qemu-thread: Use futex for QemuEvent on Windows

Use the futex-based implementation of QemuEvent on Windows to
remove code duplication and remove the overhead of event object
construction and destruction.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20250526-event-v4-6-5b784cc8e1de@daynix.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

3 files changed, 10 insertions, 16 deletions

diff --git a/include/qemu/thread-posix.h b/include/qemu/thread-posix.h
index c412623a91..758808b705 100644
--- a/include/qemu/thread-posix.h
+++ b/include/qemu/thread-posix.h
@@ -32,15 +32,6 @@ struct QemuSemaphore {
     unsigned int count;
 };
 
-struct QemuEvent {
-#ifndef CONFIG_LINUX
-    pthread_mutex_t lock;
-    pthread_cond_t cond;
-#endif
-    unsigned value;
-    bool initialized;
-};
-
 struct QemuThread {
     pthread_t thread;
 };
diff --git a/include/qemu/thread-win32.h b/include/qemu/thread-win32.h
index d95af4498f..da9e732299 100644
--- a/include/qemu/thread-win32.h
+++ b/include/qemu/thread-win32.h
@@ -28,12 +28,6 @@ struct QemuSemaphore {
     bool initialized;
 };
 
-struct QemuEvent {
-    int value;
-    HANDLE event;
-    bool initialized;
-};
-
 typedef struct QemuThreadData QemuThreadData;
 struct QemuThread {
     QemuThreadData *data;
diff --git a/include/qemu/thread.h b/include/qemu/thread.h
index 6f800aad31..573f8c9ede 100644
--- a/include/qemu/thread.h
+++ b/include/qemu/thread.h
@@ -3,13 +3,22 @@
 
 #include "qemu/processor.h"
 #include "qemu/atomic.h"
+#include "qemu/futex.h"
 
 typedef struct QemuCond QemuCond;
 typedef struct QemuSemaphore QemuSemaphore;
-typedef struct QemuEvent QemuEvent;
 typedef struct QemuLockCnt QemuLockCnt;
 typedef struct QemuThread QemuThread;
 
+typedef struct QemuEvent {
+#ifndef HAVE_FUTEX
+    pthread_mutex_t lock;
+    pthread_cond_t cond;
+#endif
+    unsigned value;
+    bool initialized;
+} QemuEvent;
+
 #ifdef _WIN32
 #include "qemu/thread-win32.h"
 #else