installed

src/db/dbServiceIO.cpp

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+
+/*  
+ *  $Id$
+ *
+ *                              
+ *                    L O S  A L A M O S
+ *              Los Alamos National Laboratory
+ *               Los Alamos, New Mexico 87545
+ *                                  
+ *  Copyright, 1986, The Regents of the University of California.
+ *                                  
+ *           
+ *	Author Jeffrey O. Hill
+ *	johill@lanl.gov
+ *	505 665 1831
+ */
+
+#include "limits.h"
+
+#include "osiMutex.h"
+#include "tsFreeList.h"
+
+#include "cadef.h"
+#include "cacIO.h"
+
+#define epicsExportSharedSymbols
+#include "db_access_routines.h"
+#include "dbCAC.h"
+
+class loadTimeInit {
+public:
+    loadTimeInit ();
+private:
+    dbServiceIO dbio;
+};
+
+static loadTimeInit lti;
+
+loadTimeInit::loadTimeInit ()
+{
+    cacGlobalServiceList.registerService ( this->dbio );
+}
+
+dbServiceIO::dbServiceIO () :
+    ctx (0), pEventCallbackCache (0), eventCallbackCacheSize (0ul)
+{
+}
+
+dbServiceIO::~dbServiceIO ()
+{
+    if ( this->pEventCallbackCache ) {
+        delete [] this->pEventCallbackCache;
+    }
+    if (this->ctx) {
+        db_close_events (this->ctx);
+    }
+}
+
+cacChannelIO *dbServiceIO::createChannelIO ( cacChannel &chan, const char *pName )
+{
+    struct dbAddr addr;
+
+    int status = db_name_to_addr ( pName, &addr );
+    if (status) {
+        return 0;
+    }
+    else {
+        return new dbChannelIO ( chan, addr, *this ); 
+    }
+}
+
+void dbServiceIO::subscriptionUpdate ( struct dbAddr &addr, unsigned type, unsigned long count, 
+        const struct db_field_log *pfl, cacNotifyIO &notify )
+{
+    unsigned long size = dbr_size_n ( type, count );
+
+    this->mutex.lock ();
+    if ( this->eventCallbackCacheSize < size) {
+        if ( this->pEventCallbackCache ) {
+            delete [] this->pEventCallbackCache;
+        }
+        this->pEventCallbackCache = new char [size];
+        if ( ! this->pEventCallbackCache ) {
+            this->eventCallbackCacheSize = 0ul;
+            this->mutex.unlock ();
+            notify.exceptionNotify ( ECA_ALLOCMEM, "unable to allocate callback cache" );
+            return;
+        }
+        this->eventCallbackCacheSize = size;
+    }
+    void *pvfl = (void *) pfl;
+    int status = db_get_field ( &addr, static_cast <int> ( type ), 
+                    this->pEventCallbackCache, static_cast <int> ( count ), pvfl );
+    if ( status ) {
+        notify.exceptionNotify ( ECA_GETFAIL, "subscription update db_get_field () completed unsuccessfuly" );
+    }
+    else { 
+        notify.completionNotify ( type, count, this->pEventCallbackCache );
+    }
+    this->mutex.unlock ();
+}
+
+extern "C" void cacAttachClientCtx ( void * pPrivate )
+{
+    int status;
+    caClientCtx clientCtx = pPrivate;
+    status = ca_attach_context ( clientCtx );
+    assert ( status == ECA_NORMAL );
+}
+
+dbEventSubscription dbServiceIO::subscribe ( struct dbAddr &addr, dbSubscriptionIO &subscr, unsigned mask )
+{
+    static const int slightlyHigherPriority = -1;
+    int status;
+    caClientCtx clientCtx;
+
+    status = ca_current_context ( &clientCtx );
+    if ( status != ECA_NORMAL ) {
+        return 0;
+    }
+
+    this->mutex.lock ();
+    if ( ! this->ctx ) {
+        this->ctx = db_init_events ();
+        if ( ! this->ctx ) {
+            this->mutex.unlock ();
+            return 0;
+        }
+        status = db_start_events ( this->ctx, "CAC event", 
+            cacAttachClientCtx, clientCtx, slightlyHigherPriority );
+        if ( status ) {
+            db_close_events (this->ctx);
+            this->ctx = 0;
+            return 0;
+        }
+    }
+    this->mutex.unlock ();
+
+    return db_add_event ( this->ctx, &addr,
+        dbSubscriptionEventCallback, (void *) &subscr, mask );
+}