First step in runtime export dispatch for the client library.

6 files changed, 41 insertions, 5 deletions

diff --git a/gpxlogger.c b/gpxlogger.c
index 63e5be1a..95d716be 100644
--- a/gpxlogger.c
+++ b/gpxlogger.c
@@ -17,8 +17,8 @@
 #endif /* S_SPLINT_S */
 
 #include "gps.h"
-#include "libgps.h" /* TEMPORARY */
 #include "gpsd_config.h"
+#include "libgps.h" /* TEMPORARY */
 #include "gpsdclient.h"
 #include "revision.h"
 
diff --git a/libgps.h b/libgps.h
index f571efa8..17dc73ea 100644
--- a/libgps.h
+++ b/libgps.h
@@ -6,6 +6,13 @@
 #ifndef _GPSD_LIBGPS_H_
 #define _GPSD_LIBGPS_H_
 
+/* 
+ * first member of each kind of privdata structure must be named 
+ * 'export' and must be of this time.  It's how we do runtime 
+ * dispatch to the different transports.
+ */
+enum export_t {sockets, shm, dbus};
+
 extern int gps_sock_open(/*@null@*/const char *, /*@null@*/const char *, 
 		      /*@out@*/struct gps_data_t *);
 extern int gps_sock_close(struct gps_data_t *);
diff --git a/libgps_core.c b/libgps_core.c
index 2196b0ab..b2e298d9 100644
--- a/libgps_core.c
+++ b/libgps_core.c
@@ -18,6 +18,17 @@
 #include "libgps.h"
 #include "gps_json.h"
 
+/*
+ * All privdata structures have export as a first member, 
+ * and can have others that the individual method libraries
+ * know about but this one doesn't.
+ */
+struct privdata_t
+{
+    enum export_t export;
+};
+#define PRIVATE(gpsdata) ((struct privdata_t *)gpsdata->privdata)
+
 #ifdef LIBGPS_DEBUG
 int libgps_debuglevel = 0;
 
diff --git a/libgps_dbus.c b/libgps_dbus.c
index c948e931..21ea129f 100644
--- a/libgps_dbus.c
+++ b/libgps_dbus.c
@@ -20,6 +20,7 @@
 
 struct privdata_t
 {
+    enum export_t export;
     void (*handler)(struct gps_data_t *);
 };
 #define PRIVATE(gpsdata) ((struct privdata_t *)(gpsdata)->privdata)
@@ -124,6 +125,7 @@ int gps_dbus_open(struct gps_data_t *gpsdata)
 	return 5;
     }
 
+    PRIVATE(gpsdata)->export = dbus;
     share_gpsdata = gpsdata;
     return 0;
 }
diff --git a/libgps_shm.c b/libgps_shm.c
index 4a26c00d..a541a53a 100644
--- a/libgps_shm.c
+++ b/libgps_shm.c
@@ -17,6 +17,7 @@ PERMISSIONS
 #include <stddef.h>
 #include <string.h>
 #include <errno.h>
+#include <stdlib.h>
 #include <sys/time.h>
 #include <sys/ipc.h>
 #include <sys/shm.h>
@@ -26,6 +27,14 @@ PERMISSIONS
 
 #ifdef SHM_EXPORT_ENABLE
 
+struct privdata_t
+{
+    enum export_t export;
+    void *shmseg;
+};
+#define PRIVATE(gpsdata) ((struct privdata_t *)(gpsdata)->privdata)
+
+
 int gps_shm_open(/*@out@*/struct gps_data_t *gpsdata)
 /* open a shared-memory connection to the daemon */
 {
@@ -39,7 +48,11 @@ int gps_shm_open(/*@out@*/struct gps_data_t *gpsdata)
 	/* daemon isn't running or failed to create shared segment */
 	return -1;
     } 
-    gpsdata->privdata = shmat(shmid, 0, 0);
+    gpsdata->privdata = (void *)malloc(sizeof(struct privdata_t));
+    if (gpsdata->privdata == NULL)
+	return -1;
+
+    PRIVATE(gpsdata)->shmseg = shmat(shmid, 0, 0);
     if ((int)(long)gpsdata->privdata == -1) {
 	/* attach failed for sume unknown reason */
 	return -2;
@@ -49,6 +62,7 @@ int gps_shm_open(/*@out@*/struct gps_data_t *gpsdata)
 #else
     gpsdata->gps_fd = (void *)(intptr_t)-1;
 #endif /* USE_QT */
+    PRIVATE(gpsdata)->export = shm;
     return 0;
 }
 
@@ -62,7 +76,7 @@ int gps_shm_read(struct gps_data_t *gpsdata)
     {
 	int before, after;
 	void *private_save = gpsdata->privdata;
-	volatile struct shmexport_t *shared = (struct shmexport_t *)gpsdata->privdata;
+	volatile struct shmexport_t *shared = (struct shmexport_t *)PRIVATE(gpsdata)->shmseg;
 	struct gps_data_t noclobber;
 
 	/*
@@ -106,8 +120,8 @@ int gps_shm_read(struct gps_data_t *gpsdata)
 
 void gps_shm_close(struct gps_data_t *gpsdata)
 {
-    if (gpsdata->privdata != NULL)
-	(void)shmdt((const void *)gpsdata->privdata);
+    if (PRIVATE(gpsdata)->shmseg != NULL)
+	(void)shmdt((const void *)PRIVATE(gpsdata)->shmseg);
 }
 
 int gps_shm_mainloop(struct gps_data_t *gpsdata, int timeout UNUSED, 
diff --git a/libgps_sock.c b/libgps_sock.c
index eee2b926..0c2347e4 100644
--- a/libgps_sock.c
+++ b/libgps_sock.c
@@ -41,6 +41,7 @@ extern char *strtok_r(char *, const char *, char **);
 
 struct privdata_t
 {
+    enum export_t export;
     bool newstyle;
     /* data buffered from the last read */
     ssize_t waiting;
@@ -85,6 +86,7 @@ int gps_sock_open(/*@null@*/const char *host, /*@null@*/const char *port,
     gpsdata->privdata = (void *)malloc(sizeof(struct privdata_t));
     if (gpsdata->privdata == NULL)
 	return -1;
+    PRIVATE(gpsdata)->export = sockets;
     PRIVATE(gpsdata)->newstyle = false;
     PRIVATE(gpsdata)->waiting = 0;