Add evloop, btpd's new event loop. This will replace libevent.

1 files changed, 142 insertions, 0 deletions

diff --git a/evloop/poll.c b/evloop/poll.c
new file mode 100644
index 0000000..0996374
--- /dev/null
+++ b/evloop/poll.c
@@ -0,0 +1,142 @@
+#include <assert.h>
+#include <errno.h>
+#include <poll.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "evloop.h"
+
+#define POLL_INIT_SIZE 64
+
+struct poll_ev {
+    struct fdev *ev;
+    evloop_cb_t cb;
+    void *arg;
+};
+
+static struct pollfd *m_pfds;
+static struct poll_ev *m_pevs;
+
+static int m_cap, m_size;
+static int m_cur = -1, m_curdel;
+
+static int
+poll_grow(void)
+{
+    int ncap = m_cap * 2;
+    struct pollfd *nm_pfds = realloc(m_pfds, ncap * sizeof(*m_pfds));
+    struct poll_ev *nm_pevs = realloc(m_pevs, ncap * sizeof(*m_pevs));
+    if (nm_pfds != NULL)
+        m_pfds = nm_pfds;
+    if (nm_pevs != NULL)
+        m_pevs = nm_pevs;
+    if (nm_pfds == NULL || nm_pevs == NULL)
+        return errno;
+    m_cap = ncap;
+    return 0;
+}
+
+int
+evloop_init(void)
+{
+    if (timeheap_init() != 0)
+        return -1;
+    m_cap = POLL_INIT_SIZE;
+    m_size = 0;
+    if ((m_pfds = calloc(m_cap, sizeof(*m_pfds))) == NULL)
+        return -1;
+    if ((m_pevs = calloc(m_cap, sizeof(*m_pevs))) == NULL) {
+        free(m_pfds);
+        return -1;
+    }
+    return 0;
+}
+
+int
+fdev_new(struct fdev *ev, int fd, uint16_t flags, evloop_cb_t cb, void *arg)
+{
+    if (m_size == m_cap && poll_grow() != 0)
+        return errno;
+    ev->i = m_size;
+    m_size++;
+    m_pfds[ev->i].fd = fd;
+    m_pfds[ev->i].events =
+        ((flags & EV_READ) ? POLLIN : 0) |
+        ((flags & EV_WRITE) ? POLLOUT : 0);
+    m_pevs[ev->i].ev = ev;
+    m_pevs[ev->i].cb = cb;
+    m_pevs[ev->i].arg = arg;
+    return 0;
+}
+
+int
+fdev_enable(struct fdev *ev, uint16_t flags)
+{
+    m_pfds[ev->i].events |= 
+        ((flags & EV_READ) ? POLLIN : 0) |
+        ((flags & EV_WRITE) ? POLLOUT : 0);
+    return 0;
+}
+
+int
+fdev_disable(struct fdev *ev, uint16_t flags)
+{
+    short pflags =
+        ((flags & EV_READ) ? POLLIN : 0) |
+        ((flags & EV_WRITE) ? POLLOUT : 0);
+    m_pfds[ev->i].events &= ~pflags;
+    return 0;
+}
+
+int
+fdev_del(struct fdev *ev)
+{
+    assert(ev->i < m_size);
+    m_size--;
+    m_pfds[ev->i] = m_pfds[m_size];
+    m_pevs[ev->i] = m_pevs[m_size];
+    m_pevs[ev->i].ev->i = ev->i;
+    if (ev->i == m_cur)
+        m_curdel = 1;
+    return 0;
+}
+
+int
+evloop(void)
+{
+    int millisecs;
+    struct timespec delay;
+    while (1) {
+        timers_run();
+
+        delay = timer_delay();
+        if (delay.tv_sec >= 0)
+            millisecs = delay.tv_sec * 1000 + delay.tv_nsec / 1000000;
+        else
+            millisecs = -1;
+
+        if (poll(m_pfds, m_size, millisecs) < 0) {
+            if (errno == EINTR)
+                continue;
+            else
+                return -1;
+        }
+
+        m_cur = 0;
+        while (m_cur < m_size) {
+            struct pollfd *pfd = &m_pfds[m_cur];
+            struct poll_ev *pev = &m_pevs[m_cur];
+            if ((pfd->events & POLLIN &&
+                    pfd->revents & (POLLIN|POLLERR|POLLHUP)))
+                pev->cb(pfd->fd, EV_READ, pev->arg);
+            if ((!m_curdel && pfd->events & POLLOUT &&
+                    pfd->revents & (POLLOUT|POLLERR|POLLHUP)))
+                pev->cb(pfd->fd, EV_WRITE, pev->arg);
+            if (!m_curdel)
+                m_cur++;
+            else
+                m_curdel = 0;
+        }
+        m_cur = -1;
+    }
+}