| /* |
| * 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. |
| * |
| * Simple memory eater. Runs as a daemon. Prints the child PID to |
| * std so you can easily kill it later. |
| * Usage: memeater <size in MB> |
| */ |
| |
| #include <stdio.h> |
| #include <unistd.h> |
| #include <stdlib.h> |
| #include <fcntl.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| |
| int main(int argc, char *argv[]) |
| { |
| pid_t pid; |
| int fd; |
| int numMb = argc > 1 ? atoi(argv[1]) : 1; |
| |
| if (argc < 2) { |
| printf("Usage: memeater <num MB to allocate>\n"); |
| exit(1); |
| } |
| |
| switch (fork()) { |
| case -1: |
| perror(argv[0]); |
| exit(1); |
| break; |
| case 0: /* child */ |
| chdir("/"); |
| umask(0); |
| setpgrp(); |
| setsid(); |
| /* fork again to fully detach from controlling terminal. */ |
| switch (pid = fork()) { |
| case -1: |
| perror("failed to fork"); |
| break; |
| case 0: /* second child */ |
| /* redirect to /dev/null */ |
| close(0); |
| open("/dev/null", 0); |
| for (fd = 3; fd < 256; fd++) { |
| close(fd); |
| } |
| |
| printf("Allocating %d MB\n", numMb); |
| fflush(stdout); |
| /* allocate memory and fill it */ |
| while (numMb > 0) { |
| // Allocate 500MB at a time at most |
| int mbToAllocate = numMb > 500 ? 500 : numMb; |
| int bytesToAllocate = mbToAllocate * 1024 * 1024; |
| char *p = malloc(bytesToAllocate); |
| if (p == NULL) { |
| printf("Failed to allocate memory\n"); |
| exit(1); |
| } |
| for (int j = 0; j < bytesToAllocate; j++) { |
| p[j] = j & 0xFF; |
| } |
| printf("Allocated %d MB %p\n", mbToAllocate, p); |
| fflush(stdout); |
| numMb -= mbToAllocate; |
| } |
| |
| close(1); |
| if (open("/dev/null", O_WRONLY) < 0) { |
| perror("/dev/null"); |
| exit(1); |
| } |
| close(2); |
| dup(1); |
| |
| /* Sit around doing nothing */ |
| while (1) { |
| usleep(1000000); |
| } |
| default: |
| /* so caller can easily kill it later. */ |
| printf("%d\n", pid); |
| exit(0); |
| break; |
| } |
| break; |
| default: |
| exit(0); |
| break; |
| } |
| return 0; |
| } |
| |