all: merge dev.cc (81884b89bd88) into default

With this change, default now contains Go 1.5 work.
Any future bug fixes for Go 1.4 in the compilers or
the runtime will have to be made directly to the
release branch.

1 files changed, 86 insertions, 0 deletions

diff --git a/src/runtime/mcache.go b/src/runtime/mcache.go
new file mode 100644
index 000000000..d3afef6be
--- /dev/null
+++ b/src/runtime/mcache.go
@@ -0,0 +1,86 @@
+// Copyright 2009 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.
+
+// Per-P malloc cache for small objects.
+//
+// See malloc.h for an overview.
+
+package runtime
+
+import "unsafe"
+
+// dummy MSpan that contains no free objects.
+var emptymspan mspan
+
+func allocmcache() *mcache {
+	lock(&mheap_.lock)
+	c := (*mcache)(fixAlloc_Alloc(&mheap_.cachealloc))
+	unlock(&mheap_.lock)
+	memclr(unsafe.Pointer(c), unsafe.Sizeof(*c))
+	for i := 0; i < _NumSizeClasses; i++ {
+		c.alloc[i] = &emptymspan
+	}
+
+	// Set first allocation sample size.
+	rate := MemProfileRate
+	if rate > 0x3fffffff { // make 2*rate not overflow
+		rate = 0x3fffffff
+	}
+	if rate != 0 {
+		c.next_sample = int32(int(fastrand1()) % (2 * rate))
+	}
+
+	return c
+}
+
+func freemcache(c *mcache) {
+	systemstack(func() {
+		mCache_ReleaseAll(c)
+		stackcache_clear(c)
+		gcworkbuffree(c.gcworkbuf)
+		lock(&mheap_.lock)
+		purgecachedstats(c)
+		fixAlloc_Free(&mheap_.cachealloc, unsafe.Pointer(c))
+		unlock(&mheap_.lock)
+	})
+}
+
+// Gets a span that has a free object in it and assigns it
+// to be the cached span for the given sizeclass.  Returns this span.
+func mCache_Refill(c *mcache, sizeclass int32) *mspan {
+	_g_ := getg()
+
+	_g_.m.locks++
+	// Return the current cached span to the central lists.
+	s := c.alloc[sizeclass]
+	if s.freelist != nil {
+		gothrow("refill on a nonempty span")
+	}
+	if s != &emptymspan {
+		s.incache = false
+	}
+
+	// Get a new cached span from the central lists.
+	s = mCentral_CacheSpan(&mheap_.central[sizeclass].mcentral)
+	if s == nil {
+		gothrow("out of memory")
+	}
+	if s.freelist == nil {
+		println(s.ref, (s.npages<<_PageShift)/s.elemsize)
+		gothrow("empty span")
+	}
+	c.alloc[sizeclass] = s
+	_g_.m.locks--
+	return s
+}
+
+func mCache_ReleaseAll(c *mcache) {
+	for i := 0; i < _NumSizeClasses; i++ {
+		s := c.alloc[i]
+		if s != &emptymspan {
+			mCentral_UncacheSpan(&mheap_.central[i].mcentral, s)
+			c.alloc[i] = &emptymspan
+		}
+	}
+}