Updated timers and time functions to microseconds (from milli).

3 files changed, 64 insertions, 39 deletions

diff --git a/docs/ccommon_api.md b/docs/ccommon_api.md
index 4d18120a..6276494b 100644
--- a/docs/ccommon_api.md
+++ b/docs/ccommon_api.md
@@ -379,25 +379,27 @@ To resume the coroutine from where it was suspended with *cco_yield()*, simply c
 |           | `cco_yield(ret)`                     | Yield/suspend execution and return ret  |
 |           | `cco_await(promise)`                 | Await/suspend until promise is true     |
 |           | `cco_await(promise, ret)`            | Await/suspend with ret value            |
-|           | `cco_sleep(long msec)`               | Sleep for milliseconds                  |
 |           | Semaphores:                          |                                         | 
 |           | `cco_sem`                            | Semaphore type                          |
 |           | `cco_sem_await(sem)`                 | Await for the semaphore count > 0       |
 |           | `cco_sem_await(sem, ret)`            | Await with ret on the semaphore         |
-| cco_sem   | `cco_sem_init(long value)`           | Set semaphore value                     |
+| `cco_sem` | `cco_sem_init(long value)`           | Set semaphore value                     |
 |           | `cco_sem_release(sem)`               | Signal the semaphore                    |
 |           | Timers:                              |                                         | 
 |           | `cco_timer`                          | Timer type                              |
 |           | `cco_timer_await(tm)`                | Await for timer to expire               |
 |           | `cco_timer_await(tm, ret)`           | Await with ret for timer to expire      |
-|           | `cco_timer_start(tm, long msecs)`    | Start timer msecs milliseconds          |
+|           | `cco_timer_start(tm, long usec)`     | Start timer for usec microseconds       |
 |           | `cco_timer_restart(tm)`              | Restart timer with same duration        |
 | `bool`    | `cco_timer_expired(tm)`              | Return true if timer is expired         |
-| `long`    | `cco_timer_remaining(tm)`            | Return milliseconds remaining           |
+|`long long`| `cco_timer_remaining(tm)`            | Return microseconds remaining           |
 |           | From caller side:                    |                                         | 
-| `void`    | `cco_stop(co)`                       | Next call of coroutine returns `cco_end()` |
+| `void`    | `cco_stop(co)`                       | Next call of coroutine finalizes        |
 | `void`    | `cco_reset(co)`                      | Reset state to initial (for reuse)      |
 | `void`    | `cco_run(co, corocall) { }`          | Run blocking until coro is done         |
+|           | Time functions:                      |                                         |
+|`long long`| `cco_utime(void)`                    | Return microseconds since Epoch         |
+|           | `cco_usleep(long long usec)`         | Sleep for microseconds                  |
 
 ---
 ## RAII scope macros
diff --git a/include/stc/algo/coroutine.h b/include/stc/algo/coroutine.h
index 05307b08..d0c9ad86 100644
--- a/include/stc/algo/coroutine.h
+++ b/include/stc/algo/coroutine.h
@@ -56,7 +56,6 @@ int main(void) {
     return 0;
 }
 */
-#include <time.h>
 #include <stc/ccommon.h>
 
 enum {
@@ -130,55 +129,77 @@ typedef struct {
  * Timer
  */
 
-typedef struct {
-    clock_t start;
-    clock_t interval;
-} cco_timer;
-
-#define cco_timer_await(...) c_MACRO_OVERLOAD(cco_timer_await, __VA_ARGS__)
-#define cco_timer_await_2(tm, msec) cco_timer_await_3(tm, msec, )
-#define cco_timer_await_3(tm, msec, ret) \
-    do { \
-        cco_timer_start(tm, msec); \
-        cco_await_2(cco_timer_expired(tm), ret); \
-    } while (0)
-
 #ifdef _WIN32
     #ifdef __cplusplus
-    extern "C"
+    #define _c_LINKC extern "C" __declspec(dllimport) 
+    #else
+    #define _c_LINKC __declspec(dllimport) 
     #endif
-    __declspec(dllimport) void __stdcall Sleep(unsigned long);
-    static inline void cco_sleep(long msec) {
-        Sleep((unsigned long)msec);
+    struct _FILETIME; struct _SECURITY_ATTRIBUTES; union _LARGE_INTEGER;
+    _c_LINKC void GetSystemTimePreciseAsFileTime(struct _FILETIME*);
+    _c_LINKC void* CreateWaitableTimerW(struct _SECURITY_ATTRIBUTES*, int, const wchar_t*);
+    _c_LINKC int SetWaitableTimer(void*, const union _LARGE_INTEGER*, long, void(*)(void*, unsigned long, unsigned long), void*, int);
+    _c_LINKC unsigned long WaitForSingleObject(void*, unsigned long);
+    _c_LINKC int CloseHandle(void*);
+
+    static inline long long cco_utime(void) {
+        static const long long epoch_offset = 11644473600000000LL; /* microseconds betweeen Jan 1,1601 - Jan 1,1970 */
+        unsigned long long quad;          /* 64-bit value, 100-nanosecond intervals since January 1, 1601 00:00 UTC */
+        GetSystemTimePreciseAsFileTime((struct _FILETIME*)&quad);
+        return (long long)quad/10 - epoch_offset; /* microseconds since epoch */
     }
+
+    static inline void cco_usleep(long long usec) {
+        unsigned long long ft = -10*usec;
+        void* timer = CreateWaitableTimerW(NULL, true, NULL);
+        SetWaitableTimer(timer, (const union _LARGE_INTEGER*)&ft, 0, NULL, NULL, 0);
+        WaitForSingleObject(timer, ~0UL);
+        CloseHandle(timer);
+    }    
 #else
     #include <sys/time.h>
-    static inline void cco_sleep(long msec) {
-        struct timeval tv = {.tv_sec=msec/1000, .tv_usec=1000*(msec % 1000)};
+    static inline long long cco_utime(void) {
+        struct timeval tv;
+        gettimeofday(&tv, NULL);
+        return tv.tv_sec*1000000LL + tv.tv_usec;
+    }
+
+    static inline void cco_usleep(long long usec) {
+        struct timeval tv = {.tv_sec=(time_t)(usec/1000000), .tv_usec=(suseconds_t)(usec % 1000000)};
         select(0, NULL, NULL, NULL, &tv);
     }
 #endif
 
