Move p9.pool to a separate package

PiperOrigin-RevId: 293617493

pkg/p9/BUILD

@@ -16,7 +16,6 @@ go_library(
         "messages.go",
         "p9.go",
         "path_tree.go",
-        "pool.go",
         "server.go",
         "transport.go",
         "transport_flipcall.go",
@@ -27,6 +26,7 @@ go_library(
         "//pkg/fdchannel",
         "//pkg/flipcall",
         "//pkg/log",
+        "//pkg/pool",
         "//pkg/sync",
         "//pkg/unet",
         "@org_golang_x_sys//unix:go_default_library",
@@ -41,7 +41,6 @@ go_test(
         "client_test.go",
         "messages_test.go",
         "p9_test.go",
-        "pool_test.go",
         "transport_test.go",
         "version_test.go",
     ],

pkg/p9/client.go

@@ -22,6 +22,7 @@ import (
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/flipcall"
 	"gvisor.dev/gvisor/pkg/log"
+	"gvisor.dev/gvisor/pkg/pool"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/unet"
 )
@@ -74,10 +75,10 @@ type Client struct {
 	socket *unet.Socket
 
 	// tagPool is the collection of available tags.
-	tagPool pool
+	tagPool pool.Pool
 
 	// fidPool is the collection of available fids.
-	fidPool pool
+	fidPool pool.Pool
 
 	// messageSize is the maximum total size of a message.
 	messageSize uint32
@@ -155,8 +156,8 @@ func NewClient(socket *unet.Socket, messageSize uint32, version string) (*Client
 	}
 	c := &Client{
 		socket:      socket,
-		tagPool:     pool{start: 1, limit: uint64(NoTag)},
-		fidPool:     pool{start: 1, limit: uint64(NoFID)},
+		tagPool:     pool.Pool{Start: 1, Limit: uint64(NoTag)},
+		fidPool:     pool.Pool{Start: 1, Limit: uint64(NoFID)},
 		pending:     make(map[Tag]*response),
 		recvr:       make(chan bool, 1),
 		messageSize: messageSize,

pkg/pool/BUILD

@@ -0,0 +1,25 @@
+load("//tools:defs.bzl", "go_library", "go_test")
+
+package(
+    default_visibility = ["//visibility:public"],
+    licenses = ["notice"],
+)
+
+go_library(
+    name = "pool",
+    srcs = [
+        "pool.go",
+    ],
+    deps = [
+        "//pkg/sync",
+    ],
+)
+
+go_test(
+    name = "pool_test",
+    size = "small",
+    srcs = [
+        "pool_test.go",
+    ],
+    library = ":pool",
+)

pkg/pool/pool.go

@@ -12,33 +12,31 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package p9
+package pool
 
 import (
 	"gvisor.dev/gvisor/pkg/sync"
 )
 
-// pool is a simple allocator.
-//
-// It is used for both tags and FIDs.
-type pool struct {
+// Pool is a simple allocator.
+type Pool struct {
 	mu sync.Mutex
 
 	// cache is the set of returned values.
 	cache []uint64
 
-	// start is the starting value (if needed).
-	start uint64
+	// Start is the starting value (if needed).
+	Start uint64
 
 	// max is the current maximum issued.
 	max uint64
 
-	// limit is the upper limit.
-	limit uint64
+	// Limit is the upper limit.
+	Limit uint64
 }
 
 // Get gets a value from the pool.
-func (p *pool) Get() (uint64, bool) {
+func (p *Pool) Get() (uint64, bool) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 
@@ -50,18 +48,18 @@ func (p *pool) Get() (uint64, bool) {
 	}
 
 	// Over the limit?
-	if p.start == p.limit {
+	if p.Start == p.Limit {
 		return 0, false
 	}
 
 	// Generate a new value.
-	v := p.start
-	p.start++
+	v := p.Start
+	p.Start++
 	return v, true
 }
 
 // Put returns a value to the pool.
-func (p *pool) Put(v uint64) {
+func (p *Pool) Put(v uint64) {
 	p.mu.Lock()
 	p.cache = append(p.cache, v)
 	p.mu.Unlock()

pkg/pool/pool_test.go

@@ -12,14 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package p9
+package pool
 
 import (
 	"testing"
 )
 
 func TestPoolUnique(t *testing.T) {
-	p := pool{start: 1, limit: 3}
+	p := Pool{Start: 1, Limit: 3}
 	got := make(map[uint64]bool)
 
 	for {
@@ -39,7 +39,7 @@ func TestPoolUnique(t *testing.T) {
 }
 
 func TestExausted(t *testing.T) {
-	p := pool{start: 1, limit: 500}
+	p := Pool{Start: 1, Limit: 500}
 	for i := 0; i < 499; i++ {
 		_, ok := p.Get()
 		if !ok {
@@ -54,7 +54,7 @@ func TestExausted(t *testing.T) {
 }
 
 func TestPoolRecycle(t *testing.T) {
-	p := pool{start: 1, limit: 500}
+	p := Pool{Start: 1, Limit: 500}
 	n1, _ := p.Get()
 	p.Put(n1)
 	n2, _ := p.Get()