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/*
* Copyright (C) 2025 Apple Inc. 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 APPLE INC. ``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 APPLE INC. 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 "config.h"
#include "WasmModuleManager.h"
#if ENABLE(WEBASSEMBLY)
WTF_ALLOW_UNSAFE_BUFFER_USAGE_BEGIN
#include "JSWebAssemblyInstance.h"
#include "JSWebAssemblyModule.h"
#include "VM.h"
#include "WasmDebugServerUtilities.h"
#include "WasmFormat.h"
#include "WasmInstanceAnchor.h"
#include "WasmModule.h"
#include "WasmModuleInformation.h"
#include <wtf/DataLog.h>
#include <wtf/HashMap.h>
#include <wtf/HexNumber.h>
#include <wtf/IterationStatus.h>
#include <wtf/TZoneMallocInlines.h>
#include <wtf/text/MakeString.h>
#include <wtf/text/StringBuilder.h>
#include <wtf/text/WTFString.h>
namespace JSC {
namespace Wasm {
WTF_MAKE_TZONE_ALLOCATED_IMPL(ModuleManager);
uint32_t ModuleManager::registerModule(Module& module)
{
Locker locker { m_lock };
uint32_t moduleId = m_nextModuleId++;
m_moduleIdToModule.set(moduleId, &module);
const auto& moduleInfo = module.moduleInformation();
moduleInfo.debugInfo->id = moduleId;
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][registerModule] - registered module with ID: ", moduleId, " size: ", moduleInfo.debugInfo->source.size(), " bytes");
return moduleId;
}
void ModuleManager::unregisterModule(Module& module)
{
Locker locker { m_lock };
uint32_t moduleId = module.debugId();
m_moduleIdToModule.remove(moduleId);
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][unregisterModule] - unregistered module with debug ID: ", moduleId);
}
uint32_t ModuleManager::registerInstance(JSWebAssemblyInstance* jsInstance)
{
Locker locker { m_lock };
uint32_t instanceId = m_nextInstanceId++;
RefPtr<InstanceAnchor> anchor = jsInstance->anchor();
RELEASE_ASSERT(anchor, "Instance must have an anchor");
amortizedCleanupIfNeeded();
m_instanceIdToInstance.set(instanceId, ThreadSafeWeakPtr { *anchor });
jsInstance->setDebugId(instanceId);
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][registerInstance] - registered instance with ID: ", instanceId, " for module ID: ", jsInstance->module().debugId());
return instanceId;
}
Module* ModuleManager::module(uint32_t moduleId) const
{
Locker locker { m_lock };
auto itr = m_moduleIdToModule.find(moduleId);
if (itr == m_moduleIdToModule.end()) {
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][module] - module not found for ID: ", moduleId);
return nullptr;
}
return itr->value;
}
JSWebAssemblyInstance* ModuleManager::jsInstance(uint32_t instanceId)
{
Locker locker { m_lock };
amortizedCleanupIfNeeded();
auto it = m_instanceIdToInstance.find(instanceId);
if (it == m_instanceIdToInstance.end()) {
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][jsInstance] - instance not found for ID: ", instanceId);
return nullptr;
}
// This function is called from the debugger thread (WasmDebugServer) to access JSWebAssemblyInstance
// objects during LLDB packet processing. Using InstanceAnchor provides thread-safe access and automatic
// cleanup when instances are destroyed.
//
// Safety guarantees:
// 1. InstanceAnchor::tearDown() is called in JSWebAssemblyInstance destructor, nulling out the pointer
// 2. VMs are stopped during debugger access per GDB remote protocol, preventing GC and ensuring stability
// 3. The anchor's lock protects concurrent access to the instance pointer
RefPtr<InstanceAnchor> anchor = it->value.get();
if (!anchor) {
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][jsInstance] - anchor is dead for ID: ", instanceId);
return nullptr;
}
Locker anchorLocker { anchor->m_lock };
JSWebAssemblyInstance* instance = anchor->instance();
if (!instance) {
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][jsInstance] - instance is null for ID: ", instanceId);
return nullptr;
}
RELEASE_ASSERT(instance->vm().debugState()->isStopped(), "Instance exists but VM is not stopped");
return instance;
}
static String generateModuleName(VirtualAddress address, const RefPtr<Module>&)
{
// FIXME: Maybe we should generate a more meaningful name?
String moduleName = WTF::makeString("wasm_module_0x"_s, address.hex(), ".wasm"_s);
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][generateModuleName] Using fallback address-based name: ", moduleName);
return moduleName;
}
String ModuleManager::generateLibrariesXML() const
{
Locker locker { m_lock };
StringBuilder xml;
xml.append("<?xml version=\"1.0\"?>\n"_s);
xml.append("<library-list>\n"_s);
for (const auto& pair : m_moduleIdToModule) {
uint32_t moduleId = pair.key;
RefPtr module = pair.value;
if (!module)
continue;
const auto& source = module->moduleInformation().debugInfo->source;
if (source.isEmpty())
continue;
VirtualAddress moduleBaseAddress = VirtualAddress::createModule(moduleId);
String moduleName = generateModuleName(moduleBaseAddress, module);
xml.append(" <library name=\""_s);
xml.append(moduleName);
xml.append("\">\n"_s);
xml.append(" <section address=\"0x"_s);
xml.append(moduleBaseAddress.hex());
xml.append("\"/>\n"_s);
xml.append(" </library>\n"_s);
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][generateLibrariesXML] - added module '", moduleName, "' ID: ", moduleId, " at ", moduleBaseAddress, " size: 0x", hex(source.size(), Lowercase));
}
xml.append("</library-list>\n"_s);
String result = xml.toString();
dataLogLnIf(Options::verboseWasmDebugger(), "[ModuleManager][generateLibrariesXML] - generated library list XML: ", m_moduleIdToModule.size(), " modules, ", result.length(), " characters");
return result;
}
uint32_t ModuleManager::nextInstanceId() const
{
Locker locker { m_lock };
return m_nextInstanceId;
}
void ModuleManager::amortizedCleanupIfNeeded()
{
if (++m_operationCountSinceLastCleanup > m_maxOperationCountWithoutCleanup) {
m_instanceIdToInstance.removeIf([](auto& entry) {
return !entry.value.get(); // Remove entries with dead anchors
});
cleanupHappened();
}
}
void ModuleManager::cleanupHappened()
{
m_operationCountSinceLastCleanup = 0;
m_maxOperationCountWithoutCleanup = std::min(std::numeric_limits<unsigned>::max() / 2, static_cast<unsigned>(m_instanceIdToInstance.size())) * 2;
}
}
} // namespace JSC::Wasm
WTF_ALLOW_UNSAFE_BUFFER_USAGE_END
#endif // ENABLE(WEBASSEMBLY)
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