cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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co-shared-resource.h (2508B)

      1/*
      2 * Helper functionality for distributing a fixed total amount of
      3 * an abstract resource among multiple coroutines.
      4 *
      5 * Copyright (c) 2019 Virtuozzo International GmbH
      6 *
      7 * Permission is hereby granted, free of charge, to any person obtaining a copy
      8 * of this software and associated documentation files (the "Software"), to deal
      9 * in the Software without restriction, including without limitation the rights
     10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     11 * copies of the Software, and to permit persons to whom the Software is
     12 * furnished to do so, subject to the following conditions:
     13 *
     14 * The above copyright notice and this permission notice shall be included in
     15 * all copies or substantial portions of the Software.
     16 *
     17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
     20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
     22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     23 * THE SOFTWARE.
     24 */
     25
     26#ifndef QEMU_CO_SHARED_RESOURCE_H
     27#define QEMU_CO_SHARED_RESOURCE_H
     28
     29/* Accesses to co-shared-resource API are thread-safe */
     30typedef struct SharedResource SharedResource;
     31
     32/*
     33 * Create SharedResource structure
     34 *
     35 * @total: total amount of some resource to be shared between clients
     36 */
     37SharedResource *shres_create(uint64_t total);
     38
     39/*
     40 * Release SharedResource structure
     41 *
     42 * This function may only be called once everything allocated by all
     43 * clients has been deallocated.
     44 */
     45void shres_destroy(SharedResource *s);
     46
     47/*
     48 * Try to allocate an amount of @n.  Return true on success, and false
     49 * if there is too little left of the collective resource to fulfill
     50 * the request.
     51 */
     52bool co_try_get_from_shres(SharedResource *s, uint64_t n);
     53
     54/*
     55 * Allocate an amount of @n, and, if necessary, yield until
     56 * that becomes possible.
     57 */
     58void coroutine_fn co_get_from_shres(SharedResource *s, uint64_t n);
     59
     60/*
     61 * Deallocate an amount of @n.  The total amount allocated by a caller
     62 * does not need to be deallocated/released with a single call, but may
     63 * be split over several calls.  For example, get(4), get(3), and then
     64 * put(5), put(2).
     65 */
     66void coroutine_fn co_put_to_shres(SharedResource *s, uint64_t n);
     67
     68
     69#endif /* QEMU_CO_SHARED_RESOURCE_H */