qemu/atomic.h: rename atomic_ to qatomic_

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>

1 files changed, 14 insertions, 14 deletions

diff --git a/util/async.c b/util/async.c
index 4266745dee..f758354c6a 100644
--- a/util/async.c
+++ b/util/async.c
@@ -70,13 +70,13 @@ static void aio_bh_enqueue(QEMUBH *bh, unsigned new_flags)
     unsigned old_flags;
 
     /*
-     * The memory barrier implicit in atomic_fetch_or makes sure that:
+     * The memory barrier implicit in qatomic_fetch_or makes sure that:
      * 1. idle & any writes needed by the callback are done before the
      *    locations are read in the aio_bh_poll.
      * 2. ctx is loaded before the callback has a chance to execute and bh
      *    could be freed.
      */
-    old_flags = atomic_fetch_or(&bh->flags, BH_PENDING | new_flags);
+    old_flags = qatomic_fetch_or(&bh->flags, BH_PENDING | new_flags);
     if (!(old_flags & BH_PENDING)) {
         QSLIST_INSERT_HEAD_ATOMIC(&ctx->bh_list, bh, next);
     }
@@ -96,13 +96,13 @@ static QEMUBH *aio_bh_dequeue(BHList *head, unsigned *flags)
     QSLIST_REMOVE_HEAD(head, next);
 
     /*
-     * The atomic_and is paired with aio_bh_enqueue().  The implicit memory
+     * The qatomic_and is paired with aio_bh_enqueue().  The implicit memory
      * barrier ensures that the callback sees all writes done by the scheduling
      * thread.  It also ensures that the scheduling thread sees the cleared
      * flag before bh->cb has run, and thus will call aio_notify again if
      * necessary.
      */
-    *flags = atomic_fetch_and(&bh->flags,
+    *flags = qatomic_fetch_and(&bh->flags,
                               ~(BH_PENDING | BH_SCHEDULED | BH_IDLE));
     return bh;
 }
@@ -185,7 +185,7 @@ void qemu_bh_schedule(QEMUBH *bh)
  */
 void qemu_bh_cancel(QEMUBH *bh)
 {
-    atomic_and(&bh->flags, ~BH_SCHEDULED);
+    qatomic_and(&bh->flags, ~BH_SCHEDULED);
 }
 
 /* This func is async.The bottom half will do the delete action at the finial
@@ -249,7 +249,7 @@ aio_ctx_prepare(GSource *source, gint    *timeout)
 {
     AioContext *ctx = (AioContext *) source;
 
-    atomic_set(&ctx->notify_me, atomic_read(&ctx->notify_me) | 1);
+    qatomic_set(&ctx->notify_me, qatomic_read(&ctx->notify_me) | 1);
 
     /*
      * Write ctx->notify_me before computing the timeout
@@ -276,7 +276,7 @@ aio_ctx_check(GSource *source)
     BHListSlice *s;
 
     /* Finish computing the timeout before clearing the flag.  */
-    atomic_store_release(&ctx->notify_me, atomic_read(&ctx->notify_me) & ~1);
+    qatomic_store_release(&ctx->notify_me, qatomic_read(&ctx->notify_me) & ~1);
     aio_notify_accept(ctx);
 
     QSLIST_FOREACH_RCU(bh, &ctx->bh_list, next) {
@@ -424,21 +424,21 @@ void aio_notify(AioContext *ctx)
      * aio_notify_accept.
      */
     smp_wmb();
-    atomic_set(&ctx->notified, true);
+    qatomic_set(&ctx->notified, true);
 
     /*
      * Write ctx->notified before reading ctx->notify_me.  Pairs
      * with smp_mb in aio_ctx_prepare or aio_poll.
      */
     smp_mb();
-    if (atomic_read(&ctx->notify_me)) {
+    if (qatomic_read(&ctx->notify_me)) {
         event_notifier_set(&ctx->notifier);
     }
 }
 
 void aio_notify_accept(AioContext *ctx)
 {
-    atomic_set(&ctx->notified, false);
+    qatomic_set(&ctx->notified, false);
 
     /*
      * Write ctx->notified before reading e.g. bh->flags.  Pairs with smp_wmb
@@ -465,7 +465,7 @@ static bool aio_context_notifier_poll(void *opaque)
     EventNotifier *e = opaque;
     AioContext *ctx = container_of(e, AioContext, notifier);
 
-    return atomic_read(&ctx->notified);
+    return qatomic_read(&ctx->notified);
 }
 
 static void co_schedule_bh_cb(void *opaque)
@@ -489,7 +489,7 @@ static void co_schedule_bh_cb(void *opaque)
         aio_context_acquire(ctx);
 
         /* Protected by write barrier in qemu_aio_coroutine_enter */
-        atomic_set(&co->scheduled, NULL);
+        qatomic_set(&co->scheduled, NULL);
         qemu_aio_coroutine_enter(ctx, co);
         aio_context_release(ctx);
     }
@@ -546,7 +546,7 @@ fail:
 void aio_co_schedule(AioContext *ctx, Coroutine *co)
 {
     trace_aio_co_schedule(ctx, co);
-    const char *scheduled = atomic_cmpxchg(&co->scheduled, NULL,
+    const char *scheduled = qatomic_cmpxchg(&co->scheduled, NULL,
                                            __func__);
 
     if (scheduled) {
@@ -577,7 +577,7 @@ void aio_co_wake(struct Coroutine *co)
      * qemu_coroutine_enter.
      */
     smp_read_barrier_depends();
-    ctx = atomic_read(&co->ctx);
+    ctx = qatomic_read(&co->ctx);
 
     aio_co_enter(ctx, co);
 }