• Bradley Smith (14/14) Jan 08 2007 I'm experimenting with using D for Java Native Interface (JNI)
• Juan Jose Comellas (5/24) Jan 09 2007 This mail is not related specifically to your problem. I just wanted to ...
• Bradley Smith (5/33) Jan 09 2007 Thanks. I was unaware of that. It appears that the JVM signal use can be...
• Juan Jose Comellas (4/40) Jan 09 2007 Not that I'm aware of. DMD/Phobos hardcode the SIGUSR1 and SIGUSR2 signa...
• Sean Kelly (12/55) Jan 09 2007 This is something that has bothered me for a while about the garbage

Bradley Smith <digitalmars-com baysmith.com> writes:

I'm experimenting with using D for Java Native Interface (JNI) 
programming. I may have encountered a bug with GDC calling a C function 
in the JavaVM invocation API. The following is the relevant code.

JNI_CreateJavaVM(&jvm, cast(void**)&env, &vm_args);
version (gdcBugWorkaround) {
   // Any statement can go here (even "int x = 0;")
   assert (jvm !is null, "JNI_CreateJavaVM failed");
}

For some reason, the program will crash unless some kinds of statements 
follow the call to JNI_CreateJavaVM. Is this a bug?

The full code and a build.bat script are in the attached zip. I'm using 
gdc --version: "gdc (GCC) 3.4.5 (mingw special) (gdc 0.21, using dmd 1.00)"

Thanks,
   Bradley

Juan Jose Comellas <jcomellas gmail.com> writes:

This mail is not related specifically to your problem. I just wanted to warn
you that both the JVM and DMD/Phobos use the same Unix signals for garbage
collection (SIGUSR1 and SIGUSR2) on Linux. All hell will break loose if you
don't remap the signals the JVM uses.


Bradley Smith wrote:

 I'm experimenting with using D for Java Native Interface (JNI)
 programming. I may have encountered a bug with GDC calling a C function
 in the JavaVM invocation API. The following is the relevant code.
 
 JNI_CreateJavaVM(&jvm, cast(void**)&env, &vm_args);
 version (gdcBugWorkaround) {
    // Any statement can go here (even "int x = 0;")
    assert (jvm !is null, "JNI_CreateJavaVM failed");
 }
 
 For some reason, the program will crash unless some kinds of statements
 follow the call to JNI_CreateJavaVM. Is this a bug?
 
 The full code and a build.bat script are in the attached zip. I'm using
 gdc --version: "gdc (GCC) 3.4.5 (mingw special) (gdc 0.21, using dmd
 1.00)"
 
 Thanks,
    Bradley

Bradley Smith <digitalmars-com baysmith.com> writes:

Thanks. I was unaware of that. It appears that the JVM signal use can be 
removed with the -Xrs option. Is it possible to do the same in DMD/Phobos?

Thanks,
   Bradley


Juan Jose Comellas wrote:
 This mail is not related specifically to your problem. I just wanted to warn
 you that both the JVM and DMD/Phobos use the same Unix signals for garbage
 collection (SIGUSR1 and SIGUSR2) on Linux. All hell will break loose if you
 don't remap the signals the JVM uses.
 
 
 Bradley Smith wrote:
 
 I'm experimenting with using D for Java Native Interface (JNI)
 programming. I may have encountered a bug with GDC calling a C function
 in the JavaVM invocation API. The following is the relevant code.

 JNI_CreateJavaVM(&jvm, cast(void**)&env, &vm_args);
 version (gdcBugWorkaround) {
    // Any statement can go here (even "int x = 0;")
    assert (jvm !is null, "JNI_CreateJavaVM failed");
 }

 For some reason, the program will crash unless some kinds of statements
 follow the call to JNI_CreateJavaVM. Is this a bug?

