From 05c1076ba2d1a68fe7f3a5ae618f786b8898d327 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 26 Sep 2005 18:32:28 +1000 Subject: Initial import. --- src/memalloc.c | 341 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 341 insertions(+) create mode 100644 src/memalloc.c (limited to 'src/memalloc.c') diff --git a/src/memalloc.c b/src/memalloc.c new file mode 100644 index 0000000..03ad4f7 --- /dev/null +++ b/src/memalloc.c @@ -0,0 +1,341 @@ +/* $NetBSD: memalloc.c,v 1.27 2003/01/22 20:36:04 dsl Exp $ */ + +/*- + * 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. + */ + +#include +#ifndef lint +#if 0 +static char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95"; +#else +__RCSID("$NetBSD: memalloc.c,v 1.27 2003/01/22 20:36:04 dsl Exp $"); +#endif +#endif /* not lint */ + +#include +#include + +#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(size_t nbytes) +{ + pointer p; + + p = malloc(nbytes); + if (p == NULL) + error("Out of space"); + return p; +} + + +/* + * Same for realloc. + */ + +pointer +ckrealloc(pointer p, size_t nbytes) +{ + p = realloc(p, nbytes); + if (p == NULL) + error("Out of space"); + return p; +} + + +/* + * Make a copy of a string in safe storage. + */ + +char * +savestr(const char *s) +{ + char *p = strdup(s); + if (!p) + error("Out of space"); + 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. + */ + +/* minimum size of a block */ +#define MINSIZE SHELL_ALIGN(504) + +struct stack_block { + struct stack_block *prev; + char space[MINSIZE]; +}; + +struct stack_block stackbase; +struct stack_block *stackp = &stackbase; +struct stackmark *markp; +char *stacknxt = stackbase.space; +size_t stacknleft = MINSIZE; +char *sstrend = stackbase.space + MINSIZE; +int herefd = -1; + +pointer +stalloc(size_t nbytes) +{ + char *p; + size_t aligned; + + aligned = SHELL_ALIGN(nbytes); + if (aligned > stacknleft) { + size_t len; + size_t blocksize; + struct stack_block *sp; + + blocksize = aligned; + if (blocksize < MINSIZE) + blocksize = MINSIZE; + len = sizeof(struct stack_block) - MINSIZE + blocksize; + if (len < blocksize) + error("Out of space"); + INTOFF; + sp = ckmalloc(len); + sp->prev = stackp; + stacknxt = sp->space; + stacknleft = blocksize; + sstrend = stacknxt + blocksize; + stackp = sp; + INTON; + } + p = stacknxt; + stacknxt += aligned; + stacknleft -= aligned; + return p; +} + + +void +stunalloc(pointer p) +{ +#ifdef DEBUG + if (!p || (stacknxt < (char *)p) || ((char *)p < stackp->space)) { + write(2, "stunalloc\n", 10); + abort(); + } +#endif + stacknleft += stacknxt - (char *)p; + stacknxt = p; +} + + + +void +setstackmark(struct stackmark *mark) +{ + mark->stackp = stackp; + mark->stacknxt = stacknxt; + mark->stacknleft = stacknleft; + mark->marknext = markp; + markp = mark; +} + + +void +popstackmark(struct stackmark *mark) +{ + struct stack_block *sp; + + INTOFF; + markp = mark->marknext; + while (stackp != mark->stackp) { + sp = stackp; + stackp = sp->prev; + ckfree(sp); + } + stacknxt = mark->stacknxt; + stacknleft = mark->stacknleft; + sstrend = mark->stacknxt + 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(void) +{ + size_t newlen; + + newlen = stacknleft * 2; + if (newlen < stacknleft) + error("Out of space"); + if (newlen < 128) + newlen += 128; + + if (stacknxt == stackp->space && stackp != &stackbase) { + struct stack_block *oldstackp; + struct stackmark *xmark; + struct stack_block *sp; + struct stack_block *prevstackp; + size_t grosslen; + + INTOFF; + oldstackp = stackp; + sp = stackp; + prevstackp = sp->prev; + grosslen = newlen + sizeof(struct stack_block) - MINSIZE; + sp = ckrealloc((pointer)sp, grosslen); + sp->prev = prevstackp; + stackp = sp; + stacknxt = sp->space; + stacknleft = newlen; + sstrend = sp->space + newlen; + + /* + * Stack marks pointing to the start of the old block + * must be relocated to point to the new block + */ + xmark = markp; + while (xmark != NULL && xmark->stackp == oldstackp) { + xmark->stackp = stackp; + xmark->stacknxt = stacknxt; + xmark->stacknleft = stacknleft; + xmark = xmark->marknext; + } + INTON; + } else { + char *oldspace = stacknxt; + int oldlen = stacknleft; + char *p = stalloc(newlen); + + /* free the space we just allocated */ + stacknxt = memcpy(p, oldspace, oldlen); + stacknleft += newlen; + } +} + +void +grabstackblock(size_t len) +{ + len = SHELL_ALIGN(len); + stacknxt += len; + stacknleft -= len; +} + +/* + * The following routines are somewhat easier to use than 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. + */ + +void * +growstackstr(void) +{ + size_t len = stackblocksize(); + if (herefd >= 0 && len >= 1024) { + xwrite(herefd, stackblock(), len); + return stackblock(); + } + growstackblock(); + return stackblock() + len; +} + +/* + * Called from CHECKSTRSPACE. + */ + +char * +makestrspace(size_t newlen, char *p) +{ + size_t len = p - stacknxt; + size_t size = stackblocksize(); + + for (;;) { + size_t nleft; + + size = stackblocksize(); + nleft = size - len; + if (nleft >= newlen) + break; + growstackblock(); + } + return stackblock() + len; +} + +char * +stnputs(const char *s, size_t n, char *p) +{ + p = makestrspace(n, p); + p = mempcpy(p, s, n); + return p; +} + +char * +stputs(const char *s, char *p) +{ + return stnputs(s, strlen(s), p); +} -- cgit 1.4.1