Firefox ESR 24 sometimes hangs during exit on Mac OS
Kathy Brade and I have observed frequent hangs during exit on Mac OS 10.8.5 with our own ESR 24 Tor Browser builds as well as a recent build supplied by gk. We are not sure what triggers the hang, but it occurs often after loading a few web pages in the browser.
Activity Monitor shows that TorBrowser is consuming 100% CPU. dtrace shows this series of system calls repeated over and over:
write(0x9, "8\a\0", 0x1) = 1 0 write(0x9, "8\a\0", 0x1) = 1 0 select(0x9, 0xB0288B20, 0xB0288AA0, 0xB0288A20, 0xB0288A18) = 1 0 read(0x8, "88\0", 0x400) = 2 0
lsof shows that file descriptors 8 and 9 are pipes:
firefox 65737 brade 8 PIPE 0xffffff804948f210 16384 ->0xffffff8049491e10 firefox 65737 brade 9 PIPE 0xffffff8049491e10 16384 ->0xffffff804948f210
So it looks like the firefox process is repeatedly writing to and reading the same data from a pipe. I am not sure what the significance of '8' is....