On 13/05/2020 16:44, Claes Redestad wrote:
Hi,
compilers can't see though and optimize away the repeated GetObjectField
calls in places such as in the io_util_md.h GET_FD macro:
#define GET_FD(this, fid) \
(*env)->GetObjectField(env, (this), (fid)) == NULL ? \
-1 : (*env)->GetIntField(env, (*env)->GetObjectField(env,
(this), (fid)), IO_fd_fdID)
This can be avoided if we turn the macros into functions which call
GetObjectField only once:
FD getFD(JNIEnv *env, jobject this, jfieldID fid) {
jobject fd = (*env)->GetObjectField(env, this, fid);
if (fd == NULL) {
return -1;
}
return (*env)->GetIntField(env, fd, IO_fd_fdID);
}
The similarly affected SET_FD is only used in one place, so I removed
that macro and applied the equivalent optimization at the call-site.
The Windows implementation returns a HANDLE rather than an int fd so
there is a bit inconsistency when compared to the network code. This
pre-dates your change and technical debt that will need attention some
time. Your changes look good.
-Alan
