improved inter-thread communication.

the in-synth-CLI still partially uses the non-synced communication. TODO!

4 files changed, 146 insertions, 71 deletions

diff --git a/synth/communication.cpp b/synth/communication.cpp
index f21e46f..4f9ce75 100644
--- a/synth/communication.cpp
+++ b/synth/communication.cpp
@@ -1,16 +1,76 @@
 #include "communication.h"
 
-pthread_mutex_t suspend_request_mutex;
-suspend_request_t suspend_request;
+#include <unistd.h>
+#include <iostream>
+
+using namespace std;
+
+jack_ringbuffer_t* request_ringbuf;
+jack_ringbuffer_t* result_ringbuf;
+pthread_mutex_t request_mutex;
+
 
 void init_communication()
 {
-	pthread_mutex_init(&suspend_request_mutex, NULL);
+	pthread_mutex_init(&request_mutex, NULL);
 	
-	suspend_request.done=true;
+	request_ringbuf=jack_ringbuffer_create(sizeof(request_t)+1);
+	result_ringbuf=jack_ringbuffer_create(sizeof(int)+1);
 }
 
 void uninit_communication()
 {
-	pthread_mutex_destroy(&suspend_request_mutex);
+	jack_ringbuffer_free(request_ringbuf);
+	jack_ringbuffer_free(result_ringbuf);
+	
+	pthread_mutex_destroy(&request_mutex);
+}
+
+int do_request(request_t request)
+{
+	pthread_mutex_lock(&request_mutex); // only one request at a time
+	
+	jack_ringbuffer_write(request_ringbuf, (char*)(&request), sizeof(request_t));
+	
+	do // wait for the answer
+	{
+		usleep(10000);
+	} while (jack_ringbuffer_read_space(result_ringbuf)<sizeof(int));
+	
+	int result;
+	if (jack_ringbuffer_read(result_ringbuf, (char*)(&result), sizeof(int)) != sizeof(int))
+		cout << "FATAL: short read from result ringbuffer, expect breakage!" << endl; // TODO handle properly
+	
+	if (jack_ringbuffer_read_space(result_ringbuf)!=0)
+		cout << "FATAL: result ringbuffer not empty, expect breakage!" << endl; // TODO handle properly
+	
+	pthread_mutex_unlock(&request_mutex);
+	
+	return result;
+}
+
+bool request_available()
+{
+	return (jack_ringbuffer_read_space(request_ringbuf)>=sizeof(request_t));
+}
+
+request_t get_request()
+{
+	request_t request;
+	
+	int len=jack_ringbuffer_read(request_ringbuf, (char*)(&request), sizeof(request_t));
+	if (len==0)
+		cout << "ERROR: no request on the ringbuffer! nothing read, continuing..." << endl;
+	else if (len!=sizeof(request_t))
+	{
+		cout << "possibly FATAL: short read from the request ringbuffer, expect breakage!" << endl;
+		request.type=request_t::NONE;
+	}
+	
+	return request;
+}
+
+void request_finished(int result)
+{
+	jack_ringbuffer_write(result_ringbuf, (char*)(&result), sizeof(int));
 }
diff --git a/synth/communication.h b/synth/communication.h
index 27f7186..8d11cd4 100644
--- a/synth/communication.h
+++ b/synth/communication.h
@@ -2,21 +2,36 @@
 #define __COMMUNICATION_H__
 
 #include <pthread.h>
+#include <jack/ringbuffer.h>
 
-struct suspend_request_t
+struct request_t
 {
-	int prog; //if negative, all programs are affected
-	bool suspend; //true->suspend, false->use them again
-	bool done; //must be set to false by the requester,
-	           //must be set to true after processing by the requestee
+	enum request_type_t { NONE, SUSPEND_PROGRAM, RESUME_PROGRAM, PANIC, RELEASE_ALL };
+	request_type_t type;
+	int prog_or_chan; //if negative, all programs/channels are affected
+	
+	request_t()
+	{
+		type=NONE;
+	}
+	
+	request_t(request_type_t type_, int poc)
+	{
+		type=type_;
+		prog_or_chan=poc;
+	}
 };
 
