Function execute_command

src/libnvm/rpc.cpp:271–322

* Execute an NVM admin command. * Lock must be held when calling this function. */

 * Lock must be held when calling this function.
 */
static int execute_command(struct local_admin* admin, const nvm_cmd_t* cmd, nvm_cpl_t* cpl)
{
    nvm_cmd_t local_copy;
    nvm_cmd_t* in_queue_cmd;
    nvm_cpl_t* in_queue_cpl;

    // Try to enqueue a message
    if ((in_queue_cmd = nvm_sq_enqueue(&admin->asq)) == NULL)
    {
        // Queue was full, but we're holding the lock so no blocking
        return EAGAIN;
    }

    // Copy command into queue slot (but keep original id)
    uint16_t in_queue_id = NVM_DEFAULT_CID(&admin->asq);

    memcpy(&local_copy, cmd, sizeof(nvm_cmd_t));

    *NVM_CMD_CID(&local_copy) = in_queue_id;
    *in_queue_cmd = local_copy;

    //for (int i = 0; i < 16; i++) {
    //    printf("cmd: %p\tdword[%d] = %x\n", in_queue_cmd, i, local_copy.dword[i]);
    //}
    std::atomic_thread_fence(std::memory_order_seq_cst);
    // Submit command and wait for completion
    nvm_sq_submit(&admin->asq);
    std::atomic_thread_fence(std::memory_order_seq_cst);
    in_queue_cpl = nvm_cq_dequeue_block(&admin->acq, admin->timeout);
    if (in_queue_cpl == NULL)
    {
        dprintf("Waiting for admin queue completion timed out\n");
        return ETIME;
    }
    std::atomic_thread_fence(std::memory_order_seq_cst);
    //for (int i = 0; i < 4; i++) {
    //    printf("cpl: %p\tdword[%d] = %x\n", in_queue_cpl, i, in_queue_cpl->dword[i]);

    //}
    //printf("cpl cmd_id: %u\tstatus and phase: %x\n", in_queue_cpl->dword[3] & 0x0000ffff, in_queue_cpl->dword[3] >> 16);

    nvm_sq_update(&admin->asq);
    std::atomic_thread_fence(std::memory_order_seq_cst);
    // Copy completion and return
    *cpl = *in_queue_cpl;
    std::atomic_thread_fence(std::memory_order_seq_cst);
    nvm_cq_update(&admin->acq);

    //*NVM_CPL_CID(cpl) = *NVM_CMD_CID(cmd);

    return 0;
}