amxp_subproc.c File Reference

#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdarg.h>
#include <sys/wait.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <poll.h>
#include <time.h>
#include <amxc/amxc_macros.h>
#include <amxc/amxc.h>
#include <amxp/amxp.h>

Go to the source code of this file.

Macros
#define	_GNU_SOURCE
#define	AMXP_SUB_PROC_NR_PIPES   3
#define	AMXP_SUBPROC_FD_PARENT   0
#define	AMXP_SUBPROC_FD_CHILD   1

Functions
static int	amxp_subproc_child_status (amxp_subproc_t *subproc, int status)
static void	amxp_subproc_close_fds (void)
static void	amxp_subproc_exec_child (amxp_subproc_t *const subproc, char **argv)
static void	amxp_subproc_sigchild (UNUSED const char *const sig_name, UNUSED const amxc_var_t *const data, UNUSED void *const priv)
static int	amxp_recalculate_timeout (struct timespec *start, int timeout_msec)
int	amxp_subproc_new (amxp_subproc_t **subproc)
	Constructor function, creates a new child process data structure. More...
int	amxp_subproc_delete (amxp_subproc_t **subproc)
	Destructor function, deletes a child process data structure. More...
int	amxp_subproc_open_fd (amxp_subproc_t *subproc, int requested)
	Opens standard file descriptor to the child process. More...
int	amxp_subproc_vstart (amxp_subproc_t *const subproc, char **argv)
	Start a child process. More...
int	amxp_subproc_start (amxp_subproc_t *const subproc, char *cmd,...)
	Start a child process. More...
int	amxp_subproc_astart (amxp_subproc_t *const subproc, amxc_array_t *cmd)
	Start a child process. More...
int	amxp_subproc_kill (const amxp_subproc_t *const subproc, const int sig)
	Sends a Linux signal to the child process. More...
amxp_subproc_t *	amxp_subproc_find (const int pid)
	Retrieve a amxp_subproc_t for a child process using it's process identifier. More...
pid_t	amxp_subproc_get_pid (const amxp_subproc_t *const subproc)
	Get the PID of a child process. More...
amxp_signal_mngr_t *	amxp_subproc_get_sigmngr (const amxp_subproc_t *const subproc)
	Get the Signal managers of the child process. More...
bool	amxp_subproc_is_running (const amxp_subproc_t *const subproc)
	Checks if the child process is running. More...
int	amxp_subproc_wait (amxp_subproc_t *subproc, int timeout_msec)
	Waits until the child process has stopped. More...
int	amxp_subproc_vstart_wait (amxp_subproc_t *subproc, int timeout_msec, char **cmd)
	Starts a child process and waits until it exits. More...
int	amxp_subproc_start_wait (amxp_subproc_t *subproc, int timeout_msec, char *cmd,...)
	Starts a child process and waits until it exits. More...
int	amxp_subproc_ifexited (amxp_subproc_t *subproc)
	Checks if the child process terminated normally. More...
int	amxp_subproc_ifsignaled (amxp_subproc_t *subproc)
	Checks if the child process was stopped because of an uncaught Linux signal. More...
int	amxp_subproc_get_exitstatus (amxp_subproc_t *subproc)
	Gets the exit code of the child process. More...
int	amxp_subproc_get_termsig (amxp_subproc_t *subproc)
	Gets the Linux signal id that caused the child process to stop. More...

Variables
static amxc_llist_t	amxp_subprocs

Macro Definition Documentation

_GNU_SOURCE

#define _GNU_SOURCE

Definition at line 56 of file amxp_subproc.c.

AMXP_SUB_PROC_NR_PIPES

#define AMXP_SUB_PROC_NR_PIPES   3

Definition at line 74 of file amxp_subproc.c.

AMXP_SUBPROC_FD_CHILD

#define AMXP_SUBPROC_FD_CHILD   1

Definition at line 77 of file amxp_subproc.c.

AMXP_SUBPROC_FD_PARENT

#define AMXP_SUBPROC_FD_PARENT   0

Definition at line 76 of file amxp_subproc.c.

Function Documentation

amxp_recalculate_timeout()

static int amxp_recalculate_timeout ( struct timespec *  start, int  timeout_msec  )

static

Definition at line 187 of file amxp_subproc.c.

