From 9900b3e929fb0ffa2542637c339fa2c1a59fe648 Mon Sep 17 00:00:00 2001 From: reinelt <> Date: Thu, 8 Apr 2004 10:48:25 +0000 Subject: [lcd4linux @ 2004-04-08 10:48:23 by reinelt] finished plugin_exec modified thread handling added '%x' format to qprintf (hexadecimal) --- plugin_exec.c | 235 ++++++++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 196 insertions(+), 39 deletions(-) (limited to 'plugin_exec.c') diff --git a/plugin_exec.c b/plugin_exec.c index 59bfb89..565ace1 100644 --- a/plugin_exec.c +++ b/plugin_exec.c @@ -1,4 +1,4 @@ -/* $Id: plugin_exec.c,v 1.1 2004/03/20 11:49:40 reinelt Exp $ +/* $Id: plugin_exec.c,v 1.2 2004/04/08 10:48:25 reinelt Exp $ * * plugin for external processes * @@ -27,6 +27,11 @@ * * * $Log: plugin_exec.c,v $ + * Revision 1.2 2004/04/08 10:48:25 reinelt + * finished plugin_exec + * modified thread handling + * added '%x' format to qprintf (hexadecimal) + * * Revision 1.1 2004/03/20 11:49:40 reinelt * forgot to add plugin_exec.c ... * @@ -46,63 +51,215 @@ #include #include #include - -// #include -// #include -// #include - -#include -#include -#include +#include +#include #include "debug.h" #include "plugin.h" #include "hash.h" #include "cfg.h" #include "thread.h" +#include "qprintf.h" + + +#define NUM_THREADS 16 +#define SHM_SIZE 256 + +typedef struct { + int delay; + int mutex; + pid_t pid; + int shmid; + char *cmd; + char *key; + char *ret; +} EXEC_THREAD; + +static EXEC_THREAD Thread[NUM_THREADS]; +static int max_thread = -1; static HASH EXEC = { 0, }; -static int fatal = 0; -static int do_exec (void) + +// x^0 + x^5 + x^12 +#define CRCPOLY 0x8408 + +static unsigned short CRC (unsigned char *s) +{ + int i; + unsigned short crc; + + // seed value + crc=0xffff; + + while (*s!='\0') { + crc ^= *s++; + for (i = 0; i < 8; i++) + crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY : 0); + } + return crc; +} + + +static void exec_thread (void *data) +{ + EXEC_THREAD *Thread = (EXEC_THREAD*)data; + FILE *pipe; + char buffer[SHM_SIZE]; + int len; + + // use a safe path + putenv ("PATH=/usr/local/bin:/usr/bin:/bin"); + + // forever... + while (1) { + pipe = popen(Thread->cmd, "r"); + if (pipe == NULL) { + error("exec error: could not run pipe '%s': %s", Thread->cmd, strerror(errno)); + len = 0; + } else { + len = fread(buffer, 1, SHM_SIZE-1, pipe); + if (len <= 0) { + error("exec error: could not read from pipe '%s': %s", Thread->cmd, strerror(errno)); + len = 0; + } + pclose(pipe); + } + + // force trailing zero + buffer[len] = '\0'; + + // remove trailing CR/LF + while (len>0 && (buffer[len-1]=='\n' || buffer[len-1]=='\r')) { + buffer[--len]='\0'; + } + + // lock shared memory + mutex_lock(Thread->mutex); + // write data + strncpy(Thread->ret, buffer, SHM_SIZE); + // unlock shared memory + mutex_unlock(Thread->mutex); + usleep (Thread->delay); + } +} + + +static void destroy_exec_thread (int n) +{ + if (Thread[n].mutex != 0) mutex_destroy(Thread[n].mutex); + if (Thread[n].cmd) free (Thread[n].cmd); + if (Thread[n].key) free (Thread[n].key); + if (Thread[n].ret) shm_destroy (Thread[n].shmid, Thread[n].ret); + + Thread[n].delay = 0; + Thread[n].mutex = 0; + Thread[n].pid = 0; + Thread[n].shmid = 0; + Thread[n].cmd = NULL; + Thread[n].key = NULL; + Thread[n].ret = NULL; +} + + +static