On Fri, Jan 16, 2009 at 01:14:28PM -0500, D. Richard Hipp wrote:
> > What do those mean? Are these errors a problem?
>
> These are simulated malloc() failures. They are important for
> embedded devices (which tend to run out of memory) but not so much on
> Solaris. When was the last time you remember that malloc() really
> failed on a workstation or a server?
That's what I expected, but you should know that on Solaris malloc() can
fail with ENOMEM. On Linux malloc() typically never fails, as Linux
takes the OOM killer approach.
> The errors you are getting seem to indicate that the memory allocation
> problems are simply not getting reported back up to the top-level.
> SQLite is able to complete whatever it was doing in spite of malloc()
> returning NULL. I do not know why. If you want to try to debug the
Is that a problem?
> problem, set a breakpoint on the routine "sqlite3Fault()" for the test
> case that is given a problem. The sqlite3Fault() routine is called
> whenever one of the simulated malloc() failures occurs. Then look at
> the stack to see where the problem is occurring.
Using DTrace I see lots of calls to sqlite3Fault(), so I used
speculative tracing to grab the stacktrace of sqlite3Fault() calls that
were followed by writes to stdout of "\nExpected: ..." and got these
stack traces for those test failures (DTrace script attached):
CPU ID FUNCTION:NAME
1 61477 sqlite3Fault:entry
testfixture`sqlite3Fault
testfixture`faultsimStep+0x27
testfixture`faultsimMalloc+0xe
testfixture`mallocWithAlarm+0x5d
testfixture`sqlite3Malloc+0x42
testfixture`sqlite3DbMallocRaw+0x70
testfixture`sqlite3DbMallocZero+0x14
testfixture`sqlite3FindFunction+0xca
testfixture`sqlite3CreateFunc+0x13c
testfixture`sqlite3_create_function+0x31
testfixture`sqlite3Fts3ExprInitTestInterface+0x22
testfixture`sqlite3Fts3Init+0x99
testfixture`openDatabase+0x320
testfixture`sqlite3_open_v2+0x18
testfixture`DbMain+0x2b1
libtcl8.4.so`TclEvalObjvInternal+0x200
libtcl8.4.so`TclExecuteByteCode+0x1199
libtcl8.4.so`TclCompEvalObj+0x112
libtcl8.4.so`Tcl_EvalObjEx+0x69
libtcl8.4.so`Tcl_CatchObjCmd+0x43
0 61477 sqlite3Fault:entry
testfixture`sqlite3Fault
testfixture`faultsimStep+0x27
testfixture`faultsimMalloc+0xe
testfixture`mallocWithAlarm+0x5d
testfixture`sqlite3Malloc+0x42
testfixture`sqlite3DbMallocRaw+0x70
testfixture`sqlite3DbMallocZero+0x14
testfixture`sqlite3FindFunction+0xca
testfixture`sqlite3CreateFunc+0x13c
testfixture`sqlite3_create_function+0x31
testfixture`sqlite3Fts3ExprInitTestInterface+0x22
testfixture`sqlite3Fts3Init+0x99
testfixture`openDatabase+0x320
testfixture`sqlite3_open_v2+0x18
testfixture`DbMain+0x2b1
libtcl8.4.so`TclEvalObjvInternal+0x200
libtcl8.4.so`TclExecuteByteCode+0x1199
libtcl8.4.so`TclCompEvalObj+0x112
libtcl8.4.so`Tcl_EvalObjEx+0x69
libtcl8.4.so`Tcl_CatchObjCmd+0x43
