Hi,
I have difficulty to get "pthread_create" to work from another thread.
When I execute the code; the output looks like this:
aps39-63-root# ./mysqlbackup -s test -v -X
...
2011-03-25.23:06:57 main::begin backup
2011-03-25.23:06:57 test@mysql main:pthread_create::<nr=0,thread=1129534518,handle=0>
2011-03-25.23:06:57 test@mysql dbwriter:start::<nr=0,thread=2,handle=0>
2011-03-25.23:06:57 test@mysql dbwriter:system:mysqldump --user=*** --single-transaction --routines --flush-logs test > /tmp/mysql.test:<nr=0,thread=2,handle=0>
2011-03-25.23:06:57 test@mysql main:pthread_create::<nr=0,thread=2,handle=0>
2011-03-25.23:06:57 test@mysql tsmwriter:start::<nr=1,thread=3,handle=0>
...
rc=to_tsm(in,p->handle,filespace,dir,file,application,username,dbrc,p->adsm_arch_or_back
2011-03-25.23:07:00 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
Memory fault(coredump)
aps39-63-root#
And If I debuging the corefile using gdb:
aps39-63-root# gdb -core core
HP gdb 6.1 for HP Itanium (32 or 64 bit) and target HP-UX 11iv2 and 11iv3.
Copyright 1986 - 2009 Free Software Foundation, Inc.
Hewlett-Packard Wildebeest 6.1 (based on GDB) is covered by the
GNU General Public License. Type "show copying" to see the conditions to
change it and/or distribute copies. Type "show warranty" for warranty/support.
Reading symbols from mysqlbackup...done.
Core was generated by `mysqlbackup'.
Program terminated with signal 11, Segmentation fault.
SEGV_MAPERR - Address not mapped to object
warning: Load module /opt/tivoli/tsm/client/icc64/icc/icclib/libicclib.so has been stripped.
Debugging information is not available.
warning: Load module /opt/tivoli/tsm/client/icc64/icc/osslib/libcrypto.so.0.9.7 has been stripped.
Debugging information is not available.
#0 0x4000000000016130:0 in to_tsm () at ../to_tsm.c:37
warning: Source file is more recent than executable mysqlbackup.
37 {
(gdb) quit
aps39-63-root#
The strange thing is that if I comment out the line where "pthread_create" is located,
which is later in the code to_tsm() function, the program works without core dump, and will print all the lines before the "pthread_create" command.!?
Here is an extract of the to_tsm() function
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <limits.h>
#include <time.h>
#include <pthread.h>
#include <unistd.h>
#include <libgen.h>
...
int16 to_tsm(int fd,dsUint32_t handle,char *filespace,char *dir,char *file,char *adsm_info,char *username,int *dbrc,int arch_or_back,dataelement *p)
{
(some variable declarations)
pthread_t threads;
pthread_attr_t attr;
printf("this works fine\n);
sleep(1);
pthread_attr_init(&attr);
printf("this works fine\n);
sleep(1);
#if defined(_OPEN_THREADS)
detached = PTHREAD_CREATE_JOINABLE
pthread_attr_setdetachstate(&attr, &detached);
#endif
printf("this works fine\n);
sleep(1);
pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
printf("this works fine\n);
sleep(1);
(some other stuffs, which is not relevant to show here)
printf("this works fine\n);
sleep(1);
threadrc=pthread_create( &threads, &attr, readinback, (void*)&r);
if(threadrc)
{
sprintf(msg,"failed, rc=%d",threadrc);
output(p,"to_tsm","pthread_create",msg,stderr);
}
(some other codes)
pthread_join( threads, (void **) &read_offset);
...
}
If I comment out the line in "red" text, the code will print all the lines before the "pthread_create", actually the complete code is working.
This code is working fine also on all other plattforms (SUN64 on x86/SPARC, AIX64, Linux 32/64).
Please help me to detect what is actually causing this failure..
The output from the code when the pthread_create is out-commented.
aps39-63-root# ./mysqlbackup -s test -v -X
...
2011-03-25.23:38:17 main::begin backup
2011-03-25.23:38:17 test@mysql main:pthread_create::<nr=0,thread=1129534518,handle=0>
2011-03-25.23:38:17 test@mysql main:pthread_create::<nr=0,thread=2,handle=0>
2011-03-25.23:38:17 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
2011-03-25.23:38:17 test@mysql tsmwriter:start::<nr=1,thread=3,handle=0>
...
2011-03-25.23:38:17 test@mysql dbwriter:start::<nr=0,thread=2,handle=0>
...
2011-03-25.23:38:17 test@mysql tsmwriter:to_tsm::<nr=1,thread=3,handle=1>
2011-03-25.23:38:17 test@mysql dbwriter:end:rc=0:<nr=0,thread=2,handle=0>
2011-03-25.23:38:17 test@mysql dbwriter:pthread_exit::<nr=0,thread=2,handle=0>
2011-03-25.23:38:18 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
2011-03-25.23:38:19 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
2011-03-25.23:38:20 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
rc=to_tsm(in,p->handle,filespace,dir,file,application,username,dbrc,p->adsm_arch_or_back
to_tsm(7,1,/mysql/test,/,/full,MySQL,root,0,66)
----
............
2011-03-25.23:38:21 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
............
2011-03-25.23:38:24 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
............
2011-03-25.23:38:25 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
............
2011-03-25.23:38:27 test@mysql main:while(running(1)>=parallel(1)):sleep(1):<nr=0,thread=2,handle=0>
this is working
...
2011-03-25.23:38:31 test@mysql tsmwriter:end::<nr=1,thread=3,handle=1>
...
2011-03-25.23:38:31 test@mysql tsmwriter:pthread_kill::<nr=1,thread=3,handle=1>
2011-03-25.23:38:31 test@mysql tsmwriter:pthread_exit::<nr=1,thread=3,handle=1>
2011-03-25.23:38:32 main:pthread_attr_destroy:
2011-03-25.23:38:32 main:pthread_join:
2011-03-25.23:38:32 main:pthread_join:
...
aps39-63-root#
Conclusion, I have difficulty to start a thread from a thread.
Please help me.
Regards Tomas
