[SOLVED] Imagick multithread problem
Posted: 2012-10-22T13:04:40-07:00
Hi all!,
I've been implementing an aplication that uses Imagick, and testing with multiple threads I found a problem with the MagickReadImageBlob function. I'm using Fedora 14, I used yum to install ImageMagick-devel-6.6.4.1-15.fc14.i686, the kernell release is 2.6.35.11-83.fc14.i686.PAE. The problem can be reproduced with:
I compile with:
If I uncomment the pthread_mutex_lock and pthread_mutex_unlock calls, everything works perfect. Otherwise most of the time generates a core with the message:
Am I doing something wrong???,
Thanks in advance
I've been implementing an aplication that uses Imagick, and testing with multiple threads I found a problem with the MagickReadImageBlob function. I'm using Fedora 14, I used yum to install ImageMagick-devel-6.6.4.1-15.fc14.i686, the kernell release is 2.6.35.11-83.fc14.i686.PAE. The problem can be reproduced with:
Code: Select all
#include <stdio.h>
#include <pthread.h>
#include <wand/MagickWand.h>
unsigned char *get_file_blob(char *file_path,size_t *length){
FILE *fd;
unsigned char *blob;
size_t sz;
fd = fopen(file_path,"r");
if(!fd)
return NULL;
fseek(fd,0L,SEEK_END);
sz = ftell(fd);
fclose(fd);
fd = fopen(file_path,"r");
if(length)
*length = sz;
blob = malloc(sz);
fread(blob,sz,1,fd);
fclose(fd);
return blob;
}
pthread_mutex_t img_lock;
void *thread(void *arg){
size_t length;
unsigned char *blob;
MagickWand *magick_wand;
char *path = (char *)arg;
//pthread_mutex_lock(&img_lock);
magick_wand = NewMagickWand();
blob = get_file_blob(path,&length);
if(!blob){
DestroyMagickWand(magick_wand);
//pthread_mutex_unlock(&img_lock);
return NULL;
}
MagickBooleanType status = MagickReadImageBlob(magick_wand, blob, length);
DestroyMagickWand(magick_wand);
//pthread_mutex_unlock(&img_lock);
free(blob);
pthread_detach(pthread_self());
return NULL;
}
int main(int argc, char *argv[]){
if(argc != 2)
return 1;
MagickWandGenesis();
int i;
pthread_mutex_init(&img_lock,NULL);
for(i = 0; i < 20; ++i){
pthread_t thread_id;
pthread_create(&thread_id,NULL,thread,argv[1]);
}
pthread_mutex_destroy(&img_lock);
MagickWandTerminus();
return 0;
}
Code: Select all
gcc -g -o test test.c `Wand-config --cflags` `Wand-config --libs` -lpthread
Code: Select all
tiff_problem: magick/hashmap.c:1975: ResetLinkedListIterator: Assertion `list_info != (LinkedListInfo *) ((void *)0)' failed.
Thanks in advance