diff options
Diffstat (limited to 'main/common/sbrk.c')
| -rw-r--r-- | main/common/sbrk.c | 133 |
1 files changed, 69 insertions, 64 deletions
diff --git a/main/common/sbrk.c b/main/common/sbrk.c index 8d55679..c7646c9 100644 --- a/main/common/sbrk.c +++ b/main/common/sbrk.c @@ -1,7 +1,7 @@ /************************************************************************** * * Copyright (c) 2013 Alcatel-Lucent - * + * * Alcatel Lucent licenses this file to You under the Apache License, * Version 2.0 (the "License"); you may not use this file except in * compliance with the License. A copy of the License is contained the @@ -20,7 +20,7 @@ * * sbrk.c: * - * Used by malloc to get memory from "somewhere". + * Used by malloc to get memory from "somewhere". * * Original author: Ed Sutter (ed.sutter@alcatel-lucent.com) * @@ -30,107 +30,112 @@ #include "genlib.h" #define NULL 0 -extern int releaseExtendedHeap(int); +extern int releaseExtendedHeap(int); static long allocbuf[ALLOCSIZE/sizeof(long)]; static char *allocp1; static char *ext_heapbase, *ext_heapspace, *ext_heapend; /* GetMemory(): - * This function is called by the guts of malloc when it needs to expand - * the size of the heap. Initially, GetMemory() will allocate memory - * from a static array (allocbuf[]) that is allocated memory space when the - * monitor is built. If the variable ext_heapbase is non-zero - * at the point when GetMemory() runs out of space in allocbuf[], it - * will start allocating memory from the block pointed to by ext_heapspase - * and ext_heapsize. - * WARNING: this feature can only be used if the malloc()/free() code - * can handle the fact that memory within its heap will be different - * blocks of non-contiguous space. + * This function is called by the guts of malloc when it needs to expand + * the size of the heap. Initially, GetMemory() will allocate memory + * from a static array (allocbuf[]) that is allocated memory space when the + * monitor is built. If the variable ext_heapbase is non-zero + * at the point when GetMemory() runs out of space in allocbuf[], it + * will start allocating memory from the block pointed to by ext_heapspase + * and ext_heapsize. + * WARNING: this feature can only be used if the malloc()/free() code + * can handle the fact that memory within its heap will be different + * blocks of non-contiguous space. */ char * GetMemory(int n) { - if (!allocp1) - allocp1 = (char *)allocbuf; - - /* First try to allocate from allocbuf[]... */ - if (allocp1 + n <= (char *)allocbuf + ALLOCSIZE) { - allocp1 += n; - return (allocp1 - n); - } - /* Else try to allocated from the extended heap (if one)... */ - else if (ext_heapbase) { - if (ext_heapspace + n <= ext_heapend) { - ext_heapspace += n; - return(ext_heapspace - n); - } - else { - return(NULL); - } - } - /* Else, no space left to allocate from. */ - else { - return (NULL); - } + if(!allocp1) { + allocp1 = (char *)allocbuf; + } + + /* First try to allocate from allocbuf[]... */ + if(allocp1 + n <= (char *)allocbuf + ALLOCSIZE) { + allocp1 += n; + return (allocp1 - n); + } + /* Else try to allocated from the extended heap (if one)... */ + else if(ext_heapbase) { + if(ext_heapspace + n <= ext_heapend) { + ext_heapspace += n; + return(ext_heapspace - n); + } else { + return(NULL); + } + } + /* Else, no space left to allocate from. */ + else { + return (NULL); + } } /* ExtendHeap(): - * Called by the heap command to provide GetMemory() with more space. - * This function can be called through the monitor API. + * Called by the heap command to provide GetMemory() with more space. + * This function can be called through the monitor API. */ int extendHeap(char *start, int size) { - /* If the size is -1, then assume this is a release request. */ - if (size == -1) - return(releaseExtendedHeap(0)); - - /* If extension is already loaded, then return -1 for failure. */ - if (ext_heapbase) - return(-1); - - if (inUmonBssSpace(start,start+size-1)) - return(-2); - - ext_heapbase = ext_heapspace = start; - ext_heapend = start + size; - return(0); + /* If the size is -1, then assume this is a release request. */ + if(size == -1) { + return(releaseExtendedHeap(0)); + } + + /* If extension is already loaded, then return -1 for failure. */ + if(ext_heapbase) { + return(-1); + } + + if(inUmonBssSpace(start,start+size-1)) { + return(-2); + } + + ext_heapbase = ext_heapspace = start; + ext_heapend = start + size; + return(0); } /* UnextendHeap(): - * Called by the heap command to "undo" the memory extension. + * Called by the heap command to "undo" the memory extension. */ void unExtendHeap(void) { - ext_heapbase = ext_heapspace = ext_heapend = 0; + ext_heapbase = ext_heapspace = ext_heapend = 0; } char * getExtHeapBase(void) { - return(ext_heapbase); + return(ext_heapbase); } /* GetMemoryLeft(): - * Return the amount of memory that has yet to be allocated from - * the static and extended heap (if one). + * Return the amount of memory that has yet to be allocated from + * the static and extended heap (if one). */ int GetMemoryLeft(void) { - int spaceleft; + int spaceleft; - if (!allocp1) - allocp1 = (char *)allocbuf; + if(!allocp1) { + allocp1 = (char *)allocbuf; + } - spaceleft = ((char *)allocbuf + ALLOCSIZE) - allocp1; + spaceleft = ((char *)allocbuf + ALLOCSIZE) - allocp1; - if (ext_heapbase) - spaceleft += (ext_heapend - ext_heapspace); + if(ext_heapbase) { + spaceleft += (ext_heapend - ext_heapspace); + } - return(spaceleft); + return(spaceleft); } #else @@ -138,7 +143,7 @@ GetMemoryLeft(void) int extendHeap(char *start, int size) { - return(-1); + return(-1); } #endif |