*
*/
-#ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0600
-#endif
-
#include "qemu/osdep.h"
-#include "qemu-common.h"
#include "qemu/thread.h"
#include "qemu/notify.h"
#include "qemu-thread-common.h"
static bool name_threads;
+typedef HRESULT (WINAPI *pSetThreadDescription) (HANDLE hThread,
+ PCWSTR lpThreadDescription);
+static pSetThreadDescription SetThreadDescriptionFunc;
+static HMODULE kernel32_module;
+
+static bool load_set_thread_description(void)
+{
+ static gsize _init_once = 0;
+
+ if (g_once_init_enter(&_init_once)) {
+ kernel32_module = LoadLibrary("kernel32.dll");
+ if (kernel32_module) {
+ SetThreadDescriptionFunc =
+ (pSetThreadDescription)GetProcAddress(kernel32_module,
+ "SetThreadDescription");
+ if (!SetThreadDescriptionFunc) {
+ FreeLibrary(kernel32_module);
+ }
+ }
+ g_once_init_leave(&_init_once, 1);
+ }
+
+ return !!SetThreadDescriptionFunc;
+}
+
void qemu_thread_naming(bool enable)
{
- /* But note we don't actually name them on Windows yet */
name_threads = enable;
- fprintf(stderr, "qemu: thread naming not supported on this host\n");
+ if (enable && !load_set_thread_description()) {
+ fprintf(stderr, "qemu: thread naming not supported on this host\n");
+ name_threads = false;
+ }
}
static void error_exit(int err, const char *msg)
return !TryEnterCriticalSection(&mutex->lock);
}
-void qemu_rec_mutex_unlock(QemuRecMutex *mutex)
+void qemu_rec_mutex_unlock_impl(QemuRecMutex *mutex, const char *file, int line)
{
assert(mutex->initialized);
LeaveCriticalSection(&mutex->lock);
qemu_mutex_post_lock(mutex, file, line);
}
+bool qemu_cond_timedwait_impl(QemuCond *cond, QemuMutex *mutex, int ms,
+ const char *file, const int line)
+{
+ int rc = 0;
+
+ assert(cond->initialized);
+ trace_qemu_mutex_unlock(mutex, file, line);
+ if (!SleepConditionVariableSRW(&cond->var, &mutex->lock, ms, 0)) {
+ rc = GetLastError();
+ }
+ trace_qemu_mutex_locked(mutex, file, line);
+ if (rc && rc != ERROR_TIMEOUT) {
+ error_exit(rc, __func__);
+ }
+ return rc != ERROR_TIMEOUT;
+}
+
void qemu_sem_init(QemuSemaphore *sem, int init)
{
/* Manual reset. */
void qemu_event_set(QemuEvent *ev)
{
assert(ev->initialized);
- /* qemu_event_set has release semantics, but because it *loads*
+
+ /*
+ * Pairs with both qemu_event_reset() and qemu_event_wait().
+ *
+ * qemu_event_set has release semantics, but because it *loads*
* ev->value we need a full memory barrier here.
*/
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) {
+ int old = qatomic_xchg(&ev->value, EV_SET);
+
+ /* Pairs with memory barrier after ResetEvent. */
+ smp_mb__after_rmw();
+ if (old == EV_BUSY) {
/* There were waiters, wake them up. */
SetEvent(ev->event);
}
void qemu_event_reset(QemuEvent *ev)
{
- unsigned value;
-
assert(ev->initialized);
- value = atomic_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);
- }
+
+ /*
+ * If there was a concurrent reset (or even reset+wait),
+ * do nothing. Otherwise change EV_SET->EV_FREE.
+ */
+ qatomic_or(&ev->value, EV_FREE);
+
+ /*
+ * Order reset before checking the condition in the caller.
+ * Pairs with the first memory barrier in qemu_event_set().
+ */
+ smp_mb__after_rmw();
}
void qemu_event_wait(QemuEvent *ev)
unsigned value;
assert(ev->initialized);
- value = atomic_read(&ev->value);
- smp_mb_acquire();
+
+ /*
+ * qemu_event_wait must synchronize with qemu_event_set even if it does
+ * not go down the slow path, so this load-acquire is needed that
+ * synchronizes with the first memory barrier in qemu_event_set().
+ *
+ * If we do go down the slow path, there is no requirement at all: we
+ * might miss a qemu_event_set() here but ultimately the memory barrier in
+ * qemu_futex_wait() will ensure the check is done correctly.
+ */
+ value = qatomic_load_acquire(&ev->value);
if (value != EV_SET) {
if (value == EV_FREE) {
- /* qemu_event_set is not yet going to call SetEvent, but we are
- * going to do another check for EV_SET below when setting EV_BUSY.
- * At that point it is safe to call WaitForSingleObject.
+ /*
+ * Here the underlying kernel event is reset, but qemu_event_set is
+ * not yet going to call SetEvent. However, there will be another
+ * check for EV_SET below when setting EV_BUSY. At that point it
+ * is safe to call WaitForSingleObject.
*/
ResetEvent(ev->event);
- /* Tell qemu_event_set that there are waiters. No need to retry
- * because there cannot be a concurent busy->free transition.
- * After the CAS, the event will be either set or busy.
+ /*
+ * It is not clear whether ResetEvent provides this barrier; kernel
+ * APIs (KeResetEvent/KeClearEvent) do not. Better safe than sorry!
+ */
+ smp_mb();
+
+ /*
+ * Leave the event reset and tell qemu_event_set that there are
+ * waiters. No need to retry, because there cannot be 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) {
- value = EV_SET;
- } else {
- value = EV_BUSY;
+ if (qatomic_cmpxchg(&ev->value, EV_FREE, EV_BUSY) == EV_SET) {
+ return;
}
}
- if (value == EV_BUSY) {
- WaitForSingleObject(ev->event, INFINITE);
- }
+
+ /*
+ * ev->value is now EV_BUSY. Since we didn't observe EV_SET,
+ * qemu_event_set() must observe EV_BUSY and call SetEvent().
+ */
+ WaitForSingleObject(ev->event, INFINITE);
}
}
return ret;
}
+static bool set_thread_description(HANDLE h, const char *name)
+{
+ HRESULT hr;
+ g_autofree wchar_t *namew = NULL;
+
+ if (!load_set_thread_description()) {
+ return false;
+ }
+
+ namew = g_utf8_to_utf16(name, -1, NULL, NULL, NULL);
+ if (!namew) {
+ return false;
+ }
+
+ hr = SetThreadDescriptionFunc(h, namew);
+
+ return SUCCEEDED(hr);
+}
+
void qemu_thread_create(QemuThread *thread, const char *name,
void *(*start_routine)(void *),
void *arg, int mode)
if (!hThread) {
error_exit(GetLastError(), __func__);
}
+ if (name_threads && name && !set_thread_description(hThread, name)) {
+ fprintf(stderr, "qemu: failed to set thread description: %s\n", name);
+ }
CloseHandle(hThread);
+
thread->data = data;
}
+int qemu_thread_set_affinity(QemuThread *thread, unsigned long *host_cpus,
+ unsigned long nbits)
+{
+ return -ENOSYS;
+}
+
+int qemu_thread_get_affinity(QemuThread *thread, unsigned long **host_cpus,
+ unsigned long *nbits)
+{
+ return -ENOSYS;
+}
+
void qemu_thread_get_self(QemuThread *thread)
{
thread->data = qemu_thread_data;
projects / mirror_qemu.git / blobdiff