From 684a0616a4a112d972062232a89e7b5d287a27ba Mon Sep 17 00:00:00 2001
From: Edward Emelianov <eddy@sao.ru>
Date: Thu, 24 Mar 2022 17:06:29 +0300
Subject: [PATCH] fixed bug with SIGPIPE @write, fixed some other big bugs

---
 CMakeLists.txt               |   2 +-
 Dummy_cameras/CMakeLists.txt |   2 +-
 FLI_cameras/CMakeLists.txt   |   2 +-
 FLI_cameras/flifunc.c        |  36 +++-
 ZWO_cameras/CMakeLists.txt   |   2 +-
 ZWO_cameras/zwofunc.c        |  13 +-
 client.c                     |  29 ++-
 client.h                     |   7 -
 locale/ru/messages.po        |  16 +-
 locale/ru/ru.po              |  16 +-
 main.c                       |   2 +-
 server.c                     | 335 +++++++++++++++--------------------
 socket.c                     |  92 ++++++----
 socket.h                     |  18 +-
 14 files changed, 296 insertions(+), 276 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0f7c528..eee70dc 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -107,7 +107,7 @@ set(RU_FILE ${LCPATH}/ru.po)
 
 # exe file
 add_executable(${PROJ} ${SOURCES} ${PO_FILE} ${MO_FILE})
-target_link_libraries(${PROJ} ${CFITSIO_LIBRARIES} ${X11_LIBRARIES} ${OPENGL_LIBRARIES} ${GLUT_LIBRARIES} ${${PROJ}_LIBRARIES} -lm)
+target_link_libraries(${PROJ} ${CFITSIO_LIBRARIES} ${X11_LIBRARIES} ${OPENGL_LIBRARIES} ${GLUT_LIBRARIES} ${${PROJ}_LIBRARIES} -lm ${CMAKE_DL_LIBS})
 include_directories(${${PROJ}_INCLUDE_DIRS} .)
 link_directories(${${PROJ}_LIBRARY_DIRS} )
 
diff --git a/Dummy_cameras/CMakeLists.txt b/Dummy_cameras/CMakeLists.txt
index 700289e..04377ef 100644
--- a/Dummy_cameras/CMakeLists.txt
+++ b/Dummy_cameras/CMakeLists.txt
@@ -9,4 +9,4 @@ include_directories(${${CCDLIB}_INCLUDE_DIRS} ..)
 link_directories(${${CCDLIB}_LIBRARY_DIRS})
 
 add_library(${CCDLIB} SHARED ${SRC})
-target_link_libraries(${CCDLIB} ${${CCDLIB}_LIBRARIES})
+target_link_libraries(${CCDLIB} ${${CCDLIB}_LIBRARIES} -fPIC)
diff --git a/FLI_cameras/CMakeLists.txt b/FLI_cameras/CMakeLists.txt
index b667ae7..edbe116 100644
--- a/FLI_cameras/CMakeLists.txt
+++ b/FLI_cameras/CMakeLists.txt
@@ -9,4 +9,4 @@ include_directories(${${CCDLIB}_INCLUDE_DIRS} ..)
 link_directories(${${CCDLIB}_LIBRARY_DIRS})
 
 add_library(${CCDLIB} SHARED ${SRC})
-target_link_libraries(${CCDLIB} ${${CCDLIB}_LIBRARIES})
+target_link_libraries(${CCDLIB} ${${CCDLIB}_LIBRARIES} -fPIC)
diff --git a/FLI_cameras/flifunc.c b/FLI_cameras/flifunc.c
index be114c2..21dc1c2 100644
--- a/FLI_cameras/flifunc.c
+++ b/FLI_cameras/flifunc.c
@@ -49,7 +49,7 @@ extern Wheel wheel;
 #define FOCSCALE        (10000.)
 
 #define TRYFUNC(f, ...)             \
-do{ if((fli_err = f(__VA_ARGS__)))  \
+do{fli_err = 0; if((fli_err = f(__VA_ARGS__)))  \
         WARNX(#f "() failed");      \
 }while(0)
 
@@ -62,7 +62,7 @@ typedef struct{
 static char camname[BUFSIZ] = {0}, whlname[BUFSIZ], focname[BUFSIZ];
 static long fli_err, tmpl;
 static cam_t *camz = NULL, *whlz = NULL, *focz = NULL;
-static flidev_t camdev, whldev, focdev;
+static flidev_t camdev = -1, whldev = -1, focdev = -1;
 static capture_status capStatus = CAPTURE_NO;
 static int curhbin = 1, curvbin = 1;
 static long filterpos = -1, filtermax = -1;  // filter position
@@ -140,15 +140,20 @@ static int fli_findCCD(){
     return TRUE;
 }
 static int fli_setActiceCam(int n){
+    DBG("SET ACTUIVE #%d", n);
     if(!camz && !fli_findCCD()) return FALSE;
     if(n >= camera.Ndevices){
         return FALSE;
     }
-    FLIClose(camdev);
+    if(camdev > -1){
+        FLIClose(camdev);
+        camdev = -1;
+    }
     TRYFUNC(FLIOpen, &camdev, camz[n].name, camz[n].domain);
     if(fli_err){
         return FALSE;
     }
+    DBG("camera fdno: %ld", camdev);
     TRYFUNC(FLIGetModel, camdev, camname, BUFSIZ);
 #ifdef EBUG
     if(!fli_err) DBG("Model: %s", camname);
@@ -205,12 +210,16 @@ static int fli_findFocuser(){
 static int fli_setActiceFocuser(int n){
     if(!focz && !fli_findFocuser()) return FALSE;
     if(n >= focuser.Ndevices) return FALSE;
-    FLIClose(focdev);
+    if(focdev > -1){
+        FLIClose(focdev);
+        focdev = -1;
+    }
     int OK = FALSE;
     for(int i = 0; i < focuser.Ndevices; ++i){
         DBG("Try %s", focz[i].name);
         TRYFUNC(FLIOpen, &focdev, focz[i].name, focz[i].domain);
         if(fli_err) continue;
+        DBG("focuser fdno: %ld", focdev);
         TRYFUNC(FLIGetModel, focdev, focname, BUFSIZ);
         DBG("MODEL '%s'", focname);
         if(fli_err) continue;
@@ -315,12 +324,16 @@ static int fli_wgetpos(int *p);
 static int fli_setActiceWheel(int n){
     if(!whlz && !fli_findWheel()) return FALSE;
     if(n >= wheel.Ndevices) return FALSE;
-    FLIClose(whldev);
+    if(whldev > -1){
+        FLIClose(whldev);
+        whldev = -1;
+    }
     int OK = FALSE;
-    for(int i = 0; i < focuser.Ndevices; ++i){
+    for(int i = 0; i < wheel.Ndevices; ++i){
         DBG("Try %s", whlz[i].name);
         TRYFUNC(FLIOpen, &whldev, whlz[i].name, whlz[i].domain);
         if(fli_err) continue;
+        DBG("wheel fdno: %ld", whldev);
         TRYFUNC(FLIGetFilterCount, whldev, &filtermax);
         if(fli_err || filtermax < 2){ // not a wheel
             DBG("Not a wheel");
@@ -351,6 +364,7 @@ static int fli_setActiceWheel(int n){
 }
 
