fix #391, copy request for async call.

@@ -562,6 +562,7 @@ Supported operating systems and hardware:
 
 ### SRS 2.0 history
 
+* v2.0, 2015-05-23, fix [#391](https://github.com/simple-rtmp-server/srs/issues/391) copy request for async call.
 * v2.0, 2015-05-22, fix [#397](https://github.com/simple-rtmp-server/srs/issues/397) the USER_HZ maybe not 100. 2.0.165
 * v2.0, 2015-05-22, for [#400](https://github.com/simple-rtmp-server/srs/issues/400), parse when got entire http header, by feilong. 2.0.164.
 * v2.0, 2015-05-19, merge from bravo system, add the rtmfp to bms(commercial srs). 2.0.163.

@@ -498,12 +498,13 @@ int SrsFlvSegment::on_reload_vhost_dvr(std::string /*vhost*/)
 
 SrsDvrAsyncCallOnDvr::SrsDvrAsyncCallOnDvr(SrsRequest* r, string p)
 {
-    req = r;
+    req = r->copy();
     path = p;
 }
 
 SrsDvrAsyncCallOnDvr::~SrsDvrAsyncCallOnDvr()
 {
+    srs_freep(req);
 }
 
 int SrsDvrAsyncCallOnDvr::call()

@@ -172,7 +172,7 @@ void SrsHlsSegment::update_duration(int64_t current_frame_dts)
 
 SrsDvrAsyncCallOnHls::SrsDvrAsyncCallOnHls(SrsRequest* r, string p, string t, string m, string mu, int s, double d)
 {
-    req = r;
+    req = r->copy();
     path = p;
     ts_url = t;
     m3u8 = m;
@@ -183,6 +183,7 @@ SrsDvrAsyncCallOnHls::SrsDvrAsyncCallOnHls(SrsRequest* r, string p, string t, st
 
 SrsDvrAsyncCallOnHls::~SrsDvrAsyncCallOnHls()
 {
+    srs_freep(req);
 }
 
 int SrsDvrAsyncCallOnHls::call()
@@ -221,12 +222,13 @@ string SrsDvrAsyncCallOnHls::to_string()
 
 SrsDvrAsyncCallOnHlsNotify::SrsDvrAsyncCallOnHlsNotify(SrsRequest* r, string u)
 {
-    req = r;
+    req = r->copy();
     ts_url = u;
 }
 
 SrsDvrAsyncCallOnHlsNotify::~SrsDvrAsyncCallOnHlsNotify()
 {
+    srs_freep(req);
 }
 
 int SrsDvrAsyncCallOnHlsNotify::call()