Documentation
¶
Overview ¶
Package runtime defines how the engine runs a container's module. The Executor interface carries no type of any WebAssembly runtime, so the native executor (runtime/wazero) and the browser executor that comes later implement the same contract.
Index ¶
Constants ¶
const ( ExitTrap = 134 // 128 + SIGABRT: the module trapped ExitKilled = 137 // 128 + SIGKILL: killed or timed out ExitNoExec = 126 // found but not runnable (not a valid module) ExitMissing = 127 // module not found )
Exit codes the engine uses for ends that are not a proc_exit, following the shell and Docker conventions (128+SIGKILL for a kill).
Variables ¶
var ( ErrNotFound = errors.New("module not found") ErrInvalid = errors.New("not a valid WebAssembly module") )
Errors a Start may return; the exit code to record goes with each.
Functions ¶
func LoadModule ¶ added in v0.2.0
LoadModule reads and checks the module a spec names: present (else ErrNotFound), a regular file with the wasm magic (else ErrInvalid).
Types ¶
type Executor ¶
type Executor interface {
// Start validates and compiles the module, then runs it in the
// background. A missing module wraps ErrNotFound, an invalid one
// ErrInvalid.
Start(ctx context.Context, spec Spec) (Process, error)
// Close releases the executor's resources.
Close(ctx context.Context) error
}
Executor starts processes.
type Mount ¶ added in v0.8.0
Mount is a tree (a volume) preopened at Path in the guest, read-only when ReadOnly.
type Process ¶
type Process interface {
// Wait blocks until the process ends.
Wait() Result
// Kill ends the process; Wait then reports Killed.
Kill()
}
Process is a started run.
type Result ¶
type Result struct {
ExitCode int
// TimedOut reports a wall-clock cancel.
TimedOut bool
// Killed reports a cancel through Process.Kill or the context.
Killed bool
// Error describes an abnormal end (a trap), empty on a normal exit.
Error string
}
Result is how a process ended.
type Spec ¶
type Spec struct {
// ID names the process in errors and logs.
ID string
// FS is the container's root filesystem, preopened as "/".
FS *rootfs.FS
// Mounts are volumes, each preopened at its own path.
Mounts []Mount
// Path is the module's absolute path inside FS.
Path string
// Args is argv, Args[0] included.
Args []string
// Env is "KEY=value" entries.
Env []string
// Stdin, Stdout and Stderr default to empty / discard.
Stdin io.Reader
Stdout, Stderr io.Writer
// MemoryLimitBytes bounds the module's linear memory (0 = executor
// default). It is rounded down to whole 64 KiB pages.
MemoryLimitBytes int64
// Timeout cancels the run after this wall-clock time (0 = none).
Timeout time.Duration
}
Spec is everything needed to run one container process.
type Stats ¶ added in v0.7.0
type Stats struct {
// MemoryBytes is the guest's linear memory now (it never shrinks);
// MemoryLimitBytes the most it may grow to.
MemoryBytes, MemoryLimitBytes int64
}
Stats is what an executor can measure of a running process.
type StatsReporter ¶ added in v0.7.0
type StatsReporter interface {
Stats() Stats
}
StatsReporter is implemented by processes that can report Stats.
Source Files
Directories
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| Path | Synopsis |
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Package browser is the Executor for GOOS=js: each container process runs in its own Web Worker (worker.js), its wasi_snapshot_preview1 imports served synchronously by the engine's WASI host (package wasi) in the worker that runs the engine, over SharedArrayBuffer and Atomics.wait.
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Package browser is the Executor for GOOS=js: each container process runs in its own Web Worker (worker.js), its wasi_snapshot_preview1 imports served synchronously by the engine's WASI host (package wasi) in the worker that runs the engine, over SharedArrayBuffer and Atomics.wait. |
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Package wazero is the native Executor: it runs a container's wasip1 module with wazero (pure Go, no cgo), the container's rootfs mounted as the guest's "/".
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Package wazero is the native Executor: it runs a container's wasip1 module with wazero (pure Go, no cgo), the container's rootfs mounted as the guest's "/". |