unicorn/qemu/util/qemu-thread-win32.c
farmdve 036763d6ae Fix memory leaks as reported by DrMemory and Valgrind.
ARM and probably the rest of the arches have significant memory leaks as
they have no release interface.

Additionally, DrMemory does not have 64-bit support and thus I can't
test the 64-bit version under Windows. Under Linux valgrind supports
both 32-bit and 64-bit but there are different macros and code for Linux
and Windows.
2016-01-08 01:42:56 +02:00

396 lines
9.8 KiB
C

/*
* Win32 implementation for mutex/cond/thread functions
*
* Copyright Red Hat, Inc. 2010
*
* Author:
* Paolo Bonzini <pbonzini@redhat.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu-common.h"
#include "qemu/thread.h"
#include <process.h>
#include <assert.h>
#include <limits.h>
#include "uc_priv.h"
static void error_exit(int err, const char *msg)
{
char *pstr;
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER,
NULL, err, 0, (LPTSTR)&pstr, 2, NULL);
fprintf(stderr, "qemu: %s: %s\n", msg, pstr);
LocalFree(pstr);
//abort();
}
void qemu_mutex_init(QemuMutex *mutex)
{
mutex->owner = 0;
InitializeCriticalSection(&mutex->lock);
}
void qemu_mutex_destroy(QemuMutex *mutex)
{
assert(mutex->owner == 0);
DeleteCriticalSection(&mutex->lock);
}
void qemu_mutex_lock(QemuMutex *mutex)
{
EnterCriticalSection(&mutex->lock);
/* Win32 CRITICAL_SECTIONs are recursive. Assert that we're not
* using them as such.
*/
assert(mutex->owner == 0);
mutex->owner = GetCurrentThreadId();
}
int qemu_mutex_trylock(QemuMutex *mutex)
{
int owned;
owned = TryEnterCriticalSection(&mutex->lock);
if (owned) {
assert(mutex->owner == 0);
mutex->owner = GetCurrentThreadId();
}
return !owned;
}
void qemu_mutex_unlock(QemuMutex *mutex)
{
assert(mutex->owner == GetCurrentThreadId());
mutex->owner = 0;
LeaveCriticalSection(&mutex->lock);
}
void qemu_cond_init(QemuCond *cond)
{
memset(cond, 0, sizeof(*cond));
cond->sema = CreateSemaphore(NULL, 0, LONG_MAX, NULL);
if (!cond->sema) {
error_exit(GetLastError(), __func__);
}
cond->continue_event = CreateEvent(NULL, /* security */
FALSE, /* auto-reset */
FALSE, /* not signaled */
NULL); /* name */
if (!cond->continue_event) {
error_exit(GetLastError(), __func__);
}
}
void qemu_cond_destroy(QemuCond *cond)
{
BOOL result;
result = CloseHandle(cond->continue_event);
if (!result) {
error_exit(GetLastError(), __func__);
}
cond->continue_event = 0;
result = CloseHandle(cond->sema);
if (!result) {
error_exit(GetLastError(), __func__);
}
cond->sema = 0;
}
void qemu_cond_signal(QemuCond *cond)
{
DWORD result;
/*
* Signal only when there are waiters. cond->waiters is
* incremented by pthread_cond_wait under the external lock,
* so we are safe about that.
*/
if (cond->waiters == 0) {
return;
}
/*
* Waiting threads decrement it outside the external lock, but
* only if another thread is executing pthread_cond_broadcast and
* has the mutex. So, it also cannot be decremented concurrently
* with this particular access.
*/
cond->target = cond->waiters - 1;
result = SignalObjectAndWait(cond->sema, cond->continue_event,
INFINITE, FALSE);
if (result == WAIT_ABANDONED || result == WAIT_FAILED) {
error_exit(GetLastError(), __func__);
}
}
void qemu_cond_broadcast(QemuCond *cond)
{
BOOLEAN result;
/*
* As in pthread_cond_signal, access to cond->waiters and
* cond->target is locked via the external mutex.
*/
if (cond->waiters == 0) {
return;
}
cond->target = 0;
result = ReleaseSemaphore(cond->sema, cond->waiters, NULL);
if (!result) {
error_exit(GetLastError(), __func__);
}
/*
* At this point all waiters continue. Each one takes its
* slice of the semaphore. Now it's our turn to wait: Since
* the external mutex is held, no thread can leave cond_wait,
* yet. For this reason, we can be sure that no thread gets
* a chance to eat *more* than one slice. OTOH, it means
* that the last waiter must send us a wake-up.
*/
WaitForSingleObject(cond->continue_event, INFINITE);
}
void qemu_cond_wait(QemuCond *cond, QemuMutex *mutex)
{
/*
* This access is protected under the mutex.
*/
cond->waiters++;
/*
* Unlock external mutex and wait for signal.
* NOTE: we've held mutex locked long enough to increment
* waiters count above, so there's no problem with
* leaving mutex unlocked before we wait on semaphore.
*/
qemu_mutex_unlock(mutex);
WaitForSingleObject(cond->sema, INFINITE);
/* Now waiters must rendez-vous with the signaling thread and
* let it continue. For cond_broadcast this has heavy contention
