Solana
BPF Programs Execution
Context
This figure appears in the 'System Architecture' section, specifically in the description of the Banking stage's Sealevel parallel smart contract runtime. The section explains that Solana programs (smart contracts) are compiled to BPF (Berkeley Packet Filter) bytecode, which is executed in a sandboxed virtual machine that provides memory safety, deterministic execution, and a compute budget to prevent runaway programs.
What This Figure Shows
The diagram illustrates how multiple user-supplied BPF programs are executed concurrently in the Sealevel runtime: each program runs in its own sandboxed BPF virtual machine, isolated from other programs' memory. Programs that access disjoint account sets are scheduled in parallel across available CPU cores, while programs with overlapping account dependencies are serialized to prevent race conditions. All programs share access to a set of intrinsic functions — syscalls provided by the Solana runtime — for operations like cryptographic hashing, cross-program invocations, and logging, without needing to inline these expensive operations in the bytecode. The BPF VM enforces a compute budget (measured in BPF instruction count analogously to EVM gas) that caps each transaction's resource consumption.
Significance
The BPF-based parallel execution model is Solana's key architectural differentiator from Ethereum's sequential EVM. By requiring programs to declare their account dependencies upfront, Sealevel converts the scheduling problem from a runtime decision into a static analysis, enabling the Banking stage to maximize CPU core utilization. The shared intrinsic call design reduces bytecode size and ensures consistent, auditable implementations of security-critical operations like signature verification across all programs.
