Crash due to SIGABRT on Linux C++ PowerPC - c++

Question

My program crashes in string assign. I cannot corner down the exact cause of it. Multiple threads execute the same code.
This is my code.
char* cTemp = new char[5];
memset(cTemp,'\0', 5);
snprintf(cTemp , 5 , "%04x" , iParameter);
string sVar1 = cTemp;
delete[] cTemp;
if(sVar1 == "0")
sVar1 = "0000";
pSharedLib->setVar1(sVar1);
The set Function(in shared library)
bool A::setVar1(CString& temp)
{
m_sVar1= temp;
return true;
}
The crash bt shows the error as
#0 0x48194444 in raise () from /lib/libc.so.6
#0 0x48194444 in raise () from /lib/libc.so.6
No symbol table info available.
#1 0x48199694 in abort () from /lib/libc.so.6
No symbol table info available.
#2 0x481d4ecc in ?? () from /lib/libc.so.6
No symbol table info available.
#3 0x481e14d4 in ?? () from /lib/libc.so.6
No symbol table info available.
#4 0x481e32b0 in free () from /lib/libc.so.6
No symbol table info available.
#5 0x480df8b8 in operator delete(void*) () from /usr/lib/libstdc++.so.6
No symbol table info available.
#6 0x480b136c in std::string::_Rep::_M_destroy(std::allocator<char> const&)
() from /usr/lib/libstdc++.so.6
No symbol table info available.
#7 0x480b35f4 in std::string::assign(std::string const&) ()
from /usr/lib/libstdc++.so.6
No symbol table info available.

Answer 1

I don't see any synchronization objects protecting the set of m_sVar1. You mentioned that setVar1 could be called from multiple threads simultaneously, the threading guarantees for STL don't guarantee that the assignment is safe from multiple threads.

Answer 2

I suspect the key to this problem is
Multiple threads execute the same code.
If there's a single string m_sVar1, and multiple threads are assigning to it simultaneously, then the chances are rather good that a race condition will lead to corruption. You need to properly protect that variable with a critical section.