summaryrefslogtreecommitdiffstats
path: root/src/core
diff options
context:
space:
mode:
Diffstat (limited to 'src/core')
-rw-r--r--src/core/arm/arm_interface.h3
-rw-r--r--src/core/arm/dynarmic/arm_dynarmic_32.cpp4
-rw-r--r--src/core/arm/dynarmic/arm_dynarmic_32.h1
-rw-r--r--src/core/arm/dynarmic/arm_dynarmic_64.cpp4
-rw-r--r--src/core/arm/dynarmic/arm_dynarmic_64.h1
-rw-r--r--src/core/core.cpp13
-rw-r--r--src/core/cpu_manager.cpp16
-rw-r--r--src/core/hle/kernel/kernel.cpp23
-rw-r--r--src/core/hle/kernel/kernel.h3
-rw-r--r--src/core/hle/kernel/physical_core.cpp38
-rw-r--r--src/core/hle/kernel/physical_core.h29
-rw-r--r--src/core/hle/kernel/scheduler.cpp20
-rw-r--r--src/core/hle/kernel/svc.cpp9
-rw-r--r--src/core/hle/kernel/thread.cpp27
-rw-r--r--src/core/hle/kernel/thread.h5
15 files changed, 124 insertions, 72 deletions
diff --git a/src/core/arm/arm_interface.h b/src/core/arm/arm_interface.h
index 1f24051e4..b3d8ceaf8 100644
--- a/src/core/arm/arm_interface.h
+++ b/src/core/arm/arm_interface.h
@@ -64,6 +64,9 @@ public:
/// Step CPU by one instruction
virtual void Step() = 0;
+ /// Exits execution from a callback, the callback must rewind the stack
+ virtual void ExceptionalExit() = 0;
+
/// Clear all instruction cache
virtual void ClearInstructionCache() = 0;
diff --git a/src/core/arm/dynarmic/arm_dynarmic_32.cpp b/src/core/arm/dynarmic/arm_dynarmic_32.cpp
index 6dc03f3b1..af23206f5 100644
--- a/src/core/arm/dynarmic/arm_dynarmic_32.cpp
+++ b/src/core/arm/dynarmic/arm_dynarmic_32.cpp
@@ -189,6 +189,10 @@ void ARM_Dynarmic_32::Run() {
jit->Run();
}
+void ARM_Dynarmic_32::ExceptionalExit() {
+ jit->ExceptionalExit();
+}
+
void ARM_Dynarmic_32::Step() {
jit->Step();
}
diff --git a/src/core/arm/dynarmic/arm_dynarmic_32.h b/src/core/arm/dynarmic/arm_dynarmic_32.h
index 2bab31b92..e16b689c8 100644
--- a/src/core/arm/dynarmic/arm_dynarmic_32.h
+++ b/src/core/arm/dynarmic/arm_dynarmic_32.h
@@ -42,6 +42,7 @@ public:
u32 GetPSTATE() const override;
void SetPSTATE(u32 pstate) override;
void Run() override;
+ void ExceptionalExit() override;
void Step() override;
VAddr GetTlsAddress() const override;
void SetTlsAddress(VAddr address) override;
diff --git a/src/core/arm/dynarmic/arm_dynarmic_64.cpp b/src/core/arm/dynarmic/arm_dynarmic_64.cpp
index 5c2060d78..1c9fd18b5 100644
--- a/src/core/arm/dynarmic/arm_dynarmic_64.cpp
+++ b/src/core/arm/dynarmic/arm_dynarmic_64.cpp
@@ -220,6 +220,10 @@ void ARM_Dynarmic_64::Run() {
jit->Run();
}
+void ARM_Dynarmic_64::ExceptionalExit() {
+ jit->ExceptionalExit();
+}
+
void ARM_Dynarmic_64::Step() {
cb->InterpreterFallback(jit->GetPC(), 1);
}
diff --git a/src/core/arm/dynarmic/arm_dynarmic_64.h b/src/core/arm/dynarmic/arm_dynarmic_64.h
index 28e11a17d..aa0a5c424 100644
--- a/src/core/arm/dynarmic/arm_dynarmic_64.h
+++ b/src/core/arm/dynarmic/arm_dynarmic_64.h
@@ -40,6 +40,7 @@ public:
void SetPSTATE(u32 pstate) override;
void Run() override;
void Step() override;
+ void ExceptionalExit() override;
