1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #ifndef mozilla_jni_Utils_h__
8 #define mozilla_jni_Utils_h__
9
10 #include <jni.h>
11
12 #include "nsIRunnable.h"
13
14 #include "mozilla/UniquePtr.h"
15
16 #if defined(DEBUG) || !defined(RELEASE_OR_BETA)
17 # define MOZ_CHECK_JNI
18 #endif
19
20 #ifdef MOZ_CHECK_JNI
21 # include <unistd.h>
22 # include "mozilla/Assertions.h"
23 # include "APKOpen.h"
24 # include "MainThreadUtils.h"
25 #endif
26
27 namespace mozilla {
28 namespace jni {
29
30 // How exception during a JNI call should be treated.
31 enum class ExceptionMode {
32 // Abort on unhandled excepion (default).
33 ABORT,
34 // Ignore the exception and return to caller.
35 IGNORE,
36 // Catch any exception and return a nsresult.
37 NSRESULT,
38 };
39
40 // Thread that a particular JNI call is allowed on.
41 enum class CallingThread {
42 // Can be called from any thread (default).
43 ANY,
44 // Can be called from the Gecko thread.
45 GECKO,
46 // Can be called from the Java UI thread.
47 UI,
48 };
49
50 // If and where a JNI call will be dispatched.
51 enum class DispatchTarget {
52 // Call happens synchronously on the calling thread (default).
53 CURRENT,
54 // Call happens synchronously on the calling thread, but the call is
55 // wrapped in a function object and is passed thru UsesNativeCallProxy.
56 // Method must return void.
57 PROXY,
58 // Call is dispatched asynchronously on the Gecko thread to the XPCOM
59 // (nsThread) event queue. Method must return void.
60 GECKO,
61 // Call is dispatched asynchronously on the Gecko thread to the widget
62 // (nsAppShell) event queue. In most cases, events in the widget event
63 // queue (aka native event queue) are favored over events in the XPCOM
64 // event queue. Method must return void.
65 GECKO_PRIORITY,
66 };
67
68 extern JavaVM* sJavaVM;
69 extern JNIEnv* sGeckoThreadEnv;
70
IsAvailable()71 inline bool IsAvailable() { return !!sGeckoThreadEnv; }
72
GetVM()73 inline JavaVM* GetVM() {
74 #ifdef MOZ_CHECK_JNI
75 MOZ_ASSERT(sJavaVM);
76 #endif
77 return sJavaVM;
78 }
79
GetGeckoThreadEnv()80 inline JNIEnv* GetGeckoThreadEnv() {
81 #ifdef MOZ_CHECK_JNI
82 MOZ_RELEASE_ASSERT(NS_IsMainThread(), "Must be on Gecko thread");
83 MOZ_RELEASE_ASSERT(sGeckoThreadEnv, "Must have a JNIEnv");
84 #endif
85 return sGeckoThreadEnv;
86 }
87
88 void SetGeckoThreadEnv(JNIEnv* aEnv);
89
90 JNIEnv* GetEnvForThread();
91
92 #ifdef MOZ_CHECK_JNI
93 # define MOZ_ASSERT_JNI_THREAD(thread) \
94 do { \
95 if ((thread) == mozilla::jni::CallingThread::GECKO) { \
96 MOZ_RELEASE_ASSERT(::NS_IsMainThread()); \
97 } else if ((thread) == mozilla::jni::CallingThread::UI) { \
98 const bool isOnUiThread = (GetUIThreadId() == ::gettid()); \
99 MOZ_RELEASE_ASSERT(isOnUiThread); \
100 } \
101 } while (0)
102 #else
103 # define MOZ_ASSERT_JNI_THREAD(thread) \
104 do { \
105 } while (0)
106 #endif
107
108 bool ThrowException(JNIEnv* aEnv, const char* aClass, const char* aMessage);
109
ThrowException(JNIEnv * aEnv,const char * aMessage)110 inline bool ThrowException(JNIEnv* aEnv, const char* aMessage) {
111 return ThrowException(aEnv, "java/lang/Exception", aMessage);
112 }
113
ThrowException(const char * aClass,const char * aMessage)114 inline bool ThrowException(const char* aClass, const char* aMessage) {
115 return ThrowException(GetEnvForThread(), aClass, aMessage);
116 }
117
ThrowException(const char * aMessage)118 inline bool ThrowException(const char* aMessage) {
119 return ThrowException(GetEnvForThread(), aMessage);
120 }
121
122 bool HandleUncaughtException(JNIEnv* aEnv);
123
124 bool ReportException(JNIEnv* aEnv, jthrowable aExc, jstring aStack);
125
126 #define MOZ_CATCH_JNI_EXCEPTION(env) \
127 do { \
128 if (mozilla::jni::HandleUncaughtException((env))) { \
129 MOZ_CRASH("JNI exception"); \
130 } \
131 } while (0)
132
133 uintptr_t GetNativeHandle(JNIEnv* env, jobject instance);
134
135 void SetNativeHandle(JNIEnv* env, jobject instance, uintptr_t handle);
136
137 jclass GetClassRef(JNIEnv* aEnv, const char* aClassName);
138
139 void DispatchToGeckoPriorityQueue(already_AddRefed<nsIRunnable> aCall);
140
141 int GetAPIVersion();
142
143 pid_t GetUIThreadId();
144
145 } // namespace jni
146 } // namespace mozilla
147
148 #endif // mozilla_jni_Utils_h__
149