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, 6 insertions, 6 deletions

diff --git a/util/qemu-thread-posix.c b/util/qemu-thread-posix.c
index b4c2359272..dcff5e7c5d 100644
--- a/util/qemu-thread-posix.c
+++ b/util/qemu-thread-posix.c
@@ -414,8 +414,8 @@ void qemu_event_set(QemuEvent *ev)
      */
     assert(ev->initialized);
     smp_mb();
-    if (atomic_read(&ev->value) != EV_SET) {
-        if (atomic_xchg(&ev->value, EV_SET) == EV_BUSY) {
+    if (qatomic_read(&ev->value) != EV_SET) {
+        if (qatomic_xchg(&ev->value, EV_SET) == EV_BUSY) {
             /* There were waiters, wake them up.  */
             qemu_futex_wake(ev, INT_MAX);
         }
@@ -427,14 +427,14 @@ void qemu_event_reset(QemuEvent *ev)
     unsigned value;
 
     assert(ev->initialized);
-    value = atomic_read(&ev->value);
+    value = qatomic_read(&ev->value);
     smp_mb_acquire();
     if (value == EV_SET) {
         /*
          * If there was a concurrent reset (or even reset+wait),
          * do nothing.  Otherwise change EV_SET->EV_FREE.
          */
-        atomic_or(&ev->value, EV_FREE);
+        qatomic_or(&ev->value, EV_FREE);
     }
 }
 
@@ -443,7 +443,7 @@ void qemu_event_wait(QemuEvent *ev)
     unsigned value;
 
     assert(ev->initialized);
-    value = atomic_read(&ev->value);
+    value = qatomic_read(&ev->value);
     smp_mb_acquire();
     if (value != EV_SET) {
         if (value == EV_FREE) {
@@ -453,7 +453,7 @@ void qemu_event_wait(QemuEvent *ev)
              * a concurrent busy->free transition.  After the CAS, the
              * event will be either set or busy.
              */
-            if (atomic_cmpxchg(&ev->value, EV_FREE, EV_BUSY) == EV_SET) {
+            if (qatomic_cmpxchg(&ev->value, EV_FREE, EV_BUSY) == EV_SET) {
                 return;
             }
         }