VAddr GetTlsAddress() const override;
void SetTlsAddress(VAddr address) override;
void SetTPIDR_EL0(u64 value) override;
diff --git a/src/core/core.cpp b/src/core/core.cpp
index 76a38ea2a..58368fe3c 100644
--- a/src/core/core.cpp
+++ b/src/core/core.cpp
@@ -245,6 +245,7 @@ struct System::Impl {
}
AddGlueRegistrationForProcess(*app_loader, *main_process);
kernel.MakeCurrentProcess(main_process.get());
+ kernel.InitializeCores();
// Initialize cheat engine
if (cheat_engine) {
@@ -490,11 +491,11 @@ const TelemetrySession& System::TelemetrySession() const {
}
ARM_Interface& System::CurrentArmInterface() {
- return impl->kernel.CurrentScheduler().GetCurrentThread()->ArmInterface();
+ return impl->kernel.CurrentPhysicalCore().ArmInterface();
}
const ARM_Interface& System::CurrentArmInterface() const {
- return impl->kernel.CurrentScheduler().GetCurrentThread()->ArmInterface();
+ return impl->kernel.CurrentPhysicalCore().ArmInterface();
}
std::size_t System::CurrentCoreIndex() const {
@@ -554,15 +555,11 @@ const Kernel::Process* System::CurrentProcess() const {
}
ARM_Interface& System::ArmInterface(std::size_t core_index) {
- auto* thread = impl->kernel.Scheduler(core_index).GetCurrentThread();
- ASSERT(thread && !thread->IsHLEThread());
- return thread->ArmInterface();
+ return impl->kernel.PhysicalCore(core_index).ArmInterface();
}
const ARM_Interface& System::ArmInterface(std::size_t core_index) const {
- auto* thread = impl->kernel.Scheduler(core_index).GetCurrentThread();
- ASSERT(thread && !thread->IsHLEThread());
- return thread->ArmInterface();
+ return impl->kernel.PhysicalCore(core_index).ArmInterface();
}
ExclusiveMonitor& System::Monitor() {
diff --git a/src/core/cpu_manager.cpp b/src/core/cpu_manager.cpp
index eeeb6e8df..0cff985e9 100644
--- a/src/core/cpu_manager.cpp
+++ b/src/core/cpu_manager.cpp
@@ -113,22 +113,23 @@ void CpuManager::MultiCoreRunGuestThread() {
auto& sched = kernel.CurrentScheduler();
sched.OnThreadStart();
}
+ auto* thread = kernel.CurrentScheduler().GetCurrentThread();
+ auto& host_context = thread->GetHostContext();
+ host_context->SetRewindPoint(GuestRewindFunction, this);
MultiCoreRunGuestLoop();
}
void CpuManager::MultiCoreRunGuestLoop() {
auto& kernel = system.Kernel();
- auto* thread = kernel.CurrentScheduler().GetCurrentThread();
+
while (true) {
auto* physical_core = &kernel.CurrentPhysicalCore();
- auto& arm_interface = thread->ArmInterface();
system.EnterDynarmicProfile();
while (!physical_core->IsInterrupted()) {
- arm_interface.Run();
+ physical_core->Run();
physical_core = &kernel.CurrentPhysicalCore();
}
system.ExitDynarmicProfile();
- arm_interface.ClearExclusiveState();
auto& scheduler = kernel.CurrentScheduler();
scheduler.TryDoContextSwitch();
}
@@ -209,6 +210,9 @@ void CpuManager::SingleCoreRunGuestThread() {
auto& sched = kernel.CurrentScheduler();
sched.OnThreadStart();
}
+ auto* thread = kernel.CurrentScheduler().GetCurrentThread();
+ auto& host_context = thread->GetHostContext();
