read_delay

romfs.cpp

#include <3ds.h>
#include <stdio.h>

#include <cstdint>
#include <string>
#include <string_view>
#include <utility>
#include <vector>

static s64 base_tick;
static std::vector<std::pair<std::string_view, s64>> thread_order;

static volatile bool request_done = false;

static u64 first_tick = 0;
static u64 last_tick = 0;

int main(int argc, char **argv)
{
    gfxInitDefault();

    //Initialize console on top screen. Using NULL as the second argument tells the console library to use the internal console structure as current one
    consoleInit(GFX_TOP, NULL);

    y2rInit();

    printf("Timing test\n\n");

    svcSetThreadPriority(CUR_THREAD_HANDLE, 0x18);

    base_tick = svcGetSystemTick();

    int times = 0;

    FILE *dataSet = fopen("busy_loop_data.txt", "w");

    Result rc = romfsInit();
    if (rc) {
        printf("romfsInit: %08lX\n", rc);
        return 0;
    }
    u32 len;
    char mystring[1000];
    Handle handle;
    FS_Path archivePath;
    archivePath.type=PATH_EMPTY;
    archivePath.size=0;
    archivePath.data=nullptr;
    char zeros[12];
    for (int i=0;i<12;i++) {
        zeros[i] = 0;
    }
    FS_Path filePath;
    filePath.type=PATH_BINARY;
    filePath.size=12;
    filePath.data=(const void*)zeros;
    rc = FSUSER_OpenFileDirectly(&handle, ARCHIVE_ROMFS, archivePath, filePath, 1, 0);
    if (rc) {
        printf("Failed to open file: %08lX\n\n", rc);
        return 0;
    }
    u32 offset=0;
    while (times++ < 10000) {

        Thread t = threadCreate([](void *arg) {
            last_tick = first_tick = svcGetSystemTick();

            while (!request_done) {
                // Record the current tick
                last_tick = svcGetSystemTick();

                // Yield the thread to another thread
                svcSleepThread(0);
            }

        }, nullptr, 0x1000, 0x19, 0, false);

        //This is the function we want to measure
        FSFILE_Read(handle, &len, 0, mystring, sizeof(mystring));

        request_done = true;

        threadJoin(t, U64_MAX);
        threadFree(t);

        fprintf(dataSet, "%lld\n", last_tick - first_tick);

        hidScanInput();
        if (hidKeysDown() & KEY_START) break;

        request_done = false;

    }

    fclose(dataSet);

    printf("\nTimeline: \n");

    std::string str;
    for (auto &sv : thread_order) {
        str = sv.first;
        printf("%s: %lld\n", str.c_str(), sv.second);
    }

    printf("Press Start to exit.\n");

    // Main loop
    while (aptMainLoop())
    {
        //Scan all the inputs. This should be done once for each frame
        hidScanInput();

        //hidKeysDown returns information about which buttons have been just pressed (and they weren't in the previous frame)
        u32 kDown = hidKeysDown();

        if (kDown & KEY_START) break; // break in order to return to hbmenu

        // Flush and swap framebuffers
        gfxFlushBuffers();
        gfxSwapBuffers();

        //Wait for VBlank
        gspWaitForVBlank();
    }

    y2rExit();
    gfxExit();

    return 0;
}

savedata.cpp

#include <3ds.h>
#include <stdio.h>

#include <array>
#include <cstdint>
#include <sstream>
#include <cstring>
#include <string>
#include <string_view>
#include <utility>
#include <vector>

static s64 base_tick;
static std::vector<std::pair<std::string_view, s64>> thread_order;

static volatile bool request_done = false;

static u64 first_tick = 0;
static u64 last_tick = 0;

struct SelfNCCHFilePath {
    u32 type;
    std::array<char, 8> exefs_filename;
};

void EndLoop() {
    printf("Press Start to exit.\n");

    // Main loop
    while (aptMainLoop())
    {
        //Scan all the inputs. This should be done once for each frame
        hidScanInput();

