT_SUCCESS, new_owner}; return {RESULT_SUCCESS, new_owner};
} }

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@ -1641,7 +1641,7 @@ static void SignalProcessWideKey(Core::System& system, VAddr condition_variable_
u32 update_val = 0; u32 update_val = 0;
const VAddr mutex_address = thread->GetMutexWaitAddress(); const VAddr mutex_address = thread->GetMutexWaitAddress();
do { do {
monitor.SetExclusive(current_core, mutex_address); monitor.SetExclusive32(current_core, mutex_address);
// If the mutex is not yet acquired, acquire it. // If the mutex is not yet acquired, acquire it.
mutex_val = memory.Read32(mutex_address); mutex_val = memory.Read32(mutex_address);

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@ -236,7 +236,7 @@ ResultVal<std::shared_ptr<Thread>> Thread::Create(Core::System& system, ThreadTy
ResetThreadContext64(thread->context_64, stack_top, entry_point, arg); ResetThreadContext64(thread->context_64, stack_top, entry_point, arg);
} }
thread->host_context = thread->host_context =
std::make_shared<Common::Fiber>(std::move(thread_start_func), thread_start_parameter); std::make_shared<Common::Fiber>(std::move(thread_start_func), thread_start_parameter);
return MakeResult<std::shared_ptr<Thread>>(std::move(thread)); return MakeResult<std::shared_ptr<Thread>>(std::move(thread));
} }
@ -412,12 +412,12 @@ ResultCode Thread::SetActivity(ThreadActivity value) {
} }
if (value == ThreadActivity::Paused) { if (value == ThreadActivity::Paused) {
if (pausing_state & static_cast<u32>(ThreadSchedFlags::ThreadPauseFlag) != 0) { if ((pausing_state & static_cast<u32>(ThreadSchedFlags::ThreadPauseFlag)) != 0) {
return ERR_INVALID_STATE; return ERR_INVALID_STATE;
} }
AddSchedulingFlag(ThreadSchedFlags::ThreadPauseFlag); AddSchedulingFlag(ThreadSchedFlags::ThreadPauseFlag);
} else { } else {
if (pausing_state & static_cast<u32>(ThreadSchedFlags::ThreadPauseFlag) == 0) { if ((pausing_state & static_cast<u32>(ThreadSchedFlags::ThreadPauseFlag)) == 0) {
return ERR_INVALID_STATE; return ERR_INVALID_STATE;
} }
RemoveSchedulingFlag(ThreadSchedFlags::ThreadPauseFlag); RemoveSchedulingFlag(ThreadSchedFlags::ThreadPauseFlag);

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@ -8,6 +8,7 @@
#include <utility> #include <utility>
#include "common/assert.h" #include "common/assert.h"
#include "common/atomic_ops.h"
#include "common/common_types.h" #include "common/common_types.h"
#include "common/logging/log.h" #include "common/logging/log.h"
#include "common/page_table.h" #include "common/page_table.h"
@ -176,6 +177,22 @@ struct Memory::Impl {
} }
} }
bool WriteExclusive8(const VAddr addr, const u8 data, const u8 expected) {
return WriteExclusive<u8>(addr, data, expected);
}
bool WriteExclusive16(const VAddr addr, const u16 data, const u16 expected) {
return WriteExclusive<u16_le>(addr, data, expected);
}
bool WriteExclusive32(const VAddr addr, const u32 data, const u32 expected) {
return WriteExclusive<u32_le>(addr, data, expected);
}
bool WriteExclusive64(const VAddr addr, const u64 data, const u64 expected) {
return WriteExclusive<u64_le>(addr, data, expected);
}
std::string ReadCString(VAddr vaddr, std::size_t max_length) { std::string ReadCString(VAddr vaddr, std::size_t max_length) {
std::string string; std::string string;
string.reserve(max_length); string.reserve(max_length);
@ -679,6 +696,67 @@ struct Memory::Impl {
} }
} }
template <typename T>
bool WriteExclusive(const VAddr vaddr, const T data, const T expected) {
u8* page_pointer = current_page_table->pointers[vaddr >> PAGE_BITS];
if (page_pointer != nullptr) {
// NOTE: Avoid adding any extra logic to this fast-path block
T volatile* pointer = reinterpret_cast<T volatile*>(&page_pointer[vaddr]);
return Common::AtomicCompareAndSwap(pointer, data, expected);
}
const Common::PageType type = current_page_table->attributes[vaddr >> PAGE_BITS];
switch (type) {
case Common::PageType::Unmapped:
LOG_ERROR(HW_Memory, "Unmapped Write{} 0x{:08X} @ 0x{:016X}", sizeof(data) * 8,
static_cast<u32>(data), vaddr);
return true;
case Common::PageType::Memory:
ASSERT_MSG(false, "Mapped memory page without a pointer @ {:016X}", vaddr);
break;
case Common::PageType::RasterizerCachedMemory: {
u8* host_ptr{GetPointerFromVMA(vaddr)};
system.GPU().InvalidateRegion(ToCacheAddr(host_ptr), sizeof(T));
T volatile* pointer = reinterpret_cast<T volatile*>(&host_ptr);
return Common::AtomicCompareAndSwap(pointer, data, expected);
break;
}
default:
UNREACHABLE();
}
return true;
}
bool WriteExclusive128(const VAddr vaddr, const u128 data, const u128 expected) {
u8* const page_pointer = current_page_table->pointers[vaddr >> PAGE_BITS];
if (page_pointer != nullptr) {
// NOTE: Avoid adding any extra logic to this fast-path block
u64 volatile* pointer = reinterpret_cast<u64 volatile*>(&page_pointer[vaddr]);
return Common::AtomicCompareAndSwap(pointer, data, expected);
}
const Common::PageType type = current_page_table->attributes[vaddr >> PAGE_BITS];
switch (type) {
case Common::PageType::Unmapped:
LOG_ERROR(HW_Memory, "Unmapped Write{} 0x{:08X} @ 0x{:016X}{:016X}", sizeof(data) * 8,
static_cast<u64>(data[1]), static_cast<u64>(data[0]), vaddr);
return true;
case Common::PageType::Memory:
ASSERT_MSG(false, "Mapped memory page without a pointer @ {:016X}", vaddr);
break;
case Common::PageType::RasterizerCachedMemory: {
u8* host_ptr{GetPointerFromVMA(vaddr)};
system.GPU().InvalidateRegion(ToCacheAddr(host_ptr), sizeof(u128));
u64 volatile* pointer = reinterpret_cast<u64 volatile*>(&host_ptr);
return Common::AtomicCompareAndSwap(pointer, data, expected);
break;
}
default:
UNREACHABLE();
}
return true;
}
Common::PageTable* current_page_table = nullptr; Common::PageTable* current_page_table = nullptr;
Core::System& system; Core::System& system;
}; };
@ -761,6 +839,26 @@ void Memory::Write64(VAddr addr, u64 data) {
impl->Write64(addr, data); impl->Write64(addr, data);
} }
bool Memory::WriteExclusive8(VAddr addr, u8 data, u8 expected) {
return impl->WriteExclusive8(addr, data, expected);
}
bool Memory::WriteExclusive16(VAddr addr, u16 data, u16 expected) {
return impl->WriteExclusive16(addr, data, expected);
}
bool Memory::WriteExclusive32(VAddr addr, u32 data, u32 expected) {
return impl->WriteExclusive32(addr, data, expected);
}
bool Memory::WriteExclusive64(VAddr addr, u64 data, u64 expected) {
return impl->WriteExclusive64(addr, data, expected);
}
bool Memory::WriteExclusive128(VAddr addr, u128 data, u128 expected) {
return impl->WriteExclusive128(addr, data, expected);
}
std::string Memory::ReadCString(VAddr vaddr, std::size_t max_length) { std::string Memory::ReadCString(VAddr vaddr, std::size_t max_length) {
return impl->ReadCString(vaddr, max_length); return impl->ReadCString(vaddr, max_length);
} }