+ host_context->SetRewindPoint(GuestRewindFunction, this);
SingleCoreRunGuestLoop();
}
@@ -217,17 +221,15 @@ void CpuManager::SingleCoreRunGuestLoop() {
auto* thread = kernel.CurrentScheduler().GetCurrentThread();
while (true) {
auto* physical_core = &kernel.CurrentPhysicalCore();
- auto& arm_interface = thread->ArmInterface();
system.EnterDynarmicProfile();
if (!physical_core->IsInterrupted()) {
- arm_interface.Run();
+ physical_core->Run();
physical_core = &kernel.CurrentPhysicalCore();
}
system.ExitDynarmicProfile();
thread->SetPhantomMode(true);
system.CoreTiming().Advance();
thread->SetPhantomMode(false);
- arm_interface.ClearExclusiveState();
PreemptSingleCore();
auto& scheduler = kernel.Scheduler(current_core);
scheduler.TryDoContextSwitch();
diff --git a/src/core/hle/kernel/kernel.cpp b/src/core/hle/kernel/kernel.cpp
index bb3e312a7..4cf9cee42 100644
--- a/src/core/hle/kernel/kernel.cpp
+++ b/src/core/hle/kernel/kernel.cpp
@@ -68,6 +68,12 @@ struct KernelCore::Impl {
InitializeSuspendThreads();
}
+ void InitializeCores() {
+ for (auto& core : cores) {
+ core.Initialize(current_process->Is64BitProcess());
+ }
+ }
+
void Shutdown() {
next_object_id = 0;
next_kernel_process_id = Process::InitialKIPIDMin;
@@ -116,7 +122,7 @@ struct KernelCore::Impl {
Core::MakeExclusiveMonitor(system.Memory(), Core::Hardware::NUM_CPU_CORES);
for (std::size_t i = 0; i < Core::Hardware::NUM_CPU_CORES; i++) {
schedulers[i] = std::make_unique<Kernel::Scheduler>(system, i);
- cores.emplace_back(system, i, *schedulers[i], interrupts[i]);
+ cores.emplace_back(i, system, *schedulers[i], interrupts);
}
}
@@ -181,6 +187,7 @@ struct KernelCore::Impl {
if (process == nullptr) {
return;
}
+
const u32 core_id = GetCurrentHostThreadID();
if (core_id < Core::Hardware::NUM_CPU_CORES) {
system.Memory().SetCurrentPageTable(*process, core_id);
@@ -372,6 +379,10 @@ void KernelCore::Initialize() {
impl->Initialize(*this);
}
+void KernelCore::InitializeCores() {
+ impl->InitializeCores();
+}
+
void KernelCore::Shutdown() {
impl->Shutdown();
}
@@ -486,12 +497,12 @@ const Core::ExclusiveMonitor& KernelCore::GetExclusiveMonitor() const {
}
void KernelCore::InvalidateAllInstructionCaches() {
- auto& threads = GlobalScheduler().GetThreadList();
- for (auto& thread : threads) {
- if (!thread->IsHLEThread()) {
- auto& arm_interface = thread->ArmInterface();
- arm_interface.ClearInstructionCache();
+ if (!IsMulticore()) {
+ for (auto& physical_core : impl->cores) {
+ physical_core.ArmInterface().ClearInstructionCache();
}
+ } else {
+ ASSERT_MSG(false, "UNIMPLEMENTED!!!!!!!!!!!");
}
}
diff --git a/src/core/hle/kernel/kernel.h b/src/core/hle/kernel/kernel.h
index 16285c3f0..a9fdc5860 100644
--- a/src/core/hle/kernel/kernel.h
+++ b/src/core/hle/kernel/kernel.h
@@ -74,6 +74,9 @@ public:
/// Resets the kernel to a clean slate for use.
void Initialize();
+ /// Initializes the CPU cores.
+ void InitializeCores();
+
/// Clears all resources in use by the kernel instance.
