1/*********************************************************************** 2* * 3* This software is part of the ast package * 4* Copyright (c) 1985-2011 AT&T Intellectual Property * 5* and is licensed under the * 6* Eclipse Public License, Version 1.0 * 7* by AT&T Intellectual Property * 8* * 9* A copy of the License is available at * 10* http://www.eclipse.org/org/documents/epl-v10.html * 11* (with md5 checksum b35adb5213ca9657e911e9befb180842) * 12* * 13* Information and Software Systems Research * 14* AT&T Research * 15* Florham Park NJ * 16* * 17* Glenn Fowler <gsf@research.att.com> * 18* David Korn <dgk@research.att.com> * 19* Phong Vo <kpv@research.att.com> * 20* * 21***********************************************************************/ 22#pragma prototyped 23 24#include <ast.h> 25 26/* 27 * return small format buffer chunk of size n 28 * spin lock for thread access 29 * format buffers are short lived 30 * only one concurrent buffer with size > sizeof(buf) 31 */ 32 33static char buf[16 * 1024]; 34static char* nxt = buf; 35static int lck = -1; 36 37static char* big; 38static size_t bigsiz; 39 40char* 41fmtbuf(size_t n) 42{ 43 register char* cur; 44 45 while (++lck) 46 lck--; 47 if (n > (&buf[elementsof(buf)] - nxt)) 48 { 49 if (n > elementsof(buf)) 50 { 51 if (n > bigsiz) 52 { 53 bigsiz = roundof(n, 8 * 1024); 54 if (!(big = newof(big, char, bigsiz, 0))) 55 { 56 lck--; 57 return 0; 58 } 59 } 60 lck--; 61 return big; 62 } 63 nxt = buf; 64 } 65 cur = nxt; 66 nxt += n; 67 lck--; 68 return cur; 69} 70