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| author | Patrick Palka <patrick@parcs.ath.cx> | 2013-08-21 15:25:18 -0400 |
|---|---|---|
| committer | Patrick Palka <patrick@parcs.ath.cx> | 2013-08-26 22:21:16 -0400 |
| commit | 036910ad0d01cfd23fa53930fca2dd880faa6536 (patch) | |
| tree | 069d6bff28cde8dd1b09835972e299966f16fd3d /rts/PrimOps.cmm | |
| parent | 776cfe28cf089c24a56a288f2f0c49494f7d9e47 (diff) | |
| download | haskell-036910ad0d01cfd23fa53930fca2dd880faa6536.tar.gz | |
UniqSupply: make mkSplitUniqSupply thread-safe
unsafeInterleaveIO is used instead of unsafeDupableInterleaveIO because
a mk_supply thunk that is simultaneously entered by two threads should
evaluate to the same UniqSupply.
The UniqSupply counter is now incremented atomically using the RTS's
atomic_inc().
To mitigate the extra overhead of unsafeInterleaveIO in the
single-threaded compiler, noDuplicate# is changed to exit early when
n_capabilities == 1.
Diffstat (limited to 'rts/PrimOps.cmm')
| -rw-r--r-- | rts/PrimOps.cmm | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/rts/PrimOps.cmm b/rts/PrimOps.cmm index ced15eec99..d8acaef77b 100644 --- a/rts/PrimOps.cmm +++ b/rts/PrimOps.cmm @@ -2008,6 +2008,11 @@ INFO_TABLE_RET(stg_noDuplicate, RET_SMALL, W_ info_ptr) stg_noDuplicatezh /* no arg list: explicit stack layout */ { + // With a single capability there's no chance of work duplication. + if (CInt[n_capabilities] == 1 :: CInt) { + jump %ENTRY_CODE(Sp(0)) []; + } + STK_CHK(WDS(1), stg_noDuplicatezh); // leave noDuplicate frame in case the current |