void Shutdown();
diff --git a/src/core/hle/kernel/physical_core.cpp b/src/core/hle/kernel/physical_core.cpp
index 6e04d025f..50aca5752 100644
--- a/src/core/hle/kernel/physical_core.cpp
+++ b/src/core/hle/kernel/physical_core.cpp
@@ -4,21 +4,43 @@
#include "common/spin_lock.h"
#include "core/arm/cpu_interrupt_handler.h"
+#include "core/arm/dynarmic/arm_dynarmic_32.h"
+#include "core/arm/dynarmic/arm_dynarmic_64.h"
#include "core/core.h"
+#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/physical_core.h"
#include "core/hle/kernel/scheduler.h"
namespace Kernel {
-PhysicalCore::PhysicalCore(Core::System& system, std::size_t id, Kernel::Scheduler& scheduler,
- Core::CPUInterruptHandler& interrupt_handler)
- : interrupt_handler{interrupt_handler},
- core_index{id}, scheduler{scheduler}, guard{std::make_unique<Common::SpinLock>()} {}
+PhysicalCore::PhysicalCore(std::size_t core_index, Core::System& system,
+ Kernel::Scheduler& scheduler, Core::CPUInterrupts& interrupts)
+ : core_index{core_index}, system{system}, scheduler{scheduler},
+ interrupts{interrupts}, guard{std::make_unique<Common::SpinLock>()} {}
PhysicalCore::~PhysicalCore() = default;
+void PhysicalCore::Initialize([[maybe_unused]] bool is_64_bit) {
+#ifdef ARCHITECTURE_x86_64
+ auto& kernel = system.Kernel();
+ if (is_64_bit) {
+ arm_interface = std::make_unique<Core::ARM_Dynarmic_64>(
+ system, interrupts, kernel.IsMulticore(), kernel.GetExclusiveMonitor(), core_index);
+ } else {
+ arm_interface = std::make_unique<Core::ARM_Dynarmic_32>(
+ system, interrupts, kernel.IsMulticore(), kernel.GetExclusiveMonitor(), core_index);
+ }
+#else
+#error Platform not supported yet.
+#endif
+}
+
+void PhysicalCore::Run() {
+ arm_interface->Run();
+}
+
void PhysicalCore::Idle() {
- interrupt_handler.AwaitInterrupt();
+ interrupts[core_index].AwaitInterrupt();
}
void PhysicalCore::Shutdown() {
@@ -26,18 +48,18 @@ void PhysicalCore::Shutdown() {
}
bool PhysicalCore::IsInterrupted() const {
- return interrupt_handler.IsInterrupted();
+ return interrupts[core_index].IsInterrupted();
}
void PhysicalCore::Interrupt() {
guard->lock();
- interrupt_handler.SetInterrupt(true);
+ interrupts[core_index].SetInterrupt(true);
guard->unlock();
}
void PhysicalCore::ClearInterrupt() {
guard->lock();
- interrupt_handler.SetInterrupt(false);
+ interrupts[core_index].SetInterrupt(false);
guard->unlock();
}
diff --git a/src/core/hle/kernel/physical_core.h b/src/core/hle/kernel/physical_core.h
index d7a7a951c..ace058a5a 100644
--- a/src/core/hle/kernel/physical_core.h
+++ b/src/core/hle/kernel/physical_core.h
@@ -4,9 +4,12 @@
#pragma once
+#include <array>
#include <cstddef>
#include <memory>
+#include "core/arm/arm_interface.h"
+
namespace Common {
class SpinLock;
}
@@ -16,7 +19,6 @@ class Scheduler;
} // namespace Kernel
namespace Core {
-class ARM_Interface;
class CPUInterruptHandler;
class ExclusiveMonitor;
class System;
@@ -26,8 +28,8 @@ namespace Kernel {
class PhysicalCore {
public:
- PhysicalCore(Core::System& system, std::size_t id, Kernel::Scheduler& scheduler,
- Core::CPUInterruptHandler& interrupt_handler);
+ PhysicalCore(std::size_t core_index, Core::System& system, Kernel::Scheduler& scheduler,
+ Core::CPUInterrupts& interrupts);
~PhysicalCore();
PhysicalCore(const PhysicalCore&) = delete;
@@ -36,7 +38,14 @@ public:
PhysicalCore(PhysicalCore&&) = default;
PhysicalCore& operator=(PhysicalCore&&) = default;
+ /// Initialize the core for the specified parameters.
