process_name.c revision dd7bc3319deb2b77c5d07a51b7d6cd7e11b5beb0
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 27static const char* process_name = "unknown"; 28static int running_in_emulator = -1; 29 30void 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 73const char* get_process_name(void) { 74 return process_name; 75} 76