refactor separate non aep specific stuff

Signed-off-by: Andy Green <andy.green@linaro.org>

9 files changed, 328 insertions, 203 deletions

diff --git a/aepd/main.c b/aepd/main.c
index aacc79f..1be825b 100644
--- a/aepd/main.c
+++ b/aepd/main.c
@@ -28,6 +28,7 @@ unsigned long max_fifo_extent_seconds = 120;
 			DOUBLES_PER_CH_SAMPLE * 10000 * max_fifo_extent_seconds)
 
 struct aepd_shared *aepd_shared;
+struct aepd_interface *aepd_interface;
 static double sam[MAX_PROBES * CHANNELS_PER_PROBE * DOUBLES_PER_CH_SAMPLE];
 extern struct libwebsocket_protocols protocols[];
 
@@ -113,7 +114,7 @@ int main(int argc, char *argv[])
 	int opts = 0;
 	char interface_name[128] = "";
 	const char *interface_ptr = NULL;
-	struct aep_result *aep_result;
+	struct aepd_interface_result *aepd_interface_result;
 	struct timeval tv;
 	unsigned long last = 0;
 	unsigned long ms10 = -1;
@@ -193,6 +194,17 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	/*
+	 * generic sample interface
+	 */
+
+	aepd_interface = aepd_interface_create();
+	if (aepd_interface == NULL) {
+		fprintf(stderr, "failed to create aepd_interface region\n");
+		return -1;
+	}
+	aep_context.aepd_interface = aepd_interface;
+
 	/* libwebsockets context */
 
 	if (!use_ssl)
@@ -210,7 +222,6 @@ int main(int argc, char *argv[])
 
 	configure(&aep_context, NULL, "/virtual", aep_context.config_filepath, NULL);
 
-
 	/*
 	 * fork off the AEP service process
 	 * runs in its own process to exploit SMP to dedicate one core for that
@@ -253,18 +264,19 @@ int main(int argc, char *argv[])
 	}
 
 	/*
-	 * this process just has to deal with servicing AEP output from the
-	 * AEP service process and making it available to the websocket
-	 * services via the fifo ring file
+	 * this process just has to deal with collecting samples from
+	 * any backend that acquired them into the shared memory
+	 * buffer, and then make them available to the websocket
+	 * callback via the aepd private fifo ring file
 	 */
 
 	aepd_shared->chans = -1;
 
 	while (loop) {
 
-		aep_result = aep_wait_for_next_result(&aep_context);
-		if (!aep_result) {
-			if (aep_context.aep_shared->finished)
+		aepd_interface_result = aep_wait_for_next_result(aep_context.aepd_interface);
+		if (!aepd_interface_result) {
+			if (aepd_interface->finished)
 				loop = 0;
 
 			continue;
@@ -274,12 +286,12 @@ int main(int argc, char *argv[])
 			goto done;
 
 		/*
-		 * we have the next result in aep_result..
+		 * we have the next result in aepd_interface_result..
 		 * voltage and current per channel
 		 */
 
 		m = 0;
-		for (n = 0; n < aep_result->chans * 2; n += 2) {
+		for (n = 0; n < aepd_interface_result->chans * 2; n += 2) {
 
 			/* 
 			 * accumulate in V, A, W per-channel.
@@ -291,9 +303,9 @@ int main(int argc, char *argv[])
 			 * Doubles are used to maximize dynamic range.
 			 */
 
-			sam[m++] += aep_result->buf[n];
-			sam[m++] += aep_result->buf[n + 1];
-			sam[m++] += aep_result->buf[n] * aep_result->buf[n + 1];
+			sam[m++] += aepd_interface_result->buf[n];
+			sam[m++] += aepd_interface_result->buf[n + 1];
+			sam[m++] += aepd_interface_result->buf[n] * aepd_interface_result->buf[n + 1];
 		}
 
 		/*
@@ -302,24 +314,24 @@ int main(int argc, char *argv[])
 		 * is not at all the same as average V * average A
 		 */
 
-		add_fifo(&sam[0], aep_result->chans * 3 * sizeof(double));
-		aepd_shared->fifo_head_time = aep_result->samtime;
+		add_fifo(&sam[0], aepd_interface_result->chans * 3 * sizeof(double));
+		aepd_shared->fifo_head_time = aepd_interface_result->samtime;
 
-		if (aepd_shared->chans != aep_result->chans) {
-			aepd_shared->chans = aep_result->chans;
+		if (aepd_shared->chans != aepd_interface_result->chans) {
+			aepd_shared->chans = aepd_interface_result->chans;
 			zero_fifo();
 		}
 done:
 		/* done with it */
 
