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Diffstat (limited to 'libparc/examples/How To Create an Object Pool')
3 files changed, 242 insertions, 0 deletions
diff --git a/libparc/examples/How To Create an Object Pool/main.c b/libparc/examples/How To Create an Object Pool/main.c new file mode 100644 index 00000000..710d3d7c --- /dev/null +++ b/libparc/examples/How To Create an Object Pool/main.c @@ -0,0 +1,35 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * 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. + */ + +#include <stdio.h> +#include <stdlib.h> + +#include "parc_SimpleBufferPool.h" + +int +main(int argc, char *argv[argc]) +{ + PARCSimpleBufferPool *pool = parcSimpleBufferPool_Create(3, 10); + + PARCBuffer *buffer = parcSimpleBufferPool_GetInstance(pool); + parcBuffer_Release(&buffer); + + buffer = parcSimpleBufferPool_GetInstance(pool); + parcBuffer_Release(&buffer); + + parcSimpleBufferPool_Release(&pool); + + return 0; +} diff --git a/libparc/examples/How To Create an Object Pool/parc_SimpleBufferPool.c b/libparc/examples/How To Create an Object Pool/parc_SimpleBufferPool.c new file mode 100644 index 00000000..fbd71b6e --- /dev/null +++ b/libparc/examples/How To Create an Object Pool/parc_SimpleBufferPool.c @@ -0,0 +1,107 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * 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. + */ + +#include <stdio.h> + +#include <parc/algol/parc_Object.h> +#include <parc/algol/parc_DisplayIndented.h> +#include <parc/algol/parc_Memory.h> + +#include <parc/algol/parc_LinkedList.h> + +#include "parc_SimpleBufferPool.h" + +struct PARCSimpleBufferPool { + size_t bufferSize; + size_t limit; + PARCLinkedList *freeList; + PARCObjectDescriptor *descriptor; +}; + +static bool +_parcSimpleBufferPool_Destructor(PARCSimpleBufferPool **instancePtr) +{ + assertNotNull(instancePtr, "Parameter must be a non-null pointer to a PARCSimpleBufferPool pointer."); + + PARCSimpleBufferPool *pool = *instancePtr; + + parcLinkedList_Apply(pool->freeList, (void (*))parcObject_SetDescriptor, (const void *) &PARCBuffer_Descriptor); + + parcLinkedList_Release(&pool->freeList); + + return true; +} + +static bool +_parcSimpleBufferPool_BufferDestructor(PARCBuffer **bufferPtr) +{ + PARCBuffer *buffer = *bufferPtr; + *bufferPtr = 0; + + PARCSimpleBufferPool *bufferPool = parcObjectDescriptor_GetTypeState(parcObject_GetDescriptor(buffer)); + + if (bufferPool->limit > parcLinkedList_Size(bufferPool->freeList)) { + parcLinkedList_Append(bufferPool->freeList, buffer); + } else { + parcBuffer_Acquire(buffer); + parcObject_SetDescriptor(buffer, &parcObject_DescriptorName(PARCBuffer)); + parcBuffer_Release(&buffer); + } + + return false; +} + +parcObject_ImplementAcquire(parcSimpleBufferPool, PARCSimpleBufferPool); + +parcObject_ImplementRelease(parcSimpleBufferPool, PARCSimpleBufferPool); + +parcObject_Override(PARCSimpleBufferPool, PARCObject, + .destructor = (PARCObjectDestructor *) _parcSimpleBufferPool_Destructor); + +PARCSimpleBufferPool * +parcSimpleBufferPool_Create(size_t limit, size_t bufferSize) +{ + PARCSimpleBufferPool *result = parcObject_CreateInstance(PARCSimpleBufferPool); + + if (result != NULL) { + result->limit = limit; + result->bufferSize = bufferSize; + result->freeList = parcLinkedList_Create(); + + char *string; + asprintf(&string, "PARCSimpleBufferPool=%zu", bufferSize); + result->descriptor = parcObjectDescriptor_CreateExtension(&parcObject_DescriptorName(PARCBuffer), string); + free(string); + result->descriptor->destructor = (PARCObjectDestructor *) _parcSimpleBufferPool_BufferDestructor; + result->descriptor->typeState = (PARCObjectTypeState *) result; + } + + return result; +} + +PARCBuffer * +parcSimpleBufferPool_GetInstance(PARCSimpleBufferPool *bufferPool) +{ + PARCBuffer *result; + + if (parcLinkedList_Size(bufferPool->freeList) > 0) { + result = parcLinkedList_RemoveFirst(bufferPool->freeList); + } else { + result = parcBuffer_Allocate(bufferPool->bufferSize); + parcObject_SetDescriptor(result, bufferPool->descriptor); + } + + return result; +} diff --git a/libparc/examples/How To Create an Object Pool/parc_SimpleBufferPool.h b/libparc/examples/How To Create an Object Pool/parc_SimpleBufferPool.h new file mode 100644 index 00000000..fe8ddf4a --- /dev/null +++ b/libparc/examples/How To Create an Object Pool/parc_SimpleBufferPool.h @@ -0,0 +1,100 @@ +/* + * Copyright (c) 2017 Cisco and/or its affiliates. + * 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. + */ + +/** + * @file parc_BufferPool.h + * @brief <#Brief Description#> + * + * <#Detailed Description#> + * + */ +#ifndef PARCLibrary_parc_BufferPool +#define PARCLibrary_parc_BufferPool +#include <stdbool.h> + +#include <parc/algol/parc_Object.h> + +parcObject_Declare(PARCSimpleBufferPool); + +/** + * Increase the number of references to a `PARCBufferPool` instance. + * + * Note that new `PARCBufferPool` is not created, + * only that the given `PARCBufferPool` reference count is incremented. + * Discard the reference by invoking `parcSimpleBufferPool_Release`. + * + * @param [in] instance A pointer to a valid PARCBufferPool instance. + * + * @return The same value as @p instance. + * + * Example: + * @code + * { + * PARCBufferPool *a = parcSimpleBufferPool_Create(); + * + * PARCBufferPool *b = parcSimpleBufferPool_Acquire(); + * + * parcSimpleBufferPool_Release(&a); + * parcSimpleBufferPool_Release(&b); + * } + * @endcode + */ +PARCSimpleBufferPool *parcSimpleBufferPool_Acquire(const PARCSimpleBufferPool *instance); + +/** + * Create an instance of PARCBufferPool + * + * <#Paragraphs Of Explanation#> + * + * @return non-NULL A pointer to a valid PARCBufferPool instance. + * @return NULL An error occurred. + * + * Example: + * @code + * { + * PARCBufferPool *a = parcSimpleBufferPool_Create(); + * + * parcSimpleBufferPool_Release(&a); + * } + * @endcode + */ +PARCSimpleBufferPool *parcSimpleBufferPool_Create(size_t highWater, size_t bufferSize); + +/** + * Release a previously acquired reference to the given `PARCBufferPool` instance, + * decrementing the reference count for the instance. + * + * The pointer to the instance is set to NULL as a side-effect of this function. + * + * If the invocation causes the last reference to the instance to be released, + * the instance is deallocated and the instance's implementation will perform + * additional cleanup and release other privately held references. + * + * @param [in,out] instancePtr A pointer to a pointer to the instance to release. + * + * Example: + * @code + * { + * PARCSimpleBufferPool *a = parcSimpleBufferPool_Create(); + * + * parcSimpleBufferPool_Release(&a); + * } + * @endcode + */ +void parcSimpleBufferPool_Release(PARCSimpleBufferPool **instancePtr); + +PARCBuffer *parcSimpleBufferPool_GetInstance(PARCSimpleBufferPool *bufferPool); + +#endif |