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LibCore: Allow adding/removing signal handlers while handling signals

This allows adding and removing of asynchronous signal handlers while
executing signal handlers, even if it is for the same signal that is
being handled right now.
This commit is contained in:
Tom 2021-01-08 10:29:11 -07:00 committed by Andreas Kling
parent 938e5c7719
commit 8548ec357c
2 changed files with 64 additions and 41 deletions

View file

@ -107,27 +107,11 @@ private:
NonnullOwnPtr<Event> event;
};
class SignalHandlers {
class SignalHandlers : public RefCounted<SignalHandlers> {
AK_MAKE_NONCOPYABLE(SignalHandlers);
AK_MAKE_NONMOVABLE(SignalHandlers);
public:
SignalHandlers(SignalHandlers&& from)
: m_signo(from.m_signo)
, m_original_handler(from.m_original_handler)
, m_handlers(move(from.m_handlers))
{
from.m_valid = false;
}
SignalHandlers& operator=(SignalHandlers&& from)
{
if (this != &from) {
m_signo = from.m_signo;
m_original_handler = from.m_original_handler;
m_handlers = move(from.m_handlers);
from.m_valid = false;
}
return *this;
}
SignalHandlers(int signo);
~SignalHandlers();
@ -137,24 +121,37 @@ private:
bool is_empty() const
{
if (m_calling_handlers) {
for (auto& handler : m_handlers_pending) {
if (handler.value)
return false; // an add is pending
}
}
return m_handlers.is_empty();
}
bool have(int handler_id) const
{
if (m_calling_handlers) {
auto it = m_handlers_pending.find(handler_id);
if (it != m_handlers_pending.end()) {
if (!it->value)
return false; // a deletion is pending
}
}
return m_handlers.contains(handler_id);
}
int m_signo;
void (*m_original_handler)(int); // TODO: can't use sighandler_t?
HashMap<int, Function<void(int)>> m_handlers;
bool m_valid { true };
HashMap<int, Function<void(int)>> m_handlers_pending;
bool m_calling_handlers { false };
};
friend class SignalHandlers;
Vector<QueuedEvent, 64> m_queued_events;
static HashMap<int, SignalHandlers> s_signal_handlers;
static int s_handling_signal;
static HashMap<int, NonnullRefPtr<SignalHandlers>> s_signal_handlers;
static int s_next_signal_id;
static pid_t s_pid;