diff options
| -rw-r--r-- | cpus.c | 9 | ||||
| -rw-r--r-- | include/qemu/main-loop.h | 10 | ||||
| -rw-r--r-- | stubs/iothread-lock.c | 5 |
3 files changed, 24 insertions, 0 deletions
@@ -1146,6 +1146,13 @@ bool qemu_in_vcpu_thread(void) return current_cpu && qemu_cpu_is_self(current_cpu); } +static __thread bool iothread_locked = false; + +bool qemu_mutex_iothread_locked(void) +{ + return iothread_locked; +} + void qemu_mutex_lock_iothread(void) { atomic_inc(&iothread_requesting_mutex); @@ -1164,10 +1171,12 @@ void qemu_mutex_lock_iothread(void) atomic_dec(&iothread_requesting_mutex); qemu_cond_broadcast(&qemu_io_proceeded_cond); } + iothread_locked = true; } void qemu_mutex_unlock_iothread(void) { + iothread_locked = false; qemu_mutex_unlock(&qemu_global_mutex); } diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h index 0f4a0fd4b2..bc18ca30e4 100644 --- a/include/qemu/main-loop.h +++ b/include/qemu/main-loop.h @@ -223,6 +223,16 @@ int qemu_add_child_watch(pid_t pid); #endif /** + * qemu_mutex_iothread_locked: Return lock status of the main loop mutex. + * + * The main loop mutex is the coarsest lock in QEMU, and as such it + * must always be taken outside other locks. This function helps + * functions take different paths depending on whether the current + * thread is running within the main loop mutex. + */ +bool qemu_mutex_iothread_locked(void); + +/** * qemu_mutex_lock_iothread: Lock the main loop mutex. * * This function locks the main loop mutex. The mutex is taken by diff --git a/stubs/iothread-lock.c b/stubs/iothread-lock.c index 5d8aca1b37..dda6f6b58d 100644 --- a/stubs/iothread-lock.c +++ b/stubs/iothread-lock.c @@ -1,6 +1,11 @@ #include "qemu-common.h" #include "qemu/main-loop.h" +bool qemu_mutex_iothread_locked(void) +{ + return true; +} + void qemu_mutex_lock_iothread(void) { } |