 static int fli_wgetname(char *x, int n){
+    if(!x) return FALSE;
     strncpy(x, whlname, n);
     return TRUE;
 }
@@ -381,7 +395,9 @@ static int fli_wgetpos(int *p){
 static int fli_wsetpos(int p){
     if(p == filterpos) return TRUE;
     if(p > filtermax || p < 0) return FALSE;
+    DBG("RUN FLISetFilterPos");
     TRYFUNC(FLISetFilterPos, whldev, (long)p);
+    DBG("end");
     if(fli_err) return FALSE;
     return TRUE;
 }
@@ -427,7 +443,7 @@ static int fli_pollcapt(capture_status *st, float *remain){
             goto retn;
         }
         if(remain) *remain = tmpl/1000.;
-        DBG("remained: %g", tmpl/1000.);
+        //DBG("remained: %g", tmpl/1000.);
         if(tmpl == 0){
             if(st) *st = CAPTURE_READY;
             capStatus = CAPTURE_NO;
@@ -506,15 +522,19 @@ typedef enum{
 } temptype;
 
 static int fli_gettemp(temptype type, float *t){
+    if(!t) return FALSE;
     double d;
     switch(type){
         case T_COLD:
+            DBG("read T_COLD");
             TRYFUNC(FLIGetTemperature, camdev, &d);
         break;
         case T_BODY:
+            DBG("read T_BODY");
             TRYFUNC(FLIReadTemperature, camdev, FLI_TEMPERATURE_EXTERNAL, &d);
         break;
         default:
+            DBG("read T_HOT");
             TRYFUNC(FLIReadTemperature, camdev, FLI_TEMPERATURE_INTERNAL, &d);
     }
     if(fli_err) return FALSE;
@@ -581,8 +601,10 @@ static int fli_setio(int io){
 
 static int fli_setexp(float t){
     long e = (long)(t*1000.); // milliseconds!
+    DBG("Try to set exp to %ldms", e);
     TRYFUNC(FLISetExposureTime, camdev, e);
     if(fli_err) return FALSE;
+    DBG("OK");
     return TRUE;
 }
 
diff --git a/ZWO_cameras/CMakeLists.txt b/ZWO_cameras/CMakeLists.txt
index 6cb099c..a55e4a3 100644
--- a/ZWO_cameras/CMakeLists.txt
+++ b/ZWO_cameras/CMakeLists.txt
@@ -9,4 +9,4 @@ include_directories(${${CCDLIB}_INCLUDE_DIRS} ..)
 link_directories(${${CCDLIB}_LIBRARY_DIRS})
 
 add_library(${CCDLIB} SHARED ${SRC})
-target_link_libraries(${CCDLIB} ${${CCDLIB}_LIBRARIES} -lASICamera2)
+target_link_libraries(${CCDLIB} ${${CCDLIB}_LIBRARIES} -lASICamera2 -fPIC)
diff --git a/ZWO_cameras/zwofunc.c b/ZWO_cameras/zwofunc.c
index 1493c2a..924f5a5 100644
--- a/ZWO_cameras/zwofunc.c
+++ b/ZWO_cameras/zwofunc.c
@@ -85,18 +85,25 @@ static int asi_checkcam(){
 static int campoll(capture_status *st, float *remain){
     if(!st) return FALSE;
     ASI_EXPOSURE_STATUS s;
-    if(ASI_SUCCESS != ASIGetExpStatus(caminfo.CameraID, &s)) return FALSE;
+    if(ASI_SUCCESS != ASIGetExpStatus(caminfo.CameraID, &s)){
+        DBG("Can't get exp status");
+        return FALSE;
+    }
     switch(s){
         case ASI_EXP_IDLE:
+            DBG("No capture");
             *st = CAPTURE_NO;
         break;
         case ASI_EXP_WORKING:
+            DBG("Capture in progress");
             *st = CAPTURE_PROCESS;
         break;
         case ASI_EXP_SUCCESS:
+            DBG("Capture ready");
             *st = CAPTURE_READY;
         break;
         default: // failed
+            DBG("Failed: %d", s);
             *st = CAPTURE_ABORTED;
     }
     if(remain){
@@ -309,8 +316,8 @@ static int gett(_U_ float *t){
 static int camsetbin(int h, int v){
     DBG("set bin %dx%d", h, v);
     if(h != v){
-        WARNX(_("BinX and BinY should be equal"));
-        return FALSE;
+        WARNX(_("BinX and BinY should be equal, take h"));
+        //return FALSE;
     }
     if(h > extrvalues.maxbin){
         WARNX(_("Maximal binning value is %d"), extrvalues.maxbin);
diff --git a/client.c b/client.c
index a8ad8fc..afe78fd 100644
--- a/client.c
+++ b/client.c
@@ -30,7 +30,7 @@
 
 static char sendbuf[BUFSIZ];
 #define SENDMSG(...) do{snprintf(sendbuf, BUFSIZ-1, __VA_ARGS__); verbose(2, "\t> %s", sendbuf); sendstrmessage(sock, sendbuf); getans(sock);}while(0)
-static int expstate = 0;
+static int expstate = CAMERA_CAPTURE;
 
 /**
  * check data from  fd (polling function for client)
@@ -77,7 +77,7 @@ static char *readmsg(int fd){
     curlen += rd;
     buf[curlen] = 0;
     if(curlen == 0) return NULL;
-    DBG("cur buffer: ----%s----", buf);
+    //DBG("cur buffer: ----%s----", buf);
     char *nl = strchr(buf, '\n');
     if(!nl) return NULL;
     *nl++ = 0;
@@ -91,11 +91,15 @@ static char *readmsg(int fd){
 // parser of CCD server messages; return TRUE to exit from polling cycle of `getans` (if receive 'FAIL', 'OK' or 'BUSY')
 static int parseans(char *ans){
     if(!ans) return FALSE;
+    //DBG("Parsing of '%s'", ans);
     if(0 == strcmp(hresult2str(RESULT_BUSY), ans)) ERRX("Server busy");
     if(0 == strcmp(hresult2str(RESULT_FAIL), ans)) return TRUE;
     if(0 == strcmp(hresult2str(RESULT_OK), ans)) return TRUE;
     char *val = get_keyval(ans); // now `ans` is a key and `val` its value
-    if(0 == strcmp(CMD_EXPSTATE, ans)) expstate = atoi(val);
+    if(0 == strcmp(CMD_EXPSTATE, ans)){
+        expstate = atoi(val);
+        DBG("Exposition state: %d", expstate);
+    }
     return FALSE;
 }
 