-		aep_free_result(&aep_context);
+		aep_free_result(aepd_interface);
 	}
 
 	close(aepd_shared->fd_fifo_write);
 	close(aepd_shared->fd_fifo_read);
 	unlink(aepd_shared->fifo_filepath);
 
-	sem_close(aep_context.semaphore);
+	aepd_interface_destroy(aepd_interface);
 
 	fprintf(stderr, "exited\n");
 	
diff --git a/aepd/websocket-protocol.c b/aepd/websocket-protocol.c
index da965db..df9d96a 100644
--- a/aepd/websocket-protocol.c
+++ b/aepd/websocket-protocol.c
@@ -249,12 +249,12 @@ bad_caliper:
 			/* signal it's a message with channel names */
 			*p++ = '=';
 
-			for (n = 0; n < aep_context.aep_shared->chans + aep_context.aep_shared->vchans; n++)
+			for (n = 0; n < aep_context.aepd_interface->chans + aep_context.aepd_interface->vchans; n++)
 				p += sprintf(p, "%s,%s,%s,%s,;",
-					aep_context.aep_shared->channel_name[n],
-					aep_context.aep_shared->supply[n],
-					aep_context.aep_shared->colour[n],
-					aep_context.aep_shared->class[n]);
+					aep_context.aepd_interface->channel_name[n],
+					aep_context.aepd_interface->supply[n],
+					aep_context.aepd_interface->colour[n],
+					aep_context.aepd_interface->class[n]);
 
 			pss->channels_sent_flag = 1;
 
diff --git a/arm-probe/arm-probe.c b/arm-probe/arm-probe.c
index 73eee51..fde030d 100644
--- a/arm-probe/arm-probe.c
+++ b/arm-probe/arm-probe.c
@@ -28,6 +28,8 @@ char stdinline[512] = "";
 int stdinpos = 0;
 int stdinlen = 0;
 
+struct aepd_interface *aepd_interface;
+
 struct aep_context aep_context = {
 	.config_filepath = "./config",
 	.highest = -1,
@@ -115,7 +117,7 @@ int main(int argc, char *argv[])
 	int m, i;
 	int periodic = 0;
 	double tt;
-	struct aep_result *aep_result;
+	struct aepd_interface_result *aepd_interface_result;
 	int first = 1;
 
 	loop = 1;
@@ -278,6 +280,19 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	/*
+	 * generic sample interface
+	 */
+
+	aepd_interface = aepd_interface_create();
+	if (aepd_interface == NULL) {
+		fprintf(stderr, "failed to create aepd_interface region\n");
+		return -1;
+	}
+	aep_context.aepd_interface = aepd_interface;
+
+	/* configure */
+
 	configure(&aep_context, NULL, "/virtual", aep_context.config_filepath, NULL);
 
 	/*
@@ -318,9 +333,9 @@ int main(int argc, char *argv[])
 
 	while (loop) {
 
-		aep_result = aep_wait_for_next_result(&aep_context);
-		if (!aep_result) {
-			if (aep_context.aep_shared->finished)
+		aepd_interface_result = aep_wait_for_next_result(aepd_interface);
+		if (!aepd_interface_result) {
+			if (aepd_interface->finished)
 				loop = 0;
 
 			continue;
@@ -328,55 +343,55 @@ int main(int argc, char *argv[])
 
 		if (first) {
 			first = 0;
-			for (n = 0; n < aep_context.aep_shared->chans + aep_context.aep_shared->vchans; n++)
+			for (n = 0; n < aepd_interface->chans + aepd_interface->vchans; n++)
 				printf("# %s\t%s\t%s\t%s\t%s\n",
-					aep_context.aep_shared->channel_name[n],
-					aep_context.aep_shared->channel_name_pretty[n],
-					aep_context.aep_shared->supply[n],
-					aep_context.aep_shared->colour[n],
-					aep_context.aep_shared->class[n]);
+					aepd_interface->channel_name[n],
+					aepd_interface->channel_name_pretty[n],
+					aepd_interface->supply[n],
+					aepd_interface->colour[n],
+					aepd_interface->class[n]);
 
 			printf("#\n#\ntime ");
-			for (n = 0; n < aep_context.aep_shared->chans; n++)
+			for (n = 0; n < aepd_interface->chans; n++)
 				if (just_power)
-					printf(" %s(W)", aep_context.aep_shared->channel_name_pretty[n]);
+					printf(" %s(W)", aepd_interface->channel_name_pretty[n]);
 				else
 					printf(" %s(V) %s(A) %s(W)",
-						aep_context.aep_shared->channel_name_pretty[n],
-						aep_context.aep_shared->channel_name_pretty[n],
-						aep_context.aep_shared->channel_name_pretty[n]);
+						aepd_interface->channel_name_pretty[n],
+						aepd_interface->channel_name_pretty[n],
+						aepd_interface->channel_name_pretty[n]);
 			printf("\n");
 		}
 
