FreeCalypso > hg > fc-selenite
diff src/nucleus/dmc.c @ 7:0f80e1e4dce4
src/nucleus: library C code import from FreeNucleus package
| author | Mychaela Falconia <falcon@freecalypso.org> |
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| date | Sun, 15 Jul 2018 20:57:33 +0000 |
| parents | |
| children |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/nucleus/dmc.c Sun Jul 15 20:57:33 2018 +0000 @@ -0,0 +1,1084 @@ +/*************************************************************************/ +/* */ +/* Copyright Mentor Graphics Corporation 2002 */ +/* All Rights Reserved. */ +/* */ +/* THIS WORK CONTAINS TRADE SECRET AND PROPRIETARY INFORMATION WHICH IS */ +/* THE PROPERTY OF MENTOR GRAPHICS CORPORATION OR ITS LICENSORS AND IS */ +/* SUBJECT TO LICENSE TERMS. */ +/* */ +/*************************************************************************/ + +/*************************************************************************/ +/* */ +/* FILE NAME VERSION */ +/* */ +/* dmc.c Nucleus PLUS 1.14 */ +/* */ +/* COMPONENT */ +/* */ +/* DM - Dynamic Memory Management */ +/* */ +/* DESCRIPTION */ +/* */ +/* This file contains the core routines for the Dynamic Memory */ +/* Management component. */ +/* */ +/* DATA STRUCTURES */ +/* */ +/* None */ +/* */ +/* FUNCTIONS */ +/* */ +/* DMC_Create_Memory_Pool Create a dynamic memory pool */ +/* DMC_Delete_Memory_Pool Delete a dynamic memory pool */ +/* DMC_Allocate_Memory Allocate a memory block from */ +/* a dynamic memory pool */ +/* DMC_Deallocate_Memory Deallocate a memory block */ +/* from a dynamic memory pool */ +/* DMC_Cleanup Cleanup on timeout or a */ +/* terminate condition */ +/* */ +/* DEPENDENCIES */ +/* */ +/* cs_extr.h Common Service functions */ +/* tc_extr.h Thread Control functions */ +/* dm_extr.h Partition functions */ +/* hi_extr.h History functions */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* 08-09-1993 Corrected pointer retrieval */ +/* loop, resulting in version 1.0a */ +/* 08-09-1993 Verified version 1.0a */ +/* 03-01-1994 Moved non-core functions into */ +/* supplemental files, changed */ +/* function interfaces to match */ +/* those in prototype, added */ +/* register options, changed */ +/* protection logic to reduce */ +/* overhead, resulting in */ +/* version 1.1 */ +/* */ +/* 03-18-1994 Verified version 1.1 */ +/* 04-17-1996 updated to version 1.2 */ +/* 03-24-1998 Released version 1.3. */ +/* 03-26-1999 Released 1.11m (new release */ +/* numbering scheme) */ +/* 04-17-2002 Released version 1.13m */ +/* 11-07-2002 Released version 1.14 */ +/*************************************************************************/ +#define NU_SOURCE_FILE + + +#include "cs_extr.h" /* Common service functions */ +#include "tc_extr.h" /* Thread control functions */ +#include "dm_extr.h" /* Dynamic memory functions */ +#include "hi_extr.h" /* History functions */ +#include "profiler.h" /* ProView interface */ + + +/* Define external inner-component global data references. */ + +extern CS_NODE *DMD_Created_Pools_List; +extern UNSIGNED DMD_Total_Pools; +extern TC_PROTECT DMD_List_Protect; + + +/* Define internal component function prototypes. */ + +VOID DMC_Cleanup(VOID *information); + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* DMC_Create_Memory_Pool */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function creates a dynamic memory pool and then places it */ +/* on the list of created dynamic memory pools. