wasmtime::Store Class Reference

Owner of all WebAssembly objects. More...

#include <store.hh>

Data Structures
class	Context
	An interior pointer into a Store. More...

Public Member Functions
	Store (Engine &engine)
	Creates a new Store within the provided Engine.
void	limiter (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...
template<typename F , std::enable_if_t< std::is_invocable_r_v< Result< DeadlineKind >, F, Context, uint64_t & >, bool > = true>
void	epoch_deadline_callback (F &&f)
	Configures epoch deadline callback to C function. More...
Context	context ()
	Explicit function to acquire a Context from this store.
void	gc ()
const wasmtime_store_t *	capi () const
	Returns the underlying C API pointer.
wasmtime_store_t *	capi ()
	Returns the underlying C API pointer.

Detailed Description

Owner of all WebAssembly objects.

A Store owns all WebAssembly objects such as instances, globals, functions, memories, etc. A Store is one of the main central points about working with WebAssembly since it's an argument to almost all APIs. The Store serves as a form of "context" to give meaning to the pointers of Func and friends.

A Store can be sent between threads but it cannot generally be shared concurrently between threads. Memory associated with WebAssembly instances will be deallocated when the Store is deallocated.

Member Function Documentation

epoch_deadline_callback()

template<typename F , std::enable_if_t< std::is_invocable_r_v< Result< DeadlineKind >, F, Context, uint64_t & >, bool > = true>

void wasmtime::Store::epoch_deadline_callback ( F &&  f )

inline

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 an error to terminate the function
• set the delta argument and return DeadlineKind::Continue to update the epoch deadline delta and resume function execution.
• set the delta argument, update the epoch deadline, and return DeadlineKind::Yield to yield (via async support) and resume function execution.

gc()

void wasmtime::Store::gc ( )

inline

Runs a garbage collection pass in the referenced store to collect loose GC-managed objects, if any are available.

limiter()

void wasmtime::Store::limiter ( int64_t  memory_size, int64_t  table_elements, int64_t  instances, int64_t  tables, int64_t  memories  )

inline

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

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.

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The documentation for this class was generated from the following file:

• store.hh