-static inline void cco_timer_start(cco_timer* tm, long msec) {
-    tm->interval = msec*(CLOCKS_PER_SEC/1000);
-    tm->start = clock();
+typedef struct { long long interval, start; } cco_timer;
+
+#define cco_timer_await(...) c_MACRO_OVERLOAD(cco_timer_await, __VA_ARGS__)
+#define cco_timer_await_2(tm, usec) cco_timer_await_3(tm, usec, )
+#define cco_timer_await_3(tm, usec, ret) \
+    do { \
+        cco_timer_start(tm, usec); \
+        cco_await_2(cco_timer_expired(tm), ret); \
+    } while (0)
+
+static inline void cco_timer_start(cco_timer* tm, long long usec) {
+    tm->interval = usec;
+    tm->start = cco_utime();
 }
 
-static inline cco_timer cco_timer_from(long msec) {
-    cco_timer tm = {msec*(CLOCKS_PER_SEC/1000), clock()};
+static inline cco_timer cco_timer_from(long long usec) {
+    cco_timer tm = {.interval=usec, .start=cco_utime()};
     return tm;
 }
 
 static inline void cco_timer_restart(cco_timer* tm) {
-    tm->start = clock();
+    tm->start = cco_utime();
 }
 
 static inline bool cco_timer_expired(cco_timer* tm) {
-    return clock() - tm->start >= tm->interval;
+    return cco_utime() - tm->start >= tm->interval;
 }
 
-static inline long cco_timer_remaining(cco_timer* tm) {
-    return (long)((double)(tm->start + tm->interval - clock())*(1000.0/CLOCKS_PER_SEC));
+static inline long long cco_timer_remaining(cco_timer* tm) {
+    return tm->start + tm->interval - cco_utime();
 }
 
 #endif
diff --git a/misc/examples/dining_philosophers.c b/misc/examples/dining_philosophers.c
index 0bf421c6..cc6e5fd2 100644
--- a/misc/examples/dining_philosophers.c
+++ b/misc/examples/dining_philosophers.c
@@ -1,5 +1,6 @@
 // https://en.wikipedia.org/wiki/Dining_philosophers_problem
 #include <stdio.h>
+#include <time.h>
 #include <stc/crand.h>
 #include <stc/algo/coroutine.h>
  
@@ -33,7 +34,7 @@ void philosopher(struct Philosopher* p)
         while (1) {
             int duration = (int)(1000 + crand() % 2000); // 1-3 seconds
             printf("Philosopher %d is thinking for %d minutes...\n", p->id, duration/100);
-            cco_timer_await(&p->tm, duration);
+            cco_timer_await(&p->tm, duration*1000);
 
             printf("Philosopher %d is hungry...\n", p->id);
             cco_sem_await(p->left_fork);
@@ -41,7 +42,7 @@ void philosopher(struct Philosopher* p)
             
             duration = (int)(500 + crand() % 1000);
             printf("Philosopher %d is eating for %d minutes...\n", p->id, duration/100);
-            cco_timer_await(&p->tm, duration);
+            cco_timer_await(&p->tm, duration*1000);
             
             cco_sem_release(p->left_fork);
             cco_sem_release(p->right_fork);
@@ -67,10 +68,11 @@ void dining(struct Dining* d)
         }
 
         while (1) {
+            // per-"frame" logic update of all philosophers states
             for (d->ph_idx = 0; d->ph_idx < num_philosophers; ++d->ph_idx) {
                 philosopher(&d->ph[d->ph_idx]);
-                cco_yield();
             }
+            cco_yield(); // suspend, return control back to main
         }
 
         cco_final:
@@ -87,13 +89,13 @@ int main()
 {
     struct Dining dine;
     cco_reset(&dine);
-    cco_timer tm = cco_timer_from(10000);
+    cco_timer tm = cco_timer_from(10*1000000); // microseconds
     csrand((uint64_t)time(NULL));
 
     while (!cco_done(&dine)) {
         if (cco_timer_expired(&tm))
             cco_stop(&dine);
         dining(&dine);
-        cco_sleep(1);
+        cco_usleep(100);
     }
 }