compute_fn

sol_dev_proc_macros

Attribute Macro compute_fn 

Source 
#[compute_fn]
Expand description

Attribute macro for instrumenting functions with compute unit logging.

This macro wraps the decorated function with additional logging statements that print the function name and the number of compute units used before and after the function execution.

§Usage

ⓘ
#[compute_fn]
fn my_function() {
    // Function body
}

§Effects

  • Adds a log message with the function name at the start of execution.
  • Logs the number of compute units before and after the function execution.
  • Adds a closing log message with the function name at the end of execution.

§Note on Compute Units Used by compute_fn!

§Testing Results (as of 2024-09-01)

TOTAL COST OF LOGGING: 445 - 36 = 409 EXTRA COST INSIDE THE FUNCTION: 101

EMPTY_WITH_LOG where nothing happens inside the log. TOTAL COMPUTE UNITS USED: 445 INNER LOG COST: 101

“Program EMPTY_WITH_LOG invoke [1]”, “Program log: Program log: process_instruction {{”, “Program consumption: 199762 units remaining”, “Program consumption: 199661 units remaining”, // 199762 - 199661 = 101 “Program log: Program log: }} // process_instruction”, “Program EMPTY_WITH_LOG consumed 445 of 200000 compute units”, “Program EMPTY_WITH_LOG success”

EMPTY where nothing happens at all. TOTAL COMPUTE UNITS USED: 36

“Program EMPTY invoke [1]”, “Program EMPTY consumed 36 of 200000 compute units”, “Program EMPTY success”

Total extra compute units used per compute_fn! call: 409 CU For more details, see:

  • https://github.com/anza-xyz/agave/blob/d88050cda335f87e872eddbdf8506bc063f039d3/programs/bpf_loader/src/syscalls/logging.rs#L70
  • https://github.com/anza-xyz/agave/blob/d88050cda335f87e872eddbdf8506bc063f039d3/program-runtime/src/compute_budget.rs#L150