 		periodic++;
 		if ((periodic & 0x1ff) == 0) {
-			if (aep_result->triggered)
+			if (aepd_interface_result->triggered)
 				fprintf(stderr, "TRIGD ");
 			else
 				fprintf(stderr, "ARMED ");
 		}
-		if (aep_result->triggered)
-			printf("%f ", aep_result->samtime);
-		for (i = 0; i < aep_result->chans * 2; i += 2) {
-			if (aep_result->triggered) {
+		if (aepd_interface_result->triggered)
+			printf("%f ", aepd_interface_result->samtime);
+		for (i = 0; i < aepd_interface_result->chans * 2; i += 2) {
+			if (aepd_interface_result->triggered) {
 				if (just_power)
-					printf(" %.5f", aep_result->buf[i] * aep_result->buf[i + 1]);
+					printf(" %.5f", aepd_interface_result->buf[i] * aepd_interface_result->buf[i + 1]);
 				else
 					printf(" %.2f %.4f %.5f",
-						aep_result->buf[i], aep_result->buf[i + 1], aep_result->buf[i] * aep_result->buf[i + 1]);
+						aepd_interface_result->buf[i], aepd_interface_result->buf[i + 1], aepd_interface_result->buf[i] * aepd_interface_result->buf[i + 1]);
 			}
 			if (periodic & 0x1ff)
 				continue;
 			if (just_power)
-				fprintf(stderr, " %.5f", aep_result->buf[i] * aep_result->buf[i + 1]);
+				fprintf(stderr, " %.5f", aepd_interface_result->buf[i] * aepd_interface_result->buf[i + 1]);
 			else
 				fprintf(stderr, " %.2f %.4f %.5f",
-						aep_result->buf[i], aep_result->buf[i + 1], aep_result->buf[i] * aep_result->buf[i + 1]);
+						aepd_interface_result->buf[i], aepd_interface_result->buf[i + 1], aepd_interface_result->buf[i] * aepd_interface_result->buf[i + 1]);
 		}
-		if (aep_result->triggered)
+		if (aepd_interface_result->triggered)
 			printf("\n");
 
-		aep_free_result(&aep_context);
+		aep_free_result(aepd_interface);
 
 		if (periodic & 0x1ff)
 			continue;
@@ -384,7 +399,7 @@ int main(int argc, char *argv[])
 
 	}
 
-	aep_context.aep_shared->finished = 1;
+	aep_context.aepd_interface->finished = 1;
 
 	/*
 	 * we are finished if we reach here...
@@ -404,14 +419,14 @@ int main(int argc, char *argv[])
 			} else
 				printf("%f", tt);
 
-			for (n = 0; n <= aep_context.aep_shared->chans; n++) {
+			for (n = 0; n <= aep_context.aepd_interface->chans; n++) {
 				if (just_power)
-					printf(" %.5f", aep_context.aep_shared->averages[n][2]);
+					printf(" %.5f", aep_context.aepd_interface->averages[n][2]);
 				else
 					printf(" %.2f %.4f %.5f",
-						aep_context.aep_shared->averages[n][0],
-						aep_context.aep_shared->averages[n][1],
-						aep_context.aep_shared->averages[n][2]);
+						aep_context.aepd_interface->averages[n][0],
+						aep_context.aepd_interface->averages[n][1],
+						aep_context.aepd_interface->averages[n][2]);
 			}
 			printf("\n");
 
@@ -425,21 +440,21 @@ int main(int argc, char *argv[])
 
 	fprintf(stderr, "\n\n");
 
-	for (n = 0; n < aep_context.aep_shared->chans; n++) {
+	for (n = 0; n < aepd_interface->chans; n++) {
 
-		if (aep_context.aep_shared->min[n][0] == 999)
+		if (aepd_interface->min[n][0] == 999)
 			continue;
 
 		fprintf(stderr, "%12s:  %4.2fV < %4.3fVavg < %4.2fV, "
 				"%6.4fA < %6.5fAavg < %6.4fA, "
 				"%9.6fW < %9.6fWavg < %9.6fW\n",
-					aep_context.aep_shared->channel_name[n],
-					aep_context.aep_shared->min[n][0], aep_context.aep_shared->averages[n][0], aep_context.aep_shared->max[n][0],
-					aep_context.aep_shared->min[n][1], aep_context.aep_shared->averages[n][1], aep_context.aep_shared->max[n][1],
-					aep_context.aep_shared->min[n][2], aep_context.aep_shared->averages[n][2], aep_context.aep_shared->max[n][2]);
+					aepd_interface->channel_name[n],
+					aepd_interface->min[n][0], aepd_interface->averages[n][0], aepd_interface->max[n][0],
+					aepd_interface->min[n][1], aepd_interface->averages[n][1], aepd_interface->max[n][1],
+					aepd_interface->min[n][2], aepd_interface->averages[n][2], aepd_interface->max[n][2]);
 	}
 
