classifier process aborts if systemd is too busy to service dbus connections

[matthewsucar]

(gdb) bt full
#0 0x00007fe0ce78a8d7 in raise () from /lib64/libc.so.6
No symbol table info available.
#1 0x00007fe0ce78bcaa in abort () from /lib64/libc.so.6
No symbol table info available.
#2 0x00007fe0cf7ea505 in ?? () from /lib64/libdbus-1.so.3
No symbol table info available.
#3 0x00007fe0cf7e1141 in ?? () from /lib64/libdbus-1.so.3
No symbol table info available.
#4 0x0000000000404394 in classify (pid=57956) at classifier.cpp:105
slice = 0x415072 "hpcjob.slice"
success = 0 '\000'
propstruct_i = {dummy1 = 0x7ffe1ad2bf01, dummy2 = 0x0, dummy3 = 0, dummy4 = 0, dummy5 = 0, dummy6 = 0, dummy7 = 0, dummy8 = 32766, dummy9 = 0, dummy10 = 0, dummy11 = 8192, pad1 = 0, pad2 = 0, pad3 = 0x0}
auxi = {dummy1 = 0x800000000, dummy2 = 0x0, dummy3 = 0, dummy4 = 0, dummy5 = 0, dummy6 = 0, dummy7 = 0, dummy8 = 0, dummy9 = 0, dummy10 = 0, dummy11 = 0, pad1 = 0, pad2 = 0, pad3 = 0x0}
pidlisti = {dummy1 = 0x0, dummy2 = 0x0, dummy3 = 0, dummy4 = 0, dummy5 = 0, dummy6 = 0, dummy7 = 0, dummy8 = 0, dummy9 = 0, dummy10 = 0, dummy11 = 0, pad1 = 0, pad2 = 0, pad3 = 0x0}
pidaryi = {dummy1 = 0x7ffe00000008, dummy2 = 0x7ffe1ad2bea0, dummy3 = 3476649568, dummy4 = 32736, dummy5 = 0, dummy6 = 0, dummy7 = 0, dummy8 = 0, dummy9 = 450018672, dummy10 = 32766, dummy11 = -818319232, pad1 = 32736, pad2 = -818319344, pad3 = 0x7fe0cf397020}
pids_s = 0x41506d "PIDs"
taskstr = 0x415085 "TasksMax"
uuid_s = "\240\363\070\317\340\177\000\000\000\000\000\000\000\000\000\000\250\022\071\317\340\177", '\000' <repeats 14 times>
num_tasks_max = 16384
con = 0x0
** dberr = {name = 0xa63ee0 "org.freedesktop.DBus.Error.LimitsExceeded", message = 0xa64da0 "The maximum number of active connections for UID 0 has been reached", dummy1 = 0, dummy2 = 0, dummy3 = 0, dummy4 = 0, dummy5 = 1, padding1 = 0x7fe0cf397020} **
mode = 0x415068 "fail"
mypid = 57956
scope = 0x0
scope_create_query = 0x7fe0cfc00bc0
slicepr = 0x41507f "Slice"
uuid = "\030P\246", '\000' <repeats 12 times>
propary_i = {dummy1 = 0x0, dummy2 = 0x0, dummy3 = 0, dummy4 = 0, dummy5 = -818317728, dummy6 = 32736, dummy7 = 0, dummy8 = 0, dummy9 = 0, dummy10 = 0, dummy11 = 0, pad1 = 0, pad2 = 0, pad3 = 0x0}
msgi = {dummy1 = 0xa62f00, dummy2 = 0x7fe0cf396ff0, dummy3 = 0, dummy4 = 0, dummy5 = 0, dummy6 = 0, dummy7 = 0, dummy8 = 0, dummy9 = 0, dummy10 = 0, dummy11 = -818361792, pad1 = 32736, pad2 = 6, pad3 = 0x0}
reply = 0xe26400006088
#5 0x0000000000404d9d in start_classifier (path=0x415488 "/run/tc_classifyd") at classifier.cpp:341
cmhdr = 0x7ffe1ad2c000
ucredrx = 0x7ffe1ad2c010
pid = 0
cs = 4
bytesr = 4
msg = {msg_name = 0x0, msg_namelen = 0, msg_iov = 0x7ffe1ad2c150, msg_iovlen = 1, msg_control = 0x7ffe1ad2c000, msg_controllen = 32, msg_flags = 0}
data = 57956
control_data = {mh = {cmsg_len = 28, cmsg_level = 1, cmsg_type = 2}, control = "\034\000\000\000\000\000\000\000\001\000\000\000\002\000\000\000d\342\000\000\210`\000\000\350\003\000\000\000\000\000"}
local = {sun_family = 1, sun_path = "/run/tc_classifyd", '\000' <repeats 90 times>}
remote = {sun_family = 1, sun_path = '\000' <repeats 107 times>}
s = 3
tru = 1
iov = {iov_base = 0x7ffe1ad2c14c, iov_len = 4}
sz = 2
len = 19
#6 0x00000000004083dd in main (argc=3, argv=0x7ffe1ad2c418) at oomkiller.c:135
longopts = {{name = 0x415688 "daemonize", has_arg = 0, flag = 0x0, val = 100}, {name = 0x415692 "cgroup", has_arg = 1, flag = 0x0, val = 103}, {name = 0x415699 "pidfile", has_arg = 1, flag = 0x0, val = 112}, {name = 0x4156a1 "restart_on_crash", has_arg = 0, flag = 0x0, val = 114}, {name = 0x4156b2 "verbose", has_arg = 0, flag = 0x0, val = 118}, {name = 0x0, has_arg = 0, flag = 0x0, val = 0}}
cl = 0
event_command = 0x10000ffff <error: Cannot access memory at address 0x10000ffff>
event_control_path = 0x7fe0000011c1 <error: Cannot access memory at address 0x7fe0000011c1>
oom_control_path = 0x408fed <__static_initialization_and_destruction_0(int, int)+70> "\311\303UH\211\345\276\377\377"
pidfile = 0x0
efdcounter = 140729348440800
sa = {__sigaction_handler = {sa_handler = 0x408b98 <child_reap>, sa_sigaction = 0x408b98 <child_reap>}, sa_mask = {__val = {0 <repeats 16 times>}}, sa_flags = 268435457, sa_restorer = 0x0}
flag = 0
PRETTY_FUNCTION = "main"
daemon_flag = 0 '\000'
restart_on_crash_flg = 0 '\000'
cgc = {efd = 450020064, ecfd = 32766, oomfd = -811536361, oomctlfd = 32736, cgroup_path = 0x1000000001 <error: Cannot access memory at address 0x1000000001>, cgroup_name = 0xa62c90 "hpcjob.slice", freezer_path = 0x7fe0cf396980 "\020\030\071\317\340\177", purgatory = 0x7fe0ce75e968}
verbose_log = 0 '\000'
ch = -1
purgatory_freeze_path = 0x3 <error: Cannot access memory at address 0x3>
freezer_fd = 0x414ffd <__libc_csu_init+77>

(gdb) list
100 char const * taskstr = "TasksMax";
101 uint64_t num_tasks_max = 16384;
102 dbus_error_init(&dberr);
103 uint32_t mypid = (uint32_t) pid;
104 con = dbus_bus_get_private(DBUS_BUS_SYSTEM, &dberr);
105 dbus_connection_set_exit_on_disconnect(con, 0);
106 uuid_t uuid;
107 char uuid_s[37];
108 char* scope = NULL;
109 char success = 0;