diff options
Diffstat (limited to 'gcc/ada/exp_ch9.adb')
| -rw-r--r-- | gcc/ada/exp_ch9.adb | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/gcc/ada/exp_ch9.adb b/gcc/ada/exp_ch9.adb index d926abe766d..9d21af2accc 100644 --- a/gcc/ada/exp_ch9.adb +++ b/gcc/ada/exp_ch9.adb @@ -81,16 +81,24 @@ package body Exp_Ch9 is -- Lock Free Data Structure -- ------------------------------ + -- A lock-free subprogram is a protected routine which references a unique + -- protected scalar component and does not contain statements that cause + -- side effects. Due to this restricted behavior, all references to shared + -- data from within the subprogram can be synchronized through the use of + -- atomic operations rather than relying on locks. + type Lock_Free_Subprogram is record Sub_Body : Node_Id; - Comp_Id : Entity_Id; + -- Reference to the body of a protected subprogram which meets the lock- + -- free requirements. + + Comp_Id : Entity_Id; + -- Reference to the scalar component referenced from within Sub_Body end record; - -- This data structure and its fields must be documented, ALL global - -- data structures must be documented. We never rely on guessing what - -- things mean from their names. - -- The following table establishes a relation between a subprogram body and - -- an unique protected component referenced in this body. + -- This table establishes a relation between a protected subprogram body + -- and a unique component it references. The table is used when building + -- the lock-free versions of a protected subprogram body. package Lock_Free_Subprogram_Table is new Table.Table ( Table_Component_Type => Lock_Free_Subprogram, |