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* DMCE_Create_Memory_Pool Error checking shell */ +/* */ +/* CALLS */ +/* */ +/* CSC_Place_On_List Add node to linked-list */ +/* [HIC_Make_History_Entry] Make entry in history log */ +/* [TCT_Check_Stack] Stack checking function */ +/* TCT_Protect Data structure protect */ +/* TCT_Unprotect Un-protect data structure */ +/* */ +/* INPUTS */ +/* */ +/* pool_ptr Memory pool control block */ +/* pointer */ +/* name Memory pool name */ +/* start_address Starting address of the pool */ +/* pool_size Number of bytes in the pool */ +/* min_allocation Minimum allocation size */ +/* suspend_type Suspension type */ +/* */ +/* OUTPUTS */ +/* */ +/* NU_SUCCESS */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* 03-01-1994 Changed function interfaces to */ +/* match those in prototype, */ +/* added register options, */ +/* resulting in version 1.1 */ +/* */ +/* 03-18-1994 Verified version 1.1 */ +/* */ +/*************************************************************************/ +STATUS DMC_Create_Memory_Pool(NU_MEMORY_POOL *pool_ptr, CHAR *name, + VOID *start_address, UNSIGNED pool_size, + UNSIGNED min_allocation, OPTION suspend_type) +{ + +R1 DM_PCB *pool; /* Pool control block ptr */ +INT i; /* Working index variable */ +DM_HEADER *header_ptr; /* Partition block header ptr*/ +NU_SUPERV_USER_VARIABLES + + /* Switch to supervisor mode */ + NU_SUPERVISOR_MODE(); + + /* Move input pool pointer into internal pointer. */ + pool = (DM_PCB *) pool_ptr; + + +#ifdef NU_ENABLE_STACK_CHECK + + /* Call stack checking function to check for an overflow condition. */ + TCT_Check_Stack(); + +#endif + +#ifdef NU_ENABLE_HISTORY + + /* Make an entry that corresponds to this function in the system history + log. */ + HIC_Make_History_Entry(NU_CREATE_MEMORY_POOL_ID, (UNSIGNED) pool, + (UNSIGNED) start_address, (UNSIGNED) pool_size); + +#endif + + /* First, clear the partition pool ID just in case it is an old + pool control block. */ + pool -> dm_id = 0; + + /* Fill in the partition pool name. */ + for (i = 0; i < NU_MAX_NAME; i++) + pool -> dm_name[i] = name[i]; + + /* Convert the pool's size into something that is evenly divisible by + the sizeof an UNSIGNED data element. */ + pool_size = (pool_size/sizeof(UNSIGNED)) * sizeof(UNSIGNED); + + /* Save the starting address and size parameters in the dynamic memory + control block. */ + pool -> dm_start_address = start_address; + pool -> dm_pool_size = pool_size; + pool -> dm_min_allocation = + ((min_allocation + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) * + sizeof(UNSIGNED); + + /* Setup the dynamic memory pool suspension type. */ + if (suspend_type == NU_FIFO) + + /* FIFO suspension is selected, setup the flag accordingly. */ + pool -> dm_fifo_suspend = NU_TRUE; + else + + /* Priority suspension is selected. */ + pool -> dm_fifo_suspend = NU_FALSE; + + /* Clear the suspension list pointer. */ + pool -> dm_suspension_list = NU_NULL; + + /* Clear the number of tasks waiting on the dynamic memory pool. */ + pool -> dm_tasks_waiting = 0; + + /* Initialize link pointers. */ + pool -> dm_created.cs_previous = NU_NULL; + pool -> dm_created.cs_next = NU_NULL; + + /* Build a single block that has all of the memory. */ + header_ptr = (DM_HEADER *) start_address; + + /* Initialize the memory parameters. */ + pool -> dm_available = pool_size - (2 * DM_OVERHEAD); + pool -> dm_memory_list = header_ptr; + pool -> dm_search_ptr = header_ptr; + + /* Build the block header. */ + header_ptr -> dm_memory_pool = pool; + header_ptr -> dm_memory_free = NU_TRUE; + header_ptr -> dm_next_memory = (DM_HEADER *) + (((BYTE_PTR) header_ptr) + pool -> dm_available + DM_OVERHEAD); + header_ptr -> dm_previous_memory = header_ptr -> dm_next_memory; + + /* Build the small trailer block that prevents block merging when the + pool wraps around. Note that the list is circular so searching can + wrap across the physical end of the memory pool. */ + header_ptr = header_ptr -> dm_next_memory; + header_ptr -> dm_next_memory = (DM_HEADER *) start_address; + header_ptr -> dm_previous_memory = (DM_HEADER *) start_address; + header_ptr -> dm_memory_pool = pool; + header_ptr -> dm_memory_free = NU_FALSE; + + /* Initialize the protection structure. */ + pool -> dm_protect.tc_tcb_pointer = NU_NULL; + + /* Protect against access to the list of created memory pools. */ + TCT_Protect(&DMD_List_Protect); + + /* At this point the dynamic memory pool is completely built. The ID can + now be set and it can be linked into the created dynamic memory + pool list. */ + pool -> dm_id = DM_DYNAMIC_ID; + + /* Link the memory pool into the list of created memory pools and + increment the total number of pools in the system. */ + CSC_Place_On_List(&DMD_Created_Pools_List, &(pool -> dm_created)); + DMD_Total_Pools++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpMemoryPool(RT_PROF_CREATE_MEMORY_POOL,pool,RT_PROF_OK); +#endif /*INCLUDE_PROVIEW*/ + /* Release protection against access to the list of created memory + pools. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return successful completion. */ + return(NU_SUCCESS); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* DMC_Delete_Memory_Pool */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function deletes a dynamic memory pool and removes it from */ +/* the list of created memory pools. All tasks suspended on the */ +/* memory pool are resumed with the appropriate error status. */ +/* Note that this function does not free any memory associated with */ +/* either the pool area or the pool control block. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* DMCE_Delete_Memory_Pool Error checking shell */ +/* */ +/* CALLS */ +/* */ +/* CSC_Remove_From_List Remove node from list */ +/* [HIC_Make_History_Entry] Make entry in history log */ +/* TCC_Resume_Task Resume a suspended task */ +/* [TCT_Check_Stack] Stack checking function */ +/* TCT_Control_To_System Transfer control to system */ +/* TCT_Protect Protect created list */ +/* TCT_Set_Current_Protect Modify current protection */ +/* TCT_System_Protect Setup system protection */ +/* TCT_System_Unprotect Release system protection */ +/* TCT_Unprotect Release protection */ +/* */ +/* INPUTS */ +/* */ +/* pool_ptr Memory pool control block */ +/* pointer */ +/* */ +/* OUTPUTS */ +/* */ +/* NU_SUCCESS */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* 03-01-1994 Changed function interfaces to */ +/* match those in prototype, */ +/* added register options, changed */ +/* protection logic to reduce */ +/* overhead, resulting in */ +/* version 1.1 */ +/* */ +/* 03-18-1994 Verified version 1.1 */ +/* */ +/*************************************************************************/ +STATUS DMC_Delete_Memory_Pool(NU_MEMORY_POOL *pool_ptr) +{ + +R1 DM_PCB *pool; /* Pool control block ptr */ +DM_SUSPEND *suspend_ptr; /* Suspend block pointer */ +DM_SUSPEND *next_ptr; /* Next suspend block */ +STATUS preempt; /* Status for resume call */ +NU_SUPERV_USER_VARIABLES + + /* Switch to supervisor mode */ + NU_SUPERVISOR_MODE(); + + /* Move input pool pointer into internal pointer. */ + pool = (DM_PCB *) pool_ptr; + +#ifdef NU_ENABLE_STACK_CHECK + + /* Call stack checking function to check for an overflow condition. */ + TCT_Check_Stack(); + +#endif + +#ifdef NU_ENABLE_HISTORY + + /* Make an entry that corresponds to this function in the system history + log. */ + HIC_Make_History_Entry(NU_DELETE_MEMORY_POOL_ID, (UNSIGNED) pool, + (UNSIGNED) 0, (UNSIGNED) 0); + +#endif + + /* Protect against simultaneous access to the memory pool. */ + TCT_Protect(&(pool -> dm_protect)); + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpMemoryPool(RT_PROF_DELETE_MEMORY_POOL,pool,RT_PROF_OK); +#endif /*INCLUDE_PROVIEW*/ + /* Clear the memory pool ID. */ + pool -> dm_id = 0; + + /* Release protection. */ + TCT_Unprotect(); + + /* Protect against access to the list of created memory pools. */ + TCT_Protect(&DMD_List_Protect); + + /* Remove the memory pool from the list of created memory pools. */ + CSC_Remove_From_List(&DMD_Created_Pools_List, &(pool -> dm_created)); + + /* Decrement the total number of created memory pools. */ + DMD_Total_Pools--; + + /* Pickup the suspended task pointer list. */ + suspend_ptr = pool -> dm_suspension_list; + + /* Walk the chain task(s) currently suspended on the memory pool. */ + preempt = 0; + while (suspend_ptr) + { + + /* Protect against system access. */ + TCT_System_Protect(); + + /* Resume the suspended task. Insure that the status returned is + NU_POOL_DELETED. */ + suspend_ptr -> dm_return_pointer = NU_NULL; + suspend_ptr -> dm_return_status = NU_POOL_DELETED; + + /* Point to the next suspend structure in the link. */ + next_ptr = (DM_SUSPEND *) (suspend_ptr -> dm_suspend_link.cs_next); + + /* Resume the specified task. */ + preempt = preempt | + TCC_Resume_Task((NU_TASK *) suspend_ptr -> dm_suspended_task, + NU_MEMORY_SUSPEND); + + /* Determine if the next is the same as the current pointer. */ + if (next_ptr == pool -> dm_suspension_list) + + /* Clear the suspension pointer to signal the end of the list + traversal. */ + suspend_ptr = NU_NULL; + else + + /* Move the next pointer into the suspend block pointer. */ + suspend_ptr = next_ptr; + + /* Modify current protection. */ + TCT_Set_Current_Protect(&DMD_List_Protect); + + /* Clear the system protection. */ + TCT_System_Unprotect(); + } + + /* Determine if preemption needs to occur. */ + if (preempt) + + /* Transfer control to system to facilitate preemption. */ + TCT_Control_To_System(); + + /* Release protection against access to the list of created memory + pools. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return a successful completion. */ + return(NU_SUCCESS); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* DMC_Allocate_Memory */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function allocates memory from the specified dynamic memory */ +/* pool. If dynamic memory is currently available, this function */ +/* is completed immediately. Otherwise, if there is not enough */ +/* memory currently available, task suspension is possible. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* DMCE_Allocate_Memory Error checking shell */ +/* */ +/* CALLS */ +/* */ +/* CSC_Place_On_List Place on suspend list */ +/* [HIC_Make_History_Entry] Make entry in history log */ +/* TCC_Suspend_Task Suspend calling task */ +/* TCC_Task_Priority Pickup task priority */ +/* [TCT_Check_Stack] Stack checking function */ +/* TCT_Current_Thread Pickup current thread pointer*/ +/* TCT_Protect Protect memory pool */ +/* TCT_Set_Suspend_Protect Save suspend protection */ +/* TCT_System_Protect Protect system structures */ +/* TCT_Unprotect Release protection */ +/* TCT_Unprotect_Specific Release specific protection */ +/* */ +/* INPUTS */ +/* */ +/* pool_ptr Memory pool pointer */ +/* return_pointer Pointer to the destination */ +/* memory pointer */ +/* size Number of bytes requested */ +/* suspend Suspension option if full */ +/* */ +/* OUTPUTS */ +/* */ +/* NU_SUCCESS If service is successful */ +/* NU_NO_MEMORY Memory not available */ +/* NU_TIMEOUT If timeout on service */ +/* NU_POOL_DELETED If memory pool deleted */ +/* during suspension */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* 03-01-1994 Changed function interfaces to */ +/* match those in prototype, */ +/* added register options, changed */ +/* protection logic to reduce */ +/* overhead, resulting in */ +/* version 1.1 */ +/* */ +/* 03-18-1994 Verified version 1.1 */ +/* */ +/*************************************************************************/ +STATUS DMC_Allocate_Memory(NU_MEMORY_POOL *pool_ptr, VOID **return_pointer, + UNSIGNED size, UNSIGNED suspend) +{ + +R1 DM_PCB *pool; /* Pool control block ptr */ +R2 DM_SUSPEND *suspend_ptr; /* Pointer to suspend block */ +DM_SUSPEND suspend_block; /* Allocate suspension block */ +R4 DM_HEADER *memory_ptr; /* Pointer to memory */ +R3 DM_HEADER *new_ptr; /* New split block pointer */ +UNSIGNED free_size; /* Size of block found */ +TC_TCB *task; /* Task pointer */ +STATUS status; /* Completion status */ +NU_SUPERV_USER_VARIABLES + + /* Switch to supervisor mode */ + NU_SUPERVISOR_MODE(); + + /* Move input pool pointer into internal pointer. */ + pool = (DM_PCB *) pool_ptr; + + +#ifdef NU_ENABLE_STACK_CHECK + + /* Call stack checking function to check for an overflow condition. */ + TCT_Check_Stack(); + +#endif + +#ifdef NU_ENABLE_HISTORY + + /* Make an entry that corresponds to this function in the system history + log. */ + HIC_Make_History_Entry(NU_ALLOCATE_MEMORY_ID, (UNSIGNED) pool, + (UNSIGNED) return_pointer, (UNSIGNED) size); + +#endif + + /* Initialize the status as successful. */ + status = NU_SUCCESS; + + /* Adjust the request to a size evenly divisible by the number of bytes + in an UNSIGNED data element. Also, check to make sure it is of the + minimum size. */ + if (size < pool -> dm_min_allocation) + + /* Change size to the minimum allocation. */ + size = pool -> dm_min_allocation; + else + + /* Insure that size is a multiple of the UNSIGNED size. */ + size = + ((size + sizeof(UNSIGNED) - 1)/sizeof(UNSIGNED)) * sizeof(UNSIGNED); + + /* Protect against simultaneous access to the memory pool. */ + TCT_Protect(&(pool -> dm_protect)); + + /* Search the memory list for the first available block of memory that + satisfies the request. Note that blocks are merged during the + deallocation function. */ + memory_ptr = pool -> dm_search_ptr; + do + { + + /* Determine if the block is free and if it can satisfy the request. */ + if (memory_ptr -> dm_memory_free) + + /* Calculate the free block size. */ + free_size = (((BYTE_PTR) (memory_ptr -> dm_next_memory)) - + ((BYTE_PTR) memory_ptr)) - DM_OVERHEAD; + else + + /* There are no free bytes available. */ + free_size = 0; + + /* Determine if the search should continue. */ + if (free_size < size) + + /* Large enough block has not been found. Move the search + pointer to the next block. */ + memory_ptr = memory_ptr -> dm_next_memory; + } while((free_size < size) && (memory_ptr != pool -> dm_search_ptr)); + + /* Determine if the memory is available. */ + if (free_size >= size) + { + + /* A block that satisfies the request has been found. */ + + /* Determine if the block needs to be split. */ + if (free_size >= (size + DM_OVERHEAD + pool -> dm_min_allocation)) + { + + /* Yes, split the block. */ + new_ptr = (DM_HEADER *) (((BYTE_PTR) memory_ptr) + size + + DM_OVERHEAD); + + /* Mark the new block as free. */ + new_ptr -> dm_memory_free = NU_TRUE; + + /* Put the pool pointer into the new block. */ + new_ptr -> dm_memory_pool = pool; + + /* Build the necessary pointers. */ + new_ptr -> dm_previous_memory = memory_ptr; + new_ptr -> dm_next_memory = memory_ptr -> dm_next_memory; + (new_ptr -> dm_next_memory) -> dm_previous_memory = new_ptr; + memory_ptr -> dm_next_memory = new_ptr; + + /* Decrement the available byte count. */ + pool -> dm_available = pool -> dm_available - size - DM_OVERHEAD; + } + else + + /* Decrement the entire free size from the available bytes + count. */ + pool -> dm_available = pool -> dm_available - free_size; + + /* Mark the allocated block as not available. */ + memory_ptr -> dm_memory_free = NU_FALSE; + + /* Should the search pointer be moved? */ + if (pool -> dm_search_ptr == memory_ptr) + + /* Move the search pointer to the next free memory slot. */ + pool -> dm_search_ptr = memory_ptr -> dm_next_memory; + + /* Return a memory address to the caller. */ + *return_pointer = (VOID *) (((BYTE_PTR) memory_ptr) + DM_OVERHEAD); +#ifdef INCLUDE_PROVIEW + _RTProf_DumpMemoryPool(RT_PROF_ALLOCATE_MEMORY,pool,RT_PROF_OK); +#endif /*INCLUDE_PROVIEW*/ + } + else + { + + /* Enough dynamic memory is not available. Determine if suspension is + required. */ + if (suspend) + { + + /* Suspension is selected. */ + + /* Increment the number of tasks waiting. */ + pool -> dm_tasks_waiting++; + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpMemoryPool(RT_PROF_ALLOCATE_MEMORY,pool,RT_PROF_WAIT); +#endif /*INCLUDE_PROVIEW*/ + /* Setup the suspend block and suspend the calling task. */ + suspend_ptr = &suspend_block; + suspend_ptr -> dm_memory_pool = pool; + suspend_ptr -> dm_request_size = size; + suspend_ptr -> dm_suspend_link.cs_next = NU_NULL; + suspend_ptr -> dm_suspend_link.cs_previous = NU_NULL; + task = (TC_TCB *) TCT_Current_Thread(); + suspend_ptr -> dm_suspended_task = task; + + /* Determine if priority or FIFO suspension is associated with the + memory pool. */ + if (pool -> dm_fifo_suspend) + { + + /* FIFO suspension is required. Link the suspend block into + the list of suspended tasks on this memory pool. */ + CSC_Place_On_List((CS_NODE **) + &(pool -> dm_suspension_list), + &(suspend_ptr -> dm_suspend_link)); + } + else + { + + /* Get the priority of the current thread so the suspend block + can be placed in the appropriate place. */ + suspend_ptr -> dm_suspend_link.cs_priority = + TCC_Task_Priority(task); + + CSC_Priority_Place_On_List((CS_NODE **) + &(pool -> dm_suspension_list), + &(suspend_ptr -> dm_suspend_link)); + } + + /* Protect against system access. */ + TCT_System_Protect(); + + /* Save the list protection in preparation for suspension. */ + TCT_Set_Suspend_Protect(&(pool -> dm_protect)); + + /* Release protection of dynamic memory pool. */ + TCT_Unprotect_Specific(&(pool -> dm_protect)); + + /* Finally, suspend the calling task. Note that the suspension call + automatically clears the system protection. */ + TCC_Suspend_Task((NU_TASK *) task, NU_MEMORY_SUSPEND, + DMC_Cleanup, suspend_ptr, suspend); + + /* Pickup the return status. */ + status = suspend_ptr -> dm_return_status; + *return_pointer = suspend_ptr -> dm_return_pointer; + } + else + { + + /* No suspension requested. Simply return an error status. */ + status = NU_NO_MEMORY; + *return_pointer = NU_NULL; +#ifdef INCLUDE_PROVIEW + _RTProf_DumpMemoryPool(RT_PROF_ALLOCATE_MEMORY,pool,RT_PROF_FAIL); +#endif /*INCLUDE_PROVIEW*/ + } + } + + /* Release protection of the memory pool. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return the completion status. */ + return(status); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* DMC_Deallocate_Memory */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function deallocates a previously allocated dynamic memory */ +/* block. The deallocated dynamic memory block is merged with any */ +/* adjacent neighbors. This insures that there are no consecutive */ +/* blocks of free memory in the pool (makes the search easier!). */ +/* If there is a task waiting for dynamic memory, a determination */ +/* of whether or not the request can now be satisfied is made after */ +/* the deallocation is complete. */ +/* */ +/* CALLED BY */ +/* */ +/* Application */ +/* DMCE_Deallocate_Memory Error checking shell */ +/* */ +/* CALLS */ +/* */ +/* CSC_Remove_From_List Remove from suspend list */ +/* [HIC_Make_History_Entry] Make entry in history log */ +/* TCC_Resume_Task Resume a suspended task */ +/* [TCT_Check_Stack] Stack checking function */ +/* TCT_Control_To_System Transfer control to system */ +/* TCT_Set_Current_Protect Set current protection */ +/* TCT_System_Protect Protect system structures */ +/* TCT_System_Unprotect Release system protection */ +/* TCT_Protect Protect dynamic memory pool */ +/* TCT_Unprotect Release protection */ +/* */ +/* INPUTS */ +/* */ +/* memory Pointer to dynamic memory */ +/* */ +/* OUTPUTS */ +/* */ +/* NU_SUCCESS */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* 03-01-1994 Added register options, changed */ +/* protection logic to reduce */ +/* overhead, resulting in */ +/* version 1.1 */ +/* */ +/* 03-18-1994 Verified version 1.1 */ +/* */ +/*************************************************************************/ +STATUS DMC_Deallocate_Memory(VOID *memory) +{ + +R1 DM_PCB *pool; /* Pool pointer */ +R3 DM_SUSPEND *suspend_ptr; /* Pointer to suspend block */ +R2 DM_HEADER *header_ptr; /* Pointer to memory hdr */ +R4 DM_HEADER *new_ptr; /* New memory block pointer */ +UNSIGNED size; /* Suspended task request */ +UNSIGNED free_size; /* Amount of free bytes */ +STATUS preempt; /* Preemption flag */ +STATUS status; /* Completion status */ +NU_SUPERV_USER_VARIABLES + + /* Switch to supervisor mode */ + NU_SUPERVISOR_MODE(); + +#ifdef NU_ENABLE_STACK_CHECK + + /* Call stack checking