FreeRDP/winpr/libwinpr/thread/apc.c
David Fort aeba30a505 winpr: correctly implement APC
This patch implements APC functions and fixes waitable timers with completions.
2021-04-07 08:15:16 +02:00

245 lines
5.0 KiB
C

/**
* FreeRDP: A Remote Desktop Protocol Implementation
* APC implementation
*
* Copyright 2021 David Fort <contact@hardening-consulting.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef _WIN32
#include "apc.h"
#include "thread.h"
#include "../log.h"
#include "../synch/pollset.h"
#define TAG WINPR_TAG("apc")
BOOL apc_init(APC_QUEUE* apc)
{
pthread_mutexattr_t attr;
BOOL ret = FALSE;
pthread_mutexattr_init(&attr);
if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) != 0)
{
WLog_ERR(TAG, "failed to initialize mutex attributes to recursive");
return FALSE;
}
memset(apc, 0, sizeof(*apc));
if (pthread_mutex_init(&apc->mutex, &attr) != 0)
{
WLog_ERR(TAG, "failed to initialize main thread APC mutex");
goto out;
}
ret = TRUE;
out:
pthread_mutexattr_destroy(&attr);
return ret;
}
BOOL apc_uninit(APC_QUEUE* apc)
{
return pthread_mutex_destroy(&apc->mutex) == 0;
}
void apc_register(WINPR_THREAD* thread, WINPR_APC_ITEM* addItem)
{
WINPR_APC_ITEM** nextp;
APC_QUEUE* apc = &thread->apc;
pthread_mutex_lock(&apc->mutex);
if (apc->tail)
{
nextp = &apc->tail->next;
addItem->last = apc->tail;
}
else
{
nextp = &apc->head;
}
*nextp = addItem;
apc->tail = addItem;
apc->length++;
addItem->markedForRemove = FALSE;
addItem->boundThread = GetCurrentThreadId();
addItem->linked = TRUE;
pthread_mutex_unlock(&apc->mutex);
}
static INLINE void apc_item_remove(APC_QUEUE* apc, WINPR_APC_ITEM* item)
{
if (!item->last)
apc->head = item->next;
else
item->last->next = item->next;
if (!item->next)
apc->tail = item->last;
else
item->next->last = item->last;
apc->length--;
}
APC_REMOVE_RESULT apc_remove(WINPR_APC_ITEM* item)
{
WINPR_THREAD* thread = winpr_GetCurrentThread();
APC_QUEUE* apc;
APC_REMOVE_RESULT ret = APC_REMOVE_OK;
if (!item->linked)
return APC_REMOVE_OK;
if (item->boundThread != GetCurrentThreadId())
{
WLog_ERR(TAG, "removing an APC entry should be done in the creating thread");
return APC_REMOVE_ERROR;
}
if (!thread)
{
WLog_ERR(TAG, "unable to retrieve current thread");
return APC_REMOVE_ERROR;
}
apc = &thread->apc;
pthread_mutex_lock(&apc->mutex);
if (apc->treatingCompletions)
{
item->markedForRemove = TRUE;
ret = APC_REMOVE_DELAY_FREE;
goto out;
}
apc_item_remove(apc, item);
out:
pthread_mutex_unlock(&apc->mutex);
item->boundThread = 0xFFFFFFFF;
item->linked = FALSE;
return ret;
}
BOOL apc_collectFds(WINPR_THREAD* thread, WINPR_POLL_SET* set, BOOL* haveAutoSignaled)
{
WINPR_APC_ITEM* item;
BOOL ret = FALSE;
APC_QUEUE* apc = &thread->apc;
*haveAutoSignaled = FALSE;
pthread_mutex_lock(&apc->mutex);
item = apc->head;
for (; item; item = item->next)
{
if (item->alwaysSignaled)
*haveAutoSignaled = TRUE;
else if (!pollset_add(set, item->pollFd, item->pollMode))
goto out;
}
ret = TRUE;
out:
pthread_mutex_unlock(&apc->mutex);
return ret;
}
int apc_executeCompletions(WINPR_THREAD* thread, WINPR_POLL_SET* set, size_t idx)
{
APC_QUEUE* apc = &thread->apc;
WINPR_APC_ITEM *item, *nextItem;
int ret = 0;
pthread_mutex_lock(&apc->mutex);
apc->treatingCompletions = TRUE;
/* first pass to compute signaled items */
for (item = apc->head; item; item = item->next)
{
item->isSignaled = item->alwaysSignaled || pollset_isSignaled(set, idx);
if (!item->alwaysSignaled)
idx++;
}
/* second pass: run completions */
for (item = apc->head; item; item = nextItem)
{
if (item->isSignaled)
{
if (item->completion && !item->markedForRemove)
item->completion(item->completionArgs);
ret++;
}
nextItem = item->next;
if (item->markedForRemove)
{
apc_item_remove(apc, item);
if (item->markedForFree)
free(item);
}
}
/* third pass: to do final cleanup */
for (item = apc->head; item; item = nextItem)
{
nextItem = item->next;
if (item->markedForRemove)
{
apc_item_remove(apc, item);
if (item->markedForFree)
free(item);
}
}
apc->treatingCompletions = FALSE;
pthread_mutex_unlock(&apc->mutex);
return ret;
}
void apc_cleanupThread(WINPR_THREAD* thread)
{
WINPR_APC_ITEM* item;
WINPR_APC_ITEM* nextItem;
APC_QUEUE* apc = &thread->apc;
pthread_mutex_lock(&apc->mutex);
item = apc->head;
for (; item; item = nextItem)
{
nextItem = item->next;
if (item->type == APC_TYPE_HANDLE_FREE)
item->completion(item->completionArgs);
item->last = item->next = NULL;
item->linked = FALSE;
if (item->markedForFree)
free(item);
}
apc->head = apc->tail = NULL;
pthread_mutex_unlock(&apc->mutex);
}
#endif