Documentation
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Overview ¶
Package crashpoint holds the production-callable half of the crash-injection machinery: the Breakpoint hook and the environment variables that drive it. It deliberately depends on nothing beyond os and syscall so that production packages (for example store/wal and store/checkpoint) can embed crash-injection points without dragging the testing package — and the test-only subprocess runner — into their production binaries.
Build-tag gating ¶
Breakpoint has two implementations selected at compile time by the gograph_crashinject build tag:
- crashpoint_disabled.go (//go:build !gograph_crashinject) — the default. Breakpoint is an empty function that the compiler elides entirely: it reads no environment variable and links no syscall. This is what every released binary contains, so GOGRAPH_CRASH_AT can never make a production process kill itself, and there is no per-call overhead on the WAL-truncate and checkpoint paths.
- crashpoint_enabled.go (//go:build gograph_crashinject) — the active hook. Breakpoint reads GOGRAPH_CRASH_AT and, on a matching name, sends SIGKILL to the current process. Only the deterministic crash-injection battery (internal/crashinject and cmd/crashinject-helper) is built with this tag.
The exported API (Breakpoint, EnvCrashAt, EnvCrashDir) is identical in both modes, so call sites never change. To exercise the crash battery, build and test with -tags gograph_crashinject.
The subprocess harness that spawns a child, sets these environment variables, and inspects the torn artefacts lives in the sibling package internal/crashinject; it re-exports the names defined here so existing call sites keep working.
Index ¶
Constants ¶
const EnvCrashAt = "GOGRAPH_CRASH_AT"
EnvCrashAt is the environment variable read by Breakpoint (in the gograph_crashinject build) to decide which named point should trigger a crash. Without that build tag Breakpoint ignores the variable entirely.
const EnvCrashDir = "GOGRAPH_CRASH_DIR"
EnvCrashDir is the environment variable that tells the helper binary where to place its artefacts (WAL files, temp data).
Variables ¶
This section is empty.
Functions ¶
func Breakpoint ¶
func Breakpoint(string)
Breakpoint is a no-op in every build that omits the gograph_crashinject tag — which is every released binary.
It takes no action: it does not read GOGRAPH_CRASH_AT and links no syscall, so an inherited GOGRAPH_CRASH_AT value cannot make a production process kill itself, and there is no per-call overhead on the durability paths (store/wal.Writer.Truncate, store/checkpoint) that embed it. The compiler inlines this empty body to nothing.
The active crash-injection implementation lives in crashpoint_enabled.go and is compiled only under the gograph_crashinject build tag.
Types ¶
This section is empty.
Source Files