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Diffstat (limited to 'polyp/cpulimit.c')
| -rw-r--r-- | polyp/cpulimit.c | 236 |
1 files changed, 0 insertions, 236 deletions
diff --git a/polyp/cpulimit.c b/polyp/cpulimit.c deleted file mode 100644 index a834b094..00000000 --- a/polyp/cpulimit.c +++ /dev/null @@ -1,236 +0,0 @@ -/* $Id$ */ - -/*** - This file is part of polypaudio. - - polypaudio is free software; you can redistribute it and/or modify - it under the terms of the GNU Lesser General Public License as - published by the Free Software Foundation; either version 2 of the - License, or (at your option) any later version. - - polypaudio is distributed in the hope that it will be useful, but - WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with polypaudio; if not, write to the Free Software - Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 - USA. -***/ - -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#include "cpulimit.h" -#include "util.h" -#include "log.h" - -#ifdef HAVE_SIGXCPU - -#include <errno.h> -#include <stdio.h> -#include <string.h> -#include <assert.h> -#include <sys/time.h> -#include <unistd.h> -#include <signal.h> - -#ifdef HAVE_SYS_RESOURCE_H -#include <sys/resource.h> -#endif - -/* This module implements a watchdog that makes sure that the current - * process doesn't consume more than 70% CPU time for 10 seconds. This - * is very useful when using SCHED_FIFO scheduling which effectively - * disables multitasking. */ - -/* Method of operation: Using SIGXCPU a signal handler is called every - * 10s process CPU time. That function checks if less than 14s system - * time have passed. In that case, it tries to contact the main event - * loop through a pipe. After two additional seconds it is checked - * whether the main event loop contact was successful. If not, the - * program is terminated forcibly. */ - -/* Utilize this much CPU time at maximum */ -#define CPUTIME_PERCENT 70 - -/* Check every 10s */ -#define CPUTIME_INTERVAL_SOFT (10) - -/* Recheck after 2s */ -#define CPUTIME_INTERVAL_HARD (2) - -/* Time of the last CPU load check */ -static time_t last_time = 0; - -/* Pipe for communicating with the main loop */ -static int the_pipe[2] = {-1, -1}; - -/* Main event loop and IO event for the FIFO */ -static pa_mainloop_api *api = NULL; -static pa_io_event *io_event = NULL; - -/* Saved sigaction struct for SIGXCPU */ -static struct sigaction sigaction_prev; - -/* Nonzero after pa_cpu_limit_init() */ -static int installed = 0; - -/* The current state of operation */ -static enum { - PHASE_IDLE, /* Normal state */ - PHASE_SOFT /* After CPU overload has been detected */ -} phase = PHASE_IDLE; - -/* Reset the SIGXCPU timer to the next t seconds */ -static void reset_cpu_time(int t) { - int r; - long n; - struct rlimit rl; - struct rusage ru; - - /* Get the current CPU time of the current process */ - r = getrusage(RUSAGE_SELF, &ru); - assert(r >= 0); - - n = ru.ru_utime.tv_sec + ru.ru_stime.tv_sec + t; - - r = getrlimit(RLIMIT_CPU, &rl); - assert(r >= 0); - - rl.rlim_cur = n; - r = setrlimit(RLIMIT_CPU, &rl); - assert(r >= 0); -} - -/* A simple, thread-safe puts() work-alike */ -static void write_err(const char *p) { - pa_loop_write(2, p, strlen(p)); -} - -/* The signal handler, called on every SIGXCPU */ -static void signal_handler(int sig) { - assert(sig == SIGXCPU); - - if (phase == PHASE_IDLE) { - time_t now; - -#ifdef PRINT_CPU_LOAD - char t[256]; -#endif - - time(&now); - -#ifdef PRINT_CPU_LOAD - snprintf(t, sizeof(t), "Using %0.1f%% CPU\n", (double)CPUTIME_INTERVAL_SOFT/(now-last_time)*100); - write_err(t); -#endif - - if (CPUTIME_INTERVAL_SOFT >= ((now-last_time)*(double)CPUTIME_PERCENT/100)) { - static const char c = 'X'; - - write_err("Soft CPU time limit exhausted, terminating.\n"); - - /* Try a soft cleanup */ - write(the_pipe[1], &c, sizeof(c)); - phase = PHASE_SOFT; - reset_cpu_time(CPUTIME_INTERVAL_HARD); - - } else { - - /* Everything's fine */ - reset_cpu_time(CPUTIME_INTERVAL_SOFT); - last_time = now; - } - - } else if (phase == PHASE_SOFT) { - write_err("Hard CPU time limit exhausted, terminating forcibly.\n"); - _exit(1); /* Forced exit */ - } -} - -/* Callback for IO events on the FIFO */ -static void callback(pa_mainloop_api*m, pa_io_event*e, int fd, pa_io_event_flags f, void *userdata) { - char c; - assert(m && e && f == PA_IO_EVENT_INPUT && e == io_event && fd == the_pipe[0]); - read(the_pipe[0], &c, sizeof(c)); - m->quit(m, 1); /* Quit the main loop */ -} - -/* Initializes CPU load limiter */ -int pa_cpu_limit_init(pa_mainloop_api *m) { - struct sigaction sa; - assert(m && !api && !io_event && the_pipe[0] == -1 && the_pipe[1] == -1 && !installed); - - time(&last_time); - - /* Prepare the main loop pipe */ - if (pipe(the_pipe) < 0) { - pa_log(__FILE__": pipe() failed: %s\n", strerror(errno)); - return -1; - } - - pa_make_nonblock_fd(the_pipe[0]); - pa_make_nonblock_fd(the_pipe[1]); - pa_fd_set_cloexec(the_pipe[0], 1); - pa_fd_set_cloexec(the_pipe[1], 1); - - api = m; - io_event = api->io_new(m, the_pipe[0], PA_IO_EVENT_INPUT, callback, NULL); - - phase = PHASE_IDLE; - - /* Install signal handler for SIGXCPU */ - memset(&sa, 0, sizeof(sa)); - sa.sa_handler = signal_handler; - sigemptyset(&sa.sa_mask); - sa.sa_flags = SA_RESTART; - - if (sigaction(SIGXCPU, &sa, &sigaction_prev) < 0) { - pa_cpu_limit_done(); - return -1; - } - - installed = 1; - - reset_cpu_time(CPUTIME_INTERVAL_SOFT); - - return 0; -} - -/* Shutdown CPU load limiter */ -void pa_cpu_limit_done(void) { - int r; - - if (io_event) { - assert(api); - api->io_free(io_event); - io_event = NULL; - api = NULL; - } - - if (the_pipe[0] >= 0) - close(the_pipe[0]); - if (the_pipe[1] >= 0) - close(the_pipe[1]); - the_pipe[0] = the_pipe[1] = -1; - - if (installed) { - r = sigaction(SIGXCPU, &sigaction_prev, NULL); - assert(r >= 0); - installed = 0; - } -} - -#else /* HAVE_SIGXCPU */ - -int pa_cpu_limit_init(PA_GCC_UNUSED pa_mainloop_api *m) { - return 0; -} - -void pa_cpu_limit_done(void) { -} - -#endif |