From e3cfc8ce61f788739c66445d903f8beacb40c93d Mon Sep 17 00:00:00 2001 From: rgrimes Date: Thu, 26 May 1994 06:18:55 +0000 Subject: BSD 4.4 Lite bin Sources --- bin/sh/memalloc.c | 292 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 292 insertions(+) create mode 100644 bin/sh/memalloc.c (limited to 'bin/sh/memalloc.c') diff --git a/bin/sh/memalloc.c b/bin/sh/memalloc.c new file mode 100644 index 0000000..5fa246a --- /dev/null +++ b/bin/sh/memalloc.c @@ -0,0 +1,292 @@ +/*- + * Copyright (c) 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Kenneth Almquist. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef lint +static char sccsid[] = "@(#)memalloc.c 8.1 (Berkeley) 5/31/93"; +#endif /* not lint */ + +#include "shell.h" +#include "output.h" +#include "memalloc.h" +#include "error.h" +#include "machdep.h" +#include "mystring.h" + +/* + * Like malloc, but returns an error when out of space. + */ + +pointer +ckmalloc(nbytes) { + register pointer p; + pointer malloc(); + + if ((p = malloc(nbytes)) == NULL) + error("Out of space"); + return p; +} + + +/* + * Same for realloc. + */ + +pointer +ckrealloc(p, nbytes) + register pointer p; + { + pointer realloc(); + + if ((p = realloc(p, nbytes)) == NULL) + error("Out of space"); + return p; +} + + +/* + * Make a copy of a string in safe storage. + */ + +char * +savestr(s) + char *s; + { + register char *p; + + p = ckmalloc(strlen(s) + 1); + scopy(s, p); + return p; +} + + +/* + * Parse trees for commands are allocated in lifo order, so we use a stack + * to make this more efficient, and also to avoid all sorts of exception + * handling code to handle interrupts in the middle of a parse. + * + * The size 504 was chosen because the Ultrix malloc handles that size + * well. + */ + +#define MINSIZE 504 /* minimum size of a block */ + + +struct stack_block { + struct stack_block *prev; + char space[MINSIZE]; +}; + +struct stack_block stackbase; +struct stack_block *stackp = &stackbase; +char *stacknxt = stackbase.space; +int stacknleft = MINSIZE; +int sstrnleft; +int herefd = -1; + + + +pointer +stalloc(nbytes) { + register char *p; + + nbytes = ALIGN(nbytes); + if (nbytes > stacknleft) { + int blocksize; + struct stack_block *sp; + + blocksize = nbytes; + if (blocksize < MINSIZE) + blocksize = MINSIZE; + INTOFF; + sp = ckmalloc(sizeof(struct stack_block) - MINSIZE + blocksize); + sp->prev = stackp; + stacknxt = sp->space; + stacknleft = blocksize; + stackp = sp; + INTON; + } + p = stacknxt; + stacknxt += nbytes; + stacknleft -= nbytes; + return p; +} + + +void +stunalloc(p) + pointer p; + { + if (p == NULL) { /*DEBUG */ + write(2, "stunalloc\n", 10); + abort(); + } + stacknleft += stacknxt - (char *)p; + stacknxt = p; +} + + + +void +setstackmark(mark) + struct stackmark *mark; + { + mark->stackp = stackp; + mark->stacknxt = stacknxt; + mark->stacknleft = stacknleft; +} + + +void +popstackmark(mark) + struct stackmark *mark; + { + struct stack_block *sp; + + INTOFF; + while (stackp != mark->stackp) { + sp = stackp; + stackp = sp->prev; + ckfree(sp); + } + stacknxt = mark->stacknxt; + stacknleft = mark->stacknleft; + INTON; +} + + +/* + * When the parser reads in a string, it wants to stick the string on the + * stack and only adjust the stack pointer when it knows how big the + * string is. Stackblock (defined in stack.h) returns a pointer to a block + * of space on top of the stack and stackblocklen returns the length of + * this block. Growstackblock will grow this space by at least one byte, + * possibly moving it (like realloc). Grabstackblock actually allocates the + * part of the block that has been used. + */ + +void +growstackblock() { + char *p; + int newlen = stacknleft * 2 + 100; + char *oldspace = stacknxt; + int oldlen = stacknleft; + struct stack_block *sp; + + if (stacknxt == stackp->space && stackp != &stackbase) { + INTOFF; + sp = stackp; + stackp = sp->prev; + sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - MINSIZE + newlen); + sp->prev = stackp; + stackp = sp; + stacknxt = sp->space; + stacknleft = newlen; + INTON; + } else { + p = stalloc(newlen); + bcopy(oldspace, p, oldlen); + stacknxt = p; /* free the space */ + stacknleft += newlen; /* we just allocated */ + } +} + + + +void +grabstackblock(len) { + len = ALIGN(len); + stacknxt += len; + stacknleft -= len; +} + + + +/* + * The following routines are somewhat easier to use that the above. + * The user declares a variable of type STACKSTR, which may be declared + * to be a register. The macro STARTSTACKSTR initializes things. Then + * the user uses the macro STPUTC to add characters to the string. In + * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is + * grown as necessary. When the user is done, she can just leave the + * string there and refer to it using stackblock(). Or she can allocate + * the space for it using grabstackstr(). If it is necessary to allow + * someone else to use the stack temporarily and then continue to grow + * the string, the user should use grabstack to allocate the space, and + * then call ungrabstr(p) to return to the previous mode of operation. + * + * USTPUTC is like STPUTC except that it doesn't check for overflow. + * CHECKSTACKSPACE can be called before USTPUTC to ensure that there + * is space for at least one character. + */ + + +char * +growstackstr() { + int len = stackblocksize(); + if (herefd >= 0 && len >= 1024) { + xwrite(herefd, stackblock(), len); + sstrnleft = len - 1; + return stackblock(); + } + growstackblock(); + sstrnleft = stackblocksize() - len - 1; + return stackblock() + len; +} + + +/* + * Called from CHECKSTRSPACE. + */ + +char * +makestrspace() { + int len = stackblocksize() - sstrnleft; + growstackblock(); + sstrnleft = stackblocksize() - len; + return stackblock() + len; +} + + + +void +ungrabstackstr(s, p) + char *s; + char *p; + { + stacknleft += stacknxt - s; + stacknxt = s; + sstrnleft = stacknleft - (p - s); +} -- cgit v1.1