-	sem_close(aep_context.semaphore);
+	aepd_interface_destroy(aepd_interface);
 
 	fprintf(stderr, "exited\n");
 	
diff --git a/libarmep/Makefile.am b/libarmep/Makefile.am
index e1ed7fc..79dc801 100644
--- a/libarmep/Makefile.am
+++ b/libarmep/Makefile.am
@@ -1,12 +1,14 @@
 lib_LTLIBRARIES=libarmep.la
-include_HEADERS=libarmep.h
+include_HEADERS=libarmep.h aepd-interface.h
 dist_libarmep_la_SOURCES=sample.c \
 				interpolation.c \
 				configuration.c \
 				avg-mean-us.c \
 				protocol.c \
 				service.c \
-				libarmep.h
+				aepd-interface.c \
+				libarmep.h \
+				aepd-interface.h
 
 libarmep_la_CFLAGS=-Wall -Werror -std=gnu99 -pedantic -pthread -D_FORTIFY_SOURCE=2 -fstack-protector
 libarmep_la_LDFLAGS=-pthread
diff --git a/libarmep/aepd-interface.c b/libarmep/aepd-interface.c
new file mode 100644
index 0000000..e78b308
--- /dev/null
+++ b/libarmep/aepd-interface.c
@@ -0,0 +1,104 @@
+/*
+ * Author: Andy Green <andy.green@linaro.org> 
+ * Copyright (C) 2012 Linaro, LTD
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <getopt.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/time.h>
+#include <semaphore.h>
+#include <sys/mman.h>
+
+#include "aepd-interface.h"
+
+struct aepd_interface *aepd_interface_create(void)
+{
+	struct aepd_interface *aepd_interface;
+	int n;
+
+	/*
+	 * create our lump of shared memory
+	 * which is usable by all forked threads
+	 */
+
+	n = open("/dev/zero", O_RDWR);
+	aepd_interface = mmap(NULL, sizeof (struct aepd_interface),
+		PROT_READ | PROT_WRITE, MAP_SHARED, n, 0);
+	close(n);
+
+	aepd_interface->head = 0;
+	aepd_interface->tail = 0;
+
+	sprintf(aepd_interface->semname, "linaro.aep.%u\n", getpid());
+
+	aepd_interface->semaphore = sem_open(aepd_interface->semname, O_CREAT | O_RDWR, 0600, 0);
+	if (aepd_interface->semaphore == SEM_FAILED) {
+		fprintf(stderr, "Failed to open sem %s\n", aepd_interface->semname);
+		return NULL;
+	}
+
+	return aepd_interface;
+}
+
+void aepd_interface_destroy(struct aepd_interface *aepd_interface)
+{
+	sem_close(aepd_interface->semaphore);
+	if (munmap(aepd_interface, sizeof (struct aepd_interface)) < 0)
+		fprintf(stderr, "munmap failed\n");
+}
+
+/*
+ * helper for user code to block until next aep_result available
+ */
+
+struct aepd_interface_result * aep_wait_for_next_result(struct aepd_interface *aepd_interface)
+{
+	struct timespec ts;
+	struct timeval tv;
+
+	gettimeofday(&tv, NULL);
+	ts.tv_sec = tv.tv_sec + 2;
+	ts.tv_nsec = 0;
+
+	if (sem_timedwait(aepd_interface->semaphore, &ts) < 0)
+		return NULL;
+
+	if (aepd_interface->tail == aepd_interface->head)
+		return NULL;
+
+	return &aepd_interface->aepd_interface_result[aepd_interface->tail];
+}
+
+/*
+ * helper for user code to deal with ringbuffer
+ */
+
+void aep_free_result(struct aepd_interface *aepd_interface)
+{
+	if (aepd_interface->tail == sizeof(aepd_interface->aepd_interface_result) / sizeof(aepd_interface->aepd_interface_result[0]) - 1)
+		aepd_interface->tail = 0;
+	else
+		aepd_interface->tail++;
+}
+
diff --git a/libarmep/aepd-interface.h b/libarmep/aepd-interface.h
new file mode 100644
index 0000000..9b43352
--- /dev/null
+++ b/libarmep/aepd-interface.h
@@ -0,0 +1,73 @@
+/*
+ * Author: Andy Green <andy.green@linaro.org> 
+ * Copyright (C) 2012 Linaro, LTD
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * These are the interface structs between the acquisition-specific
+ * code and the shared memory buffers, which are just abstracted
+ * sample and channel descriptions with no knowledge of what
+ * produced them
+ */
+
+#define AEPD_SHARED_MAX_REAL_CHANNELS (8 * 3)
+#define AEPD_SHARED_MAX_VIRTUAL_CHANNELS (8)
+
+struct aepd_interface_result {
+	int triggered; /* 0 = pretrigger 1 = triggered */
+	int chans; /* number of channels below with data */
+	double samtime; /* sample time in s */
+
+	/* For each channel: { common-mode voltage in V, current in A } */
+	double buf[AEPD_SHARED_MAX_REAL_CHANNELS * 2];
+};
+
+struct aepd_interface {
+
+	/* ringbuffer to hold channel_results until we can deal with them */
+
+	int head;
+	int tail;
+	struct aepd_interface_result aepd_interface_result[1000];
+
+	/* synchronization object signalling new result written */
+	sem_t * semaphore;
+	char semname[64];
+
+	/* metadata about the channels */
+
+	char channel_name[AEPD_SHARED_MAX_VIRTUAL_CHANNELS + AEPD_SHARED_MAX_REAL_CHANNELS][64];
+	char channel_name_pretty[AEPD_SHARED_MAX_VIRTUAL_CHANNELS + AEPD_SHARED_MAX_REAL_CHANNELS][64];
+	char supply[AEPD_SHARED_MAX_VIRTUAL_CHANNELS + AEPD_SHARED_MAX_REAL_CHANNELS][64];
+	char colour[AEPD_SHARED_MAX_VIRTUAL_CHANNELS + AEPD_SHARED_MAX_REAL_CHANNELS][16];
+	char class[AEPD_SHARED_MAX_VIRTUAL_CHANNELS + AEPD_SHARED_MAX_REAL_CHANNELS][16];
+	int chans; /* number of active acquisition channels above */
+	int vchans; /* virtual channels (summing supplies) appear after probed physical channels in the arrays */
+	int finished; /* are we going down? */
+
+	/* simple stats on what was captured */
+
+	double averages[AEPD_SHARED_MAX_REAL_CHANNELS][3];
+	double min[AEPD_SHARED_MAX_REAL_CHANNELS][3];
+	double max[AEPD_SHARED_MAX_REAL_CHANNELS][3];
+
+};
+
+extern struct aepd_interface *aepd_interface_create(void);
+extern void aepd_interface_destroy(struct aepd_interface *aepd_interface);
+extern struct aepd_interface_result * aep_wait_for_next_result(struct aepd_interface *aepd_interface);
+extern void aep_free_result(struct aepd_interface *aepd_interface);
+
diff --git a/libarmep/libarmep.h b/libarmep/libarmep.h
index 8811fce..2247b46 100644
--- a/libarmep/libarmep.h
+++ b/libarmep/libarmep.h
@@ -36,6 +36,8 @@
 #include <time.h>
 #include <semaphore.h>
 