function to check for an overflow condition. */ + TCT_Check_Stack(); + +#endif + +#ifdef NU_ENABLE_HISTORY + + /* Make an entry that corresponds to this function in the system history + log. */ + HIC_Make_History_Entry(NU_DEALLOCATE_MEMORY_ID, (UNSIGNED) memory, + (UNSIGNED) 0, (UNSIGNED) 0); + +#endif + + /* Initialize the status as successful. */ + status = NU_SUCCESS; + + /* Pickup the associated pool's pointer. It is inside the header of + each memory. */ + header_ptr = (DM_HEADER *) (((BYTE_PTR) memory) - DM_OVERHEAD); + pool = header_ptr -> dm_memory_pool; + + /* Protect against simultaneous access to the memory pool. */ + TCT_Protect(&(pool -> dm_protect)); + + /* Mark the memory as available. */ + header_ptr -> dm_memory_free = NU_TRUE; + + /* Adjust the available number of bytes. */ + pool -> dm_available = pool -> dm_available + + (((BYTE_PTR) (header_ptr -> dm_next_memory)) - + ((BYTE_PTR) header_ptr)) - DM_OVERHEAD; + + /* Determine if the block can be merged with the previous neighbor. */ + if ((header_ptr -> dm_previous_memory) -> dm_memory_free) + { + + /* Adjust the available number of bytes. */ + pool -> dm_available = pool -> dm_available + DM_OVERHEAD; + + /* Yes, merge block with previous neighbor. */ + (header_ptr -> dm_previous_memory) -> dm_next_memory = + header_ptr -> dm_next_memory; + (header_ptr -> dm_next_memory) -> dm_previous_memory = + header_ptr -> dm_previous_memory; + + /* Move header pointer to previous. */ + header_ptr = header_ptr -> dm_previous_memory; + + /* Adjust the search pointer to the new merged block. */ + pool -> dm_search_ptr = header_ptr; + } + + /* Determine if the block can be merged with the next neighbor. */ + if ((header_ptr -> dm_next_memory) -> dm_memory_free) + { + + /* Adjust the available number of bytes. */ + pool -> dm_available = pool -> dm_available + DM_OVERHEAD; + + /* Yes, merge block with next neighbor. */ + new_ptr = header_ptr -> dm_next_memory; + (new_ptr -> dm_next_memory) -> dm_previous_memory = + header_ptr; + header_ptr -> dm_next_memory = new_ptr -> dm_next_memory; + + /* Adjust the search pointer to the new merged block. */ + pool -> dm_search_ptr = header_ptr; + } + +#ifdef INCLUDE_PROVIEW + _RTProf_DumpMemoryPool(RT_PROF_DEALLOCATE_MEMORY,pool,RT_PROF_OK); +#endif /*INCLUDE_PROVIEW*/ + /* Determine if another task is waiting for memory from the pool. */ + suspend_ptr = pool -> dm_suspension_list; + preempt = 0; + while (suspend_ptr) + { + + /* Yes, another task is waiting for memory from the pool. Search + the pool in the same manner as the memory allocation function. */ + size = suspend_ptr -> dm_request_size; + header_ptr = pool -> dm_search_ptr; + do + { + + /* Determine if the block is free and if it can satisfy the request + of the first task waiting. */ + if (header_ptr -> dm_memory_free) + + /* Calculate the free block size. */ + free_size = (((BYTE_PTR) (header_ptr -> dm_next_memory)) - + ((BYTE_PTR) header_ptr)) - DM_OVERHEAD; + else + + /* There are no free bytes available. */ + free_size = 0; + + /* Determine if the search should continue. */ + if (free_size < size) + + /* Large enough block has not been found. Move the search + pointer to the next block. */ + header_ptr = header_ptr -> dm_next_memory; + } while((free_size < size) && (header_ptr != pool -> dm_search_ptr)); + + /* Determine if the memory is available. */ + if (free_size >= size) + { + + /* A block that satisfies the request has been found. */ + + /* Determine if the block needs to be split. */ + if (free_size >= (size + DM_OVERHEAD + pool -> dm_min_allocation)) + { + + /* Yes, split the block. */ + new_ptr = (DM_HEADER *) (((BYTE_PTR) header_ptr) + size + + DM_OVERHEAD); + + /* Mark the new block as free. */ + new_ptr -> dm_memory_free = NU_TRUE; + + /* Put the pool pointer into the new block. */ + new_ptr -> dm_memory_pool = pool; + + /* Build the necessary pointers. */ + new_ptr -> dm_previous_memory = header_ptr; + new_ptr -> dm_next_memory = header_ptr -> dm_next_memory; + (new_ptr -> dm_next_memory) -> dm_previous_memory = new_ptr; + header_ptr -> dm_next_memory = new_ptr; + + /* Decrement the available byte count. */ + pool -> dm_available = pool -> dm_available - + size - DM_OVERHEAD; + } + else + + /* Decrement the entire free size from the available bytes + count. */ + pool -> dm_available = pool -> dm_available - free_size; + + /* Mark the allocated block as not available. */ + header_ptr -> dm_memory_free = NU_FALSE; + + /* Should the search pointer be moved? */ + if (pool -> dm_search_ptr == header_ptr) + + /* Move the search pointer to the next free memory slot. */ + pool -> dm_search_ptr = header_ptr -> dm_next_memory; + + /* Decrement the number of tasks waiting counter. */ + pool -> dm_tasks_waiting--; + + /* Remove the first suspended block from the list. */ + CSC_Remove_From_List((CS_NODE **) &(pool -> dm_suspension_list), + &(suspend_ptr -> dm_suspend_link)); + + /* Setup the appropriate return value. */ + suspend_ptr -> dm_return_status = NU_SUCCESS; + suspend_ptr -> dm_return_pointer = (VOID *) + (((BYTE_PTR) header_ptr) + DM_OVERHEAD); + + /* Setup system protect while task is being resumed. */ + TCT_System_Protect(); + + /* Resume the suspended task. */ + preempt = preempt | + TCC_Resume_Task((NU_TASK *) suspend_ptr -> dm_suspended_task, + NU_MEMORY_SUSPEND); + + /* Switch back to the pool protection. */ + TCT_Set_Current_Protect(&(pool -> dm_protect)); + + /* Release system protection. */ + TCT_System_Unprotect(); + + /* Pickup the next suspension pointer. */ + suspend_ptr = pool -> dm_suspension_list; + } + else + + /* Not enough memory for suspended task. */ + suspend_ptr = NU_NULL; + } + + /* Determine if a preempt condition is present. */ + if (preempt) + + /* Transfer control to the system if the resumed task function + detects a preemption condition. */ + TCT_Control_To_System(); + + /* Release protection of the memory pool. */ + TCT_Unprotect(); + + /* Return to user mode */ + NU_USER_MODE(); + + /* Return the completion status. */ + return(status); +} + + +/*************************************************************************/ +/* */ +/* FUNCTION */ +/* */ +/* DMC_Cleanup */ +/* */ +/* DESCRIPTION */ +/* */ +/* This function is responsible for removing a suspension block */ +/* from a memory pool. It is not called unless a timeout or */ +/* a task terminate is in progress. Note that protection is */ +/* already in effect - the same protection at suspension time. */ +/* */ +/* CALLED BY */ +/* */ +/* TCC_Timeout Task timeout */ +/* TCC_Terminate Task terminate */ +/* */ +/* CALLS */ +/* */ +/* CSC_Remove_From_List Remove suspend block from */ +/* the suspension list */ +/* */ +/* INPUTS */ +/* */ +/* information Pointer to suspend block */ +/* */ +/* OUTPUTS */ +/* */ +/* None */ +/* */ +/* HISTORY */ +/* */ +/* DATE REMARKS */ +/* */ +/* 03-01-1993 Created initial version 1.0 */ +/* 04-19-1993 Verified version 1.0 */ +/* */ +/*************************************************************************/ +VOID DMC_Cleanup(VOID *information) +{ + +DM_SUSPEND *suspend_ptr; /* Suspension block pointer */ +NU_SUPERV_USER_VARIABLES + + /* Switch to supervisor mode */ + NU_SUPERVISOR_MODE(); + + /* Use the information pointer as a suspend pointer. */ + suspend_ptr = (DM_SUSPEND *) information; + + /* By default, indicate that the service timed-out. It really does not + matter if this function is called from a terminate request since + the task does not resume. */ + suspend_ptr -> dm_return_status = NU_TIMEOUT; + suspend_ptr -> dm_return_pointer = NU_NULL; + + /* Decrement the number of tasks waiting counter. */ + (suspend_ptr -> dm_memory_pool) -> dm_tasks_waiting--; + + /* Unlink the suspend block from the suspension list. */ + CSC_Remove_From_List((CS_NODE **) + &((suspend_ptr -> dm_memory_pool) -> dm_suspension_list), + &(suspend_ptr -> dm_suspend_link)); + + /* Return to user mode */ + NU_USER_MODE(); +} + + + + + + +