.IX \f4unbufcall\fP(D3DK)

NAME

unbufcall − cancel a pending bufcall request

SYNOPSIS

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

ARGUMENTS

idIdentifier returned from bufcall(D3DK) or esbbcall(D3DK). 

DESCRIPTION

unbufcall cancels a pending bufcall or esbbcall request.  The argument id is a non-zero identifier for the request to be canceled.  id is returned from the bufcall or esbbcall function used to issue the request. 

RETURN VALUE

None. 

LEVEL

Base or Interrupt. 

NOTES

Does not sleep. 

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

SEE ALSO

bufcall(D3DK), esbbcall(D3DK)

EXAMPLE

See bufcall for the other half of this example. 

In the module close routine, the put(D2DK) and srv(D2DK) routines are disabled by calling qprocsoff(D3DK) (line 16).  This will prevent any further bufcall or timeout requests from being issued by the service routine.  If a bufcall request is pending (line 17), we cancel it (line 18).  Otherwise, if a timeout request is pending (line 19), we cancel it (line 20).  Then the m_type field of the module’s private data structure is set to 0, indicating no pending bufcall or timeout. 

 1  struct mod {
 2toid_tm_id;
 3charm_type;
 4lock_t∗m_lock;
. . .
 5  };
 6  #define TIMEOUT1
 7  #define BUFCALL2
    . . .
 8  modclose(q, flag, crp)
 9queue_t ∗q;
10int flag;
11cred_t ∗crp;
12  {
13struct mod ∗modp;
 14modp = (struct mod ∗)q->q_ptr;
15qprocsoff(q);
16if (modp->m_type == BUFCALL)
17unbufcall(modp->m_id);
18else if (modp->m_type == TIMEOUT)
19untimeout(modp->m_id);
20modp->m_type = 0;
. . .

.IX \f4unbufcall\fP(D3DK), example
.IX \f4untimeout\fP(D3DK), example
.IX \f4qprocsoff\fP(D3DK), example

DDI/DKI  —  STREAMS