+#include "aepd-interface.h"
+
 #define MAX_PROBES 8
 #define CHANNELS_PER_PROBE 3
 
@@ -227,31 +229,6 @@ struct aep {
 	struct aep_channel ch[CHANNELS_PER_PROBE];
 };
 
-struct aep_result {
-	int triggered;
-	int chans;
-	double samtime;
-	double buf[MAX_PROBES * CHANNELS_PER_PROBE * 2];
-
-};
-
-struct aep_shared {
-	int head;
-	int tail;
-	struct aep_result aep_result[1000];
-	char channel_name[MAX_VIRTUAL_CHANNELS + MAX_PROBES * CHANNELS_PER_PROBE][64];
-	char channel_name_pretty[MAX_VIRTUAL_CHANNELS + MAX_PROBES * CHANNELS_PER_PROBE][64];
-	char supply[MAX_VIRTUAL_CHANNELS + MAX_PROBES * CHANNELS_PER_PROBE][64];
-	char colour[MAX_VIRTUAL_CHANNELS + MAX_PROBES * CHANNELS_PER_PROBE][16];
-	char class[MAX_VIRTUAL_CHANNELS + MAX_PROBES * CHANNELS_PER_PROBE][16];
-	int chans;
-	int vchans; /* appear after probed physical channels in the arrays*/
-	int finished;
-	double averages[MAX_PROBES * CHANNELS_PER_PROBE][3];
-	double min[MAX_PROBES * CHANNELS_PER_PROBE][3];
-	double max[MAX_PROBES * CHANNELS_PER_PROBE][3];
-
-};
 
 struct aep_context {
 	struct aep aeps[MAX_PROBES];
@@ -289,10 +266,9 @@ struct aep_context {
 	int poll_timeout_ms;
 	double do_average;
 