* and triggers thundering herd. So goes life.
*
* Decrease waiters count. The mutex is not taken, so we have
* to do this atomically.
*
* All waiters contend for the mutex at the end of this function
* until the signaling thread relinquishes it. To ensure
* each waiter consumes exactly one slice of the semaphore,
* the signaling thread stops until it is told by the last
* waiter that it can go on.
*/
if (InterlockedDecrement(&cond->waiters) == cond->target) {
SetEvent(cond->continue_event);
}
qemu_mutex_lock(mutex);
}
void qemu_sem_init(QemuSemaphore *sem, int init)
{
/* Manual reset. */
sem->sema = CreateSemaphore(NULL, init, LONG_MAX, NULL);
}
void qemu_sem_destroy(QemuSemaphore *sem)
{
CloseHandle(sem->sema);
}
void qemu_sem_post(QemuSemaphore *sem)
{
ReleaseSemaphore(sem->sema, 1, NULL);
}
int qemu_sem_timedwait(QemuSemaphore *sem, int ms)
{
int rc = WaitForSingleObject(sem->sema, ms);
if (rc == WAIT_OBJECT_0) {
return 0;
}
if (rc != WAIT_TIMEOUT) {
error_exit(GetLastError(), __func__);
}
return -1;
}
void qemu_sem_wait(QemuSemaphore *sem)
{
if (WaitForSingleObject(sem->sema, INFINITE) != WAIT_OBJECT_0) {
error_exit(GetLastError(), __func__);
}
}
void qemu_event_init(QemuEvent *ev, bool init)
{
/* Manual reset. */
ev->event = CreateEvent(NULL, TRUE, init, NULL);
}
void qemu_event_destroy(QemuEvent *ev)
{
CloseHandle(ev->event);
}
void qemu_event_set(QemuEvent *ev)
{
SetEvent(ev->event);
}
void qemu_event_reset(QemuEvent *ev)
{
ResetEvent(ev->event);
}
void qemu_event_wait(QemuEvent *ev)
{
WaitForSingleObject(ev->event, INFINITE);
}
struct QemuThreadData {
/* Passed to win32_start_routine. */
void *(*start_routine)(void *);
void *arg;
short mode;
/* Only used for joinable threads. */
bool exited;
void *ret;
CRITICAL_SECTION cs;
struct uc_struct *uc;
};
static unsigned __stdcall win32_start_routine(void *arg)
{
QemuThreadData *data = (QemuThreadData *) arg;
void *(*start_routine)(void *) = data->start_routine;
void *thread_arg = data->arg;
if (data->mode == QEMU_THREAD_DETACHED) {
data->uc->qemu_thread_data = NULL;
g_free(data);
data = NULL;
}
qemu_thread_exit(data->uc, start_routine(thread_arg));
abort();
}
void qemu_thread_exit(struct uc_struct *uc, void *arg)
{
QemuThreadData *data = uc->qemu_thread_data;
if (data) {
assert(data->mode != QEMU_THREAD_DETACHED);
data->ret = arg;
EnterCriticalSection(&data->cs);
data->exited = true;
LeaveCriticalSection(&data->cs);
}
_endthreadex(0);
}
void *qemu_thread_join(struct uc_struct *uc, QemuThread *thread)
{
QemuThreadData *data;
void *ret;
HANDLE handle;
data = thread->data;
if (!data) {
return NULL;
}
/*
* Because multiple copies of the QemuThread can exist via
* qemu_thread_get_self, we need to store a value that cannot
* leak there. The simplest, non racy way is to store the TID,
* discard the handle that _beginthreadex gives back, and
* get another copy of the handle here.
*/
handle = qemu_thread_get_handle(thread);
if (handle) {
WaitForSingleObject(handle, INFINITE);
CloseHandle(handle);
}
ret = data->ret;
assert(data->mode != QEMU_THREAD_DETACHED);
DeleteCriticalSection(&data->cs);
uc->qemu_thread_data = NULL;
g_free(data);
return ret;
}
int qemu_thread_create(struct uc_struct *uc, QemuThread *thread, const char *name,
void *(*start_routine)(void *),
void *arg, int mode)
{
HANDLE hThread;
struct QemuThreadData *data;
data = g_malloc(sizeof *data);
data->start_routine = start_routine;
data->arg = arg;
data->mode = mode;
data->exited = false;
data->uc = uc;
uc->qemu_thread_data = data;
if (data->mode != QEMU_THREAD_DETACHED) {
InitializeCriticalSection(&data->cs);
}
hThread = (HANDLE) _beginthreadex(NULL, 0, win32_start_routine,
data, 0, &thread->tid);
if (!hThread) {
error_exit(GetLastError(), __func__);
return -1;
}
CloseHandle(hThread);
thread->data = (mode == QEMU_THREAD_DETACHED) ? NULL : data;
return 0;
}
void qemu_thread_get_self(struct uc_struct *uc, QemuThread *thread)
{
thread->data = uc->qemu_thread_data;
thread->tid = GetCurrentThreadId();
}
HANDLE qemu_thread_get_handle(QemuThread *thread)
{
QemuThreadData *data;
HANDLE handle;
data = thread->data;
if (!data) {
return NULL;
}
assert(data->mode != QEMU_THREAD_DETACHED);
EnterCriticalSection(&data->cs);
if (!data->exited) {
handle = OpenThread(SYNCHRONIZE | THREAD_SUSPEND_RESUME, FALSE,
thread->tid);
} else {
handle = NULL;
}
LeaveCriticalSection(&data->cs);
return handle;
}
bool qemu_thread_is_self(QemuThread *thread)
{
return GetCurrentThreadId() == thread->tid;
}