Date: Wed, 28 May 2003 10:24:58 +0300 From: Petri Helenius <pete@he.iki.fi> To: Daniel Eischen <eischen@pcnet5.pcnet.com> Cc: freebsd-threads@freebsd.org Subject: Re: malloc(): error: recursive call Message-ID: <3ED4644A.6050401@he.iki.fi> In-Reply-To: <Pine.GSO.4.10.10305271924010.1039-100000@pcnet5.pcnet.com> References: <Pine.GSO.4.10.10305271924010.1039-100000@pcnet5.pcnet.com>
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Alright, here goes:
(it's ugly cut&paste with inadequate includes and stuff but fails as
expected)
Uncomment the "extra" mutexes and it runs fine.
Complied with:
gcc -g -O2 -march=pentium -D_REENTRANT -D_THREAD_SAFE -Wall -Wshadow
-Wpointer-arith -Wcast-align -Wwrite-strings -Wconversion
-Waggregate-return -Wstrict-prototypes -Wno-format -pedantic
-Wno-long-long -c ttest.c
gcc -static -g -O2 -march=pentium -D_REENTRANT -D_THREAD_SAFE -Wall
-Wshadow -Wpointer-arith -Wcast-align -Wwrite-strings -Wconversion
-Waggregate-return -Wstrict-prototypes -Wno-format -pedantic
-Wno-long-long ttest.o -o ttest -lkse
libs: # ls -l /usr/lib/libkse*
-r--r--r-- 1 root wheel 229156 May 24 14:57 /usr/lib/libkse.a
lrwxr-xr-x 1 root wheel 11 May 24 14:57 /usr/lib/libkse.so ->
libkse.so.1
-r--r--r-- 1 root wheel 121048 May 24 14:57 /usr/lib/libkse.so.1
-r--r--r-- 1 root wheel 243042 May 24 14:57 /usr/lib/libkse_p.a
kernel:
FreeBSD kompak.vuokselantie10.fi 5.1-BETA FreeBSD 5.1-BETA #7: Sat May
24 10:49:11 GMT 2003
root@kompak.vuokselantie10.fi:/usr/src/sys/i386/compile/EMTEST i386
# ./ttest
free spin
free spin
free spin
free spin
free spin
free spin
free spin
free spin
free spin
free spin
free spin
alloc spin
free spin
ttest in free(): error: recursive call
Abort (core dumped)
and the code:
(has more stuff than it needs because it has some debugging built in)
#include <stdio.h>
#include <pthread.h>
#define SLOTS 100000
void rommon_mutex_lock (pthread_mutex_t *mutex, int line)
{
int retvalue;
int lastline;
while (retvalue = pthread_mutex_lock (mutex))
{
printf ("%d locking %lx failed, line %d
(holder:%d)\n",getpid(),mutex,line,lastline);
usleep (100000);
}
}
static pthread_mutex_t foom;
static char *foo[SLOTS];
live_poll_sharedmem()
{
while (1)
{
int i;
printf ("alloc spin\n");
for ( i = 0 ; i < SLOTS; i++)
{
/* rommon_mutex_lock (&foom,__LINE__);*/
if (!foo[i])
{
asprintf (&foo[i],"slot %d",i);
}
/* pthread_mutex_unlock (&foom);*/
}
}
}
main()
{
static pthread_t smem_thread;
pthread_mutexattr_t attr;
int i;
pthread_mutexattr_init (&attr);
pthread_mutexattr_settype (&attr,PTHREAD_MUTEX_ERRORCHECK);
pthread_mutex_init (&foom,&attr);
pthread_create (&smem_thread,NULL,&live_poll_sharedmem,0);
while (1)
{
printf ("free spin\n");
for ( i = 0; i < 100000; i++)
{
/* rommon_mutex_lock (&foom,__LINE__);*/
if (foo[i])
{
free (foo[i]);
foo[i] = NULL;
}
/* pthread_mutex_unlock (&foom);*/
}
}
}
Daniel Eischen wrote:
>On Wed, 28 May 2003, Petri Helenius wrote:
>
>
>
>>>And what does `ldd libnetsnmp.so.x`, `ldd libfoo.y`, show?
>>>
>>>
>>They give empty replies.
>>
>>
>>
>>>What is `ldd yourexecutable` show?
>>>
>>>
>>It?s usually linked static but if I remove the -static line it says:
>> libnetsnmp.so.5 => /usr/local/lib/libnetsnmp.so.5 (0x2807f000)
>> libcrypto.so.3 => /usr/lib/libcrypto.so.3 (0x280fe000)
>> libpcap.so.2 => /usr/lib/libpcap.so.2 (0x28209000)
>> libkse.so.1 => /usr/lib/libkse.so.1 (0x28225000)
>> libc.so.5 => /usr/lib/libc.so.5 (0x28246000)
>>
>>
>>
>>>malloc is thread safe and we've been using it fine
>>>with all our tests. I suspect you're using another
>>>library that is using libc_r or something.
>>>
>>>
>>malloc works for me with for example linuxthreads. So I do believe that
>>the the trigger for malloc locking works, however looking at the code,
>>spinlocks are implemented differently depending on which thread library is
>>linked in.
>>
>>
>
>Also, you do need a relatively recent kernel. There are
>a couple of flags in each thread's mailbox that the
>kernel needs to recognize. This change was committed
>to the kernel around April 21, 2003
>
>
>
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