On the trunk:

mod_http2: Fix for possible CPU busy loop introduced in v1.10.3 where a stream may keep
     the session in continuous check for state changes that never happen.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1797745 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/CHANGES b/CHANGES
index 9a2954326811fa6d8b3da40601678eba1b215400..6ef36b323de5711f1ca295927d8db9ded73f1199 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,10 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache 2.5.0
 
+  *) mod_http2: Fix for possible CPU busy loop introduced in v1.10.3 where a stream may keep
+     the session in continuous check for state changes that never happen. 
+     [Stefan Eissing]
+
   *) Evaluate nested If/ElseIf/Else configuration blocks.
      [Luca Toscano, Jacob Champion]
 

diff --git a/modules/http2/h2_mplx.c b/modules/http2/h2_mplx.c
index ebe0156153a2370d3d090c318664759f4ac14e59..b126be935f92eee43de7b65fdd3c0eaa3c166d20 100644 (file)
--- a/modules/http2/h2_mplx.c
+++ b/modules/http2/h2_mplx.c
@@ -1057,19 +1057,23 @@ apr_status_t h2_mplx_idle(h2_mplx *m)
                           "h2_mplx(%ld): idle, no tasks ongoing, %d streams",
                           m->id, (int)h2_ihash_count(m->streams));
             h2_ihash_shift(m->streams, (void**)&stream, 1);
-            if (stream && stream->output) {
-                /* FIXME: this looks like a race between the session thinking
-                 * it is idle and the EOF on a stream not being sent.
-                 * Signal to caller to leave IDLE state.
-                 */
-                ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
-                              H2_STRM_MSG(stream, "output closed=%d, mplx idle"
-                              ", out has %ld bytes buffered"),
-                              h2_beam_is_closed(stream->output),
-                              (long)h2_beam_get_buffered(stream->output));
+            if (stream) {
                 h2_ihash_add(m->streams, stream);
-                check_data_for(m, stream, 0);
-                status = APR_EAGAIN;
+                if (stream->output && !stream->out_checked) {
+                    /* FIXME: this looks like a race between the session thinking
+                     * it is idle and the EOF on a stream not being sent.
+                     * Signal to caller to leave IDLE state.
+                     */
+                    ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, m->c,
+                                  H2_STRM_MSG(stream, "output closed=%d, mplx idle"
+                                              ", out has %ld bytes buffered"),
+                                  h2_beam_is_closed(stream->output),
+                                  (long)h2_beam_get_buffered(stream->output));
+                    h2_ihash_add(m->streams, stream);
+                    check_data_for(m, stream, 0);
+                    stream->out_checked = 1;
+                    status = APR_EAGAIN;
+                }
             }
         }
     }

diff --git a/modules/http2/h2_stream.h b/modules/http2/h2_stream.h
index f328714951b3c4c0067ec9bd9513be4b353c426e..c3b4b844fd41381c24f94eda2e208561744e3a28 100644 (file)
--- a/modules/http2/h2_stream.h
+++ b/modules/http2/h2_stream.h
@@ -89,6 +89,7 @@ struct h2_stream {
     unsigned int scheduled : 1; /* stream has been scheduled */
     unsigned int has_response : 1; /* response headers are known */
     unsigned int input_eof : 1; /* no more request data coming */
+    unsigned int out_checked : 1; /* output eof was double checked */
     unsigned int push_policy;   /* which push policy to use for this request */
     
     struct h2_task *task;       /* assigned task to fullfill request */