@@ -109,11 +113,13 @@ static int getans(int sock){
             if(ans) return TRUE;
             else continue;
         }
+        t0 = dtime();
         ans = s;
         DBG("Got from server: %s", ans);
         verbose(1, "\t%s", ans);
         if(parseans(ans)) break;
     }
+    DBG("GETANS: timeout, ans: %s", ans);
     return ((ans) ? TRUE : FALSE);
 }
 
@@ -121,6 +127,8 @@ static int getans(int sock){
  * @brief processData - process here some actions and make messages for server
  */
 static void process_data(int sock){
+    // common information
+    SENDMSG(CMD_INFO);
     // focuser
     if(GP->listdevices) SENDMSG(CMD_FOCLIST);
     if(GP->focdevno > -1) SENDMSG(CMD_FDEVNO "=%d", GP->focdevno);
@@ -181,8 +189,6 @@ static void process_data(int sock){
         }
         SENDMSG(CMD_HEADERFILES "=%s", buf);
     }
-    // common information
-    SENDMSG(CMD_INFO);
 }
 
 void client(int sock){
@@ -200,12 +206,16 @@ void client(int sock){
         else GP->waitexpend = TRUE; // N>1 - wait for exp ends
         SENDMSG(CMD_EXPSTATE "=%d", CAMERA_CAPTURE);
     } else {
-        getans(sock);
+        while(getans(sock));
+        DBG("RETURN: no more data");
         return;
     }
-    double timeout = GP->waitexpend ? CLIENT_TIMEOUT : 0.1;
+    double timeout = GP->waitexpend ? CLIENT_TIMEOUT : WAIT_TIMEOUT;
     verbose(1, "Exposing frame 1...");
-    if(GP->waitexpend) verbose(2, "Wait for exposition end");
+    if(GP->waitexpend){
+        expstate = CAMERA_CAPTURE; // could be changed earlier
+        verbose(2, "Wait for exposition end");
+    }
     while(dtime() - t0 < timeout){
         if(GP->waitexpend && dtime() - tw > WAIT_TIMEOUT){
             SENDMSG(CMD_TREMAIN); // get remained time
@@ -214,6 +224,7 @@ void client(int sock){
             sendstrmessage(sock, sendbuf);
         }
         if(getans(sock)){ // got next portion of data
+            DBG("server message");
             t0 = dtime();
             if(expstate == CAMERA_ERROR){
                 WARNX(_("Can't make exposition"));
@@ -240,7 +251,7 @@ void client(int sock){
                     SENDMSG(CMD_EXPSTATE "=%d", CAMERA_CAPTURE);
                 }else{
                     GP->waitexpend = 0;
-                    timeout = 0.2; // wait for last file name
+                    timeout = WAIT_TIMEOUT; // wait for last file name
                 }
             }
         }
diff --git a/client.h b/client.h
index 87cfe2b..97d9c47 100644
--- a/client.h
+++ b/client.h
@@ -20,13 +20,6 @@
 #ifndef CLIENT_H__
 #define CLIENT_H__
 
-// waiting for answer timeout
-#define ANSWER_TIMEOUT  1.0
-// wait for exposition ends (between subsequent check calls)
-#define WAIT_TIMEOUT    2.0
-// client will disconnect after this time from last server message
-#define CLIENT_TIMEOUT  10.0
-
 // client-side functions
 void client(int fd);
 
diff --git a/locale/ru/messages.po b/locale/ru/messages.po
index fc50e3d..7ed5184 100644
--- a/locale/ru/messages.po
+++ b/locale/ru/messages.po
@@ -8,7 +8,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: PACKAGE VERSION\n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2022-03-22 17:17+0300\n"
+"POT-Creation-Date: 2022-03-24 11:43+0300\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -473,12 +473,12 @@ msgstr ""
 msgid "Can't set brightness to %g"
 msgstr ""
 
-#: ccdfunc.c:703 server.c:219
+#: ccdfunc.c:703 server.c:225
 #, c-format
 msgid "Can't set binning %dx%d"
 msgstr ""
 
-#: ccdfunc.c:713 server.c:220
+#: ccdfunc.c:713 server.c:226
 msgid "Can't set given geometry"
 msgstr ""
 
@@ -528,7 +528,7 @@ msgstr ""
 msgid "Capture frame %d"
 msgstr ""
 
-#: ccdfunc.c:756 server.c:120
+#: ccdfunc.c:756 server.c:121
 msgid "Can't start exposition"
 msgstr ""
 
@@ -545,20 +545,20 @@ msgid "Can't grab image"
 msgstr ""
 
 #. %d секунд до окончания паузы\n
-#: ccdfunc.c:803 client.c:232
+#: ccdfunc.c:803 client.c:236
 #, c-format
 msgid "%d seconds till pause ends\n"
 msgstr ""
 
-#: server.c:161
+#: server.c:163
 msgid "No camera device"
 msgstr ""
 
-#: client.c:219
+#: client.c:223
 msgid "Can't make exposition"
 msgstr ""
 
-#: client.c:248
+#: client.c:252
 msgid "Server timeout"
 msgstr ""
 
diff --git a/locale/ru/ru.po b/locale/ru/ru.po
index d7e8449..d79af04 100644
--- a/locale/ru/ru.po
+++ b/locale/ru/ru.po
@@ -7,7 +7,7 @@
 msgid   ""
 msgstr  "Project-Id-Version: PACKAGE VERSION\n"
         "Report-Msgid-Bugs-To: \n"
-        "POT-Creation-Date: 2022-03-22 17:17+0300\n"
+        "POT-Creation-Date: 2022-03-24 11:10+0300\n"
         "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
         "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
         "Language-Team: LANGUAGE <LL@li.org>\n"
@@ -22,7 +22,7 @@ msgid   "%.1f seconds till exposition ends"
 msgstr  ""
 
 #. %d секунд до окончания паузы\n
-#: ccdfunc.c:803 client.c:232
+#: ccdfunc.c:803 client.c:236
 #, c-format
 msgid   "%d seconds till pause ends\n"
 msgstr  ""
@@ -117,7 +117,7 @@ msgstr  ""
 msgid   "Can't init mutex!"
 msgstr  ""
 
-#: client.c:219
+#: client.c:223
 msgid   "Can't make exposition"
 msgstr  ""
 
@@ -162,7 +162,7 @@ msgstr  ""
 msgid   "Can't set active wheel number"
 msgstr  ""
 
-#: ccdfunc.c:703 server.c:219
+#: ccdfunc.c:703 server.c:225
 #, c-format
 msgid   "Can't set binning %dx%d"
 msgstr  ""
@@ -190,7 +190,7 @@ msgstr  ""
 msgid   "Can't set gain to %g"
 msgstr  ""
 
