From: gregor herrmann <gregoa@debian.org>
Date: Mon, 3 Apr 2006 20:32:07 +0000 (-0000)
Subject: [svn-inject] Installing original source of cpulimit
X-Git-Tag: upstream/1.1
X-Git-Url: https://git.toastfreeware.priv.at/debian/cpulimit.git/commitdiff_plain/refs/tags/upstream/1.1?ds=sidebyside

[svn-inject] Installing original source of cpulimit
---

2db5b5aa767497b284795580c4f0c07a4ef32807
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..9013c27
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,7 @@
+all::	cpulimit
+
+cpulimit:	cpulimit.c
+	gcc -o cpulimit cpulimit.c -lrt -Wall -O2
+
+clean:
+	rm -f *~ cpulimit
diff --git a/cpulimit.c b/cpulimit.c
new file mode 100644
index 0000000..bd2ea0a
--- /dev/null
+++ b/cpulimit.c
@@ -0,0 +1,537 @@
+/**
+ * Copyright (c) 2005, by:      Angelo Marletta <marlonx80@hotmail.com>
+ *
+ * This file may be used subject to the terms and conditions of the
+ * GNU Library General Public License Version 2, or any later version
+ * at your option, as published by the Free Software Foundation.
+ * This program 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 Library General Public License for more details.
+ *
+ **********************************************************************
+ *
+ * Simple program to limit the cpu usage of a process
+ * If you modify this code, send me a copy please
+ *
+ * Author:  Angelo Marletta
+ * Date:    26/06/2005
+ * Version: 1.1
+ * Last version at: http://marlon80.interfree.it/cpulimit/index.html
+ *
+ * Changelog:
+ *  - Fixed a segmentation fault if controlled process exited in particular circumstances
+ *  - Better CPU usage estimate
+ *  - Fixed a <0 %CPU usage reporting in rare cases
+ *  - Replaced MAX_PATH_SIZE with PATH_MAX already defined in <limits.h>
+ *  - Command line arguments now available
+ *  - Now is possible to specify target process by pid
+ */
+
+
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <signal.h>
+#include <sys/resource.h>
+#include <string.h>
+#include <dirent.h>
+#include <errno.h>
+#include <string.h>
+
+//kernel time resolution (inverse of one jiffy interval) in Hertz
+//i don't know how to detect it, then define to the default (not very clean!)
+#define HZ 100
+
+//some useful macro
+#define min(a,b) (a<b?a:b)
+#define max(a,b) (a>b?a:b)
+
+//pid of the controlled process
+int pid=0;
+//executable file name
+char *program_name;
+//verbose mode
+int verbose=0;
+//lazy mode
+int lazy=0;
+
+//reverse byte search
+void *memrchr(const void *s, int c, size_t n);
+
+//return ta-tb in microseconds (no overflow checks!)
+inline long timediff(const struct timespec *ta,const struct timespec *tb) {
+    unsigned long us = (ta->tv_sec-tb->tv_sec)*1000000 + (ta->tv_nsec/1000 - tb->tv_nsec/1000);
+    return us;
+}
+
+int waitforpid(int pid) {
+	//switch to low priority
+	if (setpriority(PRIO_PROCESS,getpid(),19)!=0) {
+		printf("Warning: cannot renice\n");
+	}
+
+	int i=0;
+
+	while(1) {
+
+		DIR *dip;
+		struct dirent *dit;
+
+		//open a directory stream to /proc directory
+		if ((dip = opendir("/proc")) == NULL) {
+			perror("opendir");
+			return -1;
+		}
+
+		//read in from /proc and seek for process dirs
+		while ((dit = readdir(dip)) != NULL) {
+			//get pid
+			if (pid==atoi(dit->d_name)) {
+				//pid detected
+				if (kill(pid,SIGSTOP)==0 &&  kill(pid,SIGCONT)==0) {
+					//process is ok!
