httpcOpenContext fails after exactly 8 times, consistently

[zeta0134]

When opening http contexts to perform file downloads, every attempt after the 8th fails consistently, with the same error code, somewhere during the call to httpcOpenContext.

To reproduce this, I modified the http download example, and got it to repeatedly download files in a loop. It's hosted here: http://darknovagames.com:1337/3ds/http_context_test.zip. This is fairly straightforward; run the code, press A repeatedly, and after the 8th call to httpcOpenContext(), it fails consistently.

I'm testing on a 3DS XL, using firmware version 9.2.0-20U. This is through Ninjhax; I lack the ability to test on anything else. This is pretty weird; it feels like a resource is not being released somewhere, but httpcCloseContext() is definitely being called.

[plutooo]

Could you paste your test code? Thanks.

[zeta0134]

Sure, here's the contents of main.cpp.

#include <stdlib.h>
#include <string.h>

#include <string>

using namespace std;

#include <3ds.h>

Result http_download(httpcContext *context)//This error handling needs updated with proper text printing once ctrulib itself supports that.
{
    Result ret=0;
    u8* framebuf_top, *framebuf_bottom;
    u32 statuscode=0;
    u32 size=0, contentsize=0;
    u8 *buf;

    framebuf_bottom = gfxGetFramebuffer(GFX_BOTTOM, GFX_LEFT, NULL, NULL);
    memset(framebuf_bottom, 0x40, 240*320*3);
    gfxFlushBuffers();
    gfxSwapBuffers();

    framebuf_bottom = gfxGetFramebuffer(GFX_BOTTOM, GFX_LEFT, NULL, NULL);
    memset(framebuf_bottom, 0x40, 240*320*3);
    gfxFlushBuffers();
    gfxSwapBuffers();
    gspWaitForVBlank();

    ret = httpcBeginRequest(context);
    if(ret!=0)return ret;

    ret = httpcGetResponseStatusCode(context, &statuscode, 0);
    if(ret!=0)return ret;

    if(statuscode!=200)return -2;

    ret=httpcGetDownloadSizeState(context, NULL, &contentsize);
    if(ret!=0)return ret;

    buf = (u8*)malloc(contentsize);
    if(buf==NULL)return -1;
    memset(buf, 0, contentsize);

    framebuf_bottom = gfxGetFramebuffer(GFX_BOTTOM, GFX_LEFT, NULL, NULL);
    memset(framebuf_bottom, 0xc0, 240*320*3);
    gfxFlushBuffers();
    gfxSwapBuffers();

    framebuf_bottom = gfxGetFramebuffer(GFX_BOTTOM, GFX_LEFT, NULL, NULL);
    memset(framebuf_bottom, 0xc0, 240*320*3);
    gfxFlushBuffers();
    gfxSwapBuffers();
    gspWaitForVBlank();

    framebuf_top = gfxGetFramebuffer(GFX_TOP, GFX_LEFT, NULL, NULL);
    framebuf_bottom = gfxGetFramebuffer(GFX_BOTTOM, GFX_LEFT, NULL, NULL);

    ret = httpcDownloadData(context, buf, contentsize, NULL);
    if(ret!=0)
    {
        free(buf);
        return ret;
    }

    size = contentsize;
    if(size>(240*400*3))size = 240*400*3;

    memset(framebuf_bottom, 0xff, 240*320*3);
    memcpy(framebuf_top, buf + 8, size - 8); //skip past the width/height markers

    gfxFlushBuffers();
    gfxSwapBuffers();

    framebuf_top = gfxGetFramebuffer(GFX_TOP, GFX_LEFT, NULL, NULL);
    framebuf_bottom = gfxGetFramebuffer(GFX_BOTTOM, GFX_LEFT, NULL, NULL);

    memset(framebuf_bottom, 0xff, 240*320*3);
    memcpy(framebuf_top, buf + 8, size - 8);

    gfxFlushBuffers();
    gfxSwapBuffers();
    gspWaitForVBlank();

    free(buf);

    return 0;
}

void display_image(u8* data, int size) {
    u8* framebuf_bottom = gfxGetFramebuffer(GFX_BOTTOM, GFX_LEFT, NULL, NULL);
    memcpy(framebuf_bottom, data + 8, size - 8); //skip past the width/height markers
}

void download_and_display_image(string url) {
    //debug_message("Attempting to download: " + url);
    Result ret=0;
    httpcContext context;
    ret = httpcOpenContext(&context, (char*)url.c_str(), 0);//Change this to your own URL.

    if(ret==0)
    {
        ret=http_download(&context);
        httpcCloseContext(&context);
    }
}

int main()
{
    // Initialize services
    srvInit();
    aptInit();
    hidInit(NULL);
    gfxInit();
    //gfxSet3D(true); // uncomment if using stereoscopic 3D
    httpcInit();

    string image_list[3] = {"http://darknovagames.com:1337/3ds/raw1.bin","http://darknovagames.com:1337/3ds/raw2.bin","http://darknovagames.com:1337/3ds/raw3.bin"};
    int current_image = 0;

    // Main loop
    while (aptMainLoop())
    {
        gspWaitForVBlank();
        hidScanInput();

        // Your code goes here

        u32 kDown = hidKeysDown();
        if (kDown & KEY_START) {
            break; // break in order to return to hbmenu
        }

        if (kDown & KEY_A) {
            //download an image!
            download_and_display_image(image_list[current_image]);
            current_image++;
            current_image = current_image % 3;
        }

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

    // Exit services
    httpcExit();
    gfxExit();
    hidExit();
    aptExit();
    srvExit();
    return 0;
}

[zeta0134]

This is confirmed fixed on my end.

[celcodioc]

It seems to me that this has not been fixed yet: filiphsandstrom/DownloadMii-3DS#24

Looks like everyone is experiencing this; I get return code -660561894 (0xd8a0a01a) when calling httpcOpenContext the 9th+ time.

@zeta0134's modified example app doesn't work properly either for me, so I'm not sure what's going on. I'm using Ninjhax 1.1 (3DS XL, 9.2.0-20E), and the latest libctru commit (9fec42f).

[WinterMute]

Are you absolutely sure that you're using the latest libctru? @zeta0134's test code is working perfectly for me on the same setup with this patch (Ninjhax 1.1, 3DS XL, 9.2.0-20E). Is there some other version of that code that's failing?

[plutooo]

Also can you check return value of every single httpcCloseContext? Maybe your code is leaking contexts.

[plutooo]

Read my comment again.

[celcodioc]

It always closes with code 0 on my build, I assume that's what's supposed to happen?

Also, now that I'm getting the return codes from httpcCloseContext, for some reason the ninth httpcOpenContext doesn't even return anything; it simply freezes the 3DS (how that's related to storing that return value I have no idea). No problems running the apps in 3dmoo, except these messages when calling httpcCloseContext:

>> svcSendSyncRequest (0x32)
http_c_SyncRequest (line 217): CloseContext 0dadbb2a --stub--

>> svcCloseHandle (0x23)
svcCloseHandle: svcCloseHandle undefined for handle-type "service".

[plutooo]

@filfat Me too. httpcCloseContext() can fail (return non-zero) and thus leak handles.

@celcodioc Yeah, that's correct. Sounds like you might be leaking something/somewhere else. Maybe you could modify 3dmoo to verify that all handles are closed/cleaned up correctly.