-#: ccdfunc.c:713 server.c:220
+#: ccdfunc.c:713 server.c:226
 msgid   "Can't set given geometry"
 msgstr  ""
 
@@ -213,7 +213,7 @@ msgstr  ""
 msgid   "Can't set wheel position %d"
 msgstr  ""
 
-#: ccdfunc.c:756 server.c:120
+#: ccdfunc.c:756 server.c:121
 msgid   "Can't start exposition"
 msgstr  ""
 
@@ -288,7 +288,7 @@ msgstr  ""
 msgid   "Neither filename nor filename prefix pointed!"
 msgstr  ""
 
-#: server.c:161
+#: server.c:163
 msgid   "No camera device"
 msgstr  ""
 
@@ -326,7 +326,7 @@ msgstr  ""
 msgid   "Readout mode: %s"
 msgstr  ""
 
-#: client.c:248
+#: client.c:252
 msgid   "Server timeout"
 msgstr  ""
 
diff --git a/main.c b/main.c
index 1aaf02a..1c39ad1 100644
--- a/main.c
+++ b/main.c
@@ -47,7 +47,7 @@ void signals(int signo){
             signal(signo, signals);
             return;
         }
-        DBG("Master killed with sig=%d", signo);
+        WARNX("Master killed with sig=%d", signo);
         LOGERR("Master killed with sig=%d", signo);
         if(!GP->client){
             DBG("Unlink pid file");
diff --git a/server.c b/server.c
index 442c32d..8534959 100644
--- a/server.c
+++ b/server.c
@@ -52,58 +52,59 @@ typedef struct{
 
 // cat | awk '{print "{ " $3 ", \"\" }," }' | sort
 strpair allcommands[] = {
-    { "8bit", "run in 8 bit mode instead of 16 bit" },
-    { "author", "FITS 'AUTHOR' field" },
-    { "brightness", "camera brightness" },
-    { "camdevno", "camera device number" },
-    { "camlist", "list all connected cameras" },
-    { "ccdfanspeed", "fan speed of camera" },
-    { "confio", "camera IO configuration" },
-    { "dark", "don't open shutter @ exposure" },
-    { "expstate", "get exposition state" },
-    { "exptime", "exposition time" },
-    { "fastspeed", "fast readout speed" },
-    { "filename", "save file with this name, like file.fits" },
-    { "filenameprefix", "prefix of files, like ex (will be saved as exXXXX.fits)" },
-    { "focdevno", "focuser device number" },
-    { "foclist", "list all connected focusers" },
-    { "focpos", "focuser position" },
-    { "format", "camera frame format (X0,Y0,X1,Y1)" },
-    { "gain", "camera gain" },
-    { "hbin", "horizontal binning" },
-    { "headerfiles", "add FITS records from these files (comma-separated list)" },
-    { "help", "show this help" },
-    { "info", "connected devices state" },
-    { "instrument", "FITS 'INSTRUME' field" },
-    { "io", "get/set camera IO" },
-    { "lastfilename", "path to last saved file"},
-    { "maxformat", "camera maximal available format" },
-    { "nflushes", "camera number of preflushes" },
-    { "object", "FITS 'OBJECT' field" },
-    { "objtype", "FITS 'IMAGETYP' field" },
-    { "observer", "FITS 'OBSERVER' field" },
-    { "program", "FITS 'PROG-ID' field" },
-    { "rewrite", "rewrite file (if give `filename`, not `filenameprefix`" },
-    { "shutter", "camera shutter's operations" },
-    { "tcold", "camera chip temperature" },
-    { "tremain", "time (in seconds) of exposition remained" },
-    { "vbin", "vertical binning" },
-    { "wdevno", "wheel device number" },
-    { "wlist", "list all connected wheels" },
-    { "wpos", "wheel position" },
+    { CMD_8BIT,         "run in 8 bit mode instead of 16 bit" },
+    { CMD_AUTHOR,       "FITS 'AUTHOR' field" },
+    { CMD_BRIGHTNESS,   "camera brightness" },
+    { CMD_CAMDEVNO,     "camera device number" },
+    { CMD_CAMLIST,      "list all connected cameras" },
+    { CMD_CAMFANSPD,    "fan speed of camera" },
+    { CMD_CONFIO,       "camera IO configuration" },
+    { CMD_DARK,         "don't open shutter @ exposure" },
+    { CMD_EXPSTATE,     "get exposition state" },
+    { CMD_EXPOSITION,   "exposition time" },
+    { CMD_FASTSPD,      "fast readout speed" },
+    { CMD_FILENAME,     "save file with this name, like file.fits" },
+    { CMD_FILENAMEPREFIX,"prefix of files, like ex (will be saved as exXXXX.fits)" },
+    { CMD_FDEVNO,       "focuser device number" },
+    { CMD_FOCLIST,      "list all connected focusers" },
+    { CMD_FGOTO,        "focuser position" },
+    { CMD_FRAMEFORMAT,  "camera frame format (X0,Y0,X1,Y1)" },
+    { CMD_GAIN,         "camera gain" },
+    { CMD_HBIN,         "horizontal binning" },
+    { CMD_HEADERFILES,  "add FITS records from these files (comma-separated list)" },
+    { CMD_HELP,         "show this help" },
+    { CMD_INFO,         "connected devices state" },
+    { CMD_INSTRUMENT,   "FITS 'INSTRUME' field" },
+    { CMD_IO,           "get/set camera IO" },
+    { CMD_LASTFNAME,    "path to last saved file"},
+    { CMD_FRAMEMAX,     "camera maximal available format" },
+    { CMD_NFLUSHES,     "camera number of preflushes" },
+    { CMD_OBJECT,       "FITS 'OBJECT' field" },
+    { CMD_OBJTYPE,      "FITS 'IMAGETYP' field" },
+    { CMD_OBSERVER,     "FITS 'OBSERVER' field" },
+    { CMD_PROGRAM,      "FITS 'PROG-ID' field" },
+    { CMD_RESTART,      "restart server" },
+    { CMD_REWRITE,      "rewrite file (if give `filename`, not `filenameprefix`" },
+    { CMD_SHUTTER,      "camera shutter's operations" },
+    { CMD_CAMTEMPER,    "camera chip temperature" },
+    { CMD_TREMAIN,      "time (in seconds) of exposition remained" },
+    { CMD_VBIN,         "vertical binning" },
+    { CMD_WDEVNO,       "wheel device number" },
+    { CMD_WLIST,        "list all connected wheels" },
+    { CMD_WPOS,         "wheel position" },
     {NULL, NULL},
 };
 
 static IMG ima = {0};
 static void fixima(){
     FNAME();
+    if(!camera) return;
     int raw_width = curformat.w / GP->hbin,  raw_height = curformat.h / GP->vbin;
+    if(!ima.data) ima.data = MALLOC(uint16_t,  camera->array.h * camera->array.w);
     if(ima.data && raw_width == ima.w && raw_height == ima.h) return; // all OK
-    FREE(ima.data);
     DBG("curformat: %dx%d", curformat.w, curformat.h);
     ima.h = raw_height;
     ima.w = raw_width;
-    ima.data = MALLOC(uint16_t, raw_width * raw_height);
     DBG("new image: %dx%d", raw_width, raw_height);
 }
 
