From cfe9a431f976dd45a394159042dd31230daab5a0 Mon Sep 17 00:00:00 2001
From: Dhanya Thattil <dhanya.thattil@psi.ch>
Date: Fri, 26 Jun 2020 11:50:40 +0200
Subject: [PATCH] WIP, moving virtual status stop to shm from files

---
 .../slsDetectorServer/include/sharedMemory.h  |  23 ++++
 .../slsDetectorServer/src/sharedMemory.c      | 129 ++++++++++++++++++
 2 files changed, 152 insertions(+)
 create mode 100644 slsDetectorServers/slsDetectorServer/include/sharedMemory.h
 create mode 100644 slsDetectorServers/slsDetectorServer/src/sharedMemory.c

diff --git a/slsDetectorServers/slsDetectorServer/include/sharedMemory.h b/slsDetectorServers/slsDetectorServer/include/sharedMemory.h
new file mode 100644
index 000000000..c74819070
--- /dev/null
+++ b/slsDetectorServers/slsDetectorServer/include/sharedMemory.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#include <semaphore.h>
+
+typedef struct Memory {
+    int version;
+    sem_t sem;
+#ifdef VIRTUAL
+    int status;
+    int stop;
+#endif
+} sharedMem;
+
+char *getSharedMemoryError();
+void printSharedMemory(sharedMem *shm);
+int createSharedMemory(sharedMem **shm, int port);
+void initializeSharedMemory(sharedMem *shm);
+int openSharedMemory(sharedMem **shm, int port);
+int attachSharedMemory(sharedMem **shm);
+int detachSharedMemory(sharedMem **shm);
+int removeSharedMemory();
+void lockSharedMemory();
+void unlockSharedMemory();
diff --git a/slsDetectorServers/slsDetectorServer/src/sharedMemory.c b/slsDetectorServers/slsDetectorServer/src/sharedMemory.c
new file mode 100644
index 000000000..49ce6422c
--- /dev/null
+++ b/slsDetectorServers/slsDetectorServer/src/sharedMemory.c
@@ -0,0 +1,129 @@
+#include "sharedMemory.h"
+#include "clogger.h"
+#include "sls_detector_defs.h"
+
+#include <errno.h> // errno
+#include <fcntl.h> // O_CREAT, O_TRUNC..
+#include <string.h>
+#include <sys/mman.h> // shared memory
+#include <sys/stat.h> // fstat
+#include <unistd.h>
+
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <sys/types.h>
+
+#define SHM_NAME    "sls_server_shared_memory"
+#define SHM_VERSION 0x200625
+#define SHM_KEY     5678
+char shmMess[MAX_STR_LENGTH];
+int shmFd = -1;
+
+extern int isControlServer;
+
+char *getSharedMemoryError() { return shmMess; }
+
+void printSharedMemory(sharedMem *shm) {
+    LOG(logINFO, ("%s Shared Memory:\n", isControlServer ? "c" : "s"));
+    LOG(logINFO,
+        ("%s version:0x%x\n", isControlServer ? "c" : "s", shm->version));
+#ifdef VIRTUAL
+    LOG(logINFO, ("%s status: %d\n", isControlServer ? "c" : "s", shm->status));
+    LOG(logINFO, ("%s stop: %d\n", isControlServer ? "c" : "s", shm->stop));
+#endif
+}
+
+int createSharedMemory(sharedMem **shm, int port) {
+    memset(shmMess, 0, MAX_STR_LENGTH);
+
+    // if sham existed, delete old shm and create again
+    shmFd =
+        shmget(SHM_KEY + port, sizeof(sharedMem), IPC_CREAT | IPC_EXCL | 0666);
+    if (shmFd == -1 && errno == EEXIST) {
+        LOG(logWARNING, ("Removing old shared memory\n"));
+        // cuz of unknown previous shm size, it has to  be deleted like this
+        system(
+            "for i in seq `ipcs -m | cut -d ' ' -f1`; do ipcrm -M $i; done;");
+        shmFd = shmget(SHM_KEY + port, sizeof(sharedMem),
+                       IPC_CREAT | IPC_EXCL | 0666);
+    }
+    if (shmFd == -1) {
+        sprintf(shmMess, "Create shared memory failed: %s\n", strerror(errno));
+        LOG(logERROR, (shmMess));
+        return 0;
+    }
+    LOG(logINFO, ("Shared memory created\n"));
+    if (!attachSharedMemory(shm)) {
+        return 0;
+    }
+    initializeSharedMemory(*shm);
+    return 1;
+}
+
+void initializeSharedMemory(sharedMem *shm) {
+    shm->version = SHM_VERSION;
+    sem_init(&(shm->sem), 1, 1);
+#ifdef VIRTUAL
+    shm->status = 0;
+    shm->stop = 0;
+#endif
+    LOG(logINFO, ("Shared memory initialized\n"))
+}
+
+int openSharedMemory(sharedMem **shm, int port) {
+    memset(shmMess, 0, MAX_STR_LENGTH);
+    shmFd = shmget(SHM_KEY + port, sizeof(sharedMem), 0666);
+    if (shmFd == -1) {
+        sprintf(shmMess, "Open shared memory failed: %s\n", strerror(errno));
+        LOG(logERROR, (shmMess));
+        return 0;
+    }
+    if (!attachSharedMemory(shm)) {
+        return 0;
+    }
+    if ((*shm)->version != SHM_VERSION) {
+        sprintf(shmMess,
+                "Shared memory version 0x%x does not match! (expected: 0x%x)\n",
+                (*shm)->version, SHM_VERSION);
+        LOG(logERROR, (shmMess));
+    }
+    LOG(logINFO, ("Shared memory opened\n"));
+    return 1;
+}
+
+int attachSharedMemory(sharedMem **shm) {
+    *shm = (sharedMem *)shmat(shmFd, NULL, 0);
+    if (*shm == (void *)-1) {
+        sprintf(shmMess, "could not attach: %s\n", strerror(errno));
+        LOG(logERROR, (shmMess));
+        return 0;
+    }
+    LOG(logINFO, ("Shared memory attached\n"));
+    return 1;
+}
+
+int detachSharedMemory(sharedMem **shm) {
+    memset(shmMess, 0, MAX_STR_LENGTH);
+    if (shmdt(*shm) == -1) {
+        sprintf(shmMess, "could not detach: %s\n", strerror(errno));
+        LOG(logERROR, (shmMess));
+        return 0;
+    }
+    LOG(logINFO, ("Shared memory detached\n"));
+    return 1;
+}
+
+int removeSharedMemory() {
+    memset(shmMess, 0, MAX_STR_LENGTH);
+    if (shmctl(shmFd, IPC_RMID, NULL) == -1) {
+        sprintf(shmMess, "could not remove: %s\n", strerror(errno));
+        LOG(logERROR, (shmMess));
+        return 0;
+    }
+    LOG(logINFO, ("Shared memory removed\n"));
+    return 1;
+}
+
+void lockSharedMemory(sharedMem *shm) { sem_wait(&(shm->sem)); }
+
+void unlockSharedMemory(sharedMem *shm) { sem_post(&(shm->sem)); }
\ No newline at end of file