Merged commit 12741 from Michael's pcas-fake-dynamic branch

documentation/RELEASE_NOTES.html

@@ -13,6 +13,15 @@
 
 <!-- Insert new items immediately below here ... -->
 
+<h3>Add dynamic (variable length) array support to PCAS</h3>
+
+<p>Dynamic array sizing support was added to the IOC server (RSRV) in the
+Base-3.14.12 release, but has not until now been supported in the <q>Portable
+Channel Access Server</q> (PCAS). Channel Access server applications using the
+PCAS will have to be modified slightly to provide full support for variable
+length arrays, but unmodified applications will continue to build and work as
+before against this release.</p>
+
 <h3>Additional epicsTime conversion</h3>
 
 <p>The EPICS timestamp library (epicsTime) inside libCom's OSI layer has

src/cas/generic/caHdrLargeArray.h

@@ -30,7 +30,7 @@
 #   include "shareLib.h"
 #endif
 
-static const unsigned char CA_MINOR_PROTOCOL_REVISION = 12;
+static const unsigned char CA_MINOR_PROTOCOL_REVISION = 13;
 
 typedef ca_uint32_t caResId;
 

src/cas/generic/casCtx.h

@@ -18,6 +18,8 @@
 
 #include "caHdrLargeArray.h"
 
+class casStrmClient;
+
 class casCtx {
 public:
 	casCtx();
@@ -41,6 +43,7 @@ private:
 	casChannelI * pChannel;
 	casPVI * pPV;
 	unsigned nAsyncIO; // checks for improper use of async io
+    friend class casStrmClient;
 };
 
 inline const caHdrLargeArray * casCtx::getMsg() const 

src/cas/generic/casStrmClient.cc

@@ -390,14 +390,12 @@ caStatus casStrmClient::echoAction ( epicsGuard < casClientMutex > & )
 //
 // casStrmClient::verifyRequest()
 //
-caStatus casStrmClient::verifyRequest ( casChannelI * & pChan )
+caStatus casStrmClient::verifyRequest (casChannelI * & pChan , bool allowdyn)
 {
-    const caHdrLargeArray * mp = this->ctx.getMsg();
-
     //
     // channel exists for this resource id ?
     //
-    chronIntId tmpId ( mp->m_cid );
+    chronIntId tmpId ( ctx.msg.m_cid );
     pChan = this->chanTable.lookup ( tmpId );
     if ( ! pChan ) {
         return ECA_BADCHID;
@@ -406,14 +404,24 @@ caStatus casStrmClient::verifyRequest ( casChannelI * & pChan )
     //
     // data type out of range ?
     //
-    if ( mp->m_dataType > ((unsigned)LAST_BUFFER_TYPE) ) {
+    if ( ctx.msg.m_dataType > ((unsigned)LAST_BUFFER_TYPE) ) {
         return ECA_BADTYPE;
     }
 
     //
     // element count out of range ?
     //
-    if ( mp->m_count > pChan->getPVI().nativeCount() || mp->m_count == 0u ) {
+    if ( allowdyn && ctx.msg.m_count==0 &&
+        CA_V413 ( this->minor_version_number ) ) {
+        // Hack
+        // Since GDD interface doesn't support variable sized arrays
+        // we present dynamic requests as max size.
+        // This allows PCAS to claim support for dynamic arrays w/o
+        // going to the trouble of fixing GDD.
+        ctx.msg.m_count = pChan->getPVI().nativeCount();
+    }
+    else if ( ctx.msg.m_count > pChan->getPVI().nativeCount() ||
+        ctx.msg.m_count == 0u ) {
         return ECA_BADCOUNT;
     }
 
@@ -446,7 +454,7 @@ caStatus casStrmClient::readAction ( epicsGuard < casClientMutex > & guard )
     casChannelI * pChan;
 
     {
-        caStatus status = this->verifyRequest ( pChan );
+        caStatus status = this->verifyRequest ( pChan, true );
         if ( status != ECA_NORMAL ) {
             if ( pChan ) {
                 return this->sendErr ( guard, mp, pChan->getCID(), 
@@ -587,7 +595,7 @@ caStatus casStrmClient::readNotifyAction ( epicsGuard < casClientMutex > & guard
     casChannelI * pChan;
 
     {
-        caStatus status = this->verifyRequest ( pChan );
+        caStatus status = this->verifyRequest ( pChan, true );
         if ( status != ECA_NORMAL ) {
             return this->readNotifyFailureResponse ( guard, * mp, status );
         }
@@ -1942,7 +1950,7 @@ caStatus casStrmClient::eventAddAction (
 
     casChannelI *pciu;
     {
-        caStatus status = casStrmClient::verifyRequest ( pciu );
+        caStatus status = casStrmClient::verifyRequest ( pciu, true );
         if ( status != ECA_NORMAL ) {
             if ( pciu ) {
                 return this->sendErr ( guard, mp, 

src/cas/generic/casStrmClient.h

@@ -69,7 +69,7 @@ private:
     bool responseIsPending;
 
     caStatus createChannel ( const char * pName );
-    caStatus verifyRequest ( casChannelI * & pChan );
+    caStatus verifyRequest ( casChannelI * & pChan, bool allowdyn = false );
     typedef caStatus ( casStrmClient :: * pCASMsgHandler ) 
         ( epicsGuard < casClientMutex > & );
     static pCASMsgHandler const msgHandlers[CA_PROTO_LAST_CMMD+1u];