diff options
Diffstat (limited to 'src/process_group.c')
| -rw-r--r-- | src/process_group.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/src/process_group.c b/src/process_group.c new file mode 100644 index 0000000..71f180b --- /dev/null +++ b/src/process_group.c @@ -0,0 +1,203 @@ +#include <string.h> +#include <stdlib.h> +#include <limits.h> +#include <sys/time.h> +#include <signal.h> + +#include <assert.h> + +#include "process_iterator.h" +#include "process_group.h" +#include "list.h" + +// look for a process by pid +// search_pid : pid of the wanted process +// return: pid of the found process, if successful +// negative pid, if the process does not exist or if the signal fails +int find_process_by_pid(pid_t pid) +{ + return (kill(pid,0)==0) ? pid : -pid; +} + +// look for a process with a given name +// process: the name of the wanted process. it can be an absolute path name to the executable file +// or just the file name +// return: pid of the found process, if it is found +// 0, if it's not found +// negative pid, if it is found but it's not possible to control it +int find_process_by_name(const char *process_name) +{ + //whether the variable process_name is the absolute path or not + int is_absolute_path = process_name[0] == '/'; + //flag indicating if the a process with given name was found + int found = 0; + pid_t pid = -1; + + //process iterator + struct process_iterator it; + struct process proc; + struct process_filter filter; + filter.pid = 0; + filter.include_children = 0; + init_process_iterator(&it, &filter); + while (get_next_process(&it, &proc) != -1) + { + pid = proc.pid; + int size = strlen(proc.command); + + found = 0; + if (is_absolute_path && strncmp(proc.command, process_name, size)==0 && size==strlen(process_name)) { + //process found + found = 1; + } + else { + //process found + if (strncmp(proc.command + size - strlen(process_name), process_name, strlen(process_name))==0) { + found = 1; + } + } + if (found==1) { + if (kill(pid,SIGCONT)==0) { + //process is ok! + break; + } + else { + //we don't have permission to send signal to that process + //so, don't exit from the loop and look for another one with the same name + found = -1; + } + } + } + if (close_process_iterator(&it) != 1) exit(1); + if (found == 1) { + //ok, the process was found + return pid; + } + else if (found == 0) { + //no process found + return 0; + } + else if (found == -1) { + //the process was found, but we haven't permission to control it + return -pid; + } + //this MUST NOT happen + exit(2); +} + +int init_process_group(struct process_group *pgroup, int target_pid, int include_children) +{ + //hashtable initialization + memset(&pgroup->proctable, 0, sizeof(pgroup->proctable)); + pgroup->target_pid = target_pid; + pgroup->include_children = include_children; + pgroup->proclist = (struct list*)malloc(sizeof(struct list)); + init_list(pgroup->proclist, 4); + memset(&pgroup->last_update, 0, sizeof(pgroup->last_update)); + update_process_group(pgroup); + return 0; +} + +int close_process_group(struct process_group *pgroup) +{ + int i; + int size = sizeof(pgroup->proctable) / sizeof(struct process*); + for (i=0; i<size; i++) { + if (pgroup->proctable[i] != NULL) { + //free() history for each process + destroy_list(pgroup->proctable[i]); + free(pgroup->proctable[i]); + pgroup->proctable[i] = NULL; + } + } + clear_list(pgroup->proclist); + free(pgroup->proclist); + pgroup->proclist = NULL; + return 0; +} + +void remove_terminated_processes(struct process_group *pgroup) +{ + //TODO +} + +//return t1-t2 in microseconds (no overflow checks, so better watch out!) +static inline unsigned long timediff(const struct timeval *t1,const struct timeval *t2) +{ + return (t1->tv_sec - t2->tv_sec) * 1000000 + (t1->tv_usec - t2->tv_usec); +} + +//parameter in range 0-1 +#define ALFA 0.08 +#define MIN_DT 20 + +void update_process_group(struct process_group *pgroup) +{ + struct process_iterator it; + struct process tmp_process; + struct process_filter filter; + struct timeval now; + gettimeofday(&now, NULL); + //time elapsed from previous sample (in ms) + long dt = timediff(&now, &pgroup->last_update) / 1000; + filter.pid = pgroup->target_pid; + filter.include_children = pgroup->include_children; + init_process_iterator(&it, &filter); + clear_list(pgroup->proclist); + init_list(pgroup->proclist, 4); + + while (get_next_process(&it, &tmp_process) != -1) + { +// struct timeval t; +// gettimeofday(&t, NULL); +// printf("T=%ld.%ld PID=%d PPID=%d START=%d CPUTIME=%d\n", t.tv_sec, t.tv_usec, tmp_process.pid, tmp_process.ppid, tmp_process.starttime, tmp_process.cputime); + int hashkey = pid_hashfn(tmp_process.pid + tmp_process.starttime); + if (pgroup->proctable[hashkey] == NULL) + { + //empty bucket + pgroup->proctable[hashkey] = malloc(sizeof(struct list)); + struct process *new_process = malloc(sizeof(struct process)); + tmp_process.cpu_usage = -1; + memcpy(new_process, &tmp_process, sizeof(struct process)); + init_list(pgroup->proctable[hashkey], 4); + add_elem(pgroup->proctable[hashkey], new_process); + add_elem(pgroup->proclist, new_process); + } + else + { + //existing bucket + struct process *p = (struct process*)locate_elem(pgroup->proctable[hashkey], &tmp_process); + if (p == NULL) + { + //process is new. add it + struct process *new_process = malloc(sizeof(struct process)); + tmp_process.cpu_usage = -1; + memcpy(new_process, &tmp_process, sizeof(struct process)); + add_elem(pgroup->proctable[hashkey], new_process); + add_elem(pgroup->proclist, new_process); + } + else + { + assert(tmp_process.pid == p->pid); + assert(tmp_process.ppid == p->ppid); + assert(tmp_process.starttime == p->starttime); + add_elem(pgroup->proclist, p); + if (dt < MIN_DT) continue; + //process exists. update CPU usage + double sample = 1.0 * (tmp_process.cputime - p->cputime) / dt; + if (p->cpu_usage == -1) { + //initialization + p->cpu_usage = sample; + } + else { + //usage adjustment + p->cpu_usage = (1.0-ALFA) * p->cpu_usage + ALFA * sample; + } + p->cputime = tmp_process.cputime; + } + } + } + close_process_iterator(&it); + if (dt < MIN_DT) return; + pgroup->last_update = now; +} |