lockfree_hashtable

This is a lock free/wait free hashtable implemented in C. There is an alternative C++ template based implementation in the https://github.com/larytet/emcpp The hashtable's original goal is to replace SystemTap's associative arrays. The hashtable reduces the probes latency by 30% and more depending on the scenario.

Limitations

• Key is of integral type
• A single context is allowed to insert/remove a specific key. Many contexts can insert/remove different keys.
• GCC is assumed

Compile

• 'make' should be enough to build the unitest
• Load and run the SystemTap module: sudo stap -g -v -k --suppress-time-limits -D MAXSKIPPED=0 dup_probe.stp
• Shell script echo_test.sh loads a multicore system and generates significant amount of system calls
• The hashtable is in hashtable.h

Performance

The hashtable hits 50M API calls per second on a single i7 core at cost of ~20nanos for an API call.