1 files changed, 54 insertions, 1 deletions

diff --git a/ext/kgio/poll.c b/ext/kgio/poll.c
index 502f660..614d939 100644
--- a/ext/kgio/poll.c
+++ b/ext/kgio/poll.c
@@ -1,6 +1,9 @@
 #include "kgio.h"
 #if defined(USE_KGIO_POLL)
+#include <time.h>
+#include "broken_system_compat.h"
 #include <poll.h>
+#include <errno.h>
 #ifdef HAVE_RUBY_ST_H
 #  include <ruby/st.h>
 #else
@@ -16,8 +19,43 @@ struct poll_args {
         int timeout;
         VALUE ios;
         st_table *fd_to_io;
+        struct timespec start;
 };
 
+static int interrupted(void)
+{
+        switch (errno) {
+        case EINTR:
+#ifdef ERESTART
+        case ERESTART:
+#endif
+                return 1;
+        }
+        return 0;
+}
+
+static int retryable(struct poll_args *a)
+{
+        struct timespec ts;
+
+        if (a->timeout < 0)
+                return 1;
+        if (a->timeout == 0)
+                return 0;
+
+        clock_gettime(hopefully_CLOCK_MONOTONIC, &ts);
+
+        ts.tv_sec -= a->start.tv_sec;
+        ts.tv_nsec -= a->start.tv_nsec;
+        if (ts.tv_nsec < 0) {
+                ts.tv_sec--;
+                ts.tv_nsec += 1000000000;
+        }
+        a->timeout -= ts.tv_sec * 1000;
+        a->timeout -= ts.tv_nsec / 1000000;
+        return (a->timeout >= 0);
+}
+
 static int num2timeout(VALUE timeout)
 {
         switch (TYPE(timeout)) {
@@ -70,6 +108,10 @@ static void hash2pollfds(struct poll_args *a)
 static VALUE nogvl_poll(void *ptr)
 {
         struct poll_args *a = ptr;
+
+        if (a->timeout > 0)
+                clock_gettime(hopefully_CLOCK_MONOTONIC, &a->start);
+
         return (VALUE)poll(a->fds, a->nfds, a->timeout);
 }
 
@@ -100,8 +142,16 @@ static VALUE do_poll(VALUE args)
         Check_Type(a->ios, T_HASH);
         hash2pollfds(a);
 
+retry:
         nr = (int)rb_thread_blocking_region(nogvl_poll, a, RUBY_UBF_IO, NULL);
-        if (nr < 0) rb_sys_fail("poll");
+        if (nr < 0) {
+                if (interrupted()) {
+                        if (retryable(a))
+                                goto retry;
+                        return Qnil;
+                }
+                rb_sys_fail("poll");
+        }
         if (nr == 0) return Qnil;
 
         return poll_result(nr, a);
@@ -156,6 +206,9 @@ static VALUE s_poll(int argc, VALUE *argv, VALUE self)
 void init_kgio_poll(void)
 {
         VALUE mKgio = rb_define_module("Kgio");
+
+        if (check_clock() < 0)
+                return;
         rb_define_singleton_method(mKgio, "poll", s_poll, -1);
 
         sym_wait_readable = ID2SYM(rb_intern("wait_readable"));