This commit adds tooling to measure how many branches the random simulation
reaches during execution, which helps understand code coverage and identify
untested code paths.
Changes:
- Add coverage build target to Makefile with --coverage flags
- Create measure_coverage.sh script to build, run, and report branch coverage
- Add signal handlers (SIGINT/SIGTERM) to main_test.c for clean shutdown
- Update clean target to remove coverage files (*.gcda, *.gcno)
The script runs the simulation for a specified duration (default 5 seconds),
then uses gcov to analyze which branches were executed. In a 3-second run,
the simulation reaches approximately 32% of all branches (781/2431).
Usage:
./measure_coverage.sh [duration_in_seconds]
Example output shows per-file and total branch coverage statistics.
Added a simulation client that can run inside the TinyDFS simulation
framework, enabling fully deterministic end-to-end testing of the
distributed file system.
**New Files:**
- src/simulation_client.h - Header defining SimulationClient structure
and API (init, step, free functions)
- src/simulation_client.c - Implementation of simulation client with
test operations (create dir, create file, write, read, list, delete)
**Key Changes:**
**System Framework (src/system.c):**
- Added ProcessType enum (METADATA_SERVER, CHUNK_SERVER, CLIENT)
to distinguish different simulated process types
- Extended Process union to include SimulationClient
- Modified spawn_simulated_process() to detect --client flag and
initialize client processes using simulation_client_init()
- Updated update_simulation() to call simulation_client_step() for
client processes, handling timeout management
- Fixed cleanup_simulation() to properly set current_process before
freeing, preventing NULL pointer dereferences in mock_close()
- Added simulated_time static variable (struct timespec) for
deterministic clock mocking
- Added helper function is_client() to detect client processes
**API Updates (src/system.h):**
- Exported startup_simulation() function for proper initialization
- Added function declarations for simulation management
**Test Updates (src/main_test.c):**
- Added startup_simulation() call for proper initialization
- Spawns simulation client process with "--client" flag
- Increased iteration limit to 100,000 to allow operations to complete
- Added progress logging every 10,000 iterations
- Added explicit error checking and debug output
**Simulation Client Features:**
- Non-blocking operation model using tinydfs_isdone() and
tinydfs_process_events()
- State machine for sequential test operations
- Comprehensive test scenario:
1. Create directory (/test_dir)
2. Create file (/test_dir/test_file.txt)
3. Write data to file
4. Read data back
5. List directory contents
6. Delete file
- Proper integration with TinyDFS client library
- Returns poll descriptors from tinydfs_process_events()
- Timeout management for simulation scheduling
**Bug Fixes:**
- Fixed missing return statement in spawn_simulated_process()
- Fixed NULL pointer dereference in cleanup by setting current_process
- Added missing stdlib.h include for atoi()
The simulation client successfully initializes and integrates into the
simulation loop, demonstrating the framework's ability to run client
code deterministically alongside servers.
Claude
cozis