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-rw-r--r--gcc-4.8.1/libgo/runtime/lock_futex.c157
1 files changed, 0 insertions, 157 deletions
diff --git a/gcc-4.8.1/libgo/runtime/lock_futex.c b/gcc-4.8.1/libgo/runtime/lock_futex.c
deleted file mode 100644
index 5374aff6d..000000000
--- a/gcc-4.8.1/libgo/runtime/lock_futex.c
+++ /dev/null
@@ -1,157 +0,0 @@
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build freebsd linux
-
-#include "runtime.h"
-
-// This implementation depends on OS-specific implementations of
-//
-// runtime_futexsleep(uint32 *addr, uint32 val, int64 ns)
-// Atomically,
-// if(*addr == val) sleep
-// Might be woken up spuriously; that's allowed.
-// Don't sleep longer than ns; ns < 0 means forever.
-//
-// runtime_futexwakeup(uint32 *addr, uint32 cnt)
-// If any procs are sleeping on addr, wake up at most cnt.
-
-enum
-{
- MUTEX_UNLOCKED = 0,
- MUTEX_LOCKED = 1,
- MUTEX_SLEEPING = 2,
-
- ACTIVE_SPIN = 4,
- ACTIVE_SPIN_CNT = 30,
- PASSIVE_SPIN = 1,
-};
-
-// Possible lock states are MUTEX_UNLOCKED, MUTEX_LOCKED and MUTEX_SLEEPING.
-// MUTEX_SLEEPING means that there is presumably at least one sleeping thread.
-// Note that there can be spinning threads during all states - they do not
-// affect mutex's state.
-void
-runtime_lock(Lock *l)
-{
- uint32 i, v, wait, spin;
-
- if(runtime_m()->locks++ < 0)
- runtime_throw("runtime_lock: lock count");
-
- // Speculative grab for lock.
- v = runtime_xchg(&l->key, MUTEX_LOCKED);
- if(v == MUTEX_UNLOCKED)
- return;
-
- // wait is either MUTEX_LOCKED or MUTEX_SLEEPING
- // depending on whether there is a thread sleeping
- // on this mutex. If we ever change l->key from
- // MUTEX_SLEEPING to some other value, we must be
- // careful to change it back to MUTEX_SLEEPING before
- // returning, to ensure that the sleeping thread gets
- // its wakeup call.
- wait = v;
-
- // On uniprocessor's, no point spinning.
- // On multiprocessors, spin for ACTIVE_SPIN attempts.
- spin = 0;
- if(runtime_ncpu > 1)
- spin = ACTIVE_SPIN;
-
- for(;;) {
- // Try for lock, spinning.
- for(i = 0; i < spin; i++) {
- while(l->key == MUTEX_UNLOCKED)
- if(runtime_cas(&l->key, MUTEX_UNLOCKED, wait))
- return;
- runtime_procyield(ACTIVE_SPIN_CNT);
- }
-
- // Try for lock, rescheduling.
- for(i=0; i < PASSIVE_SPIN; i++) {
- while(l->key == MUTEX_UNLOCKED)
- if(runtime_cas(&l->key, MUTEX_UNLOCKED, wait))
- return;
- runtime_osyield();
- }
-
- // Sleep.
- v = runtime_xchg(&l->key, MUTEX_SLEEPING);
- if(v == MUTEX_UNLOCKED)
- return;
- wait = MUTEX_SLEEPING;
- runtime_futexsleep(&l->key, MUTEX_SLEEPING, -1);
- }
-}
-
-void
-runtime_unlock(Lock *l)
-{
- uint32 v;
-
- if(--runtime_m()->locks < 0)
- runtime_throw("runtime_unlock: lock count");
-
- v = runtime_xchg(&l->key, MUTEX_UNLOCKED);
- if(v == MUTEX_UNLOCKED)
- runtime_throw("unlock of unlocked lock");
- if(v == MUTEX_SLEEPING)
- runtime_futexwakeup(&l->key, 1);
-}
-
-// One-time notifications.
-void
-runtime_noteclear(Note *n)
-{
- n->key = 0;
-}
-
-void
-runtime_notewakeup(Note *n)
-{
- if(runtime_xchg(&n->key, 1))
- runtime_throw("notewakeup - double wakeup");
- runtime_futexwakeup(&n->key, 1);
-}
-
-void
-runtime_notesleep(Note *n)
-{
- if(runtime_m()->profilehz > 0)
- runtime_setprof(false);
- while(runtime_atomicload(&n->key) == 0)
- runtime_futexsleep(&n->key, 0, -1);
- if(runtime_m()->profilehz > 0)
- runtime_setprof(true);
-}
-
-void
-runtime_notetsleep(Note *n, int64 ns)
-{
- int64 deadline, now;
-
- if(ns < 0) {
- runtime_notesleep(n);
- return;
- }
-
- if(runtime_atomicload(&n->key) != 0)
- return;
-
- if(runtime_m()->profilehz > 0)
- runtime_setprof(false);
- deadline = runtime_nanotime() + ns;
- for(;;) {
- runtime_futexsleep(&n->key, 0, ns);
- if(runtime_atomicload(&n->key) != 0)
- break;
- now = runtime_nanotime();
- if(now >= deadline)
- break;
- ns = deadline - now;
- }
- if(runtime_m()->profilehz > 0)
- runtime_setprof(true);
-}