Re: [PATCH] 'clogging' input filters and the event MPM
+1 (concept)
On Jun 10, 2007, at 9:13 PM, Paul Querna wrote:
Attached is a patch that should let people run mod_ssl under the
Event MPM.
Previously, the event mpm would put a socket into its event thread to
wait for input, but due to issues with how mod_ssl might be buffering
data (or the entire request) in it, this would cause SSL'ized requests
to stall and fail with the event mpm.
The attach patch adds a new field, clogging_input_filters, to the
conn_rec. When this field is true, the event mpm will run a connection
just like the worker mpm is -- that is a single thread will run the
entire connection, including keepalives.
Thoughts on committing this to trunk?
Thanks,
-Paul
Index: server/mpm/experimental/event/event.c
===
--- server/mpm/experimental/event/event.c (revision 545614)
+++ server/mpm/experimental/event/event.c (working copy)
@@ -620,6 +620,16 @@
pt = cs-pfd.client_data;
}
+if (c-clogging_input_filters !c-aborted) {
+/* Since we have an input filter which 'cloggs' the input
stream,
+ * like mod_ssl, lets just do the normal read from input
filters,
+ * like the Worker MPM does.
+ */
+ap_run_process_connection(c);
+ap_lingering_close(c);
+return 0;
+}
+
read_request:
if (cs-state == CONN_STATE_READ_REQUEST_LINE) {
if (!c-aborted) {
Index: server/core.c
===
--- server/core.c (revision 545614)
+++ server/core.c (working copy)
@@ -3803,6 +3803,7 @@
c-cs-c = c;
c-cs-p = ptrans;
c-cs-bucket_alloc = alloc;
+c-clogging_input_filters = 0;
return c;
}
Index: modules/http/http_core.c
===
--- modules/http/http_core.c(revision 545614)
+++ modules/http/http_core.c(working copy)
@@ -119,11 +119,17 @@
return DEFAULT_HTTP_PORT;
}
+static int ap_process_http_connection(conn_rec *c);
+
static int ap_process_http_async_connection(conn_rec *c)
{
request_rec *r;
conn_state_t *cs = c-cs;
+if (c-clogging_input_filters) {
+return ap_process_http_connection(c);
+}
+
AP_DEBUG_ASSERT(cs-state == CONN_STATE_READ_REQUEST_LINE);
while (cs-state == CONN_STATE_READ_REQUEST_LINE) {
Index: modules/ssl/ssl_engine_io.c
===
--- modules/ssl/ssl_engine_io.c (revision 545614)
+++ modules/ssl/ssl_engine_io.c (working copy)
@@ -1665,6 +1665,9 @@
filter_ctx-pbioWrite = BIO_new(bio_filter_out_method);
filter_ctx-pbioWrite-ptr = (void *)bio_filter_out_ctx_new
(filter_ctx, c);
+/* We insert a clogging input filter. Let the core know. */
+c-clogging_input_filters = 1;
+
ssl_io_input_add_filter(filter_ctx, c, ssl);
SSL_set_bio(ssl, filter_ctx-pbioRead, filter_ctx-pbioWrite);
Index: include/httpd.h
===
--- include/httpd.h (revision 545614)
+++ include/httpd.h (working copy)
@@ -1081,6 +1081,11 @@
int data_in_input_filters;
/** Is there data pending in the output filters? */
int data_in_output_filters;
+
+/** Are there any filters that clogg/buffer the input stream,
breaking
+ * the event mpm.
+ */
+int clogging_input_filters;
};
/**
[PATCH] 'clogging' input filters and the event MPM
Attached is a patch that should let people run mod_ssl under the Event MPM.
Previously, the event mpm would put a socket into its event thread to
wait for input, but due to issues with how mod_ssl might be buffering
data (or the entire request) in it, this would cause SSL'ized requests
to stall and fail with the event mpm.
The attach patch adds a new field, clogging_input_filters, to the
conn_rec. When this field is true, the event mpm will run a connection
just like the worker mpm is -- that is a single thread will run the
entire connection, including keepalives.
Thoughts on committing this to trunk?
Thanks,
-Paul
Index: server/mpm/experimental/event/event.c
===
--- server/mpm/experimental/event/event.c (revision 545614)
+++ server/mpm/experimental/event/event.c (working copy)
@@ -620,6 +620,16 @@
pt = cs-pfd.client_data;
}
+if (c-clogging_input_filters !c-aborted) {
+/* Since we have an input filter which 'cloggs' the input stream,
+ * like mod_ssl, lets just do the normal read from input filters,
+ * like the Worker MPM does.
+ */
+ap_run_process_connection(c);
+ap_lingering_close(c);
+return 0;
+}
+
read_request:
if (cs-state == CONN_STATE_READ_REQUEST_LINE) {
if (!c-aborted) {
Index: server/core.c
===
--- server/core.c (revision 545614)
+++ server/core.c (working copy)
@@ -3803,6 +3803,7 @@
c-cs-c = c;
c-cs-p = ptrans;
c-cs-bucket_alloc = alloc;
+c-clogging_input_filters = 0;
return c;
}
Index: modules/http/http_core.c
===
--- modules/http/http_core.c(revision 545614)
+++ modules/http/http_core.c(working copy)
@@ -119,11 +119,17 @@
return DEFAULT_HTTP_PORT;
}
+static int ap_process_http_connection(conn_rec *c);
+
static int ap_process_http_async_connection(conn_rec *c)
{
request_rec *r;
conn_state_t *cs = c-cs;
+if (c-clogging_input_filters) {
+return ap_process_http_connection(c);
+}
+
AP_DEBUG_ASSERT(cs-state == CONN_STATE_READ_REQUEST_LINE);
while (cs-state == CONN_STATE_READ_REQUEST_LINE) {
Index: modules/ssl/ssl_engine_io.c
===
--- modules/ssl/ssl_engine_io.c (revision 545614)
+++ modules/ssl/ssl_engine_io.c (working copy)
@@ -1665,6 +1665,9 @@
filter_ctx-pbioWrite = BIO_new(bio_filter_out_method);
filter_ctx-pbioWrite-ptr = (void *)bio_filter_out_ctx_new(filter_ctx,
c);
+/* We insert a clogging input filter. Let the core know. */
+c-clogging_input_filters = 1;
+
ssl_io_input_add_filter(filter_ctx, c, ssl);
SSL_set_bio(ssl, filter_ctx-pbioRead, filter_ctx-pbioWrite);
Index: include/httpd.h
===
--- include/httpd.h (revision 545614)
+++ include/httpd.h (working copy)
@@ -1081,6 +1081,11 @@
int data_in_input_filters;
/** Is there data pending in the output filters? */
int data_in_output_filters;
+
+/** Are there any filters that clogg/buffer the input stream, breaking
+ * the event mpm.
+ */
+int clogging_input_filters;
};
/**
