Clarify ABI requirements for data-logging functions.

	* libitm.texi: Clarify ABI requirements for data-logging functions.

From-SVN: r192778

diff --git a/libitm/ChangeLog b/libitm/ChangeLog
index af74e974df11b214e8106e36cb47c541232dacfe..8f55f4eb3279f5cf24c95a7db13c4238e3909921 100644 (file)
--- a/libitm/ChangeLog
+++ b/libitm/ChangeLog
@@ -1,3 +1,7 @@
+2012-10-24  Torvald Riegel  <triegel@redhat.com>
+
+       * libitm.texi: Clarify ABI requirements for data-logging functions.
+
 2012-10-24  Torvald Riegel  <triegel@redhat.com>
 
        * retry.cc (gtm_thread::decide_begin_dispatch): Ask dispatch whether

diff --git a/libitm/libitm.texi b/libitm/libitm.texi
index 6cfcaf9277d008c5a48afc3ae0de876d9c39f84f..7e5c413610fb549880c3885d7501592139b79502 100644 (file)
--- a/libitm/libitm.texi
+++ b/libitm/libitm.texi
@@ -156,6 +156,13 @@ about which memory locations are shared and which are not shared with other
 threads (i.e., data must be accessed either transactionally or
 nontransactionally). Otherwise, non-write-through TM algorithms would not work.
 
+For memory locations on the stack, this requirement extends to only the
+lifetime of the stack frame that the memory location belongs to (or the
+lifetime of the transaction, whichever is shorter).  Thus, memory that is
+reused for several stack frames could be target of both data logging and
+transactional accesses; however, this is harmless because these stack frames'
+lifetimes will end before the transaction finishes.
+
 @subsection [No changes] Scatter/gather calls
 @subsection [No changes] Serial and irrevocable mode
 @subsection [No changes] Transaction descriptor