@@ -126,6 +127,7 @@ static inline void cameraidlestate(){ // idle - wait for capture commands
 static inline void cameracapturestate(){ // capturing - wait for exposition ends
     if(camflags & FLAG_CANCEL){ // cancel all expositions
         DBG("Cancel exposition");
+        LOGMSG("User canceled exposition");
         camflags &= ~(FLAG_STARTCAPTURE | FLAG_CANCEL);
         camera->cancel();
         camstate = CAMERA_IDLE;
@@ -166,34 +168,38 @@ static void* processCAM(_U_ void *d){
             LOGERR("User asks to restart");
             signals(1);
         }
-        // log
-        if(dtime() - logt > TLOG_PAUSE){
-            logt = dtime();
-            float t;
-            if(camera->getTcold(&t)){
-                LOGMSG("CCDTEMP=%f", t);
+        usleep(100);
+        if(0 == pthread_mutex_trylock(&locmutex)){
+            // log
+            if(dtime() - logt > TLOG_PAUSE){
+                logt = dtime();
+                float t;
+                if(camera->getTcold(&t)){
+                    LOGMSG("CCDTEMP=%.1f", t);
+                }
+                if(camera->getThot(&t)){
+                   LOGMSG("HOTTEMP=%.1f", t);
+                }
+                if(camera->getTbody(&t)){
+                   LOGMSG("BODYTEMP=%.1f", t);
+                }
             }
-            if(camera->getThot(&t)){
-               LOGMSG("HOTTEMP=%f", t);
+            camera_state curstate = camstate;
+            switch(curstate){
+                case CAMERA_IDLE:
+                    cameraidlestate();
+                break;
+                case CAMERA_CAPTURE:
+                    cameracapturestate();
+                break;
+                case CAMERA_FRAMERDY:
+    // do nothing: when `server` got this state it sends "expstate=2" to all clients and changes state to IDLE
+                break;
+                case CAMERA_ERROR:
+    // do nothing: when `server` got this state it sends "expstate=3" to all clients and changes state to IDLE
+                break;
             }
-            if(camera->getTbody(&t)){
-               LOGMSG("BODYTEMP=%f", t);
-            }
-        }
-        camera_state curstate = camstate;
-        switch(curstate){
-            case CAMERA_IDLE:
-                cameraidlestate();
-            break;
-            case CAMERA_CAPTURE:
-                cameracapturestate();
-            break;
-            case CAMERA_FRAMERDY:
-// do nothing: when `server` got this state it sends "expstate=2" to all clients and changes state to IDLE
-            break;
-            case CAMERA_ERROR:
-// do nothing: when `server` got this state it sends "expstate=3" to all clients and changes state to IDLE
-            break;
+            pthread_mutex_unlock(&locmutex);
         }
     }
     return NULL;
@@ -202,10 +208,8 @@ static void* processCAM(_U_ void *d){
 // functions running @ each devno change
 static int camdevini(int n){
     if(!camera) return FALSE;
-    //pthread_mutex_lock(&locmutex);
     if(!camera->setDevNo(n)){
         LOGERR("Can't set active camera number");
-        //pthread_mutex_unlock(&locmutex);
         return FALSE;
     }
     camdevno = n;
@@ -218,36 +222,29 @@ static int camdevini(int n){
     fixima();
     if(!camera->setbin(GP->hbin, GP->vbin)) WARNX(_("Can't set binning %dx%d"), GP->hbin, GP->vbin);
     if(!camera->setgeometry(&curformat)) WARNX(_("Can't set given geometry"));
-    //pthread_mutex_unlock(&locmutex);
     return TRUE;
 }
 static int focdevini(int n){
     if(!focuser) return FALSE;
-    //pthread_mutex_lock(&locmutex);
     if(!focuser->setDevNo(n)){
         LOGERR("Can't set active focuser number");
-        //pthread_mutex_unlock(&locmutex);
         return FALSE;
     }
     focdevno = n;
     LOGMSG("Set focuser device number to %d", focdevno);
     focuser->getMaxPos(&focmaxpos);
     focuser->getMinPos(&focminpos);
-    //pthread_mutex_unlock(&locmutex);
     return TRUE;
 }
 static int wheeldevini(int n){
     if(!wheel) return FALSE;
-    //pthread_mutex_unlock(&locmutex);
     if(!wheel->setDevNo(n)){
         LOGERR("Can't set active wheel number");
-        //pthread_mutex_unlock(&locmutex);
         return FALSE;
     }
     wheeldevno = n;
     LOGMSG("Set wheel device number to %d", wheeldevno);
     wheel->getMaxPos(&wmaxpos);
-    //pthread_mutex_unlock(&locmutex);
     return TRUE;
 }
 
