system/cpus: rename qemu_mutex_lock_iothread() to bql_lock()

The Big QEMU Lock (BQL) has many names and they are confusing. The
actual QemuMutex variable is called qemu_global_mutex but it's commonly
referred to as the BQL in discussions and some code comments. The
locking APIs, however, are called qemu_mutex_lock_iothread() and
qemu_mutex_unlock_iothread().

The "iothread" name is historic and comes from when the main thread was
split into into KVM vcpu threads and the "iothread" (now called the main
loop thread). I have contributed to the confusion myself by introducing
a separate --object iothread, a separate concept unrelated to the BQL.

The "iothread" name is no longer appropriate for the BQL. Rename the
locking APIs to:
- void bql_lock(void)
- void bql_unlock(void)
- bool bql_locked(void)

There are more APIs with "iothread" in their names. Subsequent patches
will rename them. There are also comments and documentation that will be
updated in later patches.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Acked-by: Fabiano Rosas <farosas@suse.de>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Acked-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Message-id: 20240102153529.486531-2-stefanha@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/util/qsp.c b/util/qsp.c
index 2fe3764906..6b783e2e7f 100644
--- a/util/qsp.c
+++ b/util/qsp.c
@@ -124,7 +124,7 @@ static const char * const qsp_typenames[] = {
     [QSP_CONDVAR]   = "condvar",
 };
 
-QemuMutexLockFunc qemu_bql_mutex_lock_func = qemu_mutex_lock_impl;
+QemuMutexLockFunc bql_mutex_lock_func = qemu_mutex_lock_impl;
 QemuMutexLockFunc qemu_mutex_lock_func = qemu_mutex_lock_impl;
 QemuMutexTrylockFunc qemu_mutex_trylock_func = qemu_mutex_trylock_impl;
 QemuRecMutexLockFunc qemu_rec_mutex_lock_func = qemu_rec_mutex_lock_impl;
@@ -439,7 +439,7 @@ void qsp_enable(void)
 {
     qatomic_set(&qemu_mutex_lock_func, qsp_mutex_lock);
     qatomic_set(&qemu_mutex_trylock_func, qsp_mutex_trylock);
-    qatomic_set(&qemu_bql_mutex_lock_func, qsp_bql_mutex_lock);
+    qatomic_set(&bql_mutex_lock_func, qsp_bql_mutex_lock);
     qatomic_set(&qemu_rec_mutex_lock_func, qsp_rec_mutex_lock);
     qatomic_set(&qemu_rec_mutex_trylock_func, qsp_rec_mutex_trylock);
     qatomic_set(&qemu_cond_wait_func, qsp_cond_wait);
@@ -450,7 +450,7 @@ void qsp_disable(void)
 {
     qatomic_set(&qemu_mutex_lock_func, qemu_mutex_lock_impl);
     qatomic_set(&qemu_mutex_trylock_func, qemu_mutex_trylock_impl);
-    qatomic_set(&qemu_bql_mutex_lock_func, qemu_mutex_lock_impl);
+    qatomic_set(&bql_mutex_lock_func, qemu_mutex_lock_impl);
     qatomic_set(&qemu_rec_mutex_lock_func, qemu_rec_mutex_lock_impl);
     qatomic_set(&qemu_rec_mutex_trylock_func, qemu_rec_mutex_trylock_impl);
     qatomic_set(&qemu_cond_wait_func, qemu_cond_wait_impl);