[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[PATCH 3/5] include: add msgh_protected_payload to mach_msg_header_t

From: Justus Winter
Subject: [PATCH 3/5] include: add msgh_protected_payload to mach_msg_header_t
Date: Fri, 21 Feb 2014 17:49:26 +0100

* include/mach/message.h (mach_msg_header_t): Add
  msgh_protected_payload as a union with msgh_local_port.
* doc/mach.texi (Message Format): Document msgh_protected_payload.
 doc/mach.texi          | 9 +++++++++
 include/mach/message.h | 5 ++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/doc/mach.texi b/doc/mach.texi
index 766cd48..6a376f7 100644
--- a/doc/mach.texi
+++ b/doc/mach.texi
@@ -1330,6 +1330,15 @@ which is conventionally used as a reply port by the 
recipient of the
 message.  The field must carry a send right, a send-once right,
 @code{MACH_PORT_NULL}, or @code{MACH_PORT_DEAD}.
+@item mach_port_t msgh_protected_payload
+The @code{msgh_protected_payload} field carries a payload that is set
+by the kernel during message delivery.  The payload is an opaque
+identifier that can be used by the receiver to lookup the associated
+data structure.
+It is only valid in received messages.  See @ref{Message Receive} for
+further information.
 @item mach_port_seqno_t msgh_seqno
 The @code{msgh_seqno} field provides a sequence number for the message.
 It is only valid in received messages; its value in sent messages is
diff --git a/include/mach/message.h b/include/mach/message.h
index f78e978..7464a57 100644
--- a/include/mach/message.h
+++ b/include/mach/message.h
@@ -136,7 +136,10 @@ typedef    struct {
     mach_msg_bits_t    msgh_bits;
     mach_msg_size_t    msgh_size;
     mach_port_t                msgh_remote_port;
-    mach_port_t                msgh_local_port;
+    union {
+        mach_port_t    msgh_local_port;
+        unsigned long  msgh_protected_payload;
+    };
     mach_port_seqno_t  msgh_seqno;
     mach_msg_id_t      msgh_id;
 } mach_msg_header_t;

reply via email to

[Prev in Thread] Current Thread [Next in Thread]