+ void Initialize(bool is_64_bit);
+
+ /// Execute current jit state
+ void Run();
+
void Idle();
+
/// Interrupt this physical core.
void Interrupt();
@@ -49,6 +58,14 @@ public:
// Shutdown this physical core.
void Shutdown();
+ Core::ARM_Interface& ArmInterface() {
+ return *arm_interface;
+ }
+
+ const Core::ARM_Interface& ArmInterface() const {
+ return *arm_interface;
+ }
+
bool IsMainCore() const {
return core_index == 0;
}
@@ -70,10 +87,12 @@ public:
}
private:
- Core::CPUInterruptHandler& interrupt_handler;
- std::size_t core_index;
+ const std::size_t core_index;
+ Core::System& system;
Kernel::Scheduler& scheduler;
+ Core::CPUInterrupts& interrupts;
std::unique_ptr<Common::SpinLock> guard;
+ std::unique_ptr<Core::ARM_Interface> arm_interface;
};
} // namespace Kernel
diff --git a/src/core/hle/kernel/scheduler.cpp b/src/core/hle/kernel/scheduler.cpp
index 6b7db5372..0805e9914 100644
--- a/src/core/hle/kernel/scheduler.cpp
+++ b/src/core/hle/kernel/scheduler.cpp
@@ -621,11 +621,14 @@ void Scheduler::OnThreadStart() {
void Scheduler::Unload() {
Thread* thread = current_thread.get();
if (thread) {
- thread->SetContinuousOnSVC(false);
thread->last_running_ticks = system.CoreTiming().GetCPUTicks();
thread->SetIsRunning(false);
+ if (thread->IsContinuousOnSVC() && !thread->IsHLEThread()) {
+ system.ArmInterface(core_id).ExceptionalExit();
+ thread->SetContinuousOnSVC(false);
+ }
if (!thread->IsHLEThread() && !thread->HasExited()) {
- Core::ARM_Interface& cpu_core = thread->ArmInterface();
+ Core::ARM_Interface& cpu_core = system.ArmInterface(core_id);
cpu_core.SaveContext(thread->GetContext32());
cpu_core.SaveContext(thread->GetContext64());
// Save the TPIDR_EL0 system register in case it was modified.
@@ -652,12 +655,11 @@ void Scheduler::Reload() {
system.Kernel().MakeCurrentProcess(thread_owner_process);
}
if (!thread->IsHLEThread()) {
- Core::ARM_Interface& cpu_core = thread->ArmInterface();
+ Core::ARM_Interface& cpu_core = system.ArmInterface(core_id);
cpu_core.LoadContext(thread->GetContext32());
cpu_core.LoadContext(thread->GetContext64());
cpu_core.SetTlsAddress(thread->GetTLSAddress());
cpu_core.SetTPIDR_EL0(thread->GetTPIDR_EL0());
- cpu_core.ChangeProcessorID(this->core_id);
cpu_core.ClearExclusiveState();
}
}
@@ -679,12 +681,11 @@ void Scheduler::SwitchContextStep2() {
system.Kernel().MakeCurrentProcess(thread_owner_process);
}
if (!selected_thread->IsHLEThread()) {
- Core::ARM_Interface& cpu_core = selected_thread->ArmInterface();
+ Core::ARM_Interface& cpu_core = system.ArmInterface(core_id);
cpu_core.LoadContext(selected_thread->GetContext32());
cpu_core.LoadContext(selected_thread->GetContext64());
cpu_core.SetTlsAddress(selected_thread->GetTLSAddress());
cpu_core.SetTPIDR_EL0(selected_thread->GetTPIDR_EL0());
- cpu_core.ChangeProcessorID(this->core_id);
cpu_core.ClearExclusiveState();
}
}
@@ -715,11 +716,14 @@ void Scheduler::SwitchContext() {
if (new_thread != nullptr && new_thread->IsSuspendThread()) {
previous_thread->SetWasRunning(true);
}
- previous_thread->SetContinuousOnSVC(false);
previous_thread->last_running_ticks = system.CoreTiming().GetCPUTicks();
previous_thread->SetIsRunning(false);
+ if (previous_thread->IsContinuousOnSVC() && !previous_thread->IsHLEThread()) {
+ system.ArmInterface(core_id).ExceptionalExit();
+ previous_thread->SetContinuousOnSVC(false);
+ }
if (!previous_thread->IsHLEThread() && !previous_thread->HasExited()) {
- Core::ARM_Interface& cpu_core = previous_thread->ArmInterface();
+ Core::ARM_Interface& cpu_core = system.ArmInterface(core_id);
cpu_core.SaveContext(previous_thread->GetContext32());
cpu_core.SaveContext(previous_thread->GetContext64());
// Save the TPIDR_EL0 system register in case it was modified.
