esbbcall(D3)esbbcall(D3)NAMEesbbcall - call a function when an externally-supplied buffer can be
allocated
SYNOPSIS
#include <sys/types.h>
#include <sys/stream.h>
#include <sys/ddi.h>
toid_t esbbcall(int pri, void (*func)(), long arg);
Arguments
pri Priority of the esballoc(D3) allocation request.
func Function to be called when a buffer becomes available.
arg Argument to the function to be called when a buffer becomes
available.
DESCRIPTION
If esballoc(D3) is unable to allocate a message block header and a data
block header to go with its externally supplied data buffer, the function
esbbcall can be used to schedule the routine func, to be called with the
argument arg when memory becomes available. esbbcall, like bufcall(D3),
serves, in effect, as a timeout call of indeterminate length.
Return Values
On success, esbbcall returns a non-zero value that identifies the
scheduling request. On failure, esbbcall returns 0.
USAGE
When func runs, all interrupts from STREAMS devices will be blocked. On
multiprocessor systems, the interrupts will be blocked only on the
processor on which func is running. func will have no user context and
may not call any function that sleeps.
Even when func is called, esballoc can still fail if another module or
driver had allocated the memory before func was able to call allocb.
The pri argument is no longer used, but is retained for compatibility.
The non-zero identifier returned by esballoc may be passed to
unbufcall(D3) to cancel the request.
Level
Base or Interrupt.
Synchronization Constraints
Does not sleep.
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esbbcall(D3)esbbcall(D3)
Driver-defined basic locks, read/write locks, and sleep locks may be held
across calls to this function.
REFERENCESallocb(D3), bufcall(D3), esballoc(D3), itimeout(D3), unbufcall(D3)
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