-	/* shared memory output buffer */
+	/* shared memory output buffer + metadata */
 
-	struct aep_shared *aep_shared;
-	sem_t * semaphore;
+	struct aepd_interface  *aepd_interface;
 };
 
 
@@ -338,6 +314,4 @@ extern void init_interpolation(void);
 
 extern int service_aeps(struct aep_context *aep_context, int fd);
 extern int aep_init_and_fork(struct aep_context *aep_context, char *argv[]);
-extern struct aep_result * aep_wait_for_next_result(struct aep_context *aep_context);
-extern void aep_free_result(struct aep_context *aep_context);
 
diff --git a/libarmep/sample.c b/libarmep/sample.c
index f17a803..df6b278 100644
--- a/libarmep/sample.c
+++ b/libarmep/sample.c
@@ -90,8 +90,8 @@ int process_sample(struct aep *aep, int ch_index)
 	struct aep_channel *ch = &aep->ch[ch_index], *ich;
 	double v1, v2, v1a, v2a, vo0 = 0, vo1 = 0;
 	int m, i, from_pretrig = 0, n, hit;
-	struct aep_shared *aep_shared;
-	struct aep_result *aep_result;
+	struct aepd_interface *aepd_interface;
+	struct aepd_interface_result *aepd_interface_result;
 
 	if (!aep->aep_context->no_correction) {
 		vo0 = ch->voffset[0];
@@ -302,12 +302,12 @@ unripe:
 
 	/* if so, output it all together */
 
-	aep_shared = aep->aep_context->aep_shared;
-	aep_result = &aep_shared->aep_result[aep_shared->head];
+	aepd_interface = aep->aep_context->aepd_interface;
+	aepd_interface_result = &aepd_interface->aepd_interface_result[aepd_interface->head];
 
-	aep_result->triggered = ch->triggered;
-	aep_result->chans = hit;
-	aep_result->samtime = ((double)ch->samples_seen - (double)ch->ring_samples) / 10000.0;
+	aepd_interface_result->triggered = ch->triggered;
+	aepd_interface_result->chans = hit;
+	aepd_interface_result->samtime = ((double)ch->samples_seen - (double)ch->ring_samples) / 10000.0;
 
 	n = 0;
 
@@ -332,17 +332,17 @@ unripe:
 			if (!ich->requested)
 				continue;
 	
-			aep_result->buf[n++] = v1a;
-			aep_result->buf[n++] = v2a;
+			aepd_interface_result->buf[n++] = v1a;
+			aepd_interface_result->buf[n++] = v2a;
 		}
 	}
 
-	if (aep_shared->head == (sizeof(aep_shared->aep_result) / sizeof(aep_shared->aep_result[0])) - 1)
-		aep_shared->head = 0;
+	if (aepd_interface->head == (sizeof(aepd_interface->aepd_interface_result) / sizeof(aepd_interface->aepd_interface_result[0])) - 1)
+		aepd_interface->head = 0;
 	else
-		aep_shared->head++;
+		aepd_interface->head++;
 
-	if (sem_post(aep->aep_context->semaphore) < 0)
+	if (sem_post(aep->aep_context->aepd_interface->semaphore) < 0)
 		fprintf(stderr, "failed to set semaphore\n");
 
 done:
diff --git a/libarmep/service.c b/libarmep/service.c
index 68a7028..d6d40b0 100644
--- a/libarmep/service.c
+++ b/libarmep/service.c
@@ -21,7 +21,6 @@
 #include "libarmep.h"
 
 #include <linux/serial.h>
-#include <sys/mman.h>
 
 void add_pollfd(struct aep_context *aep_context, int fd, int events)
 {
@@ -150,18 +149,18 @@ void probe_close(struct aep *aep)
 	close(aep->fd);
 }
 
