Changeset 92246 in vbox for trunk/include/iprt

Timestamp:

Nov 6, 2021 3:10:49 AM (3 years ago)

Author:

vboxsync

Message:

IPRT/RTR0MemObj: Added RTR0MemObjWasZeroInitialized and a couple of flags with which the backend can feed it the necessary info. It would be good to try avoid zeroing memory twice when we can. bugref:10093

Location:

trunk/include/iprt

Files:

• mangling.h (modified) (1 diff)
• memobj.h (modified) (1 diff)

trunk/include/iprt/mangling.h

@@ -1864 +1864 @@
 # define RTR0MemObjReserveUserTag                       RT_MANGLER(RTR0MemObjReserveUserTag)   /* r0drv */
 # define RTR0MemObjSize                                 RT_MANGLER(RTR0MemObjSize)             /* r0drv */
+# define RTR0MemObjWasZeroInitialized                   RT_MANGLER(RTR0MemObjWasZeroInitialized)/* r0drv */
 # define RTR0MemUserCopyFrom                            RT_MANGLER(RTR0MemUserCopyFrom)        /* r0drv */
 # define RTR0MemUserCopyTo                              RT_MANGLER(RTR0MemUserCopyTo)          /* r0drv */

trunk/include/iprt/memobj.h

@@ -109 +109 @@
  */
 RTR0DECL(RTHCPHYS) RTR0MemObjGetPagePhysAddr(RTR0MEMOBJ MemObj, size_t iPage);
+
+/**
+ * Checks whether the allocation was zero initialized or not.
+ *
+ * This only works on allocations.  It is not meaningful for mappings, reserved
+ * memory and entered physical address, and will return false for these.
+ *
+ * @returns true if the allocation was initialized to zero at allocation time,
+ *          false if not or query not meaningful to the object type.
+ * @param   hMemObj             The ring-0 memory object to be freed.
+ *
+ * @remarks It can be expected that memory allocated in the same fashion will
+ *          have the same initialization state.  So, if this returns true for
+ *          one allocation it will return true for all other similarly made
+ *          allocations.
+ */
+RTR0DECL(bool) RTR0MemObjWasZeroInitialized(PRTR0MEMOBJ hMemObj);
 
 /**