@@ -264,15 +261,13 @@ static hresult restarthandler(_U_ int fd, _U_ const char *key, _U_ const char *v
  ******************************************************************************/
 static hresult camlisthandler(int fd, _U_ const char *key, _U_ const char *val){
     char buf[BUFSIZ], modname[256];
-    //pthread_mutex_lock(&locmutex);
     for(int i = 0; i < camera->Ndevices; ++i){
         if(!camera->setDevNo(i)) continue;
         camera->getModelName(modname, 255);
         snprintf(buf, BUFSIZ-1, CMD_CAMLIST "='%s'", modname);
-        sendstrmessage(fd, buf);
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     }
     if(camdevno > -1) camera->setDevNo(camdevno);
-    //pthread_mutex_unlock(&locmutex);
     return RESULT_SILENCE;
 }
 static hresult camsetNhandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
@@ -285,61 +280,55 @@ static hresult camsetNhandler(_U_ int fd, _U_ const char *key, _U_ const char *v
         if(!camdevini(num)) return RESULT_FAIL;
     }
     snprintf(buf, 63, CMD_CAMDEVNO "=%d", camdevno);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 // exposition time setter/getter
 static hresult exphandler(int fd, _U_ const char *key, const char *val){
     char buf[64];
     if(val){
+        DBG("setexp to %s", val);
         double v = atof(val);
         if(v < DBL_EPSILON) return RESULT_BADVAL;
-        //pthread_mutex_lock(&locmutex);
         if(camera->setexp(v)){
             GP->exptime = v;
         }else LOGWARN("Can't set exptime to %g", v);
-        //pthread_mutex_unlock(&locmutex);
     }
+    DBG("expt: %g", GP->exptime);
     snprintf(buf, 63, CMD_EXPOSITION "=%g", GP->exptime);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 // show last filename of saved FITS
 static hresult lastfnamehandler(int fd, _U_ const char *key, _U_ const char *val){
     char buf[PATH_MAX+32];
-    //pthread_mutex_lock(&locmutex);
     snprintf(buf, PATH_MAX+31, CMD_LASTFNAME "=%s", lastfile);
-    sendstrmessage(fd, buf);
-    //pthread_mutex_unlock(&locmutex);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 // filename setter/getter
 static hresult namehandler(int fd, _U_ const char *key, const char *val){
     char buf[PATH_MAX+32];
     if(val){
-        //pthread_mutex_lock(&locmutex);
         char *path = makeabspath(val, FALSE);
         if(!path){
             LOGERR("Can't create file '%s'", val);
-            //pthread_mutex_unlock(&locmutex);
             return RESULT_BADVAL;
         }
         FREE(outfile);
         outfile = strdup(path);
         GP->outfile = outfile;
         GP->outfileprefix = NULL;
-        //pthread_mutex_unlock(&locmutex);
     }
     if(!GP->outfile) return RESULT_FAIL;
     snprintf(buf, PATH_MAX+31, CMD_FILENAME "=%s", GP->outfile);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 // filename prefix
 static hresult nameprefixhandler(_U_ int fd, _U_ const char *key, const char *val){
     char buf[PATH_MAX+32];
     if(val){
-        //pthread_mutex_lock(&locmutex);
         char *path = makeabspath(val, FALSE);
         if(!path){
             LOGERR("Can't create file '%s'", val);
@@ -350,11 +339,10 @@ static hresult nameprefixhandler(_U_ int fd, _U_ const char *key, const char *va
         outfile = strdup(path);
         GP->outfileprefix = outfile;
         GP->outfile = NULL;
-        //pthread_mutex_unlock(&locmutex);
     }
     if(!GP->outfileprefix) return RESULT_FAIL;
     snprintf(buf, PATH_MAX+31, CMD_FILENAMEPREFIX "=%s", GP->outfileprefix);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 // rewrite
@@ -363,12 +351,10 @@ static hresult rewritefilehandler(_U_ int fd, _U_ const char *key, const char *v
     if(val){
         int n = atoi(val);
         if(n < 0 || n > 1) return RESULT_BADVAL;
-        //pthread_mutex_lock(&locmutex);
         GP->rewrite = n;
-        //pthread_mutex_unlock(&locmutex);
     }
     snprintf(buf, 63, CMD_REWRITE "=%d", GP->rewrite);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult binhandler(_U_ int fd, const char *key, const char *val){
@@ -378,21 +364,16 @@ static hresult binhandler(_U_ int fd, const char *key, const char *val){
         if(b < 1) return RESULT_BADVAL;
         if(0 == strcmp(key, CMD_HBIN)) GP->hbin = b;
         else GP->vbin = b;
-        //pthread_mutex_lock(&locmutex);
         if(!camera->setbin(GP->hbin, GP->vbin)){
-            //pthread_mutex_unlock(&locmutex);
             return RESULT_BADVAL;
         }
-        fixima();
-        //pthread_mutex_unlock(&locmutex);
     }
-    //pthread_mutex_lock(&locmutex);
     int r = camera->getbin(&GP->hbin, &GP->vbin);
-    //pthread_mutex_unlock(&locmutex);
     if(r){
         if(0 == strcmp(key, CMD_HBIN)) snprintf(buf, 63, "%s=%d", key, GP->hbin);
         else snprintf(buf, 63, "%s=%d", key, GP->vbin);
-        sendstrmessage(fd, buf);
+        if(val) fixima();
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         return RESULT_SILENCE;
     }
     return RESULT_FAIL;
@@ -403,34 +384,26 @@ static hresult temphandler(_U_ int fd, _U_ const char *key, const char *val){
     int r;
     if(val){
         f = atof(val);
-        //pthread_mutex_lock(&locmutex);
         r = camera->setT((float)f);
-        //pthread_mutex_unlock(&locmutex);
         if(!r){
             LOGWARN("Can't set camera T to %.1f", f);
             return RESULT_FAIL;
         }
         LOGMSG("Set camera T to %.1f", f);
     }
-    //pthread_mutex_lock(&locmutex);
     r = camera->getTcold(&f);
-    //pthread_mutex_unlock(&locmutex);
     if(r){
         snprintf(buf, 63, CMD_CAMTEMPER "=%.1f", f);
-        sendstrmessage(fd, buf);
-        //pthread_mutex_lock(&locmutex);
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         r = camera->getTbody(&f);
-        //pthread_mutex_unlock(&locmutex);
         if(r){
             snprintf(buf, 63, "tbody=%.1f", f);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
-        //pthread_mutex_lock(&locmutex);
         r = camera->getThot(&f);
-        //pthread_mutex_unlock(&locmutex);
         if(r){
             snprintf(buf, 63, "thot=%.1f", f);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
         return RESULT_SILENCE;
     }else return RESULT_FAIL;
@@ -441,14 +414,12 @@ static hresult camfanhandler(_U_ int fd, _U_ const char *key, _U_ const char *va
         int spd = atoi(val);
         if(spd < 0) return RESULT_BADVAL;
         if(spd > FAN_HIGH) spd = FAN_HIGH;
-        //pthread_mutex_lock(&locmutex);
         int r = camera->setfanspeed((fan_speed)spd);
-        //pthread_mutex_unlock(&locmutex);
         if(!r) return RESULT_FAIL;
         camfanspd = spd;
     }
     snprintf(buf, 63, CMD_CAMFANSPD "=%d", camfanspd);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 const char *shutterstr[] = {"open", "close", "expose @high", "expose @low"};
@@ -456,9 +427,7 @@ static hresult shutterhandler(_U_ int fd, _U_ const char *key, const char *val){
     if(val){
         int x = atoi(val);
         if(x < 0 || x >= SHUTTER_AMOUNT) return RESULT_BADVAL;
-        //pthread_mutex_lock(&locmutex);
         int r = camera->shuttercmd((shutter_op)x);
-        //pthread_mutex_unlock(&locmutex);
         if(r){
            LOGMSG("Shutter command '%s'", shutterstr[x]);
         }else{
@@ -472,14 +441,12 @@ static hresult confiohandler(_U_ int fd, _U_ const char *key, _U_ const char *va
     char buf[64];
     if(val){
         int io = atoi(val);
-        //pthread_mutex_lock(&locmutex);
         int r = camera->confio(io);
-        //pthread_mutex_unlock(&locmutex);
         if(!r) return RESULT_FAIL;
         confio = io;
     }
     snprintf(buf, 63, CMD_CONFIO "=%d", confio);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult iohandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
@@ -487,17 +454,13 @@ static hresult iohandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
     int io;
     if(val){
         io = atoi(val);
-        //pthread_mutex_lock(&locmutex);
         int r = camera->setio(io);
-        //pthread_mutex_unlock(&locmutex);
         if(!r) return RESULT_FAIL;
     }
-    //pthread_mutex_lock(&locmutex);
     int r = camera->getio(&io);
-    //pthread_mutex_unlock(&locmutex);
     if(!r) return RESULT_FAIL;
     snprintf(buf, 63, CMD_IO "=%d", io);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult gainhandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
@@ -505,17 +468,13 @@ static hresult gainhandler(_U_ int fd, _U_ const char *key, _U_ const char *val)
     float f;
     if(val){
         f = atof(val);
-        //pthread_mutex_lock(&locmutex);
         int r = camera->setgain(f);
-        //pthread_mutex_unlock(&locmutex);
         if(!r) return RESULT_FAIL;
     }
-    //pthread_mutex_lock(&locmutex);
     int r = camera->getgain(&f);
-    //pthread_mutex_unlock(&locmutex);
     if(!r) return RESULT_FAIL;
     snprintf(buf, 63, CMD_GAIN "=%.1f", f);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult brightnesshandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
@@ -523,17 +482,13 @@ static hresult brightnesshandler(_U_ int fd, _U_ const char *key, _U_ const char
     float b;
     if(val){
         b = atof(val);
-        //pthread_mutex_lock(&locmutex);
         int r = camera->setbrightness(b);
-        //pthread_mutex_unlock(&locmutex);
         if(!r) return RESULT_FAIL;
     }
-    //pthread_mutex_lock(&locmutex);
     int r = camera->getbrightness(&b);
-    //pthread_mutex_unlock(&locmutex);
     if(!r) return RESULT_FAIL;
     snprintf(buf, 63, CMD_BRIGHTNESS "=%.1f", b);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 // set format: `format=X0,X1,Y0,Y1`
@@ -545,9 +500,7 @@ static hresult formathandler(int fd, const char *key, const char *val){
         if(strcmp(key, CMD_FRAMEFORMAT)) return RESULT_BADKEY; // can't set maxformat
         if(4 != sscanf(val, "%d,%d,%d,%d", &fmt.xoff, &fmt.yoff, &fmt.w, &fmt.h)) return RESULT_BADVAL;
         fmt.w -= fmt.xoff; fmt.h -= fmt.yoff;
-        //pthread_mutex_lock(&locmutex);
         int r = camera->setgeometry(&fmt);
-        //pthread_mutex_unlock(&locmutex);
         if(!r) return RESULT_FAIL;
         curformat = fmt;
         fixima();
@@ -556,7 +509,7 @@ static hresult formathandler(int fd, const char *key, const char *val){
         frmformatmax.xoff, frmformatmax.yoff, frmformatmax.xoff+frmformatmax.w, frmformatmax.yoff+frmformatmax.h);
     else snprintf(buf, 63, CMD_FRAMEFORMAT "=%d,%d,%d,%d",
         camera->geometry.xoff, camera->geometry.yoff, camera->geometry.xoff+camera->geometry.w, camera->geometry.yoff+camera->geometry.h);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult nflusheshandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
@@ -564,16 +517,13 @@ static hresult nflusheshandler(_U_ int fd, _U_ const char *key, _U_ const char *
     if(val){
         int n = atoi(val);
         if(n < 1) return RESULT_BADVAL;
-        //pthread_mutex_lock(&locmutex);
         if(!camera->setnflushes(n)){
-            //pthread_mutex_unlock(&locmutex);
             return RESULT_FAIL;
         }
         nflushes = n;
-        //pthread_mutex_unlock(&locmutex);
     }
     snprintf(buf, 63, CMD_NFLUSHES "=%d", nflushes);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult expstatehandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
@@ -591,15 +541,15 @@ static hresult expstatehandler(_U_ int fd, _U_ const char *key, _U_ const char *
         else return RESULT_BADVAL;
     }
     snprintf(buf, 63, CMD_EXPSTATE "=%d", camstate);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     snprintf(buf, 63, "camflags=%d", camflags);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult tremainhandler(_U_ int fd, _U_ const char *key, _U_ const char *val){
     char buf[64];
     snprintf(buf, 63, CMD_TREMAIN "=%g", tremain);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult _8bithandler(int fd, _U_ const char *key, const char *val){
@@ -612,7 +562,7 @@ static hresult _8bithandler(int fd, _U_ const char *key, const char *val){
         if(!camera->setbitdepth(s)) return RESULT_FAIL;
     }
     snprintf(buf, 63, CMD_8BIT "=%d", GP->_8bit);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult fastspdhandler(int fd, _U_ const char *key, const char *val){
@@ -624,7 +574,7 @@ static hresult fastspdhandler(int fd, _U_ const char *key, const char *val){
         if(!camera->setfastspeed(b)) return RESULT_FAIL;
     }
     snprintf(buf, 63, CMD_FASTSPD "=%d", GP->fast);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult darkhandler(int fd, _U_ const char *key, const char *val){
@@ -637,7 +587,7 @@ static hresult darkhandler(int fd, _U_ const char *key, const char *val){
         if(!camera->setframetype(d)) return RESULT_FAIL;
     }
     snprintf(buf, 63, CMD_DARK "=%d", GP->dark);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult FITSparhandler(int fd, const char *key, const char *val){
@@ -660,7 +610,7 @@ static hresult FITSparhandler(int fd, const char *key, const char *val){
         *fitskey = strdup(val);
     }
     snprintf(buf, 255, "%s=%s", key, *fitskey);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult FITSheaderhandler(int fd, _U_ const char *key, const char *val){
@@ -669,7 +619,6 @@ static hresult FITSheaderhandler(int fd, _U_ const char *key, const char *val){
     static int firstrun = 1;
     if(val){
         int sz = 10, amount = 0;
-        //pthread_mutex_lock(&locmutex);
         // first we should check `val`
         char b2[BUFSIZ], *bptr = buf;
         snprintf(b2, BUFSIZ-1, "%s", val);
@@ -715,9 +664,8 @@ static hresult FITSheaderhandler(int fd, _U_ const char *key, const char *val){
         }
         GP->addhdr = list;
         FREE(curhdr);
-        if(*val && *val != ',') curhdr = strdup(buf);
+        if(*val && *val != ',') curhdr = strdup(buf); // command with empty arg will clear curhdr
         DBG("curhdr now: %s", curhdr);
-        //pthread_mutex_unlock(&locmutex);
     }
     if(!curhdr && firstrun){
         firstrun = 0;
@@ -734,7 +682,7 @@ static hresult FITSheaderhandler(int fd, _U_ const char *key, const char *val){
         }
     }
     snprintf(buf, BUFSIZ-1, CMD_HEADERFILES "=%s", curhdr);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 /*
@@ -748,16 +696,14 @@ static hresult handler(_U_ int fd, _U_ const char *key, _U_ const char *val){
  ******************************************************************************/
 static hresult wlisthandler(int fd, _U_ const char *key, _U_ const char *val){
     if(wheel->Ndevices < 1) return RESULT_FAIL;
-    //pthread_mutex_lock(&locmutex);
     for(int i = 0; i < wheel->Ndevices; ++i){
         if(!wheel->setDevNo(i)) continue;
         char modname[256], buf[BUFSIZ];
         wheel->getModelName(modname, 255);
         snprintf(buf, BUFSIZ-1, CMD_WLIST "='%s'", modname);
-        sendstrmessage(fd, buf);
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     }
     if(wheeldevno > -1) wheel->setDevNo(wheeldevno);
-    //pthread_mutex_unlock(&locmutex);
     return RESULT_SILENCE;
 }
 static hresult wsetNhandler(int fd, _U_ const char *key, const char *val){
@@ -770,7 +716,7 @@ static hresult wsetNhandler(int fd, _U_ const char *key, const char *val){
         if(!wheeldevini(num)) return RESULT_FAIL;
     }
     snprintf(buf, 63, CMD_WDEVNO "=%d", wheeldevno);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 
@@ -779,17 +725,15 @@ static hresult wgotohandler(_U_ int fd, _U_ const char *key, _U_ const char *val
     int pos;
     if(val){
         pos = atoi(val);
-        //pthread_mutex_lock(&locmutex);
+        DBG("USER wants to %d", pos);
         int r = wheel->setPos(pos);
-        //pthread_mutex_unlock(&locmutex);
+        DBG("wheel->setPos(%d)", pos);
         if(!r) return RESULT_BADVAL;
     }
-    //pthread_mutex_lock(&locmutex);
     int r = wheel->getPos(&pos);
-    //pthread_mutex_unlock(&locmutex);
     if(!r) return RESULT_FAIL;
     snprintf(buf, 63, CMD_WPOS "=%d", pos);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 
@@ -799,16 +743,14 @@ static hresult wgotohandler(_U_ int fd, _U_ const char *key, _U_ const char *val
 
 static hresult foclisthandler(int fd, _U_ const char *key, _U_ const char *val){
     if(focuser->Ndevices < 1) return RESULT_FAIL;
-    //pthread_mutex_lock(&locmutex);
     for(int i = 0; i < focuser->Ndevices; ++i){
         char modname[256], buf[BUFSIZ];
         if(!focuser->setDevNo(i)) continue;
         focuser->getModelName(modname, 255);
         snprintf(buf, BUFSIZ-1, CMD_FOCLIST "='%s'", modname);
-        sendstrmessage(fd, buf);
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     }
     if(focdevno > -1) focuser->setDevNo(focdevno);
-    //pthread_mutex_unlock(&locmutex);
     return RESULT_SILENCE;
 }
 static hresult fsetNhandler(int fd, _U_ const char *key, const char *val){
@@ -821,7 +763,7 @@ static hresult fsetNhandler(int fd, _U_ const char *key, const char *val){
         if(!focdevini(num)) return RESULT_FAIL;
     }
     snprintf(buf, 63, CMD_FDEVNO "=%d", focdevno);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 static hresult fgotohandler(int fd, _U_ const char *key, const char *val){
@@ -831,21 +773,17 @@ static hresult fgotohandler(int fd, _U_ const char *key, const char *val){
     if(val){
         f = atof(val);
         if(f < focminpos || f > focmaxpos) return RESULT_BADVAL;
-        //pthread_mutex_lock(&locmutex);
         if(f - focminpos < __FLT_EPSILON__){
             r = focuser->home(1);
         }else{
             r = focuser->setAbsPos(1, f);
         }
-        //pthread_mutex_unlock(&locmutex);
         if(!r) return RESULT_FAIL;
     }
-    //pthread_mutex_lock(&locmutex);
     r = focuser->getPos(&f);
-    //pthread_mutex_unlock(&locmutex);
     if(!r) return RESULT_FAIL;
     snprintf(buf, 63, CMD_FGOTO "=%g", f);
-    sendstrmessage(fd, buf);
+    if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     return RESULT_SILENCE;
 }
 
