libitm/doc/the-libitm-abi/library-design-principles.rst

   1 ..
   2   Copyright 1988-2022 Free Software Foundation, Inc.
   3   This is part of the GCC manual.
   4   For copying conditions, see the copyright.rst file.
   5
   6 Library design principles
   7 *************************
   8
   9 [No changes] Calling conventions
  10 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  11
  12 [No changes] TM library algorithms
  13 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  14
  15 [No changes] Optimized load and store routines
  16 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  17
  18 [No changes] Aligned load and store routines
  19 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  20
  21 Data logging functions
  22 ^^^^^^^^^^^^^^^^^^^^^^
  23
  24 The memory locations accessed with transactional loads and stores and the
  25 memory locations whose values are logged must not overlap. This required
  26 separation only extends to the scope of the execution of one transaction
  27 including all the executions of all nested transactions.
  28
  29 The compiler must be consistent (within the scope of a single transaction)
  30 about which memory locations are shared and which are not shared with other
  31 threads (i.e., data must be accessed either transactionally or
  32 nontransactionally). Otherwise, non-write-through TM algorithms would not work.
  33
  34 For memory locations on the stack, this requirement extends to only the
  35 lifetime of the stack frame that the memory location belongs to (or the
  36 lifetime of the transaction, whichever is shorter).  Thus, memory that is
  37 reused for several stack frames could be target of both data logging and
  38 transactional accesses; however, this is harmless because these stack frames'
  39 lifetimes will end before the transaction finishes.
  40
  41 [No changes] Scatter/gather calls
  42 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  43
  44 [No changes] Serial and irrevocable mode
  45 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  46
  47 [No changes] Transaction descriptor
  48 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  49
  50 Store allocation
  51 ^^^^^^^^^^^^^^^^
  52
  53 There is no ``getTransaction`` function.
  54
  55 [No changes] Naming conventions
  56 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  57
  58 Function pointer encryption
  59 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  60
  61 Currently, this is not implemented.