+// init/uninit
+void init_communication();
+void uninit_communication();
 
-extern pthread_mutex_t suspend_request_mutex;
-extern suspend_request_t suspend_request;
-
+// for non-audio-threads. mutex-protected
+int do_request(request_t request);
 
+// for the audio-thread. NOT mutex-protected
+bool request_available();
+request_t get_request();
+void request_finished(int);
 
-void init_communication();
-void uninit_communication();
 #endif
diff --git a/synth/in_synth_cli.cpp b/synth/in_synth_cli.cpp
index 4d4ef76..069e7bd 100644
--- a/synth/in_synth_cli.cpp
+++ b/synth/in_synth_cli.cpp
@@ -1,7 +1,6 @@
 #include <iostream>
 #include <string>
 #include <signal.h>
-#include <unistd.h>
 #include <stdlib.h>
 
 #include "in_synth_cli.h"
@@ -26,33 +25,6 @@ void signal_handler(int sig)
 	cout << endl << PROMPT << flush;
 }
 
-void do_request(int prg_no, bool susp)
-{
-	pthread_mutex_lock(&suspend_request_mutex);
-	
-	suspend_request.prog=prg_no;
-	suspend_request.suspend=susp;
-	suspend_request.done=false;
-	
-	pthread_mutex_unlock(&suspend_request_mutex);
-	
-	
-	
-	while (true)
-	{
-		usleep(100000);
-
-		pthread_mutex_lock(&suspend_request_mutex);
-		if (suspend_request.done)
-		{
-			pthread_mutex_unlock(&suspend_request_mutex);
-			break;
-		}
-		else
-			pthread_mutex_unlock(&suspend_request_mutex);
-	}
-}
-
 void lock_and_load_program(int prg_no, string file)
 {
 	pthread_mutex_lock(&prog_load_mutex);
@@ -61,7 +33,7 @@ void lock_and_load_program(int prg_no, string file)
 		remove_watch(prg_no);
 	#endif
 	
-	do_request(prg_no, true);
+	do_request(request_t(request_t::SUSPEND_PROGRAM, prg_no));
 	
 	if (load_program(file,program_settings[prg_no]))
 	{
@@ -78,7 +50,7 @@ void lock_and_load_program(int prg_no, string file)
 	for (int i=0;i<N_CHANNELS;++i)
 		channel[i]->maybe_reload_program(prg_no);
 	
-	do_request(prg_no, false);
+	do_request(request_t(request_t::RESUME_PROGRAM, prg_no));
 
 	pthread_mutex_unlock(&prog_load_mutex);
 }
@@ -89,7 +61,7 @@ void lock_and_load_program_no_watch_updates(int prg_no, string file)
 {
 	pthread_mutex_lock(&prog_load_mutex);
 
-	do_request(prg_no, true);
+	do_request(request_t(request_t::SUSPEND_PROGRAM, prg_no));
 	
 	if (load_program(file,program_settings[prg_no]))
 	{
@@ -102,20 +74,20 @@ void lock_and_load_program_no_watch_updates(int prg_no, string file)
 	for (int i=0;i<N_CHANNELS;++i)
 		channel[i]->maybe_reload_program(prg_no);
 	
-	do_request(prg_no, false);
+	do_request(request_t(request_t::RESUME_PROGRAM, prg_no));
 
 	pthread_mutex_unlock(&prog_load_mutex);
 }
 
 void lock_and_change_lfo(int lfo_no, float freq)
 {
-	do_request(-1, true);
+	do_request(request_t(request_t::SUSPEND_PROGRAM, -1));
 	
 	uninit_lfo(lfo_no);
 	lfo_freq_hz[lfo_no]=freq;
 	init_lfo(lfo_no);
 	
-	do_request(-1, false);
+	do_request(request_t(request_t::RESUME_PROGRAM, -1));
 }
 
