Phase 2/4 done, working on phase 3/5

2026-04-24 15:46:04 +02:00
parent 9aa89cc0cf
commit 8b548ba1c2
43 changed files with 6800 additions and 156 deletions
@@ -0,0 +1,118 @@
+#ifndef CA_WRAPPER_H
+#define CA_WRAPPER_H
+
+#include <cadef.h>
+#include <db_access.h>
+#include <stdint.h>
+
+/*
+ * Go-exported callback declarations.
+ * These are implemented in ca_callback.go (via //export directives).
+ *
+ * goCAMonitorCallback is called for each value update received from CA.
+ * goCAConnectionCallback is called when a channel connects or disconnects.
+ */
+extern void goCAMonitorCallback(uintptr_t handle, int dbrType, long count,
+                                const void *dbr, int severity,
+                                double epicsTimeSecs);
+extern void goCAConnectionCallback(uintptr_t handle, int connected);
+
+/*
+ * CA monitor callback shim.
+ *
+ * CA calls this function with the fixed evargs signature.  We extract the
+ * relevant fields and forward them to the Go callback.
+ */
+static void caMonitorCallbackShim(struct event_handler_args args) {
+    if (args.status != ECA_NORMAL) {
+        return;
+    }
+
+    double timeSecs = 0.0;
+    int    severity = 0;
+
+    /*
+     * Determine the timestamp and alarm severity from the DBR type.
+     * We request DBR_TIME_* types so the timestamp is embedded in the value
+     * buffer right after the alarm fields (struct dbr_time_double et al.).
+     */
+    switch (args.type) {
+    case DBR_TIME_DOUBLE: {
+        const struct dbr_time_double *p = (const struct dbr_time_double *)args.dbr;
+        timeSecs = (double)p->stamp.secPastEpoch + (double)p->stamp.nsec / 1e9;
+        severity = (int)p->severity;
+        break;
+    }
+    case DBR_TIME_FLOAT: {
+        const struct dbr_time_float *p = (const struct dbr_time_float *)args.dbr;
+        timeSecs = (double)p->stamp.secPastEpoch + (double)p->stamp.nsec / 1e9;
+        severity = (int)p->severity;
+        break;
+    }
+    case DBR_TIME_LONG: {
+        const struct dbr_time_long *p = (const struct dbr_time_long *)args.dbr;
+        timeSecs = (double)p->stamp.secPastEpoch + (double)p->stamp.nsec / 1e9;
+        severity = (int)p->severity;
+        break;
+    }
+    case DBR_TIME_SHORT: {
+        const struct dbr_time_short *p = (const struct dbr_time_short *)args.dbr;
+        timeSecs = (double)p->stamp.secPastEpoch + (double)p->stamp.nsec / 1e9;
+        severity = (int)p->severity;
+        break;
+    }
+    case DBR_TIME_STRING: {
+        const struct dbr_time_string *p = (const struct dbr_time_string *)args.dbr;
+        timeSecs = (double)p->stamp.secPastEpoch + (double)p->stamp.nsec / 1e9;
+        severity = (int)p->severity;
+        break;
+    }
+    case DBR_TIME_ENUM: {
+        const struct dbr_time_enum *p = (const struct dbr_time_enum *)args.dbr;
+        timeSecs = (double)p->stamp.secPastEpoch + (double)p->stamp.nsec / 1e9;
+        severity = (int)p->severity;
+        break;
+    }
+    default:
+        break;
+    }
+
+    goCAMonitorCallback((uintptr_t)args.usr, (int)args.type, (long)args.count,
+                        args.dbr, severity, timeSecs);
+}
+
+/*
+ * CA connection callback shim.
+ *
+ * CA calls this with a connection_handler_args struct.  We map the op field
+ * to a simple boolean (1 = connected, 0 = disconnected) and forward.
+ */
+static void caConnectionCallbackShim(struct connection_handler_args args) {
+    int connected = (args.op == CA_OP_CONN_UP) ? 1 : 0;
+    goCAConnectionCallback((uintptr_t)ca_puser(args.chid), connected);
+}
+
+/*
+ * Thin helpers so CGo callers do not need to deal with C function-pointer
+ * syntax directly.  All CA API calls stay in C to avoid issues with CGo
+ * passing Go pointers across the CA callback boundary.
+ */
+
+/* Create a channel with the connection shim as the connection callback.
+ * user_handle is the Go uintptr_t that identifies this channel in the handle
+ * table.  Returns the ECA_* status code. */
+static int caCreateChannel(const char *pvName, uintptr_t userHandle,
+                           chid *pChid) {
+    return ca_create_channel(pvName, caConnectionCallbackShim,
+                             (void *)userHandle, CA_PRIORITY_DEFAULT, pChid);
+}
+
+/* Add a value-monitor event on chid.  Returns the ECA_* status code and stores
+ * the evid in *pEvid. */
+static int caAddMonitor(chid ch, short dbrType, uintptr_t userHandle,
+                        evid *pEvid) {
+    return ca_add_event(dbrType, ch, caMonitorCallbackShim,
+                        (void *)userHandle, pEvid);
+}
+
+#endif /* CA_WRAPPER_H */