Hi Ali,
Thanks for the hint and I did find that there is an error. But I'm not sure
whether it's the problem with my implementation or with M5.
Here is the problem:
void thread_main()
{
int* x = new x[10];
delete [] x;
my_exit(); // inlined assembly(asm volatile (".byte 0x61, 0x00,0x00,0x40))
}
main()
{
for(int n=0; n<4; n++)
thread_create(&thread_main); // inlined assembly(asm volatile (".byte
0x62, 0x00,0x00,0x40))
wait(); // inlined assembly(asm volatile (".byte 0x63, 0x00,0x00,0x40))
}
in the following example, I am trying to create 4 threads running
simultaneously. Each of the thread allocate some heap space and then free it.
I am expecting that the "x"s in each thread is assigned to a different address
in the heap. But I found that the 4 threads allocate exactly the same address
to the 4 "x"s, thus, when they try to free "x", it is freed four times and the
application invokes an error:
*** glibc detected *** double free or corruption (fasttop): 0x00000001201d8a40
***
and this error is always followed by the "stat64 unimplemented" message.
Can you also give me some hints about how to solve this? why does the four
threads assign their "x" the same address? how can I get around with this?
Thanks!
Jiayuan
----- Original Message -----
From: Ali Saidi
To: M5 users mailing list
Sent: 2007年6月13日 10:24 AM
Subject: Re: [m5-users] thread alloc/dealloc error and stat64 system call
I'm not sure I know why stat64 is being called. It could be that one of your
new instructions isn't what you think it is and the program execution path
changes to some error handler, or something else. You probably want to create
an instruction trace and make sure it's doing what you think it is. If that is
the case then implementing stat64 shouldn't be that difficult, just take a look
at fstat64. stat64 is the same thing but instead of argument 1 being a file
descriptor it's a path to a file.
Ali
On Jun 12, 2007, at 8:14 PM, Jiayuan Meng wrote:
Hi all,
As I am trying to run a thread in SE mode, I made up the following code:
void thread_main()
{
int* x = new x[10];
delete [] x;
my_exit(); // inlined assembly(asm volatile (".byte 0x61,
0x00,0x00,0x40))
}
main()
{
launch(&thread_main); // inlined assembly(asm volatile (".byte 0x62,
0x00,0x00,0x40))
wait(); // inlined assembly(asm volatile (".byte 0x63, 0x00,0x00,0x40))
}
To launch this thread, what I did was: allocate a stack, assign the pc, and
activate the thread context on another cpu. my_exit() will tell the simulator
that this thread is finished and the simulator will deallocate/halt its thread
context.
The extened assemblies are implemented following the M5FUNC pseudo
instructions.
I use crosstool's g++ 3.4.3 to compile the code to alpha-linux. M5 is
compiled on a 64bit x86 machine.
I get the following message:
fatal: syscall stat64 (#425) unimplemented.
how ever, if I just change the thread_main to:
void thread_main()
{
int* x = new x
delete x;
my_exit();
}
The error will be gone. What can I do to allow the first case to work? is
there any patch for system call stat64?
Thanks!
Jiayuan
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