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https://issues.apache.org/jira/browse/THRIFT-4237?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16078442#comment-16078442
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ASF GitHub Bot commented on THRIFT-4237:
----------------------------------------
Github user econner commented on a diff in the pull request:
https://github.com/apache/thrift/pull/1304#discussion_r126207049
--- Diff: lib/go/thrift/server_socket.go ---
@@ -68,15 +68,18 @@ func (p *TServerSocket) Listen() error {
func (p *TServerSocket) Accept() (TTransport, error) {
p.mu.RLock()
- defer p.mu.RUnlock()
+ listener := p.listener
+ interrupted := p.interrupted
+ p.mu.RUnlock()
--- End diff --
Hmm. It seems safest to me to unlock this mutex after the value of
``interrupted`` has been read (assuming it is only intended to protect
``interrupted``).
For example,
Thread 1 reads the value of interrupted as false
Thread 1 gets interrupted at line 74
Thread 2 sets p.interrupted to true
Thread 1 sees interrupted == false at line 75
The question is would we want thread 1 to see interrupted == true ?
This is possibly a case that does not happen. I have very limited
knowledge of what this code is doing.
> Go TServerSocket Race Conditions
> --------------------------------
>
> Key: THRIFT-4237
> URL: https://issues.apache.org/jira/browse/THRIFT-4237
> Project: Thrift
> Issue Type: Bug
> Components: Go - Library
> Affects Versions: 0.10.0
> Reporter: Zach Wasserman
> Assignee: Zach Wasserman
> Labels: concurrency
> Fix For: 0.11.0
>
>
> Run the following test with {{go test -race -run TestSocketConcurrency}}:
> {code}
> func TestSocketConcurrency(t *testing.T) {
> host := "127.0.0.1"
> port := 9090
> addr := fmt.Sprintf("%s:%d", host, port)
> socket := CreateServerSocket(t, addr)
> go func() { socket.Listen() }()
> go func() { socket.Interrupt() }()
> }
> {code}
> This will result in an error from the race detector. It looks like:
> {code}
> go test -v -race -run TestSocketConcurrency
> === RUN TestSocketConcurrency
> --- PASS: TestSocketConcurrency (0.00s)
> ==================
> WARNING: DATA RACE
> Write at 0x00c420016870 by goroutine 7:
> git.apache.org/thrift.git/lib/go/thrift.(*TServerSocket).Listen()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket.go:63
> +0x134
> git.apache.org/thrift.git/lib/go/thrift.TestSocketConcurrency.func1()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket_test.go:50
> +0x38
> Previous read at 0x00c420016870 by goroutine 8:
> git.apache.org/thrift.git/lib/go/thrift.(*TServerSocket).Close()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket.go:114
> +0x7b
> git.apache.org/thrift.git/lib/go/thrift.(*TServerSocket).Interrupt()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket.go:123
> +0x6b
> git.apache.org/thrift.git/lib/go/thrift.TestSocketConcurrency.func2()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket_test.go:51
> +0x38
> Goroutine 7 (running) created at:
> git.apache.org/thrift.git/lib/go/thrift.TestSocketConcurrency()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket_test.go:50
> +0x1a8
> testing.tRunner()
> /usr/local/Cellar/go/1.8/libexec/src/testing/testing.go:657 +0x107
> Goroutine 8 (running) created at:
> git.apache.org/thrift.git/lib/go/thrift.TestSocketConcurrency()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket_test.go:51
> +0x1ca
> testing.tRunner()
> /usr/local/Cellar/go/1.8/libexec/src/testing/testing.go:657 +0x107
> ==================
> ==================
> WARNING: DATA RACE
> Write at 0x00c420016870 by goroutine 8:
> git.apache.org/thrift.git/lib/go/thrift.(*TServerSocket).Close.func1()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket.go:112
> +0x3b
> git.apache.org/thrift.git/lib/go/thrift.(*TServerSocket).Close()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket.go:117
> +0xe6
> git.apache.org/thrift.git/lib/go/thrift.(*TServerSocket).Interrupt()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket.go:123
> +0x6b
> git.apache.org/thrift.git/lib/go/thrift.TestSocketConcurrency.func2()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket_test.go:51
> +0x38
> Previous read at 0x00c420016870 by goroutine 7:
> git.apache.org/thrift.git/lib/go/thrift.(*TServerSocket).Listen()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket.go:56
> +0x48
> git.apache.org/thrift.git/lib/go/thrift.TestSocketConcurrency.func1()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket_test.go:50
> +0x38
> Goroutine 8 (running) created at:
> git.apache.org/thrift.git/lib/go/thrift.TestSocketConcurrency()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket_test.go:51
> +0x1ca
> testing.tRunner()
> /usr/local/Cellar/go/1.8/libexec/src/testing/testing.go:657 +0x107
> Goroutine 7 (finished) created at:
> git.apache.org/thrift.git/lib/go/thrift.TestSocketConcurrency()
>
> /Users/zwass/dev/go/src/git.apache.org/thrift.git/lib/go/thrift/server_socket_test.go:50
> +0x1a8
> testing.tRunner()
> /usr/local/Cellar/go/1.8/libexec/src/testing/testing.go:657 +0x107
> ==================
> FAIL
> exit status 1
> FAIL git.apache.org/thrift.git/lib/go/thrift 0.186s
> {code}
> I believe this is because {{Interrupt()}}
>
> (https://github.com/apache/thrift/blob/master/lib/go/thrift/server_socket.go#L120)
> and {{Listen()}}
> (https://github.com/apache/thrift/blob/master/lib/go/thrift/server_socket.go#L55)
> both read and write {{p.listener}}, but only {{Interrupt()}} locks the mutex.
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