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-rw-r--r--src/lib/portmidi/ptlinux.c131
1 files changed, 64 insertions, 67 deletions
diff --git a/src/lib/portmidi/ptlinux.c b/src/lib/portmidi/ptlinux.c
index 768dd4847f7..bbf2ab1907a 100644
--- a/src/lib/portmidi/ptlinux.c
+++ b/src/lib/portmidi/ptlinux.c
@@ -1,24 +1,24 @@
/* ptlinux.c -- portable timer implementation for linux */
-/* IMPLEMENTATION NOTES (by Mark Nelson):
+/* IMPLEMENTATION NOTES (by Mark Nelson):
Unlike Windows, Linux has no system call to request a periodic callback,
so if Pt_Start() receives a callback parameter, it must create a thread
that wakes up periodically and calls the provided callback function.
-If running as superuser, use setpriority() to renice thread to -20.
+If running as superuser, use setpriority() to renice thread to -20.
One could also set the timer thread to a real-time priority (SCHED_FIFO
-and SCHED_RR), but this is dangerous for This is necessary because
+and SCHED_RR), but this is dangerous for This is necessary because
if the callback hangs it'll never return. A more serious reason
-is that the current scheduler implementation busy-waits instead
-of sleeping when realtime threads request a sleep of <=2ms (as a way
-to get around the 10ms granularity), which means the thread would never
+is that the current scheduler implementation busy-waits instead
+of sleeping when realtime threads request a sleep of <=2ms (as a way
+to get around the 10ms granularity), which means the thread would never
let anyone else on the CPU.
CHANGE LOG
18-Jul-03 Roger Dannenberg -- Simplified code to set priority of timer
- thread. Simplified implementation notes.
+ thread. Simplified implementation notes.
*/
/* stdlib, stdio, unistd, and sys/types were added because they appeared
@@ -44,95 +44,92 @@ static int pt_thread_created = FALSE;
/* note that this is static data -- we only need one copy */
typedef struct {
- int id;
- int resolution;
- PtCallback *callback;
- void *userData;
+ int id;
+ int resolution;
+ PtCallback *callback;
+ void *userData;
} pt_callback_parameters;
static int pt_callback_proc_id = 0;
static void *Pt_CallbackProc(void *p)
{
- pt_callback_parameters *parameters = (pt_callback_parameters *) p;
- int mytime = 1;
- /* to kill a process, just increment the pt_callback_proc_id */
- /* printf("pt_callback_proc_id %d, id %d\n", pt_callback_proc_id,
- parameters->id); */
- if (geteuid() == 0) setpriority(PRIO_PROCESS, 0, -20);
- while (pt_callback_proc_id == parameters->id) {
- /* wait for a multiple of resolution ms */
- struct timeval timeout;
- int delay = mytime++ * parameters->resolution - Pt_Time();
- if (delay < 0) delay = 0;
- timeout.tv_sec = 0;
- timeout.tv_usec = delay * 1000;
- select(0, NULL, NULL, NULL, &timeout);
- (*(parameters->callback))(Pt_Time(), parameters->userData);
- }
- /* printf("Pt_CallbackProc exiting\n"); */
- // free(parameters);
- return NULL;
+ pt_callback_parameters *parameters = (pt_callback_parameters *) p;
+ int mytime = 1;
+ /* to kill a process, just increment the pt_callback_proc_id */
+ /* printf("pt_callback_proc_id %d, id %d\n", pt_callback_proc_id,
+ parameters->id); */
+ if (geteuid() == 0) setpriority(PRIO_PROCESS, 0, -20);
+ while (pt_callback_proc_id == parameters->id) {
+ /* wait for a multiple of resolution ms */
+ struct timeval timeout;
+ int delay = mytime++ * parameters->resolution - Pt_Time();
+ if (delay < 0) delay = 0;
+ timeout.tv_sec = 0;
+ timeout.tv_usec = delay * 1000;
+ select(0, NULL, NULL, NULL, &timeout);
+ (*(parameters->callback))(Pt_Time(), parameters->userData);
+ }
+ /* printf("Pt_CallbackProc exiting\n"); */
+ // free(parameters);
+ return NULL;
}
PtError Pt_Start(int resolution, PtCallback *callback, void *userData)
{
- if (time_started_flag) return ptNoError;
- ftime(&time_offset); /* need this set before process runs */
- if (callback) {
- int res;
- pt_callback_parameters *parms = (pt_callback_parameters *)
- malloc(sizeof(pt_callback_parameters));
- if (!parms) return ptInsufficientMemory;
- parms->id = pt_callback_proc_id;
- parms->resolution = resolution;
- parms->callback = callback;
- parms->userData = userData;
- res = pthread_create(&pt_thread_pid, NULL,
- Pt_CallbackProc, parms);
- if (res != 0) return ptHostError;
- pt_thread_created = TRUE;
- }
- time_started_flag = TRUE;
- return ptNoError;
+ if (time_started_flag) return ptNoError;
+ ftime(&time_offset); /* need this set before process runs */
+ if (callback) {
+ int res;
+ pt_callback_parameters *parms = (pt_callback_parameters *)
+ malloc(sizeof(pt_callback_parameters));
+ if (!parms) return ptInsufficientMemory;
+ parms->id = pt_callback_proc_id;
+ parms->resolution = resolution;
+ parms->callback = callback;
+ parms->userData = userData;
+ res = pthread_create(&pt_thread_pid, NULL,
+ Pt_CallbackProc, parms);
+ if (res != 0) return ptHostError;
+ pt_thread_created = TRUE;
+ }
+ time_started_flag = TRUE;
+ return ptNoError;
}
PtError Pt_Stop()
{
- /* printf("Pt_Stop called\n"); */
- pt_callback_proc_id++;
- if (pt_thread_created) {
- pthread_join(pt_thread_pid, NULL);
- pt_thread_created = FALSE;
- }
- time_started_flag = FALSE;
- return ptNoError;
+ /* printf("Pt_Stop called\n"); */
+ pt_callback_proc_id++;
+ if (pt_thread_created) {
+ pthread_join(pt_thread_pid, NULL);
+ pt_thread_created = FALSE;
+ }
+ time_started_flag = FALSE;
+ return ptNoError;
}
int Pt_Started()
{
- return time_started_flag;
+ return time_started_flag;
}
PtTimestamp Pt_Time()
{
- long seconds, milliseconds;
- struct timeb now;
- ftime(&now);
- seconds = now.time - time_offset.time;
- milliseconds = now.millitm - time_offset.millitm;
- return seconds * 1000 + milliseconds;
+ long seconds, milliseconds;
+ struct timeb now;
+ ftime(&now);
+ seconds = now.time - time_offset.time;
+ milliseconds = now.millitm - time_offset.millitm;
+ return seconds * 1000 + milliseconds;
}
void Pt_Sleep(int32_t duration)
{
- usleep(duration * 1000);
+ usleep(duration * 1000);
}
-
-
-