3a58934eb2
Use InitializeCriticalSectionAndSpinCount instead of IntializeCriticalSection. Using spin counts for critical sections of short duration enables the calling thread to avoid the wait operation in most situations which can dramatically improve the overall performance on multiprocessor systems. On Linux this change has no effect because the new winpr critical section implementation does not use the SpinCount field under Linux because the NPTL synchronization primitives are implemented using the extremely performant futex system calls which have this magic already built in. However, on Mac OS X this change improved the overall performance of the multithreaded RemoteFX decoder by 25 percent. I've used a SpinCount of 4000 which avoided 99 percent of the wait calls. This value is also used by Microsoft's heap manager for its per-heap critical sections. Note: This change requires pull request #1397 to be merged.
178 lines
3.1 KiB
C
178 lines
3.1 KiB
C
/**
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* WinPR: Windows Portable Runtime
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* System.Collections.Stack
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*
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* Copyright 2012 Marc-Andre Moreau <marcandre.moreau@gmail.com>
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include <winpr/collections.h>
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/**
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* C equivalent of the C# Stack Class:
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* http://msdn.microsoft.com/en-us/library/system.collections.stack.aspx
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*/
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/**
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* Properties
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*/
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/**
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* Gets the number of elements contained in the Stack.
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*/
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int Stack_Count(wStack* stack)
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{
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if (stack->synchronized)
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{
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}
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return 0;
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}
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/**
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* Gets a value indicating whether access to the Stack is synchronized (thread safe).
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*/
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BOOL Stack_IsSynchronized(wStack* stack)
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{
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return stack->synchronized;
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}
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/**
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* Methods
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*/
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/**
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* Removes all objects from the Stack.
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*/
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void Stack_Clear(wStack* stack)
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{
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}
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/**
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* Determines whether an element is in the Stack.
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*/
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BOOL Stack_Contains(wStack* stack, void* obj)
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{
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return FALSE;
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}
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/**
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* Inserts an object at the top of the Stack.
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*/
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void Stack_Push(wStack* stack, void* obj)
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{
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if (stack->synchronized)
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EnterCriticalSection(&stack->lock);
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if ((stack->size + 1) >= stack->capacity)
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{
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stack->capacity *= 2;
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stack->array = (void**) realloc(stack->array, sizeof(void*) * stack->capacity);
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}
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stack->array[(stack->size)++] = obj;
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if (stack->synchronized)
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LeaveCriticalSection(&stack->lock);
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}
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/**
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* Removes and returns the object at the top of the Stack.
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*/
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void* Stack_Pop(wStack* stack)
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{
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void* obj = NULL;
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if (stack->synchronized)
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EnterCriticalSection(&stack->lock);
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if (stack->size > 0)
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obj = stack->array[--(stack->size)];
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if (stack->synchronized)
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LeaveCriticalSection(&stack->lock);
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return obj;
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}
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/**
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* Returns the object at the top of the Stack without removing it.
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*/
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void* Stack_Peek(wStack* stack)
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{
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void* obj = NULL;
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if (stack->synchronized)
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EnterCriticalSection(&stack->lock);
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if (stack->size > 0)
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obj = stack->array[stack->size];
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if (stack->synchronized)
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LeaveCriticalSection(&stack->lock);
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return obj;
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}
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/**
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* Construction, Destruction
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*/
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wStack* Stack_New(BOOL synchronized)
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{
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wStack* stack = NULL;
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stack = (wStack*) malloc(sizeof(wStack));
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if (stack)
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{
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stack->synchronized = synchronized;
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if (stack->synchronized)
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InitializeCriticalSectionAndSpinCount(&stack->lock, 4000);
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stack->size = 0;
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stack->capacity = 32;
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stack->array = (void**) malloc(sizeof(void*) * stack->capacity);
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}
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return stack;
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}
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void Stack_Free(wStack* stack)
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{
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if (stack)
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{
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if (stack->synchronized)
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DeleteCriticalSection(&stack->lock);
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free(stack->array);
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free(stack);
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}
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}
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