diff options
author | Kurt Miller <kurt@cvs.openbsd.org> | 2009-11-09 00:18:29 +0000 |
---|---|---|
committer | Kurt Miller <kurt@cvs.openbsd.org> | 2009-11-09 00:18:29 +0000 |
commit | ad0592d657a970d3b3d8200773732a354fad0461 (patch) | |
tree | 2d36a0624d8d3c7fac96e04ac86511d85bbcc56f /lib/libc/stdio/findfp.c | |
parent | 13102e76b8d893f7a1f4a778cc16d5e67e719a12 (diff) |
Fix the handle locking in stdio to use flockfile/funlockfile
internally when and where required. Macros in <stdio.h> are updated
to automatically call the underlying functions when the process is
threaded to obtain the necessary locking. A private mutex is added
to protect __sglue, the internal list of FILE handles, and another
to protect the one-time initialization. Some routines in libc that
use getc() change to use getc_unlocked() as they're either protected
by their own lock or aren't thread-safe routines anyway.
committing on behalf of and okay guenther@ now that we have install
media space available.
Diffstat (limited to 'lib/libc/stdio/findfp.c')
-rw-r--r-- | lib/libc/stdio/findfp.c | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/lib/libc/stdio/findfp.c b/lib/libc/stdio/findfp.c index 2be93a56c74..63458b18afa 100644 --- a/lib/libc/stdio/findfp.c +++ b/lib/libc/stdio/findfp.c @@ -1,4 +1,4 @@ -/* $OpenBSD: findfp.c,v 1.11 2009/10/22 01:23:16 guenther Exp $ */ +/* $OpenBSD: findfp.c,v 1.12 2009/11/09 00:18:27 kurt Exp $ */ /*- * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. @@ -39,6 +39,7 @@ #include <string.h> #include "local.h" #include "glue.h" +#include "thread_private.h" int __sdidinit; @@ -54,6 +55,8 @@ int __sdidinit; static FILE usual[FOPEN_MAX - 3]; static struct __sfileext usualext[FOPEN_MAX - 3]; static struct glue uglue = { 0, FOPEN_MAX - 3, usual }; +static struct glue *lastglue = &uglue; +_THREAD_PRIVATE_MUTEX(__sfp_mutex); struct __sfileext __sFext[3]; FILE __sF[3] = { @@ -104,16 +107,25 @@ __sfp(void) if (!__sdidinit) __sinit(); - for (g = &__sglue;; g = g->next) { + + _THREAD_PRIVATE_MUTEX_LOCK(__sfp_mutex); + for (g = &__sglue; g != NULL; g = g->next) { for (fp = g->iobs, n = g->niobs; --n >= 0; fp++) if (fp->_flags == 0) goto found; - if (g->next == NULL && (g->next = moreglue(NDYNAMIC)) == NULL) - break; } - return (NULL); + + /* release lock while mallocing */ + _THREAD_PRIVATE_MUTEX_UNLOCK(__sfp_mutex); + if ((g = moreglue(NDYNAMIC)) == NULL) + return (NULL); + _THREAD_PRIVATE_MUTEX_LOCK(__sfp_mutex); + lastglue->next = g; + lastglue = g; + fp = g->iobs; found: fp->_flags = 1; /* reserve this slot; caller sets real flags */ + _THREAD_PRIVATE_MUTEX_UNLOCK(__sfp_mutex); fp->_p = NULL; /* no current pointer */ fp->_w = 0; /* nothing to read or write */ fp->_r = 0; @@ -143,8 +155,12 @@ f_prealloc(void) n = getdtablesize() - FOPEN_MAX + 20; /* 20 for slop. */ for (g = &__sglue; (n -= g->niobs) > 0 && g->next; g = g->next) /* void */; - if (n > 0) - g->next = moreglue(n); + if (n > 0 && ((g = moreglue(n)) != NULL)) { + _THREAD_PRIVATE_MUTEX_LOCK(__sfp_mutex); + lastglue->next = g; + lastglue = g; + _THREAD_PRIVATE_MUTEX_UNLOCK(__sfp_mutex); + } } /* @@ -168,12 +184,18 @@ _cleanup(void) void __sinit(void) { + _THREAD_PRIVATE_MUTEX(__sinit_mutex); int i; + _THREAD_PRIVATE_MUTEX_LOCK(__sinit_mutex); + if (__sdidinit) + goto out; /* bail out if caller lost the race */ for (i = 0; i < FOPEN_MAX - 3; i++) { _FILEEXT_SETUP(usual+i, usualext+i); } /* make sure we clean up on exit */ __atexit_register_cleanup(_cleanup); /* conservative */ __sdidinit = 1; +out: + _THREAD_PRIVATE_MUTEX_UNLOCK(__sinit_mutex); } |