#include <wasi.h>
#include <wasm.h>
#include <wasmtime/conf.h>
#include <wasmtime/error.h>

Macros
#define	WASMTIME_UPDATE_DEADLINE_CONTINUE 0
	Directly continue to updating the deadline and executing WebAssembly.

#define	WASMTIME_UPDATE_DEADLINE_YIELD 1
	Yield control (via async support) then update the deadline.

Typedefs
typedef struct wasmtime_store	wasmtime_store_t
	Convenience alias for wasmtime_store_t.

typedef struct wasmtime_context	wasmtime_context_t
	Convenience alias for wasmtime_context.

typedef uint8_t	wasmtime_update_deadline_kind_t
	An enum for the behavior before extending the epoch deadline.

Functions
WASM_API_EXTERN wasmtime_store_t *	wasmtime_store_new (wasm_engine_t engine, void data, void(finalizer)(void ))
	Creates a new store within the specified engine. More...

WASM_API_EXTERN wasmtime_context_t *	wasmtime_store_context (wasmtime_store_t *store)
	Returns the interior wasmtime_context_t pointer to this store.

WASM_API_EXTERN void	wasmtime_store_limiter (wasmtime_store_t *store, int64_t memory_size, int64_t table_elements, int64_t instances, int64_t tables, int64_t memories)
	Provides limits for a store. Used by hosts to limit resource consumption of instances. Use negative value to keep the default value for the limit. More...

WASM_API_EXTERN void	wasmtime_store_delete (wasmtime_store_t *store)
	Deletes a store.

WASM_API_EXTERN void *	wasmtime_context_get_data (const wasmtime_context_t *context)
	Returns the user-specified data associated with the specified store.

WASM_API_EXTERN void	wasmtime_context_set_data (wasmtime_context_t context, void data)
	Overwrites the user-specified data associated with this store. More...

WASM_API_EXTERN void	wasmtime_context_gc (wasmtime_context_t *context)
	Perform garbage collection within the given context. More...

WASM_API_EXTERN wasmtime_error_t *	wasmtime_context_set_fuel (wasmtime_context_t *store, uint64_t fuel)
	Set fuel to this context's store for wasm to consume while executing. More...

WASM_API_EXTERN wasmtime_error_t *	wasmtime_context_get_fuel (const wasmtime_context_t context, uint64_t fuel)
	Returns the amount of fuel remaining in this context's store. More...

WASM_API_EXTERN wasmtime_error_t *	wasmtime_context_set_wasi (wasmtime_context_t context, wasi_config_t wasi)
	Configures WASI state within the specified store. More...

WASM_API_EXTERN void	wasmtime_context_set_epoch_deadline (wasmtime_context_t *context, uint64_t ticks_beyond_current)
	Configures the relative deadline at which point WebAssembly code will trap or invoke the callback function. More...

WASM_API_EXTERN void	wasmtime_store_epoch_deadline_callback (wasmtime_store_t store, wasmtime_error_t (func)(wasmtime_context_t context, void data, uint64_t epoch_deadline_delta, wasmtime_update_deadline_kind_t update_kind), void data, void(finalizer)(void ))
	Configures epoch deadline callback to C function. More...

Detailed Description

Wasmtime definition of a "store".

Function Documentation

◆ wasmtime_context_gc()

WASM_API_EXTERN void wasmtime_context_gc ( wasmtime_context_t * context )

Perform garbage collection within the given context.

Garbage collects externrefs that are used within this store. Any externrefs that are discovered to be unreachable by other code or objects will have their finalizers run.

The context argument must not be NULL.

◆ wasmtime_context_get_fuel()

WASM_API_EXTERN wasmtime_error_t * wasmtime_context_get_fuel	(	const wasmtime_context_t *	context,
		uint64_t *	fuel
	)

Returns the amount of fuel remaining in this context's store.

If fuel consumption is not enabled via wasmtime_config_consume_fuel_set then this function will return an error. Otherwise NULL is returned and the fuel parameter is filled in with fuel consumed so far.

Also note that fuel, if enabled, must be originally configured via wasmtime_context_set_fuel.

◆ wasmtime_context_set_data()

WASM_API_EXTERN void wasmtime_context_set_data	(	wasmtime_context_t *	context,
		void *	data
	)

Overwrites the user-specified data associated with this store.