        //hidKeysDown returns information about which buttons have been just pressed (and they weren't in the previous frame)
        u32 kDown = hidKeysDown();

        if (kDown & KEY_START) break; // break in order to return to hbmenu

        // Flush and swap framebuffers
        gfxFlushBuffers();
        gfxSwapBuffers();

        //Wait for VBlank
        gspWaitForVBlank();
    }
    y2rExit();
    gfxExit();
}

int main(int argc, char **argv)
{
    gfxInitDefault();

    //Initialize console on top screen. Using NULL as the second argument tells the console library to use the internal console structure as current one
    consoleInit(GFX_TOP, NULL);

    y2rInit();

    printf("Timing test\n\n");

    svcSetThreadPriority(CUR_THREAD_HANDLE, 0x18);

    base_tick = svcGetSystemTick();

    int times = 0;

    FILE *dataSet = nullptr;

    u32 len;
    u32 size = 10;
    Handle handle;

    FS_Path archivePath;
    archivePath.type=PATH_EMPTY;
    archivePath.size=0;
    archivePath.data=nullptr;

    char path[32] = "/Save.dat";

    FS_Path filePath;
    filePath.type=PATH_ASCII;
    filePath.size=32;
    filePath.data=(const void*)path;
    FS_Archive archive_handle;
    Result rc = FSUSER_FormatSaveData(ARCHIVE_SAVEDATA,archivePath, 0x200,7,7,7,7,false);
    if (rc) {
        printf("Failed to format archive: %08lX\n\n", rc);
        EndLoop();
        return 0;
    }
    rc = FSUSER_OpenArchive(&archive_handle, ARCHIVE_SAVEDATA, archivePath);
    if (rc) {
        printf("Failed to open archive: %08lX\n\n", rc);
        EndLoop();
        return 0;
    }
    rc = FSUSER_CreateFile(archive_handle,filePath,0,100000);
    if (rc && rc != 0xC82044B4) {
        printf("Failed to create file: %08lX\n\n", rc);
        EndLoop();
        return 0;
    }
    rc = FSUSER_OpenFileDirectly(&handle, ARCHIVE_SAVEDATA, archivePath, filePath, 7, 0);
    if (rc) {
        printf("Failed to open file: %08lX\n\n", rc);
        EndLoop();
        return 0;
    }

    char* mystring = (char *) malloc (sizeof(char) * 100000);
    rc = FSFILE_Write(handle, &len, 0, mystring, 100000, 0);
    free(mystring);
    while (size < 100000) {
        std::stringstream filename;
        filename << "busy_loop_data_" << size << ".txt";
        dataSet = fopen(filename.str().c_str(), "w");
        times = 0;
        char* mystring = (char *) malloc (sizeof(char) * size);
        while (times++ < 1000) {

            Thread t = threadCreate([](void *arg) {
                last_tick = first_tick = svcGetSystemTick();

                while (!request_done) {
                    // Record the current tick
                    last_tick = svcGetSystemTick();

                    // Yield the thread to another thread
                    svcSleepThread(0);
                }

            }, nullptr, 0x1000, 0x19, 0, false);

            //This is the function we want to measure
            rc = FSFILE_Read(handle, &len, 0, mystring, size);

            request_done = true;

            threadJoin(t, U64_MAX);
            threadFree(t);

            if(rc) {
                printf("Failed to read file: %08lX\n\n", rc);
                EndLoop();
                return 0;
            }
            if (len != size) {
                printf("Wrong size: %lu\n\n", len);
                EndLoop();
                return 0;
            }

            fprintf(dataSet, "%lld\n", last_tick - first_tick);

            hidScanInput();
            if (hidKeysDown() & KEY_START) break;

            request_done = false;
        }
        printf("\nSize %lu done \n", size);
        free(mystring);
        size=size*4;
        fclose(dataSet);
    }
    FSUSER_DeleteFile(archive_handle,filePath);

    printf("\nFinished \n");
    EndLoop();
    return 0;
}