When I originally implemented DetachCurrentThread, I assumed it didn't
make sense for the main thread to detach itself from the VM, and I was
concerned that allowing it might cause problems for any other threads
still attached. However, detaching the main thread is allowed by the
JNI spec as of Java 2, and OpenJDK's java command does this just
before calling DestroyJavaVM. Therefore, this commit ensures that the
VM doesn't abort if the main thread is detached.
We weren't adding entries to the frame map for calls to the instanceof
thunk when compiling methods. However, that thunk may trigger a GC,
in which case we'll need to unwind the stack, which will lead to a
crash if we don't have a frame map entry for that instruction.
Java requires that NaNs be converted to zero and that numbers at or
beyond the limits of integer representation be clamped to the largest
or smallest value that can be represented, respectively.
Our implementation uses Object.wait(long) to implement Thread.sleep,
which had the side effect of interpreting zero as infinity. However,
for Thread.sleep, zero just means zero. I assume that doesn't mean
"don't sleep at all", though, or else the app wouldn't have called
Thread.sleep in the first place, so this patch sleeps for one
millisecond when zero is passed -- just enough to yield the processor
for a bit. Thread.yield might be a better choice in this case, but I
assume the app would have called that directly if that's what it
wanted.
This led to fixed-position objects being considered unreachable when
they were actually still reachable, causing global weak JNI references
to be cleared prematurely, most notably leading to crashes in AWT
buffered image code.
This commit also fixes a field offset calculation mismatch in
bootimage.cpp relative to machine.cpp.
OpenJDK 7 has refactored this code relative to OpenJDK 6, and now
FontManager is an interface, with SunFontManager providing a (partial)
implementation.
On the ARM platform, Avian compiled to use OpenJDK gets this error on
startup:
java/lang/UnsatisfiedLinkError: no zip in java.library.path
at java/lang/ClassLoader.loadLibrary (line 1860)
at java/lang/Runtime.loadLibrary0 (line 845)
at java/lang/System.loadLibrary (line 1084)
at java/lang/System.initializeSystemClass (line 1145)
Using strace shows why:
[pid 22431]
stat64("/usr/lib/jvm/java-7-openjdk-armhf/jre/lib/i386/libzip.so",
0xbee377e0) = -1 ENOENT (No such file or directory)
The attached patch uses "arm" instead of "i386" in that path. This fixes the
problem.
I get this error when compiling with "make openjdk=...." on both x86_64 and
arm:
compiling test classes
test/Arrays.java:90: error: reference to equals is ambiguous, both method
equals(float[],float[]) in Arrays and method equals(Object[],Object[]) in
Arrays match
expect(java.util.Arrays.equals(null, null));
test/Arrays.java:95: error: reference to hashCode is ambiguous, both method
hashCode(double[]) in Arrays and method hashCode(Object[]) in Arrays match
java.util.Arrays.hashCode(null);
The attached patch fixes this.
Linux, FreeBSD, and QNX all use ELF, so no need to distinguish between
them when generating object files. To avoid confusion, I've switch
from using operating system names to using binary format names where
applicable.
The existing code handled such odd switch statements correctly in the
JIT case, but did the wrong thing for the AOT case, leading to an
assertion failure later on.
