mymemory, threads: add allocator specifically for Thread

clas Thread is a special exception, where user-space allocations should
happend from the model-checker context. So provide a special set of
functions to specifically differentiate these allocations.

diff --git a/mymemory.cc b/mymemory.cc
index 44985fa3aebc0d3fc32f97c0606b3c7ef11154a8..ea8670d60ccdf7250307b7ae4bb55bc89f5507c5 100644 (file)
--- a/mymemory.cc
+++ b/mymemory.cc
@@ -155,14 +155,30 @@ static bool DontFree(void *ptr)
        return (ptr >= (&bootstrapmemory[0]) && ptr < (&bootstrapmemory[BOOTSTRAPBYTES]));
 }
 
-/** @brief Snapshotting malloc implementation for user programs */
+/**
+ * @brief The allocator function for "user" allocation
+ *
+ * Should only be used for allocations which will not disturb the allocation
+ * patterns of a user thread.
+ */
+static void * user_malloc(size_t size)
+{
+       void *tmp = mspace_malloc(user_snapshot_space, size);
+       ASSERT(tmp);
+       return tmp;
+}
+
+/**
+ * @brief Snapshotting malloc implementation for user programs
+ *
+ * Do NOT call this function from a model-checker context. Doing so may disrupt
+ * the allocation patterns of a user thread.
+ */
 void *malloc(size_t size)
 {
-       if (user_snapshot_space) {
-               void *tmp = mspace_malloc(user_snapshot_space, size);
-               ASSERT(tmp);
-               return tmp;
-       } else
+       if (user_snapshot_space)
+               return user_malloc(size);
+       else
                return HandleEarlyAllocationRequest(size);
 }
 
@@ -195,6 +211,18 @@ void * calloc(size_t num, size_t size)
        }
 }
 
+/** @brief Snapshotting allocation function for use by the Thread class only */
+void * Thread_malloc(size_t size)
+{
+       return user_malloc(size);
+}
+
+/** @brief Snapshotting free function for use by the Thread class only */
+void Thread_free(void *ptr)
+{
+       free(ptr);
+}
+
 /** @brief Snapshotting new operator for user programs */
 void * operator new(size_t size) throw(std::bad_alloc)
 {

diff --git a/mymemory.h b/mymemory.h
index f2a31865ba85a9272794514de14e3179bb2da01e..a62ab83b9ce5cbcd82999bc9463b2949ba7a0394 100644 (file)
--- a/mymemory.h
+++ b/mymemory.h
@@ -56,6 +56,9 @@ void * snapshot_calloc(size_t count, size_t size);
 void * snapshot_realloc(void *ptr, size_t size);
 void snapshot_free(void *ptr);
 
+void * Thread_malloc(size_t size);
+void Thread_free(void *ptr);
+
 /** @brief Provides a non-snapshotting allocator for use in STL classes.
  *
  * The code was adapted from a code example from the book The C++

diff --git a/threads-model.h b/threads-model.h
index e77e80cc71de39663fd4078307c7c2220fee68a6..eb0fd438d388931ef0316231abd828d6e5295581 100644 (file)
--- a/threads-model.h
+++ b/threads-model.h
@@ -126,6 +126,18 @@ public:
         * to allow their allocation/deallocation to follow the same pattern as
         * the rest of the backtracked/replayed program.
         */
+       void * operator new(size_t size) {
+               return Thread_malloc(size);
+       }
+       void operator delete(void *p, size_t size) {
+               Thread_free(p);
+       }
+       void * operator new[](size_t size) {
+               return Thread_malloc(size);
+       }
+       void operator delete[](void *p, size_t size) {
+               Thread_free(p);
+       }
 private:
        int create_context();