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StoreConditional

// Constructor
SST::Interfaces::StandardMem::StoreConditional(Addr pAddr, uint64_t size, std::vector<uint8_t> data, 
    flags_t flags = 0, Addr vAddr = 0, Addr iPtr = 0, uint32_t tid = 0);

Response Type StandardMem::WriteResp  
Needs Response true

The StandardMem::StoreConditional request class defines a conditional memory write. It must follow a prior StandardMem::LoadLink. If any intervening external (i.e., not from this compute endpoint) accesses occurred to the address between the LoadLink and StoreConditional, the StoreConditional should fail. In that case it will not execute the Write and will return a WriteResp with the F_FAIL flag set. If no intervening access occurred, the write will execute and a response without the F_FAIL flag will be returned. Issuing a StandardMem::StoreConditional without first issuing a StandardMem::LoadLink is incorrect behavior and particular StandardMem implementations may return a fatal error or ignore it, resulting in undefined behavior. An interface that receives this request should return a WriteResp response acknowledging the request and setting the F_FAIL flag to denote whether the write executed or not. Fields for both a virtual and physical address are available, the interpretation of those fields is up to the underlying memory system model. physAddr is however required in the constructor.

Member variables​

Including those inherited from the StandardMem::Request base class, StandardMem::StoreConditional includes the following member variables.

  • id (id_t) A request or response identifier. A request and its response contain the same identifier.
  • flags (flags_t) A 32-bit vector indicating any special flags added to the request
  • pAddr (Addr) The physical starting byte address to write to
  • vAddr (Addr) The virtual (if any) starting byte address to write the data to
  • size (uint64_t) The number of bytes to write (same as size of data vector)
  • data (std::vector<uint8_t>) Bytes to write
  • iPtr (Addr) An instruction pointer. This is optional metadata.
  • tid (uint32_t) An optional thread ID, can be used by memory systems if needed

Member functions​

Defined in Request base class​

  • getId
  • setNoncacheable
  • unsetNoncacheable
  • getNoncacheable
  • setSuccess
  • unsetSuccess
  • getSuccess
  • setFail
  • unsetFail
  • getFail
  • setTrace
  • unsetTrace
  • getTrace
  • setFlag
  • unsetFlag
  • getFlag
  • clearAllFlags
  • getAllFlags
  • getFlagString

Virtual functions inherited from the Request base class​

makeResponse​

Request* makeResponse();

Creates a WriteResp initialized as a response to this write request.

needsResponse​

bool needsResponse();

Returns true.

convert​

SST::Event* convert(RequestConverter* converter);

Invokes convert() on the supplied converter visitor class to return an SST::Event in an implementation-specific format.

handle​

virtual void handle(RequestHandler* handler) =0;

Invokes handle() on the supplied handler visitor class to handle the event according to type.

getString​

virtual std::string getString() =0;

Returns a formatted string listing all fields of the StoreConditional.

Example Output:
ID: 817, Type: StoreConditional, Flags: [F_FAIL], PhysAddr: 0x13240, VirtAddr: 0x13240, Size: 4, InstPtr: 0x10ed8, ThreadID: 0, Payload: 0x48656c6c
#include <sst/core/interfaces/stdMem.h>