32-Bit Semaphore Structures (SEM32, OPENQ and MUXQ)

##.pb 25
 Slot  Sta BlockID  Name     Type        Addr    Symbol
 0025  blk fe81d2d0 pmshell  Sem32     8001 004b hevLazyWrite

##.d sem32 %fe81d2d0
        Type: Shared Event
       Flags: Reset
       pMuxQ: 00000000
  Post Count: 0000
      pOpenQ: fe56eb10
       pName: fd074e98
 Create Addr: 13f60088

##.pb 2f
 Slot  Sta BlockID  Name     Type        Addr    Symbol
 002f  blk fe86ffdc pmshell

##.d sem32 %fe86ffdc
        Type: Shared Event
       Flags: Reset
       pMuxQ: 00000000
  Post Count: 0000
      pOpenQ: fe56eb02
       pName: NULL (anonymous)
 Create Addr: 12d16b48

##.pb 30
 Slot  Sta BlockID  Name     Type        Addr    Symbol
 0030  blk fe86fe58 pmshell  Sem32     0001 00ce hevSleeper

##.d sem32 %fe86fe58
        Type: Private Event
       Flags: Reset
       pMuxQ: 00000000
  Post Count: 0000
  Open Count: 0001
 Create Addr: 13f62f28

Notes:

32-bit semaphores may be Event or Mutex in type, private or shared in scope and if shared, named or anonymous.

The BlockId of a thread waiting on a 32-bit semaphore is the address of the semaphore structure. The Type field in the .PB command usually indicates a 32-bit semaphore when in use, however this is not always the case. The next example shows how to determine precisely whether the blockid points to a 32-bit semaphore.

##.pb 33 Slot  Sta BlockID  Name     Type        Addr    Symbol
 0033  blk fe86fa1c pmshell
##.m %0fe86fa1c

*har     par      cpg        va    flg next prev link hash hob   hal
 0003 %feaef04c 00000400 %fe6ef000 001 0002 0023 0000 0000 0003 0000      =0000
 hob   har hobnxt flgs own  hmte  sown,cnt lt st xf
 0003  0003 fec5  0000 ffec 0000  0000 00  01 00 00 vmkrhrw
   pvmli    cs    eip     phlock   cpg      va    flg  hptda hob sig  csig
 %fe82e380 002d 0a6800a5 %ac22403c 0001 %fe83c000 0005 024b 0003 ea9f ea9f
##dd %0fe86fa1c-10 l8
%fe86fa0c  12d15b4c 54564553 ab97d220 ffc20018
%fe86fa1c  00000010 00000000 c4280001 455000a7
##.mo ffc2
ffc2 semstruc
##.d sem32 %0fe86fa1c
        Type: Private Event
       Flags: Reset
       pMuxQ: 00000000
  Post Count: 0000
  Open Count: 0001
 Create Addr: 00a7c428

##

Notes:

Except for RAMSEM, MUXWAIT, ChildWait and private conventions the BlockID is an address of a structure or routine that relates to the resource or event being waited for.

The .M command is used to identifty the owner of the BlockId. In this case it is the kernel resident heap.

Each resident heap block is prefixed with a 4 byte header. If the low order bit is 0 then the high word of the header contains the owner of the heap block.

32-bit Semaphore structures are allocated from regular resident heap blocks. Thus the owner id may be seen by displaying storage before the BlockId address.

##.pb 56 0056  blk fe88ad8c mutxwait Sem32     8001 0090 _WINOS2_Settings + 77

##.d sem32 %fe88ad8c
        Type: Shared Mutex
       Flags:
       pMuxQ: fe88ab94
  Request Ct: 0001
       Owner: 0055
Requester Ct: 0001
      pOpenQ: fe5724c2
       pName: fd084368
 Create Addr: 00022e98

##.d openq %fe5724c2

  PID   Open Count
  ----------------
  00d8     0001
  00d7     0001
  00d6     0001

##da %fd084368
%fd084368 RJM\MUTEX0

##.d muxq %fe88ab94

  pMux
  --------
  fe88aba4

##.d sem32 %fe88aba4
        Type: Shared MuxWait
       Flags: Mutex_Mux
    SR Count: 0003
  SR Pointer: fe88a8f4
  Wait Count: 0001
      pOpenQ: fe571e94
       pName: fd0843c8
 Create Addr: 00022ec4

##da %fd0843c8
%fd0843c8 RJM\MUXWAIT
##.d openq %fe571e94

  PID   Open Count
  ----------------
  00d7     0001
  00d6     0001

##dd %fe88a8f4
%fe88a8f4  00000003 00000004 80000090 00000000
%fe88a904  80000091 00000001 80000094 00000001
%fe88a914  ffbe0014 fe88aba4 00000000 5158554d
%fe88a924  fe88a916 ffc70010 fe88a958 dd2f4580
%fe88a934  000001a2 ffc70010 fe88aa88 dd2f464d
%fe88a944  00000010 ffa4000c fe88a968 000102d5
%fe88a954  ffc70010 fe88a9d8 1bd49ce0 000101a5
%fe88a964  ffa4000c fe88aa7c 0001038d ffc70010

##

Notes:

pOpenQ points to an Open Queue Structure, that list all processes that have access to the 32-bit semaphore. This is formatted using .D OPENQ.

pName points to the semaphore name, when not anonymous.

pMuxQ points to a MUXQ structure, that lists any 32-bit MUX wait semaphore address lists that have included this semaphore. In this example we see one MUX list.

The MUX list may be formatted using .D SEM32.

Instead of a pMuxQ, the MUX semaphore contains a pointer to the semaphore record (SR Pointer) and a count of the number of semaphores in the list (SR Count).

There is no special formatting command for the SR Structure - it has to be view by displaying storage directly. In this case we see then length, flags and three semaphore handles each followed by the user correlator.

For a description of the 32-bit Semaphore Structures, see the 32-bit Semaphore Structures in the System Reference.