1 /*
   2  * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 #import <AppKit/AppKit.h>
  27 #import <objc/message.h>
  28 
  29 #import "ThreadUtilities.h"
  30 
  31 
  32 // The following must be named "jvm", as there are extern references to it in AWT
  33 JavaVM *jvm = NULL;
  34 static JNIEnv *appKitEnv = NULL;
  35 static jobject appkitThreadGroup = NULL;
  36 static NSString* JavaRunLoopMode = @"javaRunLoopMode";
  37 static NSArray<NSString*> *javaModes = nil;
  38 
  39 static inline void attachCurrentThread(void** env) {
  40     if ([NSThread isMainThread]) {
  41         JavaVMAttachArgs args;
  42         args.version = JNI_VERSION_1_4;
  43         args.name = "AppKit Thread";
  44         args.group = appkitThreadGroup;
  45         (*jvm)->AttachCurrentThreadAsDaemon(jvm, env, &args);
  46     } else {
  47         (*jvm)->AttachCurrentThreadAsDaemon(jvm, env, NULL);
  48     }
  49 }
  50 
  51 @implementation ThreadUtilities
  52 
  53 + (void)initialize {
  54     /* All the standard modes plus ours */
  55     javaModes = [[NSArray alloc] initWithObjects:NSDefaultRunLoopMode,
  56                                            NSModalPanelRunLoopMode,
  57                                            NSEventTrackingRunLoopMode,
  58                                            JavaRunLoopMode,
  59                                            nil];
  60 }
  61 
  62 + (JNIEnv*)getJNIEnv {
  63 AWT_ASSERT_APPKIT_THREAD;
  64     if (appKitEnv == NULL) {
  65         attachCurrentThread((void **)&appKitEnv);
  66     }
  67     return appKitEnv;
  68 }
  69 
  70 + (JNIEnv*)getJNIEnvUncached {
  71     JNIEnv *env = NULL;
  72     attachCurrentThread((void **)&env);
  73     return env;
  74 }
  75 
  76 + (void)detachCurrentThread {
  77     (*jvm)->DetachCurrentThread(jvm);
  78 }
  79 
  80 + (void)setAppkitThreadGroup:(jobject)group {
  81     appkitThreadGroup = group;
  82 }
  83 
  84 /* This is needed because we can't directly pass a block to
  85  * performSelectorOnMainThreadWaiting .. since it expects a selector
  86  */
  87 + (void)invokeBlock:(void (^)())block {
  88   block();
  89 }
  90 
  91 /*
  92  * When running a block where either we don't wait, or it needs to run on another thread
  93  * we need to copy it from stack to heap, use the copy in the call and release after use.
  94  * Do this only when we must because it could be expensive.
  95  * Note : if waiting cross-thread, possibly the stack allocated copy is accessible ?
  96  */
  97 + (void)invokeBlockCopy:(void (^)(void))blockCopy {
  98   blockCopy();
  99   Block_release(blockCopy);
 100 }
 101 
 102 + (void)performOnMainThreadWaiting:(BOOL)wait block:(void (^)())block {
 103     if ([NSThread isMainThread] && wait == YES) {
 104         block();
 105     } else {
 106         if (wait == YES) {
 107             [self performOnMainThread:@selector(invokeBlock:) on:self withObject:block waitUntilDone:YES];
 108         } else {
 109             void (^blockCopy)(void) = Block_copy(block);
 110             [self performOnMainThread:@selector(invokeBlockCopy:) on:self withObject:blockCopy waitUntilDone:NO];
 111         }
 112     }
 113 }
 114 
 115 + (void)performOnMainThread:(SEL)aSelector on:(id)target withObject:(id)arg waitUntilDone:(BOOL)wait {
 116     if ([NSThread isMainThread] && wait == YES) {
 117         [target performSelector:aSelector withObject:arg];
 118     } else {
 119         [target performSelectorOnMainThread:aSelector withObject:arg waitUntilDone:wait modes:javaModes];
 120     }
 121 }
 122 
 123 + (NSString*)javaRunLoopMode {
 124     return JavaRunLoopMode;
 125 }
 126 
 127 @end
 128 
 129 
 130 void OSXAPP_SetJavaVM(JavaVM *vm)
 131 {
 132     jvm = vm;
 133 }
 134