app_main.cpp revision 1fe21bd1b6ca8b94c78fbf3666a1e8e0472355de 
1/*
2 * Main entry of app process.
3 *
4 * Starts the interpreted runtime, then starts up the application.
5 *
6 */
7
8#define LOG_TAG "appproc"
9
10#include <binder/IPCThreadState.h>
11#include <binder/ProcessState.h>
12#include <utils/Log.h>
13#include <cutils/process_name.h>
14#include <cutils/memory.h>
15#include <android_runtime/AndroidRuntime.h>
16#include <sys/personality.h>
17
18#include <stdlib.h>
19#include <stdio.h>
20#include <unistd.h>
21
22namespace android {
23
24void app_usage()
25{
26    fprintf(stderr,
27        "Usage: app_process [java-options] cmd-dir start-class-name [options]\n");
28}
29
30class AppRuntime : public AndroidRuntime
31{
32public:
33    AppRuntime()
34        : mParentDir(NULL)
35        , mClassName(NULL)
36        , mClass(NULL)
37        , mArgC(0)
38        , mArgV(NULL)
39    {
40    }
41
42#if 0
43    // this appears to be unused
44    const char* getParentDir() const
45    {
46        return mParentDir;
47    }
48#endif
49
50    const char* getClassName() const
51    {
52        return mClassName;
53    }
54
55    virtual void onVmCreated(JNIEnv* env)
56    {
57        if (mClassName == NULL) {
58            return; // Zygote. Nothing to do here.
59        }
60
61        /*
62         * This is a little awkward because the JNI FindClass call uses the
63         * class loader associated with the native method we're executing in.
64         * If called in onStarted (from RuntimeInit.finishInit because we're
65         * launching "am", for example), FindClass would see that we're calling
66         * from a boot class' native method, and so wouldn't look for the class
67         * we're trying to look up in CLASSPATH. Unfortunately it needs to,
68         * because the "am" classes are not boot classes.
69         *
70         * The easiest fix is to call FindClass here, early on before we start
71         * executing boot class Java code and thereby deny ourselves access to
72         * non-boot classes.
73         */
74        char* slashClassName = toSlashClassName(mClassName);
75        mClass = env->FindClass(slashClassName);
76        if (mClass == NULL) {
77            ALOGE("ERROR: could not find class '%s'\n", mClassName);
78        }
79        free(slashClassName);
80
81        mClass = reinterpret_cast<jclass>(env->NewGlobalRef(mClass));
82    }
83
84    virtual void onStarted()
85    {
86        sp<ProcessState> proc = ProcessState::self();
87        ALOGV("App process: starting thread pool.\n");
88        proc->startThreadPool();
89
90        AndroidRuntime* ar = AndroidRuntime::getRuntime();
91        ar->callMain(mClassName, mClass, mArgC, mArgV);
92
93        IPCThreadState::self()->stopProcess();
94    }
95
96    virtual void onZygoteInit()
97    {
98        sp<ProcessState> proc = ProcessState::self();
99        ALOGV("App process: starting thread pool.\n");
100        proc->startThreadPool();
101    }
102
103    virtual void onExit(int code)
104    {
105        if (mClassName == NULL) {
106            // if zygote
107            IPCThreadState::self()->stopProcess();
108        }
109
110        AndroidRuntime::onExit(code);
111    }
112
113
114    const char* mParentDir;
115    const char* mClassName;
116    jclass mClass;
117    int mArgC;
118    const char* const* mArgV;
119};
120
121}
122
123using namespace android;
124
125/*
126 * sets argv0 to as much of newArgv0 as will fit
127 */
128static void setArgv0(const char *argv0, const char *newArgv0)
129{
130    strlcpy(const_cast<char *>(argv0), newArgv0, strlen(argv0));
131}
132
133int main(int argc, char* const argv[])
134{
135#ifdef __arm__
136    /*
137     * b/7188322 - Temporarily revert to the compat memory layout
138     * to avoid breaking third party apps.
139     *
140     * THIS WILL GO AWAY IN A FUTURE ANDROID RELEASE.
141     *
142     * http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=7dbaa466
143     * changes the kernel mapping from bottom up to top-down.
144     * This breaks some programs which improperly embed
145     * an out of date copy of Android's linker.
146     */
147    if (getenv("NO_ADDR_COMPAT_LAYOUT_FIXUP") == NULL) {
148        int current = personality(0xFFFFFFFF);
149        if ((current & ADDR_COMPAT_LAYOUT) == 0) {
150            personality(current | ADDR_COMPAT_LAYOUT);
151            setenv("NO_ADDR_COMPAT_LAYOUT_FIXUP", "1", 1);
152            execv("/system/bin/app_process", argv);
153            return -1;
154        }
155    }
156#endif
157
158    // These are global variables in ProcessState.cpp
159    mArgC = argc;
160    mArgV = argv;
161
162    mArgLen = 0;
163    for (int i=0; i<argc; i++) {
164        mArgLen += strlen(argv[i]) + 1;
165    }
166    mArgLen--;
167
168    AppRuntime runtime;
169    const char* argv0 = argv[0];
170
171    // Process command line arguments
172    // ignore argv[0]
173    argc--;
174    argv++;
175
176    // Everything up to '--' or first non '-' arg goes to the vm
177
178    int i = runtime.addVmArguments(argc, argv);
179
180    // Parse runtime arguments.  Stop at first unrecognized option.
181    bool zygote = false;
182    bool startSystemServer = false;
183    bool application = false;
184    const char* parentDir = NULL;
185    const char* niceName = NULL;
186    const char* className = NULL;
187    while (i < argc) {
188        const char* arg = argv[i++];
189        if (!parentDir) {
190            parentDir = arg;
191        } else if (strcmp(arg, "--zygote") == 0) {
192            zygote = true;
193            niceName = "zygote";
194        } else if (strcmp(arg, "--start-system-server") == 0) {
195            startSystemServer = true;
196        } else if (strcmp(arg, "--application") == 0) {
197            application = true;
198        } else if (strncmp(arg, "--nice-name=", 12) == 0) {
199            niceName = arg + 12;
200        } else {
201            className = arg;
202            break;
203        }
204    }
205
206    if (niceName && *niceName) {
207        setArgv0(argv0, niceName);
208        set_process_name(niceName);
209    }
210
211    runtime.mParentDir = parentDir;
212
213    if (zygote) {
214        runtime.start("com.android.internal.os.ZygoteInit",
215                startSystemServer ? "start-system-server" : "");
216    } else if (className) {
217        // Remainder of args get passed to startup class main()
218        runtime.mClassName = className;
219        runtime.mArgC = argc - i;
220        runtime.mArgV = argv + i;
221        runtime.start("com.android.internal.os.RuntimeInit",
222                application ? "application" : "tool");
223    } else {
224        fprintf(stderr, "Error: no class name or --zygote supplied.\n");
225        app_usage();
226        LOG_ALWAYS_FATAL("app_process: no class name or --zygote supplied.");
227        return 10;
228    }
229}
230