+					goto done;
+				}
+				else {
+					fprintf(stderr,"Error: Process %d detected, but you don't have permission to control it\n",pid);
+				}
+			}
+		}
+
+		//close the dir stream and check for errors
+		if (closedir(dip) == -1) {
+			perror("closedir");
+			return -1;
+		}
+
+		//no suitable target found
+		if (i++==0) {
+			if (lazy) {
+				fprintf(stderr,"No process found\n");
+				exit(2);
+			}
+			else {
+				printf("Warning: no target process found. Waiting for it...\n");
+			}
+		}
+
+		//sleep for a while
+		sleep(2);
+	}
+
+done:
+	printf("Process %d detected\n",pid);
+	//now set high priority, if possible
+	if (setpriority(PRIO_PROCESS,getpid(),-20)!=0) {
+		printf("Warning: cannot renice.\nTo work better you should run this program as root.\n");
+	}
+	return 0;
+
+}
+
+//this function periodically scans process list and looks for executable path names
+//it should be executed in a low priority context, since precise timing does not matter
+//if a process is found then its pid is returned
+//process: the name of the wanted process, can be an absolute path name to the executable file
+//         or simply its name
+//return: pid of the found process
+int getpidof(const char *process) {
+
+	//set low priority
+	if (setpriority(PRIO_PROCESS,getpid(),19)!=0) {
+		printf("Warning: cannot renice\n");
+	}
+
+	char exelink[20];
+	char exepath[PATH_MAX+1];
+	int pid=0;
+	int i=0;
+
+	while(1) {
+
+		DIR *dip;
+		struct dirent *dit;
+
+		//open a directory stream to /proc directory
+		if ((dip = opendir("/proc")) == NULL) {
+			perror("opendir");
+			return -1;
+		}
+
+		//read in from /proc and seek for process dirs
+		while ((dit = readdir(dip)) != NULL) {
+			//get pid
+			pid=atoi(dit->d_name);
+			if (pid>0) {
+				sprintf(exelink,"/proc/%d/exe",pid);
+				int size=readlink(exelink,exepath,sizeof(exepath));
+				if (size>0) {
+					int found=0;
+					if (process[0]=='/' && strncmp(exepath,process,size)==0 && size==strlen(process)) {
+						//process starts with / then it's an absolute path
+						found=1;
+					}
+					else {
+						//process is the name of the executable file
+						if (strncmp(exepath+size-strlen(process),process,strlen(process))==0) {
+							found=1;
+						}
+					}
+					if (found==1) {
+						if (kill(pid,SIGSTOP)==0 &&  kill(pid,SIGCONT)==0) {
+							//process is ok!
+							goto done;
+						}
+						else {
+							fprintf(stderr,"Error: Process %d detected, but you don't have permission to control it\n",pid);
+						}
+					}
+				}
+			}
+		}
+
+		//close the dir stream and check for errors
+		if (closedir(dip) == -1) {
+			perror("closedir");
+			return -1;
+		}
+
+		//no suitable target found
+		if (i++==0) {
+			if (lazy) {
+				fprintf(stderr,"No process found\n");
+				exit(2);
+			}
+			else {
+				printf("Warning: no target process found. Waiting for it...\n");
+			}
+		}
+
+		//sleep for a while
+		sleep(2);
+	}
+
+done:
+	printf("Process %d detected\n",pid);
+	//now set high priority, if possible
+	if (setpriority(PRIO_PROCESS,getpid(),-20)!=0) {
+		printf("Warning: cannot renice.\nTo work better you should run this program as root.\n");
+	}
+	return pid;
+
+}
+
+//SIGINT and SIGTERM signal handler
+void quit(int sig) {
+	//let the process continue if it's stopped
+	kill(pid,SIGCONT);
+	printf("Exiting...\n");
+	exit(0);
+}
+
+//get jiffies count from /proc filesystem
+int getjiffies(int pid) {
+	static char stat[20];
+	static char buffer[1024];
+	sprintf(stat,"/proc/%d/stat",pid);
+	FILE *f=fopen(stat,"r");
+	if (f==NULL) return -1;
+	fgets(buffer,sizeof(buffer),f);
+	fclose(f);
+	char *p=buffer;
+	p=memchr(p+1,')',sizeof(buffer)-(p-buffer));
+	int sp=12;
+	while (sp--)
+		p=memchr(p+1,' ',sizeof(buffer)-(p-buffer));
+	//user mode jiffies
+	int utime=atoi(p+1);
+	p=memchr(p+1,' ',sizeof(buffer)-(p-buffer));
+	//kernel mode jiffies
+	int ktime=atoi(p+1);
+	return utime+ktime;
+}
+
+//process instant photo
+struct process_screenshot {
+	struct timespec when;	//timestamp
+	int jiffies;	//jiffies count of the process
+	int cputime;	//microseconds of work from previous screenshot to current
+};
+
+//extracted process statistics
+struct cpu_usage {
+	float pcpu;
+	float workingrate;
+};
+
+//this function is an autonomous dynamic system
+//it works with static variables (state variables of the system), that keep memory of recent past
+//its aim is to estimate the cpu usage of the process
+//to work properly it should be called in a fixed periodic way
+//perhaps i will put it in a separate thread...
