Mingjian,
Thx for your kind suggestion. I tried the verification bypass approach
on Harmony, and found it doesn't help performance (This is because
verification is not the hotspot function).
btw, can you comment more on " some class OS sharing mechanism may
reduce the second jvm startup
time?(IBM and SUN JDK 6.0+ seem using this mechanism)", I don't fully
understand what it means.
Thx, Wenlong
I changed the following verification function (in verifier_stub.cpp),
you can see the new verification is very light-weight.
bool Class::verify(const Global_Env * env) // This is the original
implementation in Harmony
{
// fast path
if (m_state >= ST_BytecodesVerified)
return true;
LMAutoUnlock aulock(m_lock);
if (m_state >= ST_BytecodesVerified)
return true;
if (is_array()) {
// no need do bytecode verification for arrays
m_state = ST_BytecodesVerified;
return true;
}
/**
* Get verifier enable status
*/
Boolean is_forced = env->verify_all;
Boolean is_strict = env->verify_strict;
Boolean is_bootstrap = m_class_loader->IsBootstrap();
Boolean is_enabled = env->verify;
/**
* Verify class
*/
if (is_enabled == 1 && !is_interface()
&& (is_bootstrap == FALSE || is_forced == TRUE)) {
char *error;
vf_Result result =
vf_verify_class(this, is_strict, &error);
if (VF_OK != result) {
aulock.ForceUnlock();
REPORT_FAILED_CLASS_CLASS(m_class_loader, this,
"java/lang/VerifyError", error);
vf_release_memory(error);
return false;
}
}
m_state = ST_BytecodesVerified;
return true;
} // Class::verify
to
bool Class::verify(const Global_Env * env) // This is the optimized
version. It could estimate the verification bypass
{
// fast path
if (m_state >= ST_BytecodesVerified)
return true;
m_state = ST_BytecodesVerified;
return true;
}
On Tue, Nov 4, 2008 at 1:20 PM, Jin Mingjian <[EMAIL PROTECTED]> wrote:
> just a note here:
> From some dynamic language implementors, it is reported that, Sun's
> jvm may treat the bootstrape classes different. (such as, some
> verification has been bypassed?)
>
> some class OS sharing mechanism may reduce the second jvm startup
> time?(IBM and SUN JDK 6.0+ seem using this mechanism)
>
