Databases
StackOverflow2013
Postsdbo
POPassing arguments to pthread_create - invalid conversion from void(*)() to void(*)(void*)
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POPassing arguments to pthread_create - invalid conversion from void(*)() to void(*)(void*)
    primarykey
    data
    text
    <p>I am writing a small simple program that implements a cyclic executive schedule using pthreads. I first wrote the program without pthreads and am now trying to correctly pass parameters into pthread_create. I know that the args are:</p> <p>int pthread_create(pthread_t *thread, const pthread_attr_t *attr, void *(*start_routine) (void *), void *arg);</p> <p>but sending the threads to ttable(the schedule) is giving me difficulty. Now that I am using threads I have added the void* x parameter even though I am not using it (is this parameter required?) I have tried leaving the schedule with no parameters and passing NULL in as the last arg of pthread_create as well. My error is currently: error: invalid conversion from 'void ( * )( )’ to ‘void ( * )(void*)’ [-fpermissive] }; ^</p> <p>Here is the code:</p> <pre><code>#include &lt;ctype.h&gt; #include &lt;unistd.h&gt; #include &lt;sys/times.h&gt; #include &lt;pthread.h&gt; #define SLOTX 6 #define CYCLEX 4 #define SLOT_T 1000 //1 second slot time #define NUM_THREADS 3 int tps; int i; int j; int rc; int cycle = 0; int slot = 0; struct tms n; void one(void* x){ printf("Task 1 running\n"); sleep(1); } void two(void* x){ printf("Task 2 running\n"); sleep(1); } void three(void* x){ printf("Task 3 running\n"); sleep(1); } void burn(void* x){ printf("Burn cycle\n"); sleep(1); } void (*ttable[SLOTX][CYCLEX])(void* x) = { {one, one, two, two}, {three, three, three, three}, {two, two, one, one}, {burn, two, two, burn}, {three, three, three, three}, {one, one, two, two} }; main(){ tps = sysconf(_SC_CLK_TCK); pthread_t thread[NUM_THREADS]; printf("clock ticks/sec = %d\n\n", tps); while(1){ printf("Starting new hyperperiod\n"); for(slot = 0; slot&lt;SLOTX; slot++){ printf("Starting new frame\n"); for(cycle = 0; cycle&lt;CYCLEX; cycle++){ for(i = 0; i&lt;NUM_THREADS; i++){ rc = pthread_create(&amp;thread[i], NULL, (*ttable[slot][cycle]), *(void*)j); } } } } } </code></pre>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USAnna
    1. USAnna
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. COUse `void one(void*)` instead of `void one()` etc or I think you need to change `(void *x)` to just `()`
      singulars
      1. POPassing arguments to pthread_create - invalid conversion from void(*)() to void(*)(void*)
      1. USJustin
    2. COchanging (void* x) to () gives me invalid conversion from void (**)() to void(*)(void*) and changing void one()/two()/three() to void one(void*) gives me invalid conversion from void(*)(void*) to void(*)()
      singulars
      1. POPassing arguments to pthread_create - invalid conversion from void(*)() to void(*)(void*)
      1. USAnna
    3. COActually, I was wrong - you need to include an argument name since it's a function definition and not a declaration. Use a dummy argument as R.. suggested.
      singulars
      1. POPassing arguments to pthread_create - invalid conversion from void(*)() to void(*)(void*)
      1. USJustin
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload