1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "rsUtils.h"
18#include "rsCppUtils.h"
19
20#include <string>
21#include <unistd.h>
22
23#ifndef RS_COMPATIBILITY_LIB
24#include <sys/wait.h>
25#endif
26
27
28namespace android {
29namespace renderscript {
30
31const char * rsuCopyString(const char *name) {
32    return rsuCopyString(name, strlen(name));
33}
34
35const char * rsuCopyString(const char *name, size_t len) {
36    char *n = new char[len+1];
37    memcpy(n, name, len);
38    n[len] = 0;
39    return n;
40}
41
42const char* rsuJoinStrings(int n, const char* const* strs) {
43    std::string tmp;
44    for (int i = 0; i < n; i++) {
45        if (i > 0) {
46            tmp.append(" ");
47        }
48        tmp.append(strs[i]);
49    }
50    return strndup(tmp.c_str(), tmp.size());
51}
52
53#ifndef RS_COMPATIBILITY_LIB
54bool rsuExecuteCommand(const char *exe, int nArgs, const char * const *args) {
55    std::unique_ptr<const char> joined(rsuJoinStrings(nArgs, args));
56    ALOGV("Invoking %s with args '%s'", exe, joined.get());
57
58    pid_t pid = fork();
59
60    switch (pid) {
61    case -1: {  // Error occurred (we attempt no recovery)
62        ALOGE("Fork of \"%s\" failed with error %s", exe, strerror(errno));
63        return false;
64    }
65    case 0: {  // Child process
66        // No (direct or indirect) call to malloc between fork and exec.  It is
67        // possible that a different thread holds the heap lock before the fork.
68
69        // ProcessManager in libcore can reap unclaimed SIGCHLDs in its process
70        // group.  To ensure that the exit signal is not caught by
71        // ProcessManager and instead sent to libRS, set the child's PGID to its
72        // PID.
73        setpgid(0, 0);
74
75        execv(exe, (char * const *)args);
76
77        ALOGE("execv() failed: %s", strerror(errno));
78        abort();
79        return false;
80    }
81    default: {  // Parent process (actual driver)
82        // Wait on child process to finish execution.
83        int status = 0;
84        pid_t w = TEMP_FAILURE_RETRY(waitpid(pid, &status, 0));
85        if (w == -1) {
86            ALOGE("Waitpid of \"%s\" failed with error %s", exe,
87                  strerror(errno));
88            return false;
89        }
90
91        if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
92            return true;
93        }
94
95        ALOGE("Child process \"%s\" terminated with status %d", exe, status);
96        return false;
97    }
98    }
99}
100#endif // RS_COMPATIBILITY_LIB
101
102// Implementation of property_get from libcutils
103int property_get(const char *key, char *value, const char *default_value) {
104    int len;
105    len = __system_property_get(key, value);
106    if (len > 0) {
107        return len;
108    }
109
110    if (default_value) {
111        len = strlen(default_value);
112        memcpy(value, default_value, len + 1);
113    }
114    return len;
115}
116
117} // namespace renderscript
118} // namespace android
119