ResourceUsageThread.cpp [plain text]
#include "config.h"
#include "ResourceUsageThread.h"
#if ENABLE(RESOURCE_USAGE)
#include "JSDOMWindow.h"
#include <thread>
#include <wtf/MainThread.h>
#include <wtf/Vector.h>
namespace WebCore {
ResourceUsageThread::ResourceUsageThread()
{
}
ResourceUsageThread& ResourceUsageThread::singleton()
{
static NeverDestroyed<ResourceUsageThread> resourceUsageThread;
return resourceUsageThread;
}
void ResourceUsageThread::addObserver(void* key, std::function<void (const ResourceUsageData&)> function)
{
auto& resourceUsageThread = ResourceUsageThread::singleton();
resourceUsageThread.createThreadIfNeeded();
{
LockHolder locker(resourceUsageThread.m_lock);
bool wasEmpty = resourceUsageThread.m_observers.isEmpty();
resourceUsageThread.m_observers.set(key, function);
if (wasEmpty)
resourceUsageThread.m_condition.notifyAll();
}
}
void ResourceUsageThread::removeObserver(void* key)
{
auto& resourceUsageThread = ResourceUsageThread::singleton();
{
LockHolder locker(resourceUsageThread.m_lock);
resourceUsageThread.m_observers.remove(key);
}
}
void ResourceUsageThread::waitUntilObservers()
{
LockHolder locker(m_lock);
while (m_observers.isEmpty())
m_condition.wait(m_lock);
}
void ResourceUsageThread::notifyObservers(ResourceUsageData&& data)
{
callOnMainThread([data = WTFMove(data)]() mutable {
Vector<std::function<void (const ResourceUsageData&)>> functions;
{
auto& resourceUsageThread = ResourceUsageThread::singleton();
LockHolder locker(resourceUsageThread.m_lock);
copyValuesToVector(resourceUsageThread.m_observers, functions);
}
for (auto& function : functions)
function(data);
});
}
void ResourceUsageThread::createThreadIfNeeded()
{
if (m_threadIdentifier)
return;
m_vm = &JSDOMWindow::commonVM();
m_threadIdentifier = createThread(threadCallback, this, "WebCore: ResourceUsage");
}
void ResourceUsageThread::threadCallback(void* resourceUsageThread)
{
static_cast<ResourceUsageThread*>(resourceUsageThread)->threadBody();
}
NO_RETURN void ResourceUsageThread::threadBody()
{
while (true) {
waitUntilObservers();
auto start = std::chrono::system_clock::now();
ResourceUsageData data;
platformThreadBody(m_vm, data);
notifyObservers(WTFMove(data));
auto duration = std::chrono::system_clock::now() - start;
auto difference = 500ms - duration;
std::this_thread::sleep_for(difference);
}
}
}
#endif // ENABLE(RESOURCE_USAGE)