2591144 - Undetected deadlock between dbcc checkalloc(sybsecurity) process and AUDIT PROCESS -- SAP ASE

• AUDIT PROCESS (with spid 11) was in 'latch sleep' and the status didn't change for a long time.
• Another hanging process (with spid 1022) was running 'dbcc checkalloc(sybsecurity)' with status 'wait for object to be returned to pool'.
• Auditing Queue object memory pool had no free object. "dbcc mempool('Auditing Queue',show)" or sybmon command "mmgrpools object brief Auditing Queue" might show 'mc_used' = 'audit queue size' value. Default value of configurable parameter 'audit queue size' = 100.
• Dbcc latch or sybmon latch command might show an allocation buffer with latchowner of spid which was running 'dbcc checkalloc(sybsecurity)', e.g.

Buffers latched by process 1022:
        pss->platchedbufs[0]: 0x215d00f38
Buffer header for buffer 0x215d00f38 (Mass head)
    page=0x1fc5bd000 bdnew=0x19011a270 bdold=0x19011a270 bhash=0x215da5890
    bmass_next=0x215d00f38 bmass_prev=0x215d00f38 bdbid=31515                         <--- dbid of sybsecurity database
    bvirtpg= [ 0x215d00ff0 vpgdevno=23 vpvpn=215554 vdisk=0x19c7689d0 ]
    bmass_head=0x215d00f38 bmass_tail=0x215d00f38
    bcache_desc=0x1c7b805c8 (cache name='default data cache')
    bpool_desc=0x1c7b91ea0 bdbtable=0x1902935e0
    Mass bkeep=2 Mass bpawaited=1 Mass btripsleft=0 Mass btripsleft_orig=0
    bmass_size=4096 (4K pool) bunref_cnt=0
    bmass_stat=0x45111008 (0x40000000 (MASS_CLOCK_SEEN), 0x04000000 (MASS_DONT_DISCARD), 0x01000000 (MASS_BUFPIN
PLC), 0x00100000 (MASS_CHANGING), 0x00010000 (MASS_DIRTY), 0x00001000 (MASS_HASHED), 0x00000008 (MASS_KEPT))
    bbuf_stat=0x1 (0x00000001 (BUF_PG_REF))
    Buffer blpageno=353792 bpg_size=4k Mass blpageno=353792 (Buffer slot #: 0)
    bxls_pin=0x0 bxls_next=0x0 bspid=1022
    bxls_flushseq=193809070 bxls_pinseq=194048537 bcurrxdes=0x0
Latch and the wait queue:
Latch (address: 0x215d00f68)
        latchmode: 0x2 (EX_LATCH)
        latchowner: 1022                           
        latchnoofowners: 1
        latchwaitq: 0x1945b7080 latchwaitqt: 0x1945b7080

Latch wait queue:
LATCHWAIT struct at 0x1945b7080
Latch wait struct (at address=0x1945b7080) of Spid 11          <-- AUDIT PROCESS with spid=11 was waiting for an EX_LATCH
        Address of buffer being waited for=0x215d00f38
        lwqnext=0x0     lwmode=0x2 (EX_LATCH)
        lwstatus=0x1 (Sleeping) lwevent=0x1945b7080

AUDIT PROCESS, latch sleep, 'wait for object to be returned to pool', audit queue size, 'dbcc checkalloc(sybsecurity)', undetected deadlock, CR 777553, CR777553, CR#777553, 777553 , KBA , BC-SYB-ASE , Sybase ASE Database Platform (non Business Suite) , Bug Filed