                                                                              {
    int err;
    struct timespec stop;
    int remaining_timeout = 0;
 
    int msec_passed;
    time_t sec_to_msec;
    long nsec_to_msec;
 
    err = clock_gettime(CLOCK_REALTIME, &stop);
    when_failed(err, exit);
 
    sec_to_msec = (( stop.tv_sec - start->tv_sec ) * ((time_t) 1000));
    nsec_to_msec = (( stop.tv_nsec - start->tv_nsec) / ((long) 1000000));
 
    msec_passed = (int) sec_to_msec + (int) nsec_to_msec;
    remaining_timeout = timeout_msec - msec_passed;
 
    if(remaining_timeout < 0) {
        // this is to avoid that a timeout gets converted
        // to wait indefinitely
        remaining_timeout = 0;
    }
 
exit:
    return remaining_timeout;
}

amxp_subproc_child_status()

static int amxp_subproc_child_status ( amxp_subproc_t *  subproc, int  status  )

static

Definition at line 81 of file amxp_subproc.c.

                                                                          {
    int retval = -1;
    amxc_var_t* exit_info = NULL;
    amxc_var_t data;
 
    subproc->is_running = false;
    subproc->status = status;
 
    amxc_var_init(&data);
    amxc_var_new(&exit_info);
    amxc_var_set_type(exit_info, AMXC_VAR_ID_HTABLE);
 
    amxc_var_set(int64_t, &data, subproc->pid);
    amxc_var_set_key(exit_info, "PID", &data, AMXC_VAR_FLAG_COPY);
 
    if(WIFEXITED(status)) {
        amxc_var_set(int64_t, &data, WEXITSTATUS(status));
        amxc_var_set_key(exit_info, "ExitCode", &data, AMXC_VAR_FLAG_COPY);
    } else if(WIFSIGNALED(status)) {
        if(WCOREDUMP(status)) {
            amxc_var_set(bool, &data, true);
            amxc_var_set_key(exit_info, "CoreDump", &data, AMXC_VAR_FLAG_COPY);
        } else {
            amxc_var_set(bool, &data, true);
            amxc_var_set_key(exit_info, "CoreDump", &data, AMXC_VAR_FLAG_COPY);
        }
        amxc_var_set(bool, &data, true);
        amxc_var_set_key(exit_info, "Signalled", &data, AMXC_VAR_FLAG_COPY);
        amxc_var_set(int64_t, &data, WTERMSIG(status));
        amxc_var_set_key(exit_info, "Signal", &data, AMXC_VAR_FLAG_COPY);
    } else {
        goto exit;
    }
 
 
    amxp_sigmngr_emit_signal(subproc->sigmngr, "stop", exit_info);
    amxc_var_delete(&exit_info);
 
    retval = 0;
 
exit:
    return retval;
}

amxp_subproc_close_fds()

static void amxp_subproc_close_fds ( void  )

static

Definition at line 125 of file amxp_subproc.c.

                                         {
    struct rlimit limit;
    int max_files = 1024;
 
    int ret = getrlimit(RLIMIT_NOFILE, &limit);
    if(ret == 0) {
        max_files = limit.rlim_cur;
    }
 
    for(int i = 3; i < max_files; i++) {
        close(i);
    }
}

amxp_subproc_exec_child()

static void amxp_subproc_exec_child ( amxp_subproc_t *const  subproc, char **  argv  )

static

Definition at line 139 of file amxp_subproc.c.

                                                 {
    int fd_null = -1;
    sigset_t sig_set;
 
    prctl(PR_SET_PDEATHSIG, SIGKILL);
 
    fd_null = open("/dev/null", O_RDWR);
    for(int i = 0; i < AMXP_SUB_PROC_NR_PIPES; i++) {
        if(subproc->fd[i][AMXP_SUBPROC_FD_CHILD] >= 0) {
            if(i != subproc->fd[i][AMXP_SUBPROC_FD_CHILD]) {
                close(i);
                dup2(subproc->fd[i][AMXP_SUBPROC_FD_CHILD], i);
            }
        } else {
            dup2(fd_null, i);
        }
    }
 
    amxp_subproc_close_fds();
 
    pthread_sigmask(SIG_SETMASK, NULL, &sig_set);
    pthread_sigmask(SIG_UNBLOCK, &sig_set, NULL);
 
    execvp(argv[0], argv);
 
    _exit(EXIT_FAILURE);
}

amxp_subproc_sigchild()

static void amxp_subproc_sigchild ( UNUSED const char *const  sig_name, UNUSED const amxc_var_t *const  data, UNUSED void *const  priv  )

static

Definition at line 168 of file amxp_subproc.c.

                                                           {
    int status = -1;
    pid_t ret = -1;
    amxp_subproc_t* subproc;
 
    while((ret = waitpid(-1, &status, WNOHANG)) > 0) {
        subproc = amxp_subproc_find(ret);
        if(subproc == NULL) {
            continue;
        }
 
        amxp_subproc_child_status(subproc, status);
    }
 
    return;
}

Variable Documentation

amxp_subprocs

amxc_llist_t amxp_subprocs

static

Definition at line 79 of file amxp_subproc.c.