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| author | Ronan Desplanques <desplanques@adacore.com> | 2024-04-02 09:09:31 +0200 |
|---|---|---|
| committer | Marc Poulhiès <poulhies@adacore.com> | 2024-05-21 09:26:47 +0200 |
| commit | 0cb4e7f41b6466718715ea71fce6621c9e93ecfd (patch) | |
| tree | f23710189e9735dc9d18088c363f1d915ef22f82 /gcc/ada/libgnarl | |
| parent | 238fba24a43280e692fc9c53852657837bbc94bc (diff) | |
| download | gcc-0cb4e7f41b6466718715ea71fce6621c9e93ecfd.zip gcc-0cb4e7f41b6466718715ea71fce6621c9e93ecfd.tar.gz gcc-0cb4e7f41b6466718715ea71fce6621c9e93ecfd.tar.bz2 | |
ada: Remove some explicit yields in tasking run-time
This patch removes three occurrences where tasking run-time
subprograms yielded control shortly before conditional calls to Sleep,
in order to avoid these calls more often. It was intended as an
optimization on systems where calls to Sleep are costly and in
particular VMS.
A problem was that two of the yields contained data races that were
reported by thread sanitizing tools on some platforms, and that's the
motivation for removing them.
gcc/ada/
* libgnarl/s-taenca.adb (Wait_For_Completion): Remove call to
Yield.
* libgnarl/s-tasren.adb (Timed_Selective_Wait, Wait_For_Call):
Remove calls to Yield.
Diffstat (limited to 'gcc/ada/libgnarl')
| -rw-r--r-- | gcc/ada/libgnarl/s-taenca.adb | 12 | ||||
| -rw-r--r-- | gcc/ada/libgnarl/s-tasren.adb | 24 |
2 files changed, 0 insertions, 36 deletions
diff --git a/gcc/ada/libgnarl/s-taenca.adb b/gcc/ada/libgnarl/s-taenca.adb index cd9c53b..1dc8ec5 100644 --- a/gcc/ada/libgnarl/s-taenca.adb +++ b/gcc/ada/libgnarl/s-taenca.adb @@ -410,18 +410,6 @@ package body System.Tasking.Entry_Calls is Self_Id.Common.State := Entry_Caller_Sleep; - -- Try to remove calls to Sleep in the loop below by letting the caller - -- a chance of getting ready immediately, using Unlock & Yield. - -- See similar action in Wait_For_Call & Timed_Selective_Wait. - - STPO.Unlock (Self_Id); - - if Entry_Call.State < Done then - STPO.Yield; - end if; - - STPO.Write_Lock (Self_Id); - loop Check_Pending_Actions_For_Entry_Call (Self_Id, Entry_Call); diff --git a/gcc/ada/libgnarl/s-tasren.adb b/gcc/ada/libgnarl/s-tasren.adb index d65b9f0..6face7e 100644 --- a/gcc/ada/libgnarl/s-tasren.adb +++ b/gcc/ada/libgnarl/s-tasren.adb @@ -1317,18 +1317,6 @@ package body System.Tasking.Rendezvous is Self_Id.Common.State := Acceptor_Delay_Sleep; - -- Try to remove calls to Sleep in the loop below by letting the - -- caller a chance of getting ready immediately, using Unlock - -- Yield. See similar action in Wait_For_Completion/Wait_For_Call. - - Unlock (Self_Id); - - if Self_Id.Open_Accepts /= null then - Yield; - end if; - - Write_Lock (Self_Id); - -- Check if this task has been aborted while the lock was released if Self_Id.Pending_ATC_Level < Self_Id.ATC_Nesting_Level then @@ -1510,18 +1498,6 @@ package body System.Tasking.Rendezvous is begin Self_Id.Common.State := Acceptor_Sleep; - -- Try to remove calls to Sleep in the loop below by letting the caller - -- a chance of getting ready immediately, using Unlock & Yield. - -- See similar action in Wait_For_Completion & Timed_Selective_Wait. - - Unlock (Self_Id); - - if Self_Id.Open_Accepts /= null then - Yield; - end if; - - Write_Lock (Self_Id); - -- Check if this task has been aborted while the lock was released if Self_Id.Pending_ATC_Level < Self_Id.ATC_Nesting_Level then |