Added EVENTS_EVENT_SIZE define for calculated queue allocations

In the events library, the structure of an event is correctly not
part of the public api. Unfortunately, this makes it difficult to
calculate the space needed for a finite set of events.

EVENTS_EVENT_SIZE is defined as the space needed for the smallest
event, the event allocated in event_call.

This allows queues to be created based on a number of events:
equeue_create(&q, 12 * (EVENTS_EVENT_SIZE+sizeof(struct context)));

README.md

@@ -13,9 +13,9 @@ void print(void *s) {
 }
 
 int main() {
-    // creates a queue with 32 events with default size
+    // creates a queue with space for 32 basic events
     equeue_t queue;
-    equeue_create(&queue, 32, 0);
+    equeue_create(&queue, 32*EVENTS_EVENT_SIZE);
 
     // events are simple callbacks
     event_call(&queue, print, "called immediately");

events.h

@@ -17,6 +17,10 @@ extern "C" {
 #include "events_sema.h"
 
 
+// Definition of the minimum size of an event
+// This size fits the events created in the event_call set of functions.
+#define EVENTS_EVENT_SIZE (sizeof(struct event) + 3*sizeof(void*))
+
 // Event/queue structures
 struct event {
     struct event *next;
@@ -51,6 +55,7 @@ typedef struct equeue {
     events_mutex_t freelock;
 } equeue_t;
 
+
 // Queue operations
 //
 // Creation results in negative value on failure.

tests/prof.c

@@ -126,7 +126,7 @@ void events_tick_prof(void) {
 
 void event_alloc_prof(void) {
     struct equeue q;
-    equeue_create(&q, 2*32*sizeof(struct event));
+    equeue_create(&q, 32*EVENTS_EVENT_SIZE);
 
     prof_loop() {
         prof_start();
@@ -141,7 +141,7 @@ void event_alloc_prof(void) {
 
 void event_alloc_many_prof(int count) {
     struct equeue q;
-    equeue_create(&q, 2*count*sizeof(struct event));
+    equeue_create(&q, count*EVENTS_EVENT_SIZE);
 
     void *es[count];
 
@@ -166,7 +166,7 @@ void event_alloc_many_prof(int count) {
 
 void event_post_prof(void) {
     struct equeue q;
-    equeue_create(&q, 2*sizeof(struct event));
+    equeue_create(&q, EVENTS_EVENT_SIZE);
 
     prof_loop() {
         void *e = event_alloc(&q, 0);
@@ -183,7 +183,7 @@ void event_post_prof(void) {
 
 void event_post_many_prof(int count) {
     struct equeue q;
-    equeue_create(&q, 2*count*sizeof(struct event));
+    equeue_create(&q, count*EVENTS_EVENT_SIZE);
 
     for (int i = 0; i < count; i++) {
         event_call(&q, no_func, 0);
@@ -204,7 +204,7 @@ void event_post_many_prof(int count) {
 
 void event_post_future_prof(void) {
     struct equeue q;
-    equeue_create(&q, 2*sizeof(struct event));
+    equeue_create(&q, EVENTS_EVENT_SIZE);
 
     prof_loop() {
         void *e = event_alloc(&q, 0);
@@ -222,7 +222,7 @@ void event_post_future_prof(void) {
 
 void event_post_future_many_prof(int count) {
     struct equeue q;
-    equeue_create(&q, 2*count*sizeof(struct event));
+    equeue_create(&q, count*EVENTS_EVENT_SIZE);
 
     for (int i = 0; i < count; i++) {
         event_call(&q, no_func, 0);
@@ -244,7 +244,7 @@ void event_post_future_many_prof(int count) {
 
 void equeue_dispatch_prof(void) {
     struct equeue q;
-    equeue_create(&q, 2*sizeof(struct event));
+    equeue_create(&q, EVENTS_EVENT_SIZE);
 
     prof_loop() {
         event_call(&q, no_func, 0);
@@ -259,7 +259,7 @@ void equeue_dispatch_prof(void) {
 
 void equeue_dispatch_many_prof(int count) {
     struct equeue q;
-    equeue_create(&q, 2*count*sizeof(struct event));
+    equeue_create(&q, count*EVENTS_EVENT_SIZE);
 
     prof_loop() {
         for (int i = 0; i < count; i++) {
@@ -276,7 +276,7 @@ void equeue_dispatch_many_prof(int count) {
 
 void event_cancel_prof(void) {
     struct equeue q;
-    equeue_create(&q, 2*sizeof(struct event));
+    equeue_create(&q, EVENTS_EVENT_SIZE);
 
     prof_loop() {
         int id = event_call(&q, no_func, 0);
@@ -291,7 +291,7 @@ void event_cancel_prof(void) {
 
 void event_cancel_many_prof(int count) {
     struct equeue q;
-    equeue_create(&q, 2*count*sizeof(struct event));
+    equeue_create(&q, count*EVENTS_EVENT_SIZE);
 
     for (int i = 0; i < count; i++) {
         event_call(&q, no_func, 0);
@@ -309,7 +309,7 @@ void event_cancel_many_prof(int count) {
 }
 
 void event_alloc_size_prof(void) {
-    size_t size = 2*32*sizeof(struct event);
+    size_t size = 32*EVENTS_EVENT_SIZE;
 
     struct equeue q;
     equeue_create(&q, size);
@@ -321,7 +321,7 @@ void event_alloc_size_prof(void) {
 }
 
 void event_alloc_many_size_prof(int count) {
-    size_t size = 2*count*sizeof(struct event);
+    size_t size = count*EVENTS_EVENT_SIZE;
 
     struct equeue q;
     equeue_create(&q, size);
@@ -336,7 +336,7 @@ void event_alloc_many_size_prof(int count) {
 }
 
 void event_alloc_fragmented_size_prof(int count) {
-    size_t size = 2*count*sizeof(struct event);
+    size_t size = count*EVENTS_EVENT_SIZE;
 
     struct equeue q;
     equeue_create(&q, size);

tests/tests.c

@@ -265,7 +265,7 @@ void break_test(void) {
 // Barrage tests
 void simple_barrage_test(int N) {
     equeue_t q;
-    int err = equeue_create(&q, N * 56);
+    int err = equeue_create(&q, N*(EVENTS_EVENT_SIZE+sizeof(struct timing)));
     test_assert(!err);
 
     for (int i = 0; i < N; i++) {
@@ -288,7 +288,8 @@ void simple_barrage_test(int N) {
 
 void fragmenting_barrage_test(int N) {
     equeue_t q;
-    int err = equeue_create(&q, N * 1000);
+    int err = equeue_create(&q,
+            2*N*(EVENTS_EVENT_SIZE+sizeof(struct fragment)+N*sizeof(int)));
     test_assert(!err);
 
     for (int i = 0; i < N; i++) {
@@ -325,7 +326,7 @@ static void *ethread_dispatch(void *p) {
 
 void multithreaded_barrage_test(int N) {
     equeue_t q;
-    int err = equeue_create(&q, N * 56);
+    int err = equeue_create(&q, N*(EVENTS_EVENT_SIZE+sizeof(struct timing)));
     test_assert(!err);
 
     struct ethread t;