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		d73415a315
		
	
	
	
	
		
			
			clang's C11 atomic_fetch_*() functions only take a C11 atomic type
pointer argument. QEMU uses direct types (int, etc) and this causes a
compiler error when a QEMU code calls these functions in a source file
that also included <stdatomic.h> via a system header file:
  $ CC=clang CXX=clang++ ./configure ... && make
  ../util/async.c:79:17: error: address argument to atomic operation must be a pointer to _Atomic type ('unsigned int *' invalid)
Avoid using atomic_*() names in QEMU's atomic.h since that namespace is
used by <stdatomic.h>. Prefix QEMU's APIs with 'q' so that atomic.h
and <stdatomic.h> can co-exist. I checked /usr/include on my machine and
searched GitHub for existing "qatomic_" users but there seem to be none.
This patch was generated using:
  $ git grep -h -o '\<atomic\(64\)\?_[a-z0-9_]\+' include/qemu/atomic.h | \
    sort -u >/tmp/changed_identifiers
  $ for identifier in $(</tmp/changed_identifiers); do
        sed -i "s%\<$identifier\>%q$identifier%g" \
            $(git grep -I -l "\<$identifier\>")
    done
I manually fixed line-wrap issues and misaligned rST tables.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200923105646.47864-1-stefanha@redhat.com>
		
	
			
		
			
				
	
	
		
			73 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			73 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * AioContext wait support
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|  *
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|  * Copyright (C) 2018 Red Hat, Inc.
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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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| 
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| #include "qemu/osdep.h"
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| #include "qemu/main-loop.h"
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| #include "block/aio-wait.h"
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| 
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| AioWait global_aio_wait;
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| 
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| static void dummy_bh_cb(void *opaque)
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| {
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|     /* The point is to make AIO_WAIT_WHILE()'s aio_poll() return */
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| }
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| 
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| void aio_wait_kick(void)
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| {
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|     /* The barrier (or an atomic op) is in the caller.  */
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|     if (qatomic_read(&global_aio_wait.num_waiters)) {
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|         aio_bh_schedule_oneshot(qemu_get_aio_context(), dummy_bh_cb, NULL);
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|     }
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| }
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| 
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| typedef struct {
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|     bool done;
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|     QEMUBHFunc *cb;
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|     void *opaque;
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| } AioWaitBHData;
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| 
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| /* Context: BH in IOThread */
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| static void aio_wait_bh(void *opaque)
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| {
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|     AioWaitBHData *data = opaque;
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| 
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|     data->cb(data->opaque);
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| 
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|     data->done = true;
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|     aio_wait_kick();
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| }
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| 
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| void aio_wait_bh_oneshot(AioContext *ctx, QEMUBHFunc *cb, void *opaque)
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| {
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|     AioWaitBHData data = {
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|         .cb = cb,
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|         .opaque = opaque,
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|     };
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| 
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|     assert(qemu_get_current_aio_context() == qemu_get_aio_context());
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| 
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|     aio_bh_schedule_oneshot(ctx, aio_wait_bh, &data);
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|     AIO_WAIT_WHILE(ctx, !data.done);
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| }
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