qemu/docs/spin/aio_notify.promela
Paolo Bonzini ac06724a71 docs: create config/, devel/ and spin/ subdirectories
Developer documentation should be its own manual.  As a start, move all
developer-oriented files to a separate directory.

Also move non-text files to their own directories: docs/config/ for
QEMU -readconfig input, and docs/spin/ for formal models to be used
with the SPIN model checker.

Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-06-07 18:22:03 +02:00

94 lines
1.8 KiB
Promela

/*
* This model describes the interaction between ctx->notify_me
* and aio_notify().
*
* Author: Paolo Bonzini <pbonzini@redhat.com>
*
* This file is in the public domain. If you really want a license,
* the WTFPL will do.
*
* To simulate it:
* spin -p docs/aio_notify.promela
*
* To verify it:
* spin -a docs/aio_notify.promela
* gcc -O2 pan.c
* ./a.out -a
*
* To verify it (with a bug planted in the model):
* spin -a -DBUG docs/aio_notify.promela
* gcc -O2 pan.c
* ./a.out -a
*/
#define MAX 4
#define LAST (1 << (MAX - 1))
#define FINAL ((LAST << 1) - 1)
bool notify_me;
bool event;
int req;
int done;
active proctype waiter()
{
int fetch;
do
:: true -> {
notify_me++;
if
#ifndef BUG
:: (req > 0) -> skip;
#endif
:: else ->
// Wait for a nudge from the other side
do
:: event == 1 -> { event = 0; break; }
od;
fi;
notify_me--;
atomic { fetch = req; req = 0; }
done = done | fetch;
}
od
}
active proctype notifier()
{
int next = 1;
do
:: next <= LAST -> {
// generate a request
req = req | next;
next = next << 1;
// aio_notify
if
:: notify_me == 1 -> event = 1;
:: else -> printf("Skipped event_notifier_set\n"); skip;
fi;
// Test both synchronous and asynchronous delivery
if
:: 1 -> do
:: req == 0 -> break;
od;
:: 1 -> skip;
fi;
}
od;
}
never { /* [] done < FINAL */
accept_init:
do
:: done < FINAL -> skip;
od;
}