-static void copy_public_ch_info_to_shared(struct aep_shared *aep_shared, int chan, struct aep_channel *ch)
+static void copy_public_ch_info_to_shared(struct aepd_interface *aepd_interface, int chan, struct aep_channel *ch)
 {
-	strncpy(aep_shared->channel_name[chan], ch->channel_name, sizeof(aep_shared->channel_name[0]));
-	aep_shared->channel_name[chan][sizeof(aep_shared->channel_name[0]) - 1] = '\0';
-	strncpy(aep_shared->channel_name_pretty[chan], ch->channel_name_pretty, sizeof(aep_shared->channel_name_pretty[0]));
-	aep_shared->channel_name_pretty[chan][sizeof(aep_shared->channel_name_pretty[0]) - 1] = '\0';
-	strncpy(aep_shared->supply[chan], ch->supply, sizeof(aep_shared->supply[0]));
-	aep_shared->supply[chan][sizeof(aep_shared->supply[0]) - 1] = '\0';
-	strncpy(aep_shared->colour[chan], ch->colour, sizeof(aep_shared->colour[0]));
-	aep_shared->colour[chan][sizeof(aep_shared->colour[0]) - 1] = '\0';
-	strncpy(aep_shared->class[chan], ch->class, sizeof(aep_shared->class[0]));
-	aep_shared->class[chan][sizeof(aep_shared->class[0]) - 1] = '\0';
+	strncpy(aepd_interface->channel_name[chan], ch->channel_name, sizeof(aepd_interface->channel_name[0]));
+	aepd_interface->channel_name[chan][sizeof(aepd_interface->channel_name[0]) - 1] = '\0';
+	strncpy(aepd_interface->channel_name_pretty[chan], ch->channel_name_pretty, sizeof(aepd_interface->channel_name_pretty[0]));
+	aepd_interface->channel_name_pretty[chan][sizeof(aepd_interface->channel_name_pretty[0]) - 1] = '\0';
+	strncpy(aepd_interface->supply[chan], ch->supply, sizeof(aepd_interface->supply[0]));
+	aepd_interface->supply[chan][sizeof(aepd_interface->supply[0]) - 1] = '\0';
+	strncpy(aepd_interface->colour[chan], ch->colour, sizeof(aepd_interface->colour[0]));
+	aepd_interface->colour[chan][sizeof(aepd_interface->colour[0]) - 1] = '\0';
+	strncpy(aepd_interface->class[chan], ch->class, sizeof(aepd_interface->class[0]));
+	aepd_interface->class[chan][sizeof(aepd_interface->class[0]) - 1] = '\0';
 
 }
 
@@ -374,10 +373,10 @@ bail:
 				if (!ch->requested)
 					continue;
 
-				copy_public_ch_info_to_shared(aep_context->aep_shared, chan, ch);
+				copy_public_ch_info_to_shared(aep_context->aepd_interface, chan, ch);
 
 				chan++;
-				aep_context->aep_shared->chans = chan;
+				aep_context->aepd_interface->chans = chan;
 			}
 
 			aep_context->aeps[m].started = 1;
@@ -386,8 +385,8 @@ bail:
 		}
 
 		for (m = 0; m < aep_context->count_virtual_channels; m++) {
-			copy_public_ch_info_to_shared(aep_context->aep_shared, chan++, &aep_context->vch[m]);
-			aep_context->aep_shared->vchans++;
+			copy_public_ch_info_to_shared(aep_context->aepd_interface, chan++, &aep_context->vch[m]);
+			aep_context->aepd_interface->vchans++;
 		}
 
 	}
@@ -530,7 +529,7 @@ service:
 	if (aep_context->scans > (5 * MAX_PROBES) &&
 			aep_context->awaiting_capture == 0 && aep_context->exit_after_capture) {
 		fprintf(stderr, "done all capture\n");
-		aep_context->aep_shared->finished = 1;
+		aep_context->aepd_interface->finished = 1;
 		return -1;
 	}
 
@@ -556,37 +555,21 @@ void sighandler(int sig)
 }
 
 
+/*
+ * you should have called aepd_interface_create() above
+ * and set aep_context->aepd_interface to the result
+ * before calling this
+ */
+
 int aep_init_and_fork(struct aep_context *aep_context, char *argv[])
 {
 	int n, m, i;
 	struct aep_channel *ch;
-	char semname[64];
 
 	loop = 1;
 
 	init_interpolation();
 
-	/*
-	 * create our lump of shared memory
-	 * which is usable by all forked threads
-	 */
-
-	n = open("/dev/zero", O_RDWR);
-	aep_context->aep_shared = mmap(NULL, sizeof (struct aep_shared),
-		PROT_READ | PROT_WRITE, MAP_SHARED, n, 0);
-	close(n);
-
-	aep_context->aep_shared->head = 0;
-	aep_context->aep_shared->tail = 0;
-
-	sprintf(semname, "linaro.aep.%u\n", getpid());
-
-	aep_context->semaphore = sem_open(semname, O_CREAT | O_RDWR, 0600, 0);
-	if (aep_context->semaphore == SEM_FAILED) {
-		fprintf(stderr, "Failed to open sem %s\n", semname);
-		return -1;
-	}
-
 	/* fork off aep service loop */
 
 	n = fork();
@@ -603,31 +586,31 @@ int aep_init_and_fork(struct aep_context *aep_context, char *argv[])
 	if (argv)
 		strcpy(argv[0] + strlen(argv[0]), " - AEP server");
 
