Move p9.pool to a separate package

PiperOrigin-RevId: 293617493

4 files changed, 6 insertions, 138 deletions

diff --git a/pkg/p9/BUILD b/pkg/p9/BUILD
index 4ccc1de86..8904afad9 100644
--- a/pkg/p9/BUILD
+++ b/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",
     ],
diff --git a/pkg/p9/client.go b/pkg/p9/client.go
index 4045e41fa..a6f493b82 100644
--- a/pkg/p9/client.go
+++ b/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,
diff --git a/pkg/p9/pool.go b/pkg/p9/pool.go
deleted file mode 100644
index 2b14a5ce3..000000000
--- a/pkg/p9/pool.go
+++ /dev/null
@@ -1,68 +0,0 @@
-// Copyright 2018 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package p9
-
-import (
-	"gvisor.dev/gvisor/pkg/sync"
-)
-
-// pool is a simple allocator.
-//
-// It is used for both tags and FIDs.
-type pool struct {
-	mu sync.Mutex
-
-	// cache is the set of returned values.
-	cache []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
-}
-
-// Get gets a value from the pool.
-func (p *pool) Get() (uint64, bool) {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-
-	// Anything cached?
-	if len(p.cache) > 0 {
-		v := p.cache[len(p.cache)-1]
-		p.cache = p.cache[:len(p.cache)-1]
-		return v, true
-	}
-
-	// Over the limit?
-	if p.start == p.limit {
-		return 0, false
-	}
-
-	// Generate a new value.
-	v := p.start
-	p.start++
-	return v, true
-}
-
-// Put returns a value to the pool.
-func (p *pool) Put(v uint64) {
-	p.mu.Lock()
-	p.cache = append(p.cache, v)
-	p.mu.Unlock()
-}
diff --git a/pkg/p9/pool_test.go b/pkg/p9/pool_test.go
deleted file mode 100644
index e4746b8da..000000000
--- a/pkg/p9/pool_test.go
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2018 The gVisor Authors.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-package p9
-
-import (
-	"testing"
-)
-
-func TestPoolUnique(t *testing.T) {
-	p := pool{start: 1, limit: 3}
-	got := make(map[uint64]bool)
-
-	for {
-		n, ok := p.Get()
-		if !ok {
-			break
-		}
-
-		// Check unique.
-		if _, ok := got[n]; ok {
-			t.Errorf("pool spit out %v multiple times", n)
-		}
-
-		// Record.
-		got[n] = true
-	}
-}
-
-func TestExausted(t *testing.T) {
-	p := pool{start: 1, limit: 500}
-	for i := 0; i < 499; i++ {
-		_, ok := p.Get()
-		if !ok {
-			t.Fatalf("pool exhausted before 499 items")
-		}
-	}
-
-	_, ok := p.Get()
-	if ok {
-		t.Errorf("pool not exhausted when it should be")
-	}
-}
-
-func TestPoolRecycle(t *testing.T) {
-	p := pool{start: 1, limit: 500}
-	n1, _ := p.Get()
-	p.Put(n1)
-	n2, _ := p.Get()
-	if n1 != n2 {
-		t.Errorf("pool not recycling items")
-	}
-}