unbufcall(D3)

NAME
     unbufcall - cancel a pending bufcall request

SYNOPSIS
     #include <sys/stream.h>
     #include <sys/ddi.h>
     void unbufcall(toid_t id);

   Arguments
     id        Non-zero identifier returned from a prior call to bufcall(D3)
               or esbbcall(D3).

DESCRIPTION
     unbufcall cancels the pending bufcall or esbbcall request specified by
     id.

   Return Values
     None

USAGE
     If unbufcall is called while any function called by the pending bufcall
     or esbbcall request is running, the call to unbufcall has no effect.

   Level
     Base or Interrupt.

   Synchronization Constraints
     Does not sleep.

     Driver-defined basic locks, read/write locks, and sleep locks may not be
     held across calls to this function.

   Example
     See bufcall for the other half of this example.

     In the module close routine, if a bufcall request is pending (line 14),
     we cancel it (line 15).  Otherwise, if a itimeout request is pending
     (line 16), we cancel it (line 17).  Then the m_type field in the module's
     private data structure is set to 0, indicating no pending bufcall or
     itimeout.

      1  struct mod {
      2   long m_id;
      3   char m_type;
          ...
      4  };
      5  #define TIMEOUT 1
      6  #define BUFCALL 2
         ...
      7  modclose(q, flag, crp)
      8   queue_t *q;
      9   int flag;
     10   cred_t *crp;
     11  {
     12   struct mod *modp;
     13   modp = (struct mod *)q->q_ptr;
     14   if (modp->m_type == BUFCALL)
     15        unbufcall(modp->m_id);
     16   else if (modp->m_type == TIMEOUT)
     17        untimeout(modp->m_id);
     18   modp->m_type = 0;
          ...

REFERENCES
     bufcall(D3), esbbcall(D3)