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If you have a program with more than one thread and run it in non-stop mode, the CommandCache in MIMemory does not get properly cleared, and old memory is shown. 1- Run your program and stop the *second* thread (not the first one). 2- Show a memory while that second thread is selected. 3- Step the second thread 4- The memory is fetched from the command cache, even though the program has stepped. The reason is that the MIMemory command cache is cleared based on the resumed and/or stopped event which in this case is for a single thread (thread 2). On the other hand, GDBMemory_7_0#readMemoryBlock() arbitrarily chooses the first thread of the program for all memory requests. Therefore, the memory is requested for thread 1 but we cleared the cache for thread 2, so we get a stale value. I have to look into why readMemoryBlock() uses a thread and not a container to request memory...
Created attachment 189225 [details] Clearing the cache for the memory context not the execution context (In reply to comment #0) > I have to look into why readMemoryBlock() uses a thread and not a container to > request memory... readMemoryBlock() uses a thread for two reasons: 1- it is the only way to tell GDB to select a particular process (before GDB 7.2, there was no way to select a process explicitly, except by selecting a thread within that process) 2- in non-stop mode, some threads may be running and GDB cannot read memory when the current thread is running. Therefore we must select a stopped thread first. See Bug 337460. The bug here is that we clear the CommandCache using the dmc that was resumed or suspended. In all-stop that is ok because the dmc is a container which is the same thing as a memory context, and will clear everything for that memory context. In non-stop however, the resumed or suspended dmc is an execution context (thread); in that case, we do not want to only clear the memory command cache for that thread, since any thread can modify any memory; therefore, as soon as a thread runs, we must still clear the entire memory cache. This patch does exactly that.
*** cdt cvs genie on behalf of mkhouzam *** Bug 337452: Wrong memory shown for non-stop multi-threaded programs. Cache was not being cleared properly. [*] MIMemory.java 1.7 http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.cdt/dsf-gdb/org.eclipse.cdt.dsf.gdb/src/org/eclipse/cdt/dsf/mi/service/MIMemory.java?root=Tools_Project&r1=1.6&r2=1.7
Committed to HEAD and 7_0. I realize I missed CDT 7.0.2 but I still want the fix the branch for my own use. Pawel can you review this small fix?
*** cdt cvs genie on behalf of mkhouzam *** Bug 337452 -Wrong memory shown for non-stop multi-threaded programs. Cached was not being cleared properly [*] MIMemory.java 1.5.2.1 http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.cdt/dsf-gdb/org.eclipse.cdt.dsf.gdb/src/org/eclipse/cdt/dsf/mi/service/MIMemory.java?root=Tools_Project&r1=1.5&r2=1.5.2.1
