xcomp@xxxxxxxx wrote:
> Hi all,
> I have written a small test case which simply creates a new context, swaps to it and returns to the main function. I am allocating memory for the ucontext_t structures and the stack on which the context is executed using malloc.
Because of this I also want to deallocate the memory again using free.
The problem is I can't deallocate the memory after swapping back. It
runs only if all three free() calls are commented out. Otherwise a
segmentation fault occurs. Does swapcontext handle this on its own? Can
anyone explain this behavior? I didn't find anything concerning this
problem in the web.
> I am running this program on Ubuntu 8.04 with the following system information: Linux
ubuntu8041 2.6.24-23-generic #1 SMP i686 GNU/Linux
(...)
> main_context = (ucontext*) malloc(sizeof(ucontext));
> thread_context = (ucontext*) malloc(sizeof(ucontext));
changing:
main_context = (ucontext_t*) malloc(sizeof(ucontext_t));
thread_context = (ucontext_t*) malloc(sizeof(ucontext_t));
and compiling with free() I got:
#./a.out
start
Allocated memory:
main_context: 0x804b008
thread_context: 0x804b168
thread_stack: 0x804b2c8
thread_function was called...
swapcontext() returned. Freeing memory starts now...
thread_stack was deallocated...
thread_context was deallocated...
main_context was deallocated...
I'm using glibc version 2.8.
--tm
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