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@ -244,6 +244,71 @@ public:
*/ */
void Write64(VAddr addr, u64 data); void Write64(VAddr addr, u64 data);
/**
* Writes a 8-bit unsigned integer to the given virtual address in
* the current process' address space if and only if the address contains
* the expected value. This operation is atomic.
*
* @param addr The virtual address to write the 8-bit unsigned integer to.
* @param data The 8-bit unsigned integer to write to the given virtual address.
* @param expected The 8-bit unsigned integer to check against the given virtual address.
*
* @post The memory range [addr, sizeof(data)) contains the given data value.
*/
bool WriteExclusive8(VAddr addr, u8 data, u8 expected);
/**
* Writes a 16-bit unsigned integer to the given virtual address in
* the current process' address space if and only if the address contains
* the expected value. This operation is atomic.
*
* @param addr The virtual address to write the 16-bit unsigned integer to.
* @param data The 16-bit unsigned integer to write to the given virtual address.
* @param expected The 16-bit unsigned integer to check against the given virtual address.
*
* @post The memory range [addr, sizeof(data)) contains the given data value.
*/
bool WriteExclusive16(VAddr addr, u16 data, u16 expected);
/**
* Writes a 32-bit unsigned integer to the given virtual address in
* the current process' address space if and only if the address contains
* the expected value. This operation is atomic.
*
* @param addr The virtual address to write the 32-bit unsigned integer to.
* @param data The 32-bit unsigned integer to write to the given virtual address.
* @param expected The 32-bit unsigned integer to check against the given virtual address.
*
* @post The memory range [addr, sizeof(data)) contains the given data value.
*/
bool WriteExclusive32(VAddr addr, u32 data, u32 expected);
/**
* Writes a 64-bit unsigned integer to the given virtual address in
* the current process' address space if and only if the address contains
* the expected value. This operation is atomic.
*
* @param addr The virtual address to write the 64-bit unsigned integer to.
* @param data The 64-bit unsigned integer to write to the given virtual address.
* @param expected The 64-bit unsigned integer to check against the given virtual address.
*
* @post The memory range [addr, sizeof(data)) contains the given data value.
*/
bool WriteExclusive64(VAddr addr, u64 data, u64 expected);
/**
* Writes a 128-bit unsigned integer to the given virtual address in
* the current process' address space if and only if the address contains
* the expected value. This operation is atomic.
*
* @param addr The virtual address to write the 128-bit unsigned integer to.
* @param data The 128-bit unsigned integer to write to the given virtual address.
* @param expected The 128-bit unsigned integer to check against the given virtual address.
*
* @post The memory range [addr, sizeof(data)) contains the given data value.
*/
bool WriteExclusive128(VAddr addr, u128 data, u128 expected);
/** /**
* Reads a null-terminated string from the given virtual address. * Reads a null-terminated string from the given virtual address.
* This function will continually read characters until either: * This function will continually read characters until either: