[Bug go/64005] New: make check FAIL: sync

["ubizjak at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64005

            Bug ID: 64005
           Summary: make check FAIL: sync
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: go
          Assignee: ian at airs dot com
          Reporter: ubizjak at gmail dot com
                CC: cmang at google dot com

The sync libgo test fails on alphaev68-linux-gnu:

--- FAIL: TestPoolGC (1.07 seconds)
        testing.go:253: only 1 out of 100 resources are finalized
FAIL

If a breakpoint is set in line 81 of libgo/go/sync/pool_test.go:

(gdb) r
Starting program:
/space/uros/gcc-build/alphaev68-unknown-linux-gnu/libgo/gotest27281/test/a.out 
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/libthread_db.so.1".
[New Thread 0x20002b751e0 (LWP 10813)]
[New Thread 0x200034751e0 (LWP 10814)]
[Switching to Thread 0x200034751e0 (LWP 10814)]

Breakpoint 1, sync_test.$nested23 (vv=<optimized out>) at pool_test.go:81
81                              atomic.AddUint32(&fin, 1)
(gdb) list
76              var fin uint32
77              const N = 100
78              for i := 0; i < N; i++ {
79                      v := new(string)
80                      runtime.SetFinalizer(v, func(vv *string) {
81                              atomic.AddUint32(&fin, 1)
82                      })
83                      p.Put(v)
84              }
85              for i := 0; i < N; i++ {
(gdb) c
Continuing.
[New Thread 0x20003c751e0 (LWP 10913)]
--- FAIL: TestPoolGC (91.01 seconds)
        testing.go:253: only 1 out of 100 resources are finalized
[New Thread 0x200087ff1e0 (LWP 10914)]
[New Thread 0x20008fff1e0 (LWP 10915)]
[New Thread 0x200097ff1e0 (LWP 10916)]
[New Thread 0x20009fff1e0 (LWP 10917)]
[New Thread 0x2000a7ff1e0 (LWP 10918)]
[New Thread 0x2000afff1e0 (LWP 10919)]
FAIL
[Thread 0x2000afff1e0 (LWP 10919) exited]
[Thread 0x20009fff1e0 (LWP 10917) exited]
[Thread 0x200097ff1e0 (LWP 10916) exited]
[Thread 0x20008fff1e0 (LWP 10915) exited]
[Thread 0x200087ff1e0 (LWP 10914) exited]
[Thread 0x20003c751e0 (LWP 10913) exited]
[Thread 0x200034751e0 (LWP 10814) exited]
[Thread 0x20002b751e0 (LWP 10813) exited]
[Thread 0x2000002ead0 (LWP 10812) exited]
[Inferior 1 (process 10812) exited with code 01]
(gdb)

then the breakpoint hits only once (vs. many times on x86_64-linux-gnu).