blocking functions do not raise Errno::EINTR

Blocking functions should not raise Errno::EINTR to match
existing semantics of Ruby IO methods (e.g. IO.select, IO#read,
IO#write).  This makes user code easier to read/write.

Like th Ruby methods we emulate, we only reacquire the GVL on
EINTR to fire signal handlers, but otherwise emulate SA_RESTART
semantics.

This is a backwards-incompatible API change (but unlikely
to break existing code).

1 files changed, 11 insertions, 1 deletions

diff --git a/ext/posix_mq/posix_mq.c b/ext/posix_mq/posix_mq.c
index 2958352..df667e3 100644
--- a/ext/posix_mq/posix_mq.c
+++ b/ext/posix_mq/posix_mq.c
@@ -542,8 +542,11 @@ static VALUE _send(int sflags, int argc, VALUE *argv, VALUE self)
         x.timeout = convert_timeout(&expire, timeout);
         x.msg_prio = NIL_P(prio) ? 0 : NUM2UINT(prio);
 
+retry:
         rv = (mqd_t)rb_thread_blocking_region(xsend, &x, RUBY_UBF_IO, 0);
         if (rv == MQD_INVALID) {
+                if (errno == EINTR)
+                        goto retry;
                 if (errno == EAGAIN && (sflags & PMQ_TRY))
                         return Qfalse;
                 rb_sys_fail("mq_send");
@@ -574,9 +577,13 @@ static VALUE send0(VALUE self, VALUE buffer)
         x.timeout = NULL;
         x.msg_prio = 0;
 
+retry:
         rv = (mqd_t)rb_thread_blocking_region(xsend, &x, RUBY_UBF_IO, 0);
-        if (rv == MQD_INVALID)
+        if (rv == MQD_INVALID) {
+                if (errno == EINTR)
+                        goto retry;
                 rb_sys_fail("mq_send");
+        }
 
         return self;
 }
@@ -678,8 +685,11 @@ static VALUE _receive(int rflags, int argc, VALUE *argv, VALUE self)
         x.msg_len = (size_t)mq->attr.mq_msgsize;
         x.des = mq->des;
 
+retry:
         r = (ssize_t)rb_thread_blocking_region(xrecv, &x, RUBY_UBF_IO, 0);
         if (r < 0) {
+                if (errno == EINTR)
+                        goto retry;
                 if (errno == EAGAIN && (rflags & PMQ_TRY))
                         return Qnil;
                 rb_sys_fail("mq_receive");