dalvik-cache location defined in

./dalvik/libdex/OptInvocation.c


Cyanogen uses : -

    /* Build the name of the cache directory.
     */

    /* load paths from the system environment */
    cacheRoot = getenv("ANDROID_CACHE");
    dataRoot = getenv("ANDROID_DATA");
    systemRoot = getenv("ANDROID_ROOT");

    /* make sure we didn't get any NULL values */
    if (cacheRoot == NULL)
        cacheRoot = "/cache";

    if (dataRoot == NULL)
        dataRoot = "/data";

    if (systemRoot == NULL)
        systemRoot = "/system";

    if (dexRoot == NULL)
        dexRoot = "/data";

    /* Cache anything stored on /system in cacheRoot, everything else in dataRoot */
    if (!strncmp(absoluteFile, systemRoot, strlen(systemRoot))) {
        property_get("dalvik.vm.dexopt-data-only", dexoptDataOnly, "");
        if (strcmp(dexoptDataOnly, "1") != 0) {
            dexRoot = cacheRoot;




Xdandroid uses

 /* Build the name of the cache directory.
     */
    dataRoot = getenv("ANDROID_DATA");
    if (dataRoot == NULL)
        dataRoot = "/data";