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authorOri Bernstein <ori@eigenstate.org>2015-09-17 23:28:01 -0700
committerOri Bernstein <ori@eigenstate.org>2015-09-17 23:53:51 -0700
commita8a61e673c000c9802adb0d5a6fccca87967a90e (patch)
tree407bec405270710ab9a2c02aaae46dd1341fdf60 /lib/thread
parentb4a8cf6eb24355953d0510d74a19966938907de8 (diff)
downloadmc-a8a61e673c000c9802adb0d5a6fccca87967a90e.tar.gz
Simplify the condvar a bit.
Diffstat (limited to 'lib/thread')
-rw-r--r--lib/thread/condvar+linux.myr43
1 files changed, 13 insertions, 30 deletions
diff --git a/lib/thread/condvar+linux.myr b/lib/thread/condvar+linux.myr
index 072e450..d8f048b 100644
--- a/lib/thread/condvar+linux.myr
+++ b/lib/thread/condvar+linux.myr
@@ -10,58 +10,41 @@ pkg thread =
_seq : int32
;;
- const mkcond : (-> cond)
- const condwait : (cond : cond#, mtx : mutex# -> void)
+ const mkcond : (mtx : mutex# -> cond)
+ const condwait : (cond : cond# -> void)
const condsignal : (cond : cond# -> void)
const condbroadcast : (cond : cond# -> void)
;;
generic Zptr = 0 castto(@a#)
-const Zmtx = 0 castto(mutex#)
-const mkcond = {
- -> [._mtx = Zmtx, ._seq = 0]
+const mkcond = {mtx
+ -> [._mtx = mtx, ._seq = 0]
}
-const condwait = {cond, mtx
+const condwait = {cond
var seq
+ var mtx
+ mtx = cond._mtx
seq = cond._seq
- if cond._mtx != mtx
- if cond._mtx != Zmtx
- std.die("multiple mutexes used with cond var")
- ;;
- mtxcas(&cond._mtx, Zmtx, mtx)
- if cond._mtx != Zmtx
- std.die("multiple mutexes used with cond var")
- ;;
- ;;
- mtxunlock(cond._mtx)
+
+ mtxunlock(mtx)
sys.futex(&cond._seq, sys.Futexwait | sys.Futexpriv, seq, Zptr, Zptr, 0)
+ /* We need to atomically set the mutex to contended */
while xchg(&mtx._state, Contended) != Unlocked
sys.futex(&mtx._state, sys.Futexwait | sys.Futexpriv, Contended, Zptr, Zptr, 0)
;;
}
-const condsig = {cond : cond#
+const condsignal = {cond : cond#
xadd(&cond._seq, 1)
sys.futex(&cond._seq, sys.Futexwake | sys.Futexpriv, 1, Zptr, Zptr, 0)
}
const condbroadcast = {cond : cond#
- var m
-
- m = cond._mtx
- if m != Zmtx
- xadd(&cond._seq, 1)
- sys.futex(&cond._seq, sys.Futexrequeue | sys.Futexpriv, 1, Zptr, &m._state, 0)
- ;;
-}
-
-const mtxcas = {mtxp, old, new
- -> xcas(mtxp castto(std.intptr#), \
- old castto(std.intptr), \
- new castto(std.intptr)) castto(mutex#)
+ xadd(&cond._seq, 1)
+ sys.futex(&cond._seq, sys.Futexrequeue | sys.Futexpriv, 1, Zptr, &cond._mtx._state, 0)
}