1 /*
2 * Copyright (C) 2008 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 <string.h>
18 #include <cutils/process_name.h>
19 #include <cutils/properties.h>
20 #include <unistd.h>
21 #include <sys/types.h>
22 #include <sys/stat.h>
23 #include <fcntl.h>
24
25 #define PROCESS_NAME_DEVICE "/sys/qemu_trace/process_name"
26
27 static const char* process_name = "unknown";
28 static int running_in_emulator = -1;
29
set_process_name(const char * new_name)30 void set_process_name(const char* new_name) {
31 char propBuf[PROPERTY_VALUE_MAX];
32
33 if (new_name == NULL) {
34 return;
35 }
36
37 // We never free the old name. Someone else could be using it.
38 char* copy = (char*) malloc(strlen(new_name) + 1);
39 strcpy(copy, new_name);
40 process_name = (const char*) copy;
41
42 // If we know we are not running in the emulator, then return.
43 if (running_in_emulator == 0) {
44 return;
45 }
46
47 // If the "running_in_emulator" variable has not been initialized,
48 // then do it now.
49 if (running_in_emulator == -1) {
50 property_get("ro.kernel.qemu", propBuf, "");
51 if (propBuf[0] == '1') {
52 running_in_emulator = 1;
53 } else {
54 running_in_emulator = 0;
55 return;
56 }
57 }
58
59 // If the emulator was started with the "-trace file" command line option
60 // then we want to record the process name in the trace even if we are
61 // not currently tracing instructions (so that we will know the process
62 // name when we do start tracing instructions). We do not need to execute
63 // this code if we are just running in the emulator without the "-trace"
64 // command line option, but we don't know that here and this function
65 // isn't called frequently enough to bother optimizing that case.
66 int fd = open(PROCESS_NAME_DEVICE, O_RDWR);
67 if (fd < 0)
68 return;
69 write(fd, process_name, strlen(process_name) + 1);
70 close(fd);
71 }
72
get_process_name(void)73 const char* get_process_name(void) {
74 return process_name;
75 }
76