 
@@ -183,13 +155,12 @@ void do_in_synth_cli()
 		else if (command=="panic")
 		{
 			if ((params=="") || (params=="all"))
-				for (int i=0;i<N_CHANNELS;++i)
-					channel[i]->panic();
+				do_request(request_t(request_t::PANIC, -1));
 			else if (isnum(params))
 			{
 				num=atoi(params.c_str());
 				if ((num>=0) && (num<N_CHANNELS))
-					channel[num]->panic();
+					do_request(request_t(request_t::PANIC, num));
 				else
 					cout << "error: channel-number must be one of 0.."<<N_CHANNELS-1<<endl;
 			}
@@ -197,17 +168,18 @@ void do_in_synth_cli()
 		else if (command=="release")
 		{
 			if ((params=="") || (params=="all"))
-				for (int i=0;i<N_CHANNELS;++i)
-					channel[i]->release_all();
+				do_request(request_t(request_t::RELEASE_ALL, -1));
 			else if (isnum(params))
 			{
 				num=atoi(params.c_str());
 				if ((num>=0) && (num<N_CHANNELS))
-					channel[num]->release_all();
+					do_request(request_t(request_t::RELEASE_ALL, num));
 				else
 					cout << "error: channel-number must be one of 0.."<<N_CHANNELS-1<<endl;
 			}
 		}
+		// TODO: from here, no proper synchronisation with the audio thread
+		//       is done. use do_request() everywhere!
 		else if (command=="kill_program")
 		{
 			string prgstr, chanstr;
diff --git a/synth/jack.cpp b/synth/jack.cpp
index c86cbce..882d5fb 100644
--- a/synth/jack.cpp
+++ b/synth/jack.cpp
@@ -34,15 +34,45 @@ void manage_program_lock(int prog, bool lock) //TODO woandershinschieben?
 			channel[i]->kill_program(prog);
 }
 
-void process_request()
+void process_request(request_t request)
 {
-	if (suspend_request.prog==-1)
-		for (int i=0;i<128;++i)
-			manage_program_lock(i,suspend_request.suspend);
-	else
-		manage_program_lock(suspend_request.prog,suspend_request.suspend);
+	switch (request.type)
+	{
+		case request_t::NONE: break;
+		
+		case request_t::SUSPEND_PROGRAM:
+		case request_t::RESUME_PROGRAM:
+			if (request.prog_or_chan==-1)
+				for (int i=0;i<128;++i)
+					manage_program_lock(i,request.type==request_t::SUSPEND_PROGRAM);
+			else
+				manage_program_lock(request.prog_or_chan,request.type==request_t::SUSPEND_PROGRAM);
+			
+			break;
+		
+		case request_t::PANIC:
+			if (request.prog_or_chan==-1)
+				for (int i=0;i<N_CHANNELS;++i)
+					channel[i]->panic();
+			else
+				channel[request.prog_or_chan]->panic();
+			
+			break;
+			
+		case request_t::RELEASE_ALL:
+			if (request.prog_or_chan==-1)
+				for (int i=0;i<N_CHANNELS;++i)
+					channel[i]->release_all();
+			else
+				channel[request.prog_or_chan]->release_all();
+			
+			break;
+		
+		default:
+			cout << "ERROR: bad request, ignoring it." << endl;
+	}
 	
-	suspend_request.done=true;
+	request_finished(0);
 }
 
 
@@ -217,10 +247,10 @@ int xrun_callback(void *notused)
 	
 	if (history.size() >= xrun_n)
 	{
-		cout << "PANIC -- TOO MANY XRUNs! killing all voices" << endl<<endl;
-		for (int i=0;i<N_CHANNELS;++i)
-			channel[i]->panic();
-			
+		cout << "PANIC -- TOO MANY XRUNs! killing all voices" << flush;
+		do_request(request_t(request_t::PANIC, -1));
+		cout << "  (done)" << endl << endl;
+		
 		history.clear();
 	}
 		
@@ -254,11 +284,9 @@ int process_callback(jack_nframes_t nframes, void *notused)
 	}
 
 
-
-	pthread_mutex_lock(&suspend_request_mutex);
-	if (suspend_request.done==false)
-		process_request();
-	pthread_mutex_unlock(&suspend_request_mutex);
+	if (request_available())
+		process_request(get_request());
+