Note that this does not execute the original finalizer for the provided data, and the original finalizer will be executed for the provided data when the store is deleted.

◆ wasmtime_context_set_epoch_deadline()

WASM_API_EXTERN void wasmtime_context_set_epoch_deadline	(	wasmtime_context_t *	context,
		uint64_t	ticks_beyond_current
	)

Configures the relative deadline at which point WebAssembly code will trap or invoke the callback function.

This function configures the store-local epoch deadline after which point WebAssembly code will trap or invoke the callback function.

◆ wasmtime_context_set_fuel()

WASM_API_EXTERN wasmtime_error_t * wasmtime_context_set_fuel	(	wasmtime_context_t *	store,
		uint64_t	fuel
	)

Set fuel to this context's store for wasm to consume while executing.

For this method to work fuel consumption must be enabled via wasmtime_config_consume_fuel_set. By default a store starts with 0 fuel for wasm to execute with (meaning it will immediately trap). This function must be called for the store to have some fuel to allow WebAssembly to execute.

Note that when fuel is entirely consumed it will cause wasm to trap.

If fuel is not enabled within this store then an error is returned. If fuel is successfully added then NULL is returned.

◆ wasmtime_context_set_wasi()

WASM_API_EXTERN wasmtime_error_t * wasmtime_context_set_wasi	(	wasmtime_context_t *	context,
		wasi_config_t *	wasi
	)

Configures WASI state within the specified store.

This function is required if wasmtime_linker_define_wasi is called. This will configure the WASI state for instances defined within this store to the configuration specified.

This function does not take ownership of context but it does take ownership of wasi. The caller should no longer use wasi after calling this function (even if an error is returned).

◆ wasmtime_store_epoch_deadline_callback()

WASM_API_EXTERN void wasmtime_store_epoch_deadline_callback	(	wasmtime_store_t *	store,
		wasmtime_error_t ()(wasmtime_context_t context, void data, uint64_t epoch_deadline_delta, wasmtime_update_deadline_kind_t update_kind)	func,
		void *	data,
		void()(void )	finalizer
	)

Configures epoch deadline callback to C function.

This function configures a store-local callback function that will be called when the running WebAssembly function has exceeded its epoch deadline. That function can:

return a wasmtime_error_t to terminate the function
set the delta argument and return NULL to update the epoch deadline delta and resume function execution.
set the delta argument, update the epoch deadline, set update_kind to WASMTIME_UPDATE_DEADLINE_YIELD, and return NULL to yield (via async support) and resume function execution.

To use WASMTIME_UPDATE_DEADLINE_YIELD async support must be enabled for this store.

◆ wasmtime_store_limiter()

WASM_API_EXTERN void wasmtime_store_limiter	(	wasmtime_store_t *	store,
		int64_t	memory_size,
		int64_t	table_elements,
		int64_t	instances,
		int64_t	tables,
		int64_t	memories
	)

Provides limits for a store. Used by hosts to limit resource consumption of instances. Use negative value to keep the default value for the limit.

Parameters

store	store where the limits should be set.
memory_size	the maximum number of bytes a linear memory can grow to. Growing a linear memory beyond this limit will fail. By default, linear memory will not be limited.
table_elements	the maximum number of elements in a table. Growing a table beyond this limit will fail. By default, table elements will not be limited.
instances	the maximum number of instances that can be created for a Store. Module instantiation will fail if this limit is exceeded. This value defaults to 10,000.
tables	the maximum number of tables that can be created for a Store. Module instantiation will fail if this limit is exceeded. This value defaults to 10,000.
memories	the maximum number of linear memories that can be created for a Store. Instantiation will fail with an error if this limit is exceeded. This value defaults to 10,000.

Use any negative value for the parameters that should be kept on the default values.

Note that the limits are only used to limit the creation/growth of resources in the future, this does not retroactively attempt to apply limits to the store.

◆ wasmtime_store_new()

WASM_API_EXTERN wasmtime_store_t * wasmtime_store_new	(	wasm_engine_t *	engine,
		void *	data,
		void()(void )	finalizer
	)

Creates a new store within the specified engine.