0 61477 sqlite3Fault:entry
testfixture`sqlite3Fault
testfixture`faultsimStep+0x27
testfixture`faultsimMalloc+0xe
testfixture`mallocWithAlarm+0x5d
testfixture`sqlite3Malloc+0x42
testfixture`sqlite3DbMallocRaw+0x70
testfixture`sqlite3DbMallocZero+0x14
testfixture`sqlite3FindFunction+0xca
testfixture`sqlite3CreateFunc+0x13c
testfixture`sqlite3_create_function+0x31
testfixture`sqlite3Fts3ExprInitTestInterface+0x22
testfixture`sqlite3Fts3Init+0x99
testfixture`openDatabase+0x320
testfixture`sqlite3_open16+0x51
testfixture`test_open16+0x2e
libtcl8.4.so`TclEvalObjvInternal+0x200
libtcl8.4.so`TclExecuteByteCode+0x1199
libtcl8.4.so`TclCompEvalObj+0x112
libtcl8.4.so`Tcl_EvalObjEx+0x69
libtcl8.4.so`Tcl_CatchObjCmd+0x43
0 61477 sqlite3Fault:entry
testfixture`sqlite3Fault
testfixture`faultsimStep+0x27
testfixture`faultsimMalloc+0xe
testfixture`mallocWithAlarm+0x5d
testfixture`sqlite3Malloc+0x42
testfixture`sqlite3DbMallocRaw+0x70
testfixture`sqlite3DbMallocZero+0x14
testfixture`sqlite3FindFunction+0xca
testfixture`sqlite3CreateFunc+0x13c
testfixture`sqlite3_create_function+0x31
testfixture`sqlite3Fts3ExprInitTestInterface+0x22
testfixture`sqlite3Fts3Init+0x99
testfixture`openDatabase+0x320
testfixture`sqlite3_open_v2+0x18
testfixture`DbMain+0x2b1
libtcl8.4.so`TclEvalObjvInternal+0x200
libtcl8.4.so`TclExecuteByteCode+0x1199
libtcl8.4.so`TclCompEvalObj+0x112
libtcl8.4.so`Tcl_EvalObjEx+0x69
libtcl8.4.so`Tcl_CatchObjCmd+0x43
0 61477 sqlite3Fault:entry
testfixture`sqlite3Fault
testfixture`faultsimStep+0x27
testfixture`faultsimMalloc+0xe
testfixture`mallocWithAlarm+0x5d
testfixture`sqlite3Malloc+0x42
testfixture`sqlite3DbMallocRaw+0x70
testfixture`sqlite3DbMallocZero+0x14
testfixture`sqlite3FindFunction+0xca
testfixture`sqlite3CreateFunc+0x13c
testfixture`sqlite3_create_function+0x31
testfixture`sqlite3Fts3ExprInitTestInterface+0x22
testfixture`sqlite3Fts3Init+0x99
testfixture`openDatabase+0x320
testfixture`sqlite3_open_v2+0x18
testfixture`DbMain+0x2b1
libtcl8.4.so`TclEvalObjvInternal+0x200
libtcl8.4.so`TclExecuteByteCode+0x1199
libtcl8.4.so`TclCompEvalObj+0x112
libtcl8.4.so`Tcl_EvalObjEx+0x69
libtcl8.4.so`Tcl_CatchObjCmd+0x43
#!/usr/sbin/dtrace -s
pid$1::sqlite3Fault:entry
/!self->spec/
{
self->spec = speculation();
}
pid$1::sqlite3Fault:entry
/self->spec/
{
speculate(self->spec);
ustack();
}
syscall::write:entry
/pid == $1 && arg0 == 1 && arg2 > 3/
{
self->str1 = stringof(copyin(arg1, 3));
}
syscall::write:entry
/pid == $1 && arg0 == 1 && arg2 > 3/
{
self->str2 = stringof(copyin(arg1, arg2));
}
syscall::write:entry
/self->str1 == " Ok"/
{
discard(self->spec);
self->spec = 0;
}
syscall::write:entry
/self->str1 == "\nEx"/
{
speculate(self->spec);
trace(self->str2);
}
syscall::write:entry
/self->str1 == "\nEx"/
{
commit(self->spec);
self->spec = 0;
}
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