-	aep_context->semaphore = sem_open(semname, O_RDWR, 0600, 0);
-	if (aep_context->semaphore == SEM_FAILED) {
-		fprintf(stderr, "Child failed to open sem %s\n", semname);
+	aep_context->aepd_interface->semaphore = sem_open(aep_context->aepd_interface->semname, O_RDWR, 0600, 0);
+	if (aep_context->aepd_interface->semaphore == SEM_FAILED) {
+		fprintf(stderr, "Child failed to open sem %s\n", aep_context->aepd_interface->semname);
 		return -1;
 	}
 
-	aep_context->aep_shared->finished = 0;
+	aep_context->aepd_interface->finished = 0;
 	aep_context->poll_timeout_ms = 10;
 
-	while (!aep_context->aep_shared->finished && loop && getppid() != 1) {
+	while (!aep_context->aepd_interface->finished && loop && getppid() != 1) {
 
 		n = poll(aep_context->pollfds, aep_context->count_pollfds, aep_context->poll_timeout_ms);
 		if (n < 0)
-			aep_context->aep_shared->finished = 1;
+			aep_context->aepd_interface->finished = 1;
 
 		for (n = 0; n < aep_context->count_pollfds; n++)
 			if (aep_context->pollfds[n].revents)
 				if (service_aeps(aep_context, aep_context->pollfds[n].fd) < 0)
-					aep_context->aep_shared->finished = 1;
+					aep_context->aepd_interface->finished = 1;
 
 		if (service_aeps(aep_context, -1) < 0)
-			aep_context->aep_shared->finished = 1;
+			aep_context->aepd_interface->finished = 1;
 	}
 
-	sem_close(aep_context->semaphore);
+	sem_close(aep_context->aepd_interface->semaphore);
 
 	/*
 	 * Compute and stash the averages
@@ -645,15 +628,15 @@ int aep_init_and_fork(struct aep_context *aep_context, char *argv[])
 					aep_context->config_filepath, ch) < 0)
 				fprintf(stderr, "failed to update config\n");
 
-			aep_context->aep_shared->averages[m][0] = ch->simple_avg[0] / ch->avg_count;
-			aep_context->aep_shared->averages[m][1] = ch->simple_avg[1] / ch->avg_count;
-			aep_context->aep_shared->averages[m][2] = ch->simple_avg[2] / ch->avg_count;
-			aep_context->aep_shared->min[m][0] = ch->min[0];
-			aep_context->aep_shared->min[m][1] = ch->min[1];
-			aep_context->aep_shared->min[m][2] = ch->min[2];
-			aep_context->aep_shared->max[m][0] = ch->max[0];
-			aep_context->aep_shared->max[m][1] = ch->max[1];
-			aep_context->aep_shared->max[m][2] = ch->max[2];
+			aep_context->aepd_interface->averages[m][0] = ch->simple_avg[0] / ch->avg_count;
+			aep_context->aepd_interface->averages[m][1] = ch->simple_avg[1] / ch->avg_count;
+			aep_context->aepd_interface->averages[m][2] = ch->simple_avg[2] / ch->avg_count;
+			aep_context->aepd_interface->min[m][0] = ch->min[0];
+			aep_context->aepd_interface->min[m][1] = ch->min[1];
+			aep_context->aepd_interface->min[m][2] = ch->min[2];
+			aep_context->aepd_interface->max[m][0] = ch->max[0];
+			aep_context->aepd_interface->max[m][1] = ch->max[1];
+			aep_context->aepd_interface->max[m][2] = ch->max[2];
 			m++;
 		}
 
@@ -663,43 +646,5 @@ int aep_init_and_fork(struct aep_context *aep_context, char *argv[])
 	return 0;
 }
 
-/*
- * helper for user code to block until next aep_result available
- */
-
-struct aep_result * aep_wait_for_next_result(struct aep_context *aep_context)
-{
-	struct timespec ts;
-	struct timeval tv;
-	struct aep_shared *aep_shared = aep_context->aep_shared;
-
-	gettimeofday(&tv, NULL);
-	ts.tv_sec = tv.tv_sec + 2;
-	ts.tv_nsec = 0;
-
-	if (sem_timedwait(aep_context->semaphore, &ts) < 0)
-		return NULL;
-
-	if (aep_shared->tail == aep_shared->head)
-		return NULL;
-
-//	fprintf(stderr, "%d %d, ", aep_shared->tail, aep_shared->head);
-
-	return &aep_shared->aep_result[aep_shared->tail];
-}
-
-/*
- * helper for user code to deal with ringbuffer
- */
-
-void aep_free_result(struct aep_context *aep_context)
-{
-	struct aep_shared *aep_shared = aep_context->aep_shared;
-
-	if (aep_shared->tail == sizeof(aep_shared->aep_result) / sizeof(aep_shared->aep_result[0]) - 1)
-		aep_shared->tail = 0;
-	else
-		aep_shared->tail++;
-}