Android Dalvik VM GC options 命令控制参数

} else if (strncmp(argv[i], "-Xgc:", 5) == 0) {
    //In VM thread, there is a register map for marking each stack item's status whether it is an object or internal value. And In GC step, only object item will be marked. If this value is OFF, all stack will be marked even if the item is only an integer.
    if (strcmp(argv[i] + 5, "precise") == 0)
        gDvm.preciseGc = true;
    else if (strcmp(argv[i] + 5, "noprecise") == 0)
        gDvm.preciseGc = false;
    //Only for GC verify check
    else if (strcmp(argv[i] + 5, "preverify") == 0)
        gDvm.preVerify = true;
    else if (strcmp(argv[i] + 5, "nopreverify") == 0)
        gDvm.preVerify = false;
    else if (strcmp(argv[i] + 5, "postverify") == 0)
        gDvm.postVerify = true;
    else if (strcmp(argv[i] + 5, "nopostverify") == 0)
        gDvm.postVerify = false;
    //Open/Close Dalvik vm GC markseep is concurrent or not
    else if (strcmp(argv[i] + 5, "concurrent") == 0)
        gDvm.concurrentMarkSweep = true;
    else if (strcmp(argv[i] + 5, "noconcurrent") == 0)
        gDvm.concurrentMarkSweep = false;
    //Only for GC verify cardtable which is used for marking the concurrent marksweep dirty field
    else if (strcmp(argv[i] + 5, "verifycardtable") == 0)
        gDvm.verifyCardTable = true;
    else if (strcmp(argv[i] + 5, "noverifycardtable") == 0)
        gDvm.verifyCardTable = false; 
    else {
        dvmFprintf(stderr, "Bad value for -Xgc");
        return -1;
    }
    ALOGV("Precise GC configured %s", gDvm.preciseGc ? "ON" : "OFF");
}

主要用于控制：

• 是否在线程栈上标记对象(precise)
• 是否对ＧＣ进行验证(xxxVerify)
• 是否打开并行GC(concurrent)

 

http://stackoverflow.com/questions/14235842/how-to-enable-logs-specific-to-garbage-collector-in-dalvikvm