add version of Tupdate that takes a Page* instead of a pageid

src/stasis/operations/set.c

@@ -90,16 +90,20 @@ typedef struct {
   slotid_t slot;
 } set_range_t;
 
-int Tset(int xid, recordid rid, const void * dat) {
-  Page * p = loadPage(xid, rid.page);
+Page * TsetWithPage(int xid, recordid rid, Page *p, const void * dat) {
   readlock(p->rwlatch,0);
   rid = stasis_record_dereference(xid,p,rid);
+  if(rid.page != p->id) {
+    unlock(p->rwlatch);
+    releasePage(p);
+    p = loadPage(xid, rid.page);
+    readlock(p->rwlatch,0);
+  }
   short type = stasis_record_type_read(xid,p,rid);
 
   if(type == BLOB_SLOT) {
     stasis_blob_write(xid,p,rid,dat);
     unlock(p->rwlatch);
-    releasePage(p);
   } else {
     rid.size = stasis_record_type_to_size(rid.size);
     if(rid.page == p->id) {
@@ -107,7 +111,6 @@ int Tset(int xid, recordid rid, const void * dat) {
       assert(rid.size == stasis_record_length_read(xid, p, rid));
     }
     unlock(p->rwlatch);
-    releasePage(p);
 
     size_t sz = sizeof(slotid_t) + sizeof(int64_t) + 2 * rid.size;
     byte * const buf = malloc(sz);
@@ -117,11 +120,17 @@ int Tset(int xid, recordid rid, const void * dat) {
     *(int64_t*)  b = rid.size;    b += sizeof(int64_t);
     memcpy(b, dat, rid.size);
     b += rid.size;
-    Tread(xid, rid, b);
+    TreadWithPage(xid, rid, p, b);
 
-    Tupdate(xid,rid.page,buf,sz,OPERATION_SET);
+    TupdateWithPage(xid,rid.page,p,buf,sz,OPERATION_SET);
     free(buf);
   }
+  return p;
+}
+
+int Tset(int xid, recordid rid, const void * dat) {
+  Page * p = loadPage(xid, rid.page);
+  releasePage( TsetWithPage(xid, rid, p, dat) );
   return 0;
 }
 

src/stasis/transactional2.c

@@ -138,14 +138,12 @@ int Tbegin() {
   }
 }
 
-void Tupdate(int xid, pageid_t page,
-					       const void * dat, size_t datlen, int op) {
+void TupdateWithPage(int xid, pageid_t page, Page *p, const void * dat, size_t datlen, int op) {
   assert(stasis_initted);
   assert(page != INVALID_PAGE);
   LogEntry * e;
   stasis_transaction_table_entry_t * xact = stasis_transaction_table_get(stasis_transaction_table, xid);
   assert(xact);
-  Page * p = loadPageForOperation(xid, page, op, 0);
 
   if(globalLockManager.writeLockPage && p) {
     globalLockManager.writeLockPage(xid, page);
@@ -178,6 +176,11 @@ void Tupdate(int xid, pageid_t page,
   }
 
   if(p) unlock(p->rwlatch);
+}
+
+void Tupdate(int xid, pageid_t page, const void * dat, size_t datlen, int op) {
+  Page * p = loadPageForOperation(xid, page, op, 0);
+  TupdateWithPage(xid, page, p, dat, datlen, op);
   if(p) releasePage(p);
 }
 
@@ -249,12 +252,7 @@ void TreadStr(int xid, recordid rid, char * dat) {
   Tread(xid, rid, dat);
 }
 
-compensated_function void Tread(int xid, recordid rid, void * dat) {
-  Page * p;
-  try {
-    p = loadPage(xid, rid.page);
-  } end;
-
+Page * TreadWithPage(int xid, recordid rid, Page *p, void * dat) {
   readlock(p->rwlatch,0);
 
   rid = stasis_record_dereference(xid, p, rid);
@@ -273,7 +271,16 @@ compensated_function void Tread(int xid, recordid rid, void * dat) {
     stasis_record_read(xid, p, rid, dat);
   }
   unlock(p->rwlatch);
-  releasePage(p);
+  return p;
+}
+
+compensated_function void Tread(int xid, recordid rid, void * dat) {
+  Page * p;
+  try {
+    p = loadPage(xid, rid.page);
+  } end;
+
+  releasePage( TreadWithPage(xid, rid, p, dat) );
 }
 
 compensated_function void TreadRaw(int xid, recordid rid, void * dat) {

stasis/operations/set.h

@@ -61,6 +61,7 @@ terms specified in this license.
     @param dat the new value of the record.
 */ 
 int Tset(int xid, recordid rid, const void * dat);
+Page * TsetWithPage(int xid, recordid rid, Page *p, const void * dat);
 
 int TsetRaw(int xid, recordid rid, const void * dat);
 

stasis/transactional.h

@@ -602,8 +602,8 @@ int Tbegin(void);
  *
  * @see operations.h For an overview of the operations API
  */
-void Tupdate(int xid, pageid_t page,
-				  const void *dat, size_t datlen, int op);
+void Tupdate(int xid, pageid_t page, const void *dat, size_t datlen, int op);
+void TupdateWithPage(int xid, pageid_t page, Page *p, const void *dat, size_t datlen, int op);
 /**
    @deprecated Only exists to work around swig/python limitations.
  */
@@ -633,6 +633,7 @@ void TreorderableWritebackUpdate(int xid, void* h,
  * @param dat buffer into which data goes
  */
 compensated_function void Tread(int xid, recordid rid, void *dat);
+Page * TreadWithPage(int xid, recordid rid, Page *p, void *dat);
 /**
  * Read a value of a record without first dereferencing the record.
  * Use Tread() unless you're implementing code that provides