From 68d807c915f3fe124e50e47fcc4080d1d3e5bb9d Mon Sep 17 00:00:00 2001
From: Andrew Hanushevsky <abh@stanford.edu>
Date: Mon, 18 Mar 2019 13:16:50 -0700
Subject: [PATCH] [SSI] Expose refresh flag for better request retry control.

---
 src/XrdSsi/XrdSsiRRAgent.hh  |  8 ++++++++
 src/XrdSsi/XrdSsiRequest.cc  | 15 ++++++++++++++-
 src/XrdSsi/XrdSsiRequest.hh  | 13 ++++++++++++-
 src/XrdSsi/XrdSsiSessReal.cc |  9 +++++++--
 4 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/src/XrdSsi/XrdSsiRRAgent.hh b/src/XrdSsi/XrdSsiRRAgent.hh
index 05f54d1f5dd..81671b2a8cd 100644
--- a/src/XrdSsi/XrdSsiRRAgent.hh
+++ b/src/XrdSsi/XrdSsiRRAgent.hh
@@ -47,6 +47,14 @@ static void            Dispose(XrdSsiRequest &reqR) {reqR.Dispose();}
 
 static XrdSsiErrInfo  &ErrInfoRef(XrdSsiRequest *rP) {return rP->errInfo;}
 
+static bool            isaRetry(XrdSsiRequest *rP)
+                               {if (rP->flags & XrdSsiRequest::isaRetry)
+                                   {rP->flags &= ~XrdSsiRequest::isaRetry;
+                                    return true;
+                                   }
+                                return false;
+                               }
+
 static void            onServer(XrdSsiRequest *rP) {rP->onClient = false;}
 
 static XrdSsiRequest  *Request(XrdSsiResponder *rP) {return rP->reqP;}
diff --git a/src/XrdSsi/XrdSsiRequest.cc b/src/XrdSsi/XrdSsiRequest.cc
index 334cbb6dfbf..7690364af54 100644
--- a/src/XrdSsi/XrdSsiRequest.cc
+++ b/src/XrdSsi/XrdSsiRequest.cc
@@ -52,7 +52,7 @@ XrdSsiMutex ubMutex(XrdSsiMutex::Recursive);
 XrdSsiRequest::XrdSsiRequest(const char *reqid, uint16_t tmo)
                             : reqID(reqid), rrMutex(&XrdSsi::ubMutex),
                               theRespond(0), rsvd1(0), epNode(0),
-                              detTTL(0), tOut(0), onClient(true), rsvd2(0) {}
+                              detTTL(0), tOut(0), onClient(true), flags(0) {}
   
 /******************************************************************************/
 /* Private:                     C l e a n U p                                */
@@ -185,3 +185,16 @@ void XrdSsiRequest::ReleaseRequestBuffer()
    XrdSsiMutexMon lck(rrMutex);
    RelRequestBuffer();
 }
+
+/******************************************************************************/
+/*                              S e t R e t r y                               */
+/******************************************************************************/
+  
+void XrdSsiRequest::SetRetry(bool onoff)
+{
+
+// Set flag as needed
+//
+if (onoff) flags |=  isaRetry;
+   else    flags &= ~isaRetry;
+}
diff --git a/src/XrdSsi/XrdSsiRequest.hh b/src/XrdSsi/XrdSsiRequest.hh
index 8ae496c8b33..f722b2fa1b0 100644
--- a/src/XrdSsi/XrdSsiRequest.hh
+++ b/src/XrdSsi/XrdSsiRequest.hh
@@ -268,6 +268,16 @@ virtual void    RelRequestBuffer() {}
 
 inline void     SetDetachTTL(uint32_t dttl) {detTTL = dttl;}
 
+//-----------------------------------------------------------------------------
+//! Set request retry notification. If a non-default value is desired, it must
+//! be set prior to calling XrdSsiService::ProcessRequest(). This is a one-time
+//! request and retry mode is turned off in the request object afterwards.
+//!
+//! @param onoff   True to turn retry on and false to turn it off.
+//-----------------------------------------------------------------------------
+
+       void     SetRetry(bool onoff);
+
 //-----------------------------------------------------------------------------
 //! Set timeout for initiating the request. If a non-default value is desired,
 //! it must be set prior to calling XrdSsiService::ProcessRequest().
@@ -302,6 +312,7 @@ const char      *epNode;
 uint32_t         detTTL;
 uint16_t         tOut;
 bool             onClient;
-char             rsvd2;
+char             flags;
+static const int isaRetry = 1;
 };
 #endif
diff --git a/src/XrdSsi/XrdSsiSessReal.cc b/src/XrdSsi/XrdSsiSessReal.cc
index e5999cfae6e..4c57bbf62f9 100644
--- a/src/XrdSsi/XrdSsiSessReal.cc
+++ b/src/XrdSsi/XrdSsiSessReal.cc
@@ -227,12 +227,17 @@ bool XrdSsiSessReal::Provision(XrdSsiRequest *reqP, const char *epURL)
    EPNAME("Provision");
    XrdCl::XRootDStatus epStatus;
    XrdSsiMutexMon rHelp(&sessMutex);
+   XrdCl::OpenFlags::Flags oFlags = XrdCl::OpenFlags::Read;
+
+// Set retry flag as appropriate
+//
+   if (XrdSsiRRAgent::isaRetry(reqP)) oFlags |= XrdCl::OpenFlags::Refresh;
 
 // Issue the open and if the open was started, return success.
 //
    DEBUG("Provisioning " <<epURL);
-   epStatus = epFile.Open((const std::string)epURL,
-                          XrdCl::OpenFlags::Read, (XrdCl::Access::Mode)0,
+   epStatus = epFile.Open((const std::string)epURL, oFlags,
+                          (XrdCl::Access::Mode)0,
                           (XrdCl::ResponseHandler *)this,
                           reqP->GetTimeOut());