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Diffstat (limited to 'thirdparty/nRF5_SDK_15.0.0_a53641a/external/protothreads/pt-1.4/example-small.c')
-rw-r--r-- | thirdparty/nRF5_SDK_15.0.0_a53641a/external/protothreads/pt-1.4/example-small.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/thirdparty/nRF5_SDK_15.0.0_a53641a/external/protothreads/pt-1.4/example-small.c b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/protothreads/pt-1.4/example-small.c new file mode 100644 index 0000000..37c1716 --- /dev/null +++ b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/protothreads/pt-1.4/example-small.c @@ -0,0 +1,97 @@ +/** + * This is a very small example that shows how to use + * protothreads. The program consists of two protothreads that wait + * for each other to toggle a variable. + */ + +/* We must always include pt.h in our protothreads code. */ +#include "pt.h" + +#include <stdio.h> /* For printf(). */ + +/* Two flags that the two protothread functions use. */ +static int protothread1_flag, protothread2_flag; + +/** + * The first protothread function. A protothread function must always + * return an integer, but must never explicitly return - returning is + * performed inside the protothread statements. + * + * The protothread function is driven by the main loop further down in + * the code. + */ +static int +protothread1(struct pt *pt) +{ + /* A protothread function must begin with PT_BEGIN() which takes a + pointer to a struct pt. */ + PT_BEGIN(pt); + + /* We loop forever here. */ + while(1) { + /* Wait until the other protothread has set its flag. */ + PT_WAIT_UNTIL(pt, protothread2_flag != 0); + printf("Protothread 1 running\n"); + + /* We then reset the other protothread's flag, and set our own + flag so that the other protothread can run. */ + protothread2_flag = 0; + protothread1_flag = 1; + + /* And we loop. */ + } + + /* All protothread functions must end with PT_END() which takes a + pointer to a struct pt. */ + PT_END(pt); +} + +/** + * The second protothread function. This is almost the same as the + * first one. + */ +static int +protothread2(struct pt *pt) +{ + PT_BEGIN(pt); + + while(1) { + /* Let the other protothread run. */ + protothread2_flag = 1; + + /* Wait until the other protothread has set its flag. */ + PT_WAIT_UNTIL(pt, protothread1_flag != 0); + printf("Protothread 2 running\n"); + + /* We then reset the other protothread's flag. */ + protothread1_flag = 0; + + /* And we loop. */ + } + PT_END(pt); +} + +/** + * Finally, we have the main loop. Here is where the protothreads are + * initialized and scheduled. First, however, we define the + * protothread state variables pt1 and pt2, which hold the state of + * the two protothreads. + */ +static struct pt pt1, pt2; +int +main(void) +{ + /* Initialize the protothread state variables with PT_INIT(). */ + PT_INIT(&pt1); + PT_INIT(&pt2); + + /* + * Then we schedule the two protothreads by repeatedly calling their + * protothread functions and passing a pointer to the protothread + * state variables as arguments. + */ + while(1) { + protothread1(&pt1); + protothread2(&pt2); + } +} |