(gdb) bt
#0  0x00007f3bf2f7a420 in sem_wait () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x0000000000439080 in ngx_shmtx_lock (mtx=0x7f3b2232f320) at src/core/ngx_shmtx.c:111
#2  0x00000000004eb975 in ngx_http_push_stream_assing_subscription_to_channel (shpool=shpool@entry=0x7f3b2113b000, channel=0x7f3b22753f00, subscription=0x7f3be63c6b38, subscriptions=subscriptions@entry=0x7f3be63c6b08, log=0x20ca550)
    at /home/pdobryakov/245/nginx-1.10.1/debian/modules/nginx-push-stream-module/src/ngx_http_push_stream_module_subscriber.c:626
#3  0x00000000004ebb9c in ngx_http_push_stream_subscriber_assign_channel (r=r@entry=0x7f3be7d24880, if_modified_since=<optimized out>, tag=<optimized out>, last_event_id=0x0, subscriber=subscriber@entry=0x7f3be63c6b00, 
    temp_pool=<error reading variable: Unhandled dwarf expression opcode 0xfa>, requested_channel=<error reading variable: Unhandled dwarf expression opcode 0xfa>, 
    requested_channel=<error reading variable: Unhandled dwarf expression opcode 0xfa>, cf=<error reading variable: Unhandled dwarf expression opcode 0xfa>, mcf=<error reading variable: Unhandled dwarf expression opcode 0xfa>)
    at /home/pdobryakov/245/nginx-1.10.1/debian/modules/nginx-push-stream-module/src/ngx_http_push_stream_module_subscriber.c:278
#4  0x00000000004ef8d8 in ngx_http_push_stream_websocket_handler (r=0x7f3be7d24880) at /home/pdobryakov/245/nginx-1.10.1/debian/modules/nginx-push-stream-module/src/ngx_http_push_stream_module_websocket.c:142
#5  0x00000000004668bf in ngx_http_core_content_phase (r=0x7f3be7d24880, ph=<optimized out>) at src/http/ngx_http_core_module.c:1370
#6  0x0000000000460d35 in ngx_http_core_run_phases (r=r@entry=0x7f3be7d24880) at src/http/ngx_http_core_module.c:847
#7  0x0000000000460e1c in ngx_http_handler (r=r@entry=0x7f3be7d24880) at src/http/ngx_http_core_module.c:830
#8  0x0000000000467666 in ngx_http_internal_redirect (r=0x7f3be7d24880, uri=<optimized out>, args=<optimized out>) at src/http/ngx_http_core_module.c:2611
#9  0x00007f3becd27d62 in ngx_http_perl_handle_request () from /usr/lib/nginx/modules/ngx_http_perl_module.so
#10 0x00007f3becd27db8 in ?? () from /usr/lib/nginx/modules/ngx_http_perl_module.so
#11 0x00000000004668bf in ngx_http_core_content_phase (r=0x7f3be7d24880, ph=<optimized out>) at src/http/ngx_http_core_module.c:1370
#12 0x0000000000460d35 in ngx_http_core_run_phases (r=r@entry=0x7f3be7d24880) at src/http/ngx_http_core_module.c:847
#13 0x0000000000460e1c in ngx_http_handler (r=r@entry=0x7f3be7d24880) at src/http/ngx_http_core_module.c:830
#14 0x000000000046d271 in ngx_http_process_request (r=0x7f3be7d24880) at src/http/ngx_http_request.c:1910
#15 0x000000000046db6c in ngx_http_process_request_headers (rev=rev@entry=0x7f3b00d35e80) at src/http/ngx_http_request.c:1342
#16 0x000000000046e176 in ngx_http_process_request_line (rev=0x7f3b00d35e80) at src/http/ngx_http_request.c:1022
#17 0x0000000000453ef1 in ngx_epoll_process_events (cycle=0x7f3be54e3380, timer=<optimized out>, flags=<optimized out>) at src/event/modules/ngx_epoll_module.c:822
#18 0x0000000000449f62 in ngx_process_events_and_timers (cycle=cycle@entry=0x7f3be54e3380) at src/event/ngx_event.c:242
#19 0x0000000000451cc5 in ngx_worker_process_cycle (cycle=cycle@entry=0x7f3be54e3380, data=data@entry=0x0) at src/os/unix/ngx_process_cycle.c:753
#20 0x0000000000450797 in ngx_spawn_process (cycle=cycle@entry=0x7f3be54e3380, proc=proc@entry=0x451c80 <ngx_worker_process_cycle>, data=data@entry=0x0, name=name@entry=0xd139e2 "worker process", respawn=respawn@entry=-4)
    at src/os/unix/ngx_process.c:198
#21 0x0000000000451fb4 in ngx_start_worker_processes (cycle=cycle@entry=0x7f3be54e3380, n=12, type=type@entry=-4) at src/os/unix/ngx_process_cycle.c:358
#22 0x0000000000452ebc in ngx_master_process_cycle (cycle=0x7f3be54e3380, cycle@entry=0x20c7000) at src/os/unix/ngx_process_cycle.c:243
#23 0x000000000042b012 in main (argc=<optimized out>, argv=<optimized out>) at src/core/nginx.c:367

(gdb) select-frame 2
(gdb) info args
shpool = 0x7f3b2113b000
channel = 0x7f3b22753f00
subscription = 0x7f3be63c6b38
subscriptions = 0x7f3be63c6b08
log = 0x20ca550
(gdb) print *(ngx_http_push_stream_channel_t*)0x7f3b22753f00
$1 = {node = {key = 3539878064, left = 0x7f3b22330000, right = 0x7f3b22330000, parent = 0x7f3b22817400, color = 1 '\001', data = 114 'r'}, queue = {prev = 0x7f3b2273cc28, next = 0x7f3b22539a28}, id = {len = 10, 
    data = 0x7f3b2238da50 "my11406628"}, last_message_id = 0, last_message_time = 0, last_message_tag = 0, stored_messages = 0, subscribers = 0, workers_with_subscribers = {prev = 0x7f3b22753f70, next = 0x7f3b22753f70}, message_queue = {
    prev = 0x7f3b22753f80, next = 0x7f3b22753f80}, expires = 1477577239, deleted = 0, wildcard = 0, for_events = 0 '\000', channel_deleted_message = 0x0, mutex = 0x7f3b2232f320}

(gdb) print *(ngx_slab_pool_t*)0x7f3b2113b000
$1 = {lock = {lock = 0, wait = 0}, min_size = 8, min_shift = 3, pages = 0x7f3b2113b190, last = 0x7f3b22320400, free = {slab = 0, next = 0x7f3b21140740, prev = 139891934737216}, start = 0x7f3b22321000 "", end = 0x7f3be113b000 "", 
  mutex = {lock = 0x7f3b2113b000, wait = 0x7f3b2113b008, semaphore = 1, sem = {__size = '\000' <repeats 31 times>, __align = 0}, spin = 2048}, log_ctx = 0x7f3b2113b0a0 "", zero = 0 '\000', log_nomem = 1, data = 0x0, 
  addr = 0x7f3b2113b000}