IPC: Difference between revisions

Line 79:

The type of parameter is described by the bits 1-3 in the translation descriptor. Parameter types accepted for sending by the kernel are: 0, 1, 2, 5, 6, 7.

Type 0 is used to send handles across processes:

~~if desc & 0x30~~ == ~~0x20:~~

Type 0 is used to send handles across processes. The corresponding translation descriptor looks as follows:

~~write process id to value~~

{| class="wikitable" border="1"

~~else:~~

|-

~~translate handle~~

! Bits

~~if desc & 0x30 == 0x10:~~

! Description

~~close~~ handle for caller

|-

| 4

| If set, the handle is closed for the caller. Ignored if bit5 is set.

|-

| 5

| If set, the process ID is written to value. Otherwise, translate the handle between client and server.

|}

For replies, only 0, 1, 5, 6, 7 are allowed. In other words any type 2 fields must be zeroed before calling svcReplyAndReceive on the server-side. For replies, type 0, 1, and 2 are ignored. Types 5, 6, and 7 do something with the mem pointer upon reply. The type 0 descriptor can be used to ignore parameters. The number of parameters covered by a type-0 descriptor is (desc >> 26) + 1.

@@ Line 79: / Line 79: @@
 The type of parameter is described by the bits 1-3 in the translation descriptor. Parameter types accepted for sending by the kernel are: 0, 1, 2, 5, 6, 7.
-Type 0 is used to send handles across processes:
- if desc & 0x30 == 0x20:
+Type 0 is used to send handles across processes. The corresponding translation descriptor looks as follows:
-   write process id to value
+{| class="wikitable" border="1"
-  else:
+|-
-   translate handle
+!  Bits
-   if desc & 0x30 == 0x10:
+!  Description
-     close handle for caller
+|-
+| 4
+| If set, the handle is closed for the caller. Ignored if bit5 is set.
+|-
+| 5
+| If set, the process ID is written to value. Otherwise, translate the handle between client and server.
+|}
 For replies, only 0, 1, 5, 6, 7 are allowed. In other words any type 2 fields must be zeroed before calling svcReplyAndReceive on the server-side. For replies, type 0, 1, and 2 are ignored. Types 5, 6, and 7 do something with the mem pointer upon reply. The type 0 descriptor can be used to ignore parameters. The number of parameters covered by a type-0 descriptor is (desc >> 26) + 1.