diff --git a/src/core/hle/kernel/svc.cpp b/src/core/hle/kernel/svc.cpp
index e3b770d66..95d6e2b4d 100644
--- a/src/core/hle/kernel/svc.cpp
+++ b/src/core/hle/kernel/svc.cpp
@@ -2639,6 +2639,9 @@ void Call(Core::System& system, u32 immediate) {
auto& kernel = system.Kernel();
kernel.EnterSVCProfile();
+ auto* thread = system.CurrentScheduler().GetCurrentThread();
+ thread->SetContinuousOnSVC(true);
+
const FunctionDef* info = system.CurrentProcess()->Is64BitProcess() ? GetSVCInfo64(immediate)
: GetSVCInfo32(immediate);
if (info) {
@@ -2652,6 +2655,12 @@ void Call(Core::System& system, u32 immediate) {
}
kernel.ExitSVCProfile();
+
+ if (!thread->IsContinuousOnSVC()) {
+ auto* host_context = thread->GetHostContext().get();
+ host_context->Rewind();
+ }
+
system.EnterDynarmicProfile();
}
diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp
index da0cb26b6..3abe12810 100644
--- a/src/core/hle/kernel/thread.cpp
+++ b/src/core/hle/kernel/thread.cpp
@@ -12,7 +12,6 @@
#include "common/fiber.h"
#include "common/logging/log.h"
#include "common/thread_queue_list.h"
-#include "core/arm/arm_interface.h"
#include "core/core.h"
#include "core/cpu_manager.h"
#include "core/hardware_properties.h"
@@ -62,7 +61,6 @@ void Thread::Stop() {
// Mark the TLS slot in the thread's page as free.
owner_process->FreeTLSRegion(tls_address);
}
- arm_interface.reset();
has_exited = true;
}
global_handle = 0;
@@ -217,22 +215,9 @@ ResultVal<std::shared_ptr<Thread>> Thread::Create(Core::System& system, ThreadTy
thread->tls_address = 0;
}
- thread->arm_interface.reset();
+ // TODO(peachum): move to ScheduleThread() when scheduler is added so selected core is used
+ // to initialize the context
if ((type_flags & THREADTYPE_HLE) == 0) {
-#ifdef ARCHITECTURE_x86_64
- if (owner_process && !owner_process->Is64BitProcess()) {
- thread->arm_interface = std::make_unique<Core::ARM_Dynarmic_32>(
- system, kernel.Interrupts(), kernel.IsMulticore(), kernel.GetExclusiveMonitor(),
- processor_id);
- } else {
- thread->arm_interface = std::make_unique<Core::ARM_Dynarmic_64>(
- system, kernel.Interrupts(), kernel.IsMulticore(), kernel.GetExclusiveMonitor(),
- processor_id);
- }
-#else
-#error Platform not supported yet.
-#endif
-
ResetThreadContext32(thread->context_32, static_cast<u32>(stack_top),
static_cast<u32>(entry_point), static_cast<u32>(arg));
ResetThreadContext64(thread->context_64, stack_top, entry_point, arg);
@@ -268,14 +253,6 @@ VAddr Thread::GetCommandBufferAddress() const {
return GetTLSAddress() + command_header_offset;
}
-Core::ARM_Interface& Thread::ArmInterface() {
- return *arm_interface;
-}
-
-const Core::ARM_Interface& Thread::ArmInterface() const {
- return *arm_interface;
-}
-
void Thread::SetStatus(ThreadStatus new_status) {
if (new_status == status) {
return;
diff --git a/src/core/hle/kernel/thread.h b/src/core/hle/kernel/thread.h
index 8daf79fac..20e86fb81 100644
--- a/src/core/hle/kernel/thread.h
+++ b/src/core/hle/kernel/thread.h
@@ -248,10 +248,6 @@ public:
void SetSynchronizationResults(SynchronizationObject* object, ResultCode result);
- Core::ARM_Interface& ArmInterface();
-
- const Core::ARM_Interface& ArmInterface() const;
-
SynchronizationObject* GetSignalingObject() const {
return signaling_object;
}
@@ -586,7 +582,6 @@ private:
Common::SpinLock context_guard{};
ThreadContext32 context_32{};
ThreadContext64 context_64{};
- std::unique_ptr<Core::ARM_Interface> arm_interface{};
std::shared_ptr<Common::Fiber> host_context{};
u64 thread_id = 0;