4.4.2. MpHash Class

4.4.2. `MpHash` Class

MpHash is a closed hash table, whose entries are linked lists of MpEntry entities (see Section 4.4.3). Each entry represents one breakpoint or watchpoint. Five types of matchpoint are supported:

BP_MEMORYliteral>. A memory (soft) breakpoint.
BP_HARDWARE. A hardware breakpoint
WP_WRITE. A hardware write watchpoint
WP_READ. A hardware read watchpoint
WP_ACCESS. A hardware access (read or write) watchpoint.

Entries are keyed on both the address and type of the matchpoint. It is quite possible to have both a breakpoint and watchpoint on the same location, but they are separate entities.

	Note
	Although all five matchpoint types are supported in the matchpoint table, the current implementation of the GDB server does not provide an implementation for hardware breakpoints or any watchpoints.

The public interface to MpHash is as follows:

MpHash. The constructor. Takes an optional argument specifying the size of hash table to allocate (default value 1021). Allocates a new array for the hash table in private variable hashTab (an array of pointers to MpEntry) and sets all the pointers to NULL to mark the table as empty.
~MpHash. Destructor. Deletes the allocated hash table.
add. Adds a new entry to the hash table if it isn't already there. If it is there already it does nothing.
lookup. Look for an entry in the hash table. If the entry is found, return a pointer to its MpEntry, if not return NULL.
remove. Remove an entry from the hash table. Return true if the entry was found and deleted, false otherwise.