+int compute_cpu_usage(int pid,int last_working_quantum,struct cpu_usage *pusage) {
+	#define MEM_ORDER 10
+	//circular buffer containing last MEM_ORDER process screenshots
+	static struct process_screenshot ps[MEM_ORDER];
+	//the last screenshot recorded in the buffer
+	static int front=-1;
+	//the oldest screenshot recorded in the buffer
+	static int tail=0;
+
+	if (pusage==NULL) {
+		//reinit static variables
+		front=-1;
+		tail=0;
+		return 0;
+	}
+
+	//let's advance front index and save the screenshot
+	front=(front+1)%MEM_ORDER;
+	int j=getjiffies(pid);
+	if (j>=0) ps[front].jiffies=j;
+	else return -1;	//error: pid does not exist
+	clock_gettime(CLOCK_REALTIME,&(ps[front].when));
+	ps[front].cputime=last_working_quantum;
+
+	//buffer actual size is: (front-tail+MEM_ORDER)%MEM_ORDER+1
+	int size=(front-tail+MEM_ORDER)%MEM_ORDER+1;
+
+	if (size==1) {
+		//not enough samples taken (it's the first one!), return -1
+		pusage->pcpu=-1;
+		pusage->workingrate=1;
+		return 0;
+	}
+	else {
+		//now we can calculate cpu usage, interval dt and dtwork are expressed in microseconds
+		long dt=timediff(&(ps[front].when),&(ps[tail].when));
+		long dtwork=0;
+		int i=(tail+1)%MEM_ORDER;
+		int max=(front+1)%MEM_ORDER;
+		do {
+			dtwork+=ps[i].cputime;
+			i=(i+1)%MEM_ORDER;
+		} while (i!=max);
+		int used=ps[front].jiffies-ps[tail].jiffies;
+		float usage=(used*1000000.0/HZ)/dtwork;
+		pusage->workingrate=1.0*dtwork/dt;
+		pusage->pcpu=usage*pusage->workingrate;
+		if (size==MEM_ORDER)
+			tail=(tail+1)%MEM_ORDER;
+		return 0;
+	}
+	#undef MEM_ORDER
+}
+
+void print_caption() {
+	printf("\n%%CPU\twork quantum\tsleep quantum\tactive rate\n");
+}
+
+void print_usage(FILE *stream,int exit_code) {
+	fprintf(stream, "Usage: %s TARGET [OPTIONS...]\n",program_name);
+	fprintf(stream, "   TARGET must be exactly one of these:\n");
+	fprintf(stream, "      -p, --pid=N        pid of the process\n");
+	fprintf(stream, "      -e, --exe=FILE     name of the executable program file\n");
+	fprintf(stream, "      -P, --path=PATH    absolute path name of the executable program file\n");
+	fprintf(stream, "   OPTIONS\n");
+	fprintf(stream, "      -l, --limit=N      percentage of cpu allowed from 0 to 100 (mandatory)\n");
+	fprintf(stream, "      -v, --verbose      show control statistics\n");
+	fprintf(stream, "      -z, --lazy         exit if there is no suitable target process, or if it dies\n");
+	fprintf(stream, "      -h, --help         display this help and exit\n");
+	exit(exit_code);
+}
+
+int main(int argc, char **argv) {
+
+	//get program name
+	char *p=(char*)memrchr(argv[0],(unsigned int)'/',strlen(argv[0]));
+	program_name = p==NULL?argv[0]:(p+1);
+	//parse arguments
+	int next_option;
+	/* A string listing valid short options letters. */
+	const char* short_options="p:e:P:l:vzh";
+	/* An array describing valid long options. */
+	const struct option long_options[] = {
+		{ "pid", 0, NULL, 'p' },
+		{ "exe", 1, NULL, 'e' },
+		{ "path", 0, NULL, 'P' },
+		{ "limit", 0, NULL, 'l' },
+		{ "verbose", 0, NULL, 'v' },
+		{ "lazy", 0, NULL, 'z' },
+		{ "help", 0, NULL, 'h' },
+		{ NULL, 0, NULL, 0 }
+	};
+	//argument variables
+	const char *exe=NULL;
+	const char *path=NULL;
+	int perclimit=0;
+	int pid_ok=0;
+	int process_ok=0;
+	int limit_ok=0;
+
+	do {
+		next_option = getopt_long (argc, argv, short_options,long_options, NULL);
+		switch(next_option) {
+			case 'p':
+				pid=atoi(optarg);
+				pid_ok=1;
+				break;
+			case 'e':
+				exe=optarg;
+				process_ok=1;
+				break;
+			case 'P':
+				path=optarg;
+				process_ok=1;
+				break;
+			case 'l':
+				perclimit=atoi(optarg);
+				limit_ok=1;
+				break;
+			case 'v':
+				verbose=1;
+				break;
+			case 'z':
+				lazy=1;
+				break;
+			case 'h':
+				print_usage (stdout, 1);
+				break;
+			case '?':
+				print_usage (stderr, 1);
+				break;
+			case -1:
+				break;
+			default:
+				abort();
+		}
+	} while(next_option != -1);
+
+	if (!process_ok && !pid_ok) {
+		fprintf(stderr,"Error: You must specify a target process\n");
+		print_usage (stderr, 1);
+		exit(1);
+	}
+	if ((exe!=NULL && path!=NULL) || (pid_ok && (exe!=NULL || path!=NULL))) {
+		fprintf(stderr,"Error: You must specify exactly one target process\n");
+		print_usage (stderr, 1);
+		exit(1);
+	}
+	if (!limit_ok) {
+		fprintf(stderr,"Error: You must specify a cpu limit\n");
+		print_usage (stderr, 1);
+		exit(1);
+	}
+	float limit=perclimit/100.0;
+	if (limit<0 || limit >1) {
+		fprintf(stderr,"Error: limit must be in the range 0-100\n");
+		print_usage (stderr, 1);
+		exit(1);
+	}
+	//parameters are all ok!
