OpenJDK7: libnet.so getting closed twice

[Phil Phillips]

Hey all,

I have some code running on the latest version of OpenJDK7.  In one 
thread, it opens a ServerSocket.  In another, it loads a configuration 
file. Once in a while, the config file fails to load with:

Caused by: java.io.FileNotFoundException: global.properties (Bad file 
descriptor)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(FileInputStream.java:138)
    at java.io.FileInputStream.<init>(FileInputStream.java:97)
    at java.io.FileReader.<init>(FileReader.java:58)

Digging in a little deeper with truss, I see something like:

open("/usr/local/openjdk7/jre/lib/amd64/libnet.so",O_RDONLY,01) = 63 (0x3f)
close(63)                                        = 0 (0x0)
close(63)                                        ERR#9 'Bad file 
descriptor'\
...
open("global.properties",O_RDONLY,00)            = 63 (0x3f)
fstat(63,{ mode=-rw-rw-r-- ,inode=32200398,size=18260,blksize=16384 }) = 
0 (0x0)
fcntl(63,F_GETFD,)

libnet.so is getting opened (interestingly, not read - though it was 
read previously) and then closed *twice*.  It looks like there's a race 
condition that can cause the "bad file descriptor" error if:

1) libnet.so opened
2) libnet.so closed (1st time)
3) config file opened (inherits now-free file descriptor)
4) libnet.so closed (2nd time - invalidates file descriptor for config file)

I don't see this kind of behavior in OpenJDK6.  Does anyone know what 
might cause libnet.so to be closed twice in OpenJDK7?

Thanks,
Phil