Add simple timer manager

timerfd_manager.cpp

@@ -0,0 +1,160 @@
+#include <sys/timerfd.h>
+#include <sys/poll.h>
+#include <unistd.h>
+#include "timerfd_manager.h"
+
+timerfd_manager_t::timerfd_manager_t(ring_loop_t *ringloop)
+{
+    wait_state = 0;
+    timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK);
+    if (timerfd < 0)
+    {
+        throw std::runtime_error(std::string("timerfd_create: ") + strerror(errno));
+    }
+    consumer.loop = [this]() { loop(); };
+    ringloop->register_consumer(&consumer);
+    this->ringloop = ringloop;
+}
+
+timerfd_manager_t::~timerfd_manager_t()
+{
+    ringloop->unregister_consumer(&consumer);
+    close(timerfd);
+}
+
+void timerfd_manager_t::inc_timer(timerfd_timer_t & t)
+{
+    t.next.tv_sec += t.millis/1000;
+    t.next.tv_nsec += (t.millis%1000)*1000000;
+    if (t.next.tv_nsec > 1000000000)
+    {
+        t.next.tv_sec++;
+        t.next.tv_nsec -= 1000000000;
+    }
+}
+
+int timerfd_manager_t::set_timer(uint64_t millis, bool repeat, std::function<void(int)> callback)
+{
+    timespec start;
+    clock_gettime(CLOCK_MONOTONIC, &start);
+    timers.push_back({
+        .id = id++,
+        .millis = millis,
+        .start = start,
+        .next = start,
+        .repeat = repeat,
+        .callback = callback,
+    });
+    inc_timer(timers[timers.size()-1]);
+    set_nearest();
+    set_wait();
+    return id;
+}
+
+void timerfd_manager_t::clear_timer(int timer_id)
+{
+    for (int i = 0; i < timers.size(); i++)
+    {
+        if (timers[i].id == timer_id)
+        {
+            timers.erase(timers.begin()+i, timers.begin()+i+1);
+            if (nearest == i)
+            {
+                nearest = -1;
+                wait_state = wait_state & ~1;
+            }
+            else if (nearest > i)
+            {
+                nearest--;
+            }
+            set_nearest();
+            set_wait();
+            break;
+        }
+    }
+}
+
+void timerfd_manager_t::set_nearest()
+{
+    if (!timers.size())
+    {
+        nearest = -1;
+        itimerspec exp = { 0 };
+        if (timerfd_settime(timerfd, 0, &exp, NULL))
+        {
+            throw std::runtime_error(std::string("timerfd_settime: ") + strerror(errno));
+        }
+        wait_state = wait_state & ~1;
+    }
+    else
+    {
+        nearest = 0;
+        for (int i = 1; i < timers.size(); i++)
+        {
+            if (timers[i].next.tv_sec < timers[nearest].next.tv_sec ||
+                timers[i].next.tv_sec == timers[nearest].next.tv_sec &&
+                timers[i].next.tv_nsec < timers[nearest].next.tv_nsec)
+            {
+                nearest = i;
+            }
+        }
+        itimerspec exp = {
+            .it_interval = { 0 },
+            .it_value = timers[nearest].next,
+        };
+        if (timerfd_settime(timerfd, 0, &exp, NULL))
+        {
+            throw std::runtime_error(std::string("timerfd_settime: ") + strerror(errno));
+        }
+        wait_state = wait_state | 1;
+    }
+}
+
+void timerfd_manager_t::loop()
+{
+    if (!(wait_state & 1) && timers.size())
+    {
+        set_nearest();
+    }
+    set_wait();
+}
+
+void timerfd_manager_t::set_wait()
+{
+    if ((wait_state & 3) == 1)
+    {
+        io_uring_sqe *sqe = ringloop->get_sqe();
+        if (!sqe)
+        {
+            return;
+        }
+        ring_data_t *data = ((ring_data_t*)sqe->user_data);
+        my_uring_prep_poll_add(sqe, timerfd, POLLIN);
+        data->callback = [&](ring_data_t *data)
+        {
+            if (data->res < 0)
+            {
+                throw std::runtime_error(std::string("waiting for timer failed: ") + strerror(-data->res));
+            }
+            uint64_t n;
+            read(timerfd, &n, 8);
+            if (nearest >= 0)
+            {
+                timers[nearest].callback(timers[nearest].id);
+                if (!timers[nearest].repeat)
+                {
+                    timers.erase(timers.begin()+nearest, timers.begin()+nearest+1);
+                }
+                else
+                {
+                    inc_timer(timers[nearest]);
+                }
+                nearest = -1;
+            }
+            wait_state = 0;
+            set_nearest();
+            set_wait();
+        };
+        wait_state = 3;
+    }
+}