+	signal(SIGINT,quit);
+	signal(SIGTERM,quit);
+
+	//time quantum in microseconds. it's splitted in a working period and a sleeping one
+	int period=100000;
+	struct timespec twork,tsleep;   //working and sleeping intervals
+	memset(&twork,0,sizeof(struct timespec));
+	memset(&tsleep,0,sizeof(struct timespec));
+
+wait_for_process:
+
+	//look for the target process..or wait for it
+	if (exe!=NULL)
+		pid=getpidof(exe);
+	else if (path!=NULL)
+		pid=getpidof(path);
+	else {
+		waitforpid(pid);
+	}
+	//process detected...let's play
+
+	//init compute_cpu_usage internal stuff
+	compute_cpu_usage(0,0,NULL);
+	//main loop counter
+	int i=0;
+
+	struct timespec startwork,endwork;
+	long workingtime=0;		//last working time in microseconds
+
+	if (verbose) print_caption();
+
+	float pcpu_avg=0;
+
+	//here we should already have high priority, for time precision
+	while(1) {
+
+		//estimate how much the controlled process is using the cpu in its working interval
+		struct cpu_usage cu;
+		if (compute_cpu_usage(pid,workingtime,&cu)==-1) {
+			fprintf(stderr,"Process %d dead!\n",pid);
+			if (lazy) exit(2);
+			//wait until our process appears
+			goto wait_for_process;		
+		}
+
+		//cpu actual usage of process (range 0-1)
+		float pcpu=cu.pcpu;
+		//rate at which we are keeping active the process (range 0-1)
+		float workingrate=cu.workingrate;
+
+		//adjust work and sleep time slices
+		if (pcpu>0) {
+			twork.tv_nsec=min(period*limit*1000/pcpu*workingrate,period*1000);
+		}
+		else if (pcpu==0) {
+			twork.tv_nsec=period*1000;
+		}
+		else if (pcpu==-1) {
+			//not yet a valid idea of cpu usage
+			pcpu=limit;
+			workingrate=limit;
+			twork.tv_nsec=min(period*limit*1000,period*1000);
+		}
+		tsleep.tv_nsec=period*1000-twork.tv_nsec;
+
+		//update average usage
+		pcpu_avg=(pcpu_avg*i+pcpu)/(i+1);
+
+		if (verbose && i%10==0 && i>0) {
+			printf("%0.2f%%\t%6ld us\t%6ld us\t%0.2f%%\n",pcpu*100,twork.tv_nsec/1000,tsleep.tv_nsec/1000,workingrate*100);
+		}
+
+		if (limit<1 && limit>0) {
+			//resume process
+			if (kill(pid,SIGCONT)!=0) {
+				fprintf(stderr,"Process %d dead!\n",pid);
+				if (lazy) exit(2);
+				//wait until our process appears
+				goto wait_for_process;
+			}
+		}
+
+		clock_gettime(CLOCK_REALTIME,&startwork);
+		nanosleep(&twork,NULL);		//now process is working	
+		clock_gettime(CLOCK_REALTIME,&endwork);
+		workingtime=timediff(&endwork,&startwork);
+
+		if (limit<1) {
+			//stop process, it has worked enough
+			if (kill(pid,SIGSTOP)!=0) {
+				fprintf(stderr,"Process %d dead!\n",pid);
+				if (lazy) exit(2);
+				//wait until our process appears
+				goto wait_for_process;
+			}
+			nanosleep(&tsleep,NULL);	//now process is sleeping
+		}
+		i++;
+	}
+
+}