Re: [BUG] reading from FIFO broken

Herbert Xu <[email protected]> wrote:
>
> and it still worked with your test case.  This is what I see through
> strace on Linux with a stubbed out tee call:

For comparison this is with a working tee call:

395566 <... fcntl resumed>)             = 10
395565 <... fcntl resumed>)             = 10
395566 close(1 <unfinished ...>
395565 close(0 <unfinished ...>
395566 <... close resumed>)             = 0
395565 <... close resumed>)             = 0
395566 dup2(3, 1 <unfinished ...>
395565 dup2(3, 0 <unfinished ...>
395566 <... dup2 resumed>)              = 1
395565 <... dup2 resumed>)              = 0
395566 close(3 <unfinished ...>
395565 close(3 <unfinished ...>
395566 <... close resumed>)             = 0
395565 <... close resumed>)             = 0
395565 ioctl(0, TCGETS <unfinished ...>
395566 write(1, "OK\n", 3 <unfinished ...>
395565 <... ioctl resumed>, 0x7ffef74e9c00) = -1 ENOTTY (Inappropriate ioctl for device)
395565 lseek(0, 0, SEEK_CUR <unfinished ...>
395566 <... write resumed>)             = 3
395565 <... lseek resumed>)             = -1 ESPIPE (Illegal seek)
395566 dup2(10, 1 <unfinished ...>
395565 pipe2( <unfinished ...>
395566 <... dup2 resumed>)              = 1
395565 <... pipe2 resumed>[3, 4], 0)    = 0
395566 close(10 <unfinished ...>
395565 fcntl(3, F_DUPFD_CLOEXEC, 10 <unfinished ...>
395566 <... close resumed>)             = 0
395565 <... fcntl resumed>)             = 11
395565 close(3 <unfinished ...>
395566 exit_group(0 <unfinished ...>
395565 <... close resumed>)             = 0
395566 <... exit_group resumed>)        = ?
395565 fcntl(4, F_DUPFD_CLOEXEC, 10)    = 12
395565 close(4)                         = 0
395565 tee(0, 12, 8192, 0 <unfinished ...>
395566 +++ exited with 0 +++
395565 <... tee resumed>)               = 3
395565 --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=395566, si_uid=1000, si_status=0, si_utime=0, si_stime=0} ---
395565 rt_sigreturn({mask=[]})          = 3
395565 read(11, "OK\n", 3)              = 3
395565 wait4(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], WNOHANG, NULL) = 395566
395565 wait4(-1, 0x7ffef74e9cec, WNOHANG, NULL) = -1 ECHILD (No child processes)
395565 read(0, "OK\n", 3)               = 3
395565 dup2(10, 0)                      = 0
395565 close(10)                        = 0
395565 write(1, "2:OK\n", 5)            = 5
395565 exit_group(0)                    = ?
395565 +++ exited with 0 +++

Cheers,
-- 
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt