diff options
author | marcel <marcel@FreeBSD.org> | 2003-02-24 08:07:05 +0000 |
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committer | marcel <marcel@FreeBSD.org> | 2003-02-24 08:07:05 +0000 |
commit | 373501e7698edb87caaa1fd8a3d346c402e6a263 (patch) | |
tree | 3425f7c8a22e2648be9c0b364b854a32e438ec8c /bin/sh/memalloc.c | |
parent | 46e9534a1104c1180ef23cf7a272df465cdc02ba (diff) | |
download | FreeBSD-src-373501e7698edb87caaa1fd8a3d346c402e6a263.zip FreeBSD-src-373501e7698edb87caaa1fd8a3d346c402e6a263.tar.gz |
Third attempt at removing machdep.h and using ALIGN from <sys/param.h>.
The initial stack_block is staticly allocated and will be aligned
according to the alignment requirements of pointers, which does not
necessarily match the alignment enforced by ALIGN. To solve this a
more involved change is required: remove the static initial stack
and deal with an initial condition of not having a stack at all. This
change is therefore more risky than the previous ones, but unavoidable
(other than not using the platform default alignment).
Discussed with: tjr
Approved and reviewed by: tjr
Tested on: alpha, i386, ia64 and sparc64
Diffstat (limited to 'bin/sh/memalloc.c')
-rw-r--r-- | bin/sh/memalloc.c | 101 |
1 files changed, 53 insertions, 48 deletions
diff --git a/bin/sh/memalloc.c b/bin/sh/memalloc.c index a50d661..cfe087e 100644 --- a/bin/sh/memalloc.c +++ b/bin/sh/memalloc.c @@ -42,11 +42,11 @@ static char sccsid[] = "@(#)memalloc.c 8.3 (Berkeley) 5/4/95"; #include <sys/cdefs.h> __FBSDID("$FreeBSD$"); +#include <sys/param.h> #include "shell.h" #include "output.h" #include "memalloc.h" #include "error.h" -#include "machdep.h" #include "mystring.h" #include "expand.h" #include <stdlib.h> @@ -100,27 +100,47 @@ savestr(char *s) * 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. + * The size 496 was chosen because with 16-byte alignment the total size + * for the allocated block is 512. */ -#define MINSIZE 504 /* minimum size of a block */ +#define MINSIZE 496 /* minimum size of a block. */ struct stack_block { struct stack_block *prev; - char space[MINSIZE]; + /* Data follows */ }; +#define SPACE(sp) ((char*)(sp) + ALIGN(sizeof(struct stack_block))) -struct stack_block stackbase; -struct stack_block *stackp = &stackbase; +struct stack_block *stackp; struct stackmark *markp; -char *stacknxt = stackbase.space; -int stacknleft = MINSIZE; +char *stacknxt; +int stacknleft; int sstrnleft; int herefd = -1; +static void +stnewblock(int nbytes) +{ + struct stack_block *sp; + int allocsize; + + if (nbytes < MINSIZE) + nbytes = MINSIZE; + + allocsize = ALIGN(sizeof(struct stack_block)) + ALIGN(nbytes); + + INTOFF; + sp = ckmalloc(allocsize); + sp->prev = stackp; + stacknxt = SPACE(sp); + stacknleft = allocsize - (stacknxt - (char*)sp); + stackp = sp; + INTON; +} + pointer stalloc(int nbytes) @@ -128,22 +148,8 @@ stalloc(int nbytes) 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; - } + if (nbytes > stacknleft) + stnewblock(nbytes); p = stacknxt; stacknxt += nbytes; stacknleft -= nbytes; @@ -212,41 +218,40 @@ growstackblock(void) int oldlen; struct stack_block *sp; struct stack_block *oldstackp; + struct stackmark *xmark; - newlen = ALIGN(stacknleft * 2 + 100); + newlen = (stacknleft == 0) ? MINSIZE : stacknleft * 2 + 100; + newlen = ALIGN(newlen); oldspace = stacknxt; oldlen = stacknleft; - if (stacknxt == stackp->space && stackp != &stackbase) { + if (stackp != NULL && stacknxt == SPACE(stackp)) { INTOFF; oldstackp = stackp; - sp = stackp; - stackp = sp->prev; - sp = ckrealloc((pointer)sp, sizeof(struct stack_block) - - MINSIZE + newlen); + stackp = oldstackp->prev; + sp = ckrealloc((pointer)oldstackp, newlen); sp->prev = stackp; stackp = sp; - stacknxt = sp->space; - stacknleft = newlen; - { - /* Stack marks pointing to the start of the old block - * must be relocated to point to the new block - */ - struct stackmark *xmark; - xmark = markp; - while (xmark != NULL && xmark->stackp == oldstackp) { - xmark->stackp = stackp; - xmark->stacknxt = stacknxt; - xmark->stacknleft = stacknleft; - xmark = xmark->marknext; - } + stacknxt = SPACE(sp); + stacknleft = newlen - (stacknxt - (char*)sp); + + /* + * 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 { p = stalloc(newlen); - memcpy(p, oldspace, oldlen); - stacknxt = p; /* free the space */ - stacknleft += newlen; /* we just allocated */ + if (oldlen != 0) + memcpy(p, oldspace, oldlen); + stunalloc(p); } } |