platform_system_core/libcutils/process_name.c

96 lines
2.8 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <stdlib.h>
#include <string.h>
#include <cutils/process_name.h>
#ifdef HAVE_ANDROID_OS
#include <cutils/properties.h>
#endif
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#if defined(HAVE_PRCTL)
#include <sys/prctl.h>
#endif
#define PROCESS_NAME_DEVICE "/sys/qemu_trace/process_name"
static const char* process_name = "unknown";
static int running_in_emulator = -1;
void set_process_name(const char* new_name) {
#ifdef HAVE_ANDROID_OS
char propBuf[PROPERTY_VALUE_MAX];
#endif
if (new_name == NULL) {
return;
}
// We never free the old name. Someone else could be using it.
int len = strlen(new_name);
char* copy = (char*) malloc(len + 1);
strcpy(copy, new_name);
process_name = (const char*) copy;
#if defined(HAVE_PRCTL)
if (len < 16) {
prctl(PR_SET_NAME, (unsigned long) new_name, 0, 0, 0);
} else {
prctl(PR_SET_NAME, (unsigned long) new_name + len - 15, 0, 0, 0);
}
#endif
#ifdef HAVE_ANDROID_OS
// If we know we are not running in the emulator, then return.
if (running_in_emulator == 0) {
return;
}
// If the "running_in_emulator" variable has not been initialized,
// then do it now.
if (running_in_emulator == -1) {
property_get("ro.kernel.qemu", propBuf, "");
if (propBuf[0] == '1') {
running_in_emulator = 1;
} else {
running_in_emulator = 0;
return;
}
}
// If the emulator was started with the "-trace file" command line option
// then we want to record the process name in the trace even if we are
// not currently tracing instructions (so that we will know the process
// name when we do start tracing instructions). We do not need to execute
// this code if we are just running in the emulator without the "-trace"
// command line option, but we don't know that here and this function
// isn't called frequently enough to bother optimizing that case.
int fd = open(PROCESS_NAME_DEVICE, O_RDWR);
if (fd < 0)
return;
write(fd, process_name, strlen(process_name) + 1);
close(fd);
#endif
}
const char* get_process_name(void) {
return process_name;
}