shithub: mc

--- a/alloc.myr

+++ b/alloc.myr

@@ -13,11 +13,16 @@

 /* null pointers */

 const Zbyte	= 0 castto(byte*)

 const Zslab	= 0 castto(slab*)

-const Zbin	= 0 castto(bin*)

+const Zchunk	= 0 castto(chunk*)

 const Pagesz 	= 4096	/* on the systems this supports, anyways... */

-const Bucketmax	= 1024	/* Pagesz / 4; a tolerable balance. */

+const Cachemax	= 16	/* maximum number of slabs in the cache */

+const Bucketmax	= 1024	/* Pagesz / 8; a balance. */

 const Align	= 16	/* minimum allocation alignment */

+var buckets	: bucket[32] /* excessive */

+var initdone	: int

 type bucket = struct

 	sz	: size	/* aligned size */

 	nper	: size	/* max number of elements per slab */

@@ -28,17 +33,14 @@

 type slab = struct

 	next	: slab* /* the next slab on the chain */

-	freehd	: bin*	/* the nodes we're allocating */

+	freehd	: chunk*	/* the nodes we're allocating */

 	nfree	: size  /* the number of free nodes */

;;

-type bin = struct	/* NB: must be smaller than sizeof(slab) */

-	next	: bin*	/* the next bin in the free list */

+type chunk = struct	/* NB: must be smaller than sizeof(slab) */

+	next	: chunk*	/* the next chunk in the free list */

;;

-var buckets : bucket[32] /* excessive */

-var initdone : int

 generic alloc = {-> @a*

 	-> bytealloc(sizeof(@a)) castto(@a*)

@@ -52,14 +54,14 @@

 	var bkt

 	if !initdone

-		for i = 0; i < buckets.len && (Align << i) < Bucketmax; i++

-			allocinit(&buckets[i], Align << i)

+		for i = 0; i < buckets.len && (Align << i) <= Bucketmax; i++

+			bktinit(&buckets[i], Align << i)

;;

 		initdone = 1

;;

-	if (sz < Bucketmax)

-		bkt = &buckets[bucketnum(sz)]

+	if (sz <= Bucketmax)

+		bkt = &buckets[bktnum(sz)]

 		-> bktalloc(bkt)

 	else

 		-> mmap(Zbyte, sz, Mprotrw, Mpriv | Manon, -1, 0)

@@ -70,7 +72,7 @@

 	var bkt

 	if (sz < Bucketmax)

-		bkt = &buckets[bucketnum(sz)]

+		bkt = &buckets[bktnum(sz)]

 		bktfree(bkt, m)

 	else

 		munmap(m, sz)

@@ -77,7 +79,7 @@

;;

-const allocinit = {b : bucket*, sz

+const bktinit = {b : bucket*, sz

 	b.sz = align(sz, Align)

 	b.nper = (Pagesz - sizeof(slab))/b.sz

 	b.slabs = Zslab

@@ -91,8 +93,13 @@

 	var s

 	var b

 	var bnext

-	var off /* offset of bin head */

+	var off /* offset of chunk head */

+	if bkt.ncache > 0

+		s = bkt.cache

+		bkt.cache = s.next

+		bkt.ncache--

+	;;

 	p = mmap(Zbyte, Pagesz, Mprotrw, Mpriv | Manon, -1, 0)

 	if p == Mapbad

 		die("Unable to mmap")

@@ -102,18 +109,18 @@

 	s.nfree = bkt.nper

 	/* skip past the slab header */

 	off = align(sizeof(slab), Align)

-	bnext = nextbin(s castto(bin*), off)

+	bnext = nextchunk(s castto(chunk*), off)

 	s.freehd = bnext

 	for i = 0; i < bkt.nper; i++

 		b = bnext

-		bnext = nextbin(b, bkt.sz)

+		bnext = nextchunk(b, bkt.sz)

 		b.next = bnext

;;

-	b.next = Zbin

+	b.next = Zchunk

 	-> s

-const bktalloc = {bkt : bucket*

+const bktalloc = {bkt

 	var s

 	var b

@@ -127,7 +134,7 @@

 		bkt.slabs = s

;;

-	/* grab the first bin on the slab */

+	/* grab the first chunk on the slab */

 	b = s.freehd

 	s.freehd = b.next

 	s.nfree--

@@ -139,15 +146,22 @@

 	-> b castto(byte*)

-const bktfree = {bkt : bucket*, m : byte*

+const bktfree = {bkt, m

 	var s

 	var b

 	s = mtrunc(m, Pagesz) castto(slab*)

-	b = m castto(bin*)

+	b = m castto(chunk*)

 	if s.nfree == 0

 		s.next = bkt.slabs

 		bkt.slabs = s

+	elif s.nfree == bkt.nper

+		if bkt.ncache < Cachemax

+			s.next = bkt.cache

+			bkt.cache = s

+		else

+			munmap(s castto(byte*), Pagesz)

+		;;

;;

 	s.nfree++

 	b.next = s.freehd

@@ -154,16 +168,12 @@

 	s.freehd = b

-const delslab = {s : slab*

-}

-const bucketnum = {sz

+const bktnum = {sz

 	var i

 	var bktsz

 	bktsz = Align

-	for i = 0; bktsz < Bucketmax; i++

+	for i = 0; bktsz <= Bucketmax; i++

 		if bktsz >= sz

 			-> i

;;

@@ -172,9 +182,9 @@

 	die("Size does not match any buckets")

-/* bins are variable sizes, so we can't just take a slice */

-const nextbin = {b, sz

-	-> ((b castto(intptr)) + sz) castto(bin*)

+/* chunks are variable sizes, so we can't just take a slice */

+const nextchunk = {b, sz

+	-> ((b castto(intptr)) + sz) castto(chunk*)

 const align = {v, align

--- a/test.myr

+++ b/test.myr

@@ -1,12 +1,17 @@

 use std

 const main = {

-	var x

+	var x : byte*[1024]

+	var sz

 	var i

-	for i = 0; i < 128; i++

-		x = std.bytealloc(32)

+	for sz = 1; sz < 65536; sz *= 2

+		for i = 0; i < 1024; i++

+			x[i] = std.bytealloc(sz)

+		;;

+		for i = 0; i < 1024; i++

+			std.bytefree(x[i], sz)

+		;;

;;

-	std.bytefree(x, 32)

 	std.write(1, "Hello world\n")