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/**
* @brief C11 Threads Example
*/
/*
* This file's license is 2-clause BSD as in this distribution's
* LICENSE.2 file.
*/
#include <stdio.h>
#include <stdlib.h>
#include <threads.h>
#include <assert.h>
static thrd_t thread1;
static mtx_t buffer_mutex;
static cnd_t buffer_cnd;
static int buffer_value;
static int buffer_init(void)
{
int rc;
puts("buffer - mtx_init()");
rc = mtx_init(&buffer_mutex, mtx_timed);
assert(rc == thrd_success);
puts("buffer - cnd_init()");
rc = cnd_init(&buffer_cnd);
assert(rc == thrd_success);
buffer_value = -1;
}
void buffer_destroy(void)
{
puts("buffer - mtx_destroy()" );
mtx_destroy(&buffer_mutex);
puts("buffer - cnd_destroy()" );
cnd_destroy(&buffer_cnd);
}
static int buffer_get(void)
{
int rc;
int value;
// puts("buffer - mtx_lock()");
rc = mtx_lock(&buffer_mutex);
assert(rc == thrd_success);
while (buffer_value == -1) {
// puts("buffer - cnd_wait()");
rc = cnd_wait(&buffer_cnd, &buffer_mutex);
assert(rc = thrd_success);
}
value = buffer_value;
buffer_value = -1;
// puts("buffer - return value");
// puts("buffer - mtx_unlock()");
rc = mtx_unlock(&buffer_mutex);
assert(rc == thrd_success);
return value;
}
static void buffer_put(int value)
{
int rc;
int old_value;
// puts("buffer - mtx_lock()");
rc = mtx_lock(&buffer_mutex);
assert(rc == thrd_success);
old_value = buffer_value;
buffer_value = value;
if (old_value == -1) {
// puts("buffer - cnd_signal()");
rc = cnd_signal(&buffer_cnd);
assert(rc = thrd_success);
}
// puts("buffer - mtx_unlock()");
rc = mtx_unlock(&buffer_mutex);
assert(rc == thrd_success);
}
int Thread1_Body(void *arg)
{
int rc;
int value;
(void) arg;
puts("Thread1 - Loop for values");
while (1) {
value = buffer_get();
printf("Thread1 value = %d\n", value);
}
return 0;
}
int main(int argc, char **argv)
{
int rc;
int value;
struct timespec delay = {1, 0};
puts("*** START OF C11 CONDITION VARIABLE EXAMPLE ***");
puts("main - Create Thread1");
rc = thrd_create(&thread1, Thread1_Body, &thread1);
assert(rc == thrd_success);
buffer_init();
puts("main - yield to Thread1" );
thrd_yield();
for (value=1 ; value <= 3 ; value++) {
printf("main - put value = %d\n", value * 10);
buffer_put(value * 10);
puts("main - sleep to let Thread1 get the value");
rc = thrd_sleep(&delay, NULL);
assert(rc == 0);
}
buffer_destroy();
puts("*** END OF C11 CONDITION VARIABLE EXAMPLE ***");
return 0;
}
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