This bug was reported by the Linux user community. Communicator 4.5 (which uses the old NSPR1) sometimes freezes on the new Linux 2.2 kernel because it is doing a blocking write to a full pipe. Because NSPR1 uses emulated user-level threads, if a thread blocks in write(), the whole process blocks. This pipe is created by the "event" code in ns/nspr/src/swmon.c, which is inherited by NSPR20 in mozilla/nsprpub/lib/ds/plevent.c. (Nobody seems to have reported this bug for SeaMonkey.) The fix is to create the pipe in nonblocking mode and have the reads and writes deal with the possibile EAGAIN/EWOULDBLOCK error. Since we may still use user-level threads on some Unix platforms, I suggest that we check in this fix to NSPR 3.1.

The fix is checked into the tip. /cvsroot/mozilla/nsprpub/lib/ds/plevent.c, revision 3.14. The fix is also checked into the internal CVS repository. /m/src/ns/nspr20/lib/ds/plevent.c, revision 2.14.

For the record, the reporter was Stanislav Meduna (stano@trillian.eunet.sk). He did the detective work. Thanks Stano!

For the record, the reporter was Stanislav Meduna (stano@trillian.eunet.sk). He did the detective work. Thanks Stano!

Marked bug as verified.

NSPR now has its own Bugzilla product. Moving this bug to the NSPR product.