[PATCH 2/2] common/ptid.h: Mention that process_stratum targets should prefer ptid.lwp.

[Pedro Alves <palves@redhat.com>]

It's best that we standardize on process_stratum targets using the
ptid.lwp field to store thread ids.  The idea being leave the ptid.tid
field free for any thread_stratum target that might want to sit on
top.

gdb/
2014-02-12  Pedro Alves  <palves@redhat.com>

	* common/ptid.h (struct ptid): Mention that process_stratum
	targets should prefer ptid.lwp.
---
 gdb/common/ptid.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/gdb/common/ptid.h b/gdb/common/ptid.h
index 362882d..cc1825e 100644
--- a/gdb/common/ptid.h
+++ b/gdb/common/ptid.h
@@ -25,7 +25,12 @@
    consists of the process id (pid), lightweight process id (lwp) and
    thread id (tid).  When manipulating ptids, the constructors,
    accessors, and predicates declared in this file should be used.  Do
-   NOT access the struct ptid members directly.  */
+   NOT access the struct ptid members directly.
+
+   process_stratum targets that handle threading themselves should
+   prefer using the ptid.lwp field, leaving the ptid.tid field for any
+   thread_stratum target that might want to sit on top.
+*/
 
 struct ptid
 {
-- 
1.7.11.7