int create_exec_thread (char *cmd, char *key, int delay) { - int age; + char name[10]; + + if (max_thread >= NUM_THREADS) { + error ("cannot create exec thread <%s>: thread buffer full!", cmd); + return -1; + } + + max_thread++; + Thread[max_thread].delay = delay; + Thread[max_thread].mutex = mutex_create(); + Thread[max_thread].pid = -1; + Thread[max_thread].cmd = strdup(cmd); + Thread[max_thread].key = strdup(key); + Thread[max_thread].ret = NULL; + + // create communication buffer + Thread[max_thread].shmid = shm_create ((void**)&Thread[max_thread].ret, SHM_SIZE); + + // catch error + if (Thread[max_thread].shmid < 0) { + error ("cannot create exec thread <%s>: shared memory allocation failed!", cmd); + destroy_exec_thread (max_thread--); + return -1; + } - // if a fatal error occured, do nothing - if (fatal != 0) return -1; + // create thread + qprintf(name, sizeof(name), "exec-%s", key); + Thread[max_thread].pid = thread_create (name, exec_thread, &Thread[max_thread]); + + // catch error + if (Thread[max_thread].pid < 0) { + error ("cannot create exec thread <%s>: fork failed?!", cmd); + destroy_exec_thread (max_thread--); + return -1; + } - // reread every 100 msec only - age=hash_age(&EXEC, NULL, NULL); - if (age>0 && age<=100) return 0; return 0; -} +} -static void my_junk (char *name) + +static int do_exec (char *cmd, char *key, int delay) { - int i; + int i, age; + + age = hash_age(&EXEC, key, NULL); - debug ("junk thread starting!"); + if (age < 0) { + hash_set (&EXEC, key, ""); + // first-time call: create thread + if (delay < 10) { + error ("exec(%s): delay %d is too short! using 10 msec", cmd, delay); + delay = 10; + } + if (create_exec_thread (cmd, key, 1000*delay)) { + return -1; + } + return 0; + } + + // reread every 10 msec only + if (age > 0 && age <= 10) return 0; - for (i=0; i<10; i++) { - debug ("junk look %d", i); - sleep (1); + // find thread + for (i = 0; i <= max_thread; i++) { + if (strcmp(key, Thread[i].key) == 0) { + // lock shared memory + mutex_lock(Thread[i].mutex); + // copy data + hash_set (&EXEC, key, Thread[i].ret); + // unlock shared memory + mutex_unlock(Thread[i].mutex); + return 0; + } } - debug ("junk thread done!"); + + error ("internal error: could not find thread exec-%s", key); + return -1; } - -static void my_exec (RESULT *result, int argc, RESULT *argv[]) +static void my_exec (RESULT *result, RESULT *arg1, RESULT *arg2) { - char *key, *val; + char *cmd, key[5], *val; + int delay; - if (do_exec()<0) { + cmd = R2S(arg1); + delay = (int)R2N(arg2); + + qprintf (key, sizeof(key), "%x", CRC(cmd)); + + if (do_exec(cmd, key, delay) < 0) { SetResult(&result, R_STRING, ""); return; } - // key=R2S(arg1); - val=hash_get(&EXEC, key); - if (val==NULL) val=""; + val = hash_get(&EXEC, key); + if (val == NULL) val = ""; SetResult(&result, R_STRING, val); } @@ -110,18 +267,18 @@ static void my_exec (RESULT *result, int argc, RESULT *argv[]) int plugin_init_exec (void) { - int junk; - - AddFunction ("exec", -1, my_exec); - - // junk=thread_create ("Junk", my_junk); - // debug ("junk=%d", junk); - + AddFunction ("exec", 2, my_exec); return 0; } void plugin_exit_exec(void) { + int i; + + for (i=0; i<=max_thread; i++) { + destroy_exec_thread(i); + } + hash_destroy(&EXEC); } -- cgit v1.2.3