6133b39f3c
The previous patch fixed a race condition, in which there were coroutines being executing doubly, or after coroutine deletion. We can detect common scenarios when this happens, and print an error message and abort before we corrupt memory / data, or segfault. This patch will abort if an attempt to enter a coroutine is made while it is currently pending execution, either in a specific AioContext bh, or pending execution via a timer. It will also abort if a coroutine is scheduled, before a prior scheduled run has occurred. We cannot rely on the existing co->caller check for recursive re-entry to catch this, as the coroutine may run and exit with COROUTINE_TERMINATE before the scheduled coroutine executes. (This is the scenario that was occurring and fixed in the previous patch). This patch also re-orders the Coroutine struct elements in an attempt to optimize caching. Signed-off-by: Jeff Cody <jcody@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
74 lines
2.4 KiB
C
74 lines
2.4 KiB
C
/*
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* Coroutine internals
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*
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* Copyright (c) 2011 Kevin Wolf <kwolf@redhat.com>
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#ifndef QEMU_COROUTINE_INT_H
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#define QEMU_COROUTINE_INT_H
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#include "qemu/queue.h"
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#include "qemu/coroutine.h"
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#define COROUTINE_STACK_SIZE (1 << 20)
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typedef enum {
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COROUTINE_YIELD = 1,
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COROUTINE_TERMINATE = 2,
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COROUTINE_ENTER = 3,
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} CoroutineAction;
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struct Coroutine {
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CoroutineEntry *entry;
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void *entry_arg;
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Coroutine *caller;
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/* Only used when the coroutine has terminated. */
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QSLIST_ENTRY(Coroutine) pool_next;
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size_t locks_held;
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/* Only used when the coroutine has yielded. */
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AioContext *ctx;
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/* Used to catch and abort on illegal co-routine entry.
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* Will contain the name of the function that had first
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* scheduled the coroutine. */
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const char *scheduled;
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QSIMPLEQ_ENTRY(Coroutine) co_queue_next;
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/* Coroutines that should be woken up when we yield or terminate.
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* Only used when the coroutine is running.
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*/
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QSIMPLEQ_HEAD(, Coroutine) co_queue_wakeup;
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QSLIST_ENTRY(Coroutine) co_scheduled_next;
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};
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Coroutine *qemu_coroutine_new(void);
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void qemu_coroutine_delete(Coroutine *co);
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CoroutineAction qemu_coroutine_switch(Coroutine *from, Coroutine *to,
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CoroutineAction action);
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void coroutine_fn qemu_co_queue_run_restart(Coroutine *co);
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#endif
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