From fadb0acbc486f85e31f4a784c8d4005033e078af Mon Sep 17 00:00:00 2001
From: Brandon Skari <brandon@skari.org>
Date: Wed, 24 Feb 2016 21:48:00 -0700
Subject: [PATCH] Ignore certain signals

---
 src/RpiDma.c              | 41 ++++++++++++++++++++++++++++++++++-----
 src/RpiDma.h              |  2 +-
 src/RpiTx.c               | 13 +++++++------
 src/RpiTx.h               |  5 +++--
 src/python/_rpitxmodule.c |  9 ++++++++-
 5 files changed, 55 insertions(+), 15 deletions(-)

diff --git a/src/RpiDma.c b/src/RpiDma.c
index 133679f..7d17275 100644
--- a/src/RpiDma.c
+++ b/src/RpiDma.c
@@ -3,7 +3,21 @@
 #include <signal.h>
 #include "RpiDma.h"
 #include "RpiGpio.h"
-char InitDma(void *FunctionTerminate)
+
+static int compareInts(const void* first, const void* second) {
+	const int firstInt = *((int*)first);
+	const int secondInt = *((int*)second);
+	if (firstInt < secondInt) {
+		return -1;
+	}
+	if (firstInt == secondInt) {
+		return 0;
+	}
+	return 1;
+}
+
+
+char InitDma(void *FunctionTerminate, int* skipSignals)
 {
 	DMA_CHANNEL=4;
 	char *line = NULL;
@@ -31,15 +45,32 @@ char InitDma(void *FunctionTerminate)
 	pclose(flinux);
 	//printf("Init DMA\n");
 	
+	int sentinel[] = {0};
+	if (skipSignals == NULL) {
+		skipSignals = sentinel;
+	}
+	int sentinelIndex;
+	for (sentinelIndex = 0; ; ++sentinelIndex) {
+		if (skipSignals[sentinelIndex] == 0) {
+			break;
+		}
+	}
+	qsort(skipSignals, sentinelIndex, sizeof(int), compareInts);
+
 	// Catch all signals possible - it is vital we kill the DMA engine
 	// on process exit!
 	int i;
 	for (i = 0; i < 64; i++) {
-		struct sigaction sa;
+		// Some signals are fine, so don't catch them
+		if (i == *skipSignals) {
+			++skipSignals;
+		} else {
+			struct sigaction sa;
 
-		memset(&sa, 0, sizeof(sa));
-		sa.sa_handler = FunctionTerminate;//terminate;
-		sigaction(i, &sa, NULL);
+			memset(&sa, 0, sizeof(sa));
+			sa.sa_handler = FunctionTerminate;//terminate;
+			sigaction(i, &sa, NULL);
+		}
 	}
 
 	//NUM_SAMPLES = NUM_SAMPLES_MAX;
diff --git a/src/RpiDma.h b/src/RpiDma.h
index 9058b0c..e585b1c 100644
--- a/src/RpiDma.h
+++ b/src/RpiDma.h
@@ -16,7 +16,7 @@
 #include <sys/mman.h>
 #include "mailbox.h"
 
-char InitDma(void *FunctionTerminate);
+char InitDma(void *FunctionTerminate, int* skipSignals);
 uint32_t mem_virt_to_phys(volatile void *virt);
 uint32_t mem_phys_to_virt(volatile uint32_t phys);
 
diff --git a/src/RpiTx.c b/src/RpiTx.c
index 2c2b251..f47d3d0 100644
--- a/src/RpiTx.c
+++ b/src/RpiTx.c
@@ -173,7 +173,7 @@ terminate(int dummy)
 {
 	stop_dma();
 	//munmap(virtbase,NUM_PAGES * PAGE_SIZE); 
-	printf("END OF PiTx\n", dummy);
+	printf("END OF PiTx\n");
 	exit(1);
 }
 
@@ -951,10 +951,10 @@ void update_ppm(
   }
 }
 
-int pitx_init(int SampleRate,double TuningFrequency)
+int pitx_init(int SampleRate, double TuningFrequency, int* skipSignals)
 {
 	InitGpio();
-	InitDma(terminate);
+	InitDma(terminate, skipSignals);
 	
 	SetupGpioClock(SampleRate,TuningFrequency);
 	
@@ -1141,7 +1141,7 @@ main(int argc, char* argv[])
 	}
 
 	resetFile();
-	return pitx_run(Mode, SampleRate, SetFrequency, ppmpll, NoUsePwmFrequency, readFile, resetFile);
+	return pitx_run(Mode, SampleRate, SetFrequency, ppmpll, NoUsePwmFrequency, readFile, resetFile, NULL);
 }
 
 int pitx_run(
@@ -1151,7 +1151,8 @@ int pitx_run(
 	const float ppmpll,
 	const char NoUsePwmFrequency,
 	ssize_t (*readWrapper)(void *buffer, size_t count),
-	void (*reset)(void)
+	void (*reset)(void),
+	int* skipSignals
 ) {
 	int i;
 	//char pagemap_fn[64];
@@ -1213,7 +1214,7 @@ int pitx_run(
 
 	
 	pitx_SetTuneFrequency(SetFrequency*1000.0);
-	pitx_init(SampleRate,GlobalTuningFrequency);
+	pitx_init(SampleRate, GlobalTuningFrequency, skipSignals);
 	
 
 	
diff --git a/src/RpiTx.h b/src/RpiTx.h
index 0671da6..0e1e4f8 100644
--- a/src/RpiTx.h
+++ b/src/RpiTx.h
@@ -2,7 +2,7 @@
 #define RPITX_H
 #include <ctype.h>
 
-int pitx_init(int SampleRate,double TuningFrequency);
+int pitx_init(int SampleRate, double TuningFrequency, int* skipSignals);
 int pitx_SetTuneFrequencyu(uint32_t Frequency);
 
 #define MODE_IQ 0
@@ -20,7 +20,8 @@ int pitx_run(
 	// Wrapper around read to read wav file bytes
 	ssize_t (*readWrapper)(void *buffer, size_t count),
 	// Wrapper to reset file for looping
-	void (*reset)(void)
+	void (*reset)(void),
+	int* skipSignals
 );
 
 
diff --git a/src/python/_rpitxmodule.c b/src/python/_rpitxmodule.c
index fa65fb6..09b0561 100644
--- a/src/python/_rpitxmodule.c
+++ b/src/python/_rpitxmodule.c
@@ -135,7 +135,14 @@ _rpitx_broadcast_fm(PyObject* self, PyObject* args) {
 	}
 	bitRate = sfInfo.samplerate;
 
-	pitx_run(MODE_RF, bitRate, frequency * 1000.0, 0.0, 0, formatRfWrapper, reset);
+	int skipSignals[] = {
+		SIGALRM,
+		SIGVTALRM,
+		SIGCHLD,  // We fork whenever calling broadcast_fm
+		SIGWINCH,  // Window resized
+        0
+	};
+	pitx_run(MODE_RF, bitRate, frequency * 1000.0, 0.0, 0, formatRfWrapper, reset, skipSignals);
 	sf_close(sndFile);
 
 	Py_RETURN_NONE;