 The full code and a build.bat script are in the attached zip. I'm using
 gdc --version: "gdc (GCC) 3.4.5 (mingw special) (gdc 0.21, using dmd
 1.00)"

 Thanks,
    Bradley

 

Juan Jose Comellas <jcomellas gmail.com> writes:

Not that I'm aware of. DMD/Phobos hardcode the SIGUSR1 and SIGUSR2 signals
to start and stop the garbage collection cycle, as all threads need to be
paused while the garbage collector is running.


Bradley Smith wrote:

 Thanks. I was unaware of that. It appears that the JVM signal use can be
 removed with the -Xrs option. Is it possible to do the same in DMD/Phobos?
 
 Thanks,
    Bradley
 
 
 Juan Jose Comellas wrote:
 This mail is not related specifically to your problem. I just wanted to
 warn you that both the JVM and DMD/Phobos use the same Unix signals for
 garbage collection (SIGUSR1 and SIGUSR2) on Linux. All hell will break
 loose if you don't remap the signals the JVM uses.
 
 
 Bradley Smith wrote:
 
 I'm experimenting with using D for Java Native Interface (JNI)
 programming. I may have encountered a bug with GDC calling a C function
 in the JavaVM invocation API. The following is the relevant code.

 JNI_CreateJavaVM(&jvm, cast(void**)&env, &vm_args);
 version (gdcBugWorkaround) {
    // Any statement can go here (even "int x = 0;")
    assert (jvm !is null, "JNI_CreateJavaVM failed");
 }

 For some reason, the program will crash unless some kinds of statements
 follow the call to JNI_CreateJavaVM. Is this a bug?

 The full code and a build.bat script are in the attached zip. I'm using
 gdc --version: "gdc (GCC) 3.4.5 (mingw special) (gdc 0.21, using dmd
 1.00)"

 Thanks,
    Bradley

Sean Kelly <sean f4.ca> writes:

This is something that has bothered me for a while about the garbage 
collection mechanism in D, but I'm not aware of a way around it.  An 
interrupt must be sent between threads to suspend and resume processing, 
and SIGUSR1/SIGUSR2 are the only reasonable means of doing so that I'm 
aware of.  Worse yet, only one signal handler can be registered for each 
signal at a time (as far as I'm aware), so SIGUSR1 and SIGUSR2 are 
effectively reserved for use by the GC in D.  In Windows, since signals 
are essentially unsupported, some debug routines are used instead to 
externally suspend and resume running threads.  This actually works a 
bit better than the Unix solution because it doesn't cancel kernel 
routines that may be processing in the thread to be suspended.

Juan Jose Comellas wrote:
 Not that I'm aware of. DMD/Phobos hardcode the SIGUSR1 and SIGUSR2 signals
 to start and stop the garbage collection cycle, as all threads need to be
 paused while the garbage collector is running.
 
 
 Bradley Smith wrote:
 
 Thanks. I was unaware of that. It appears that the JVM signal use can be
 removed with the -Xrs option. Is it possible to do the same in DMD/Phobos?

 Thanks,
    Bradley


 Juan Jose Comellas wrote:
 This mail is not related specifically to your problem. I just wanted to
 warn you that both the JVM and DMD/Phobos use the same Unix signals for
 garbage collection (SIGUSR1 and SIGUSR2) on Linux. All hell will break
 loose if you don't remap the signals the JVM uses.


 Bradley Smith wrote:

 I'm experimenting with using D for Java Native Interface (JNI)
 programming. I may have encountered a bug with GDC calling a C function
 in the JavaVM invocation API. The following is the relevant code.

 JNI_CreateJavaVM(&jvm, cast(void**)&env, &vm_args);
 version (gdcBugWorkaround) {
    // Any statement can go here (even "int x = 0;")
    assert (jvm !is null, "JNI_CreateJavaVM failed");
 }

 For some reason, the program will crash unless some kinds of statements
 follow the call to JNI_CreateJavaVM. Is this a bug?

 The full code and a build.bat script are in the attached zip. I'm using
 gdc --version: "gdc (GCC) 3.4.5 (mingw special) (gdc 0.21, using dmd
 1.00)"

 Thanks,
    Bradley