@@ -861,48 +799,52 @@ static hresult infohandler(int fd, _U_ const char *key, _U_ const char *val){
     if(camera){
         if(camera->getModelName(buf1, 255)){
             snprintf(buf, BUFSIZ-1, CMD_CAMLIST "='%s'", buf1);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
-        namehandler(fd, CMD_FILENAME, NULL);
-        binhandler(fd, CMD_HBIN, NULL);
-        binhandler(fd, CMD_VBIN, NULL);
-        temphandler(fd, CMD_CAMTEMPER, NULL);
-        exphandler(fd, CMD_EXPOSITION, NULL);
-        lastfnamehandler(fd, CMD_LASTFNAME, NULL);
-        expstatehandler(fd, CMD_EXPSTATE, NULL);
+#define RUN(f, arg) do{if(RESULT_DISCONNECTED == f(fd, arg, NULL)) return RESULT_DISCONNECTED;}while(0)
+        RUN(namehandler, CMD_FILENAME);
+        RUN(binhandler, CMD_HBIN);
+        RUN(binhandler, CMD_VBIN);
+        RUN(temphandler, CMD_CAMTEMPER);
+        RUN(exphandler, CMD_EXPOSITION);
+        RUN(lastfnamehandler, CMD_LASTFNAME);
+        RUN(expstatehandler, CMD_EXPSTATE);
+#undef RUN
     }
+    DBG("chk wheel");
     if(wheel){
+        DBG("Wname");
         if(wheel->getModelName(buf1, 255)){
             snprintf(buf, BUFSIZ-1, CMD_WLIST "='%s'", buf1);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
         if(wheel->getTbody(&f)){
             snprintf(buf, BUFSIZ-1, "wtemp=%.1f", f);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
         if(wheel->getPos(&i)){
             snprintf(buf, BUFSIZ-1, CMD_WPOS "=%d", i);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
         snprintf(buf, BUFSIZ-1, "wmaxpos=%d", wmaxpos);
-        sendstrmessage(fd, buf);
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
     }
     if(focuser){
         if(focuser->getModelName(buf1, 255)){
             snprintf(buf, BUFSIZ-1, CMD_FOCLIST "='%s'", buf1);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
         if(focuser->getTbody(&f)){
             snprintf(buf, BUFSIZ-1, "foctemp=%.1f", f);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
         snprintf(buf, BUFSIZ-1, "focminpos=%g", focminpos);
-        sendstrmessage(fd, buf);
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         snprintf(buf, BUFSIZ-1, "focmaxpos=%g", focmaxpos);
-        sendstrmessage(fd, buf);
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         if(focuser->getPos(&f)){
             snprintf(buf, BUFSIZ-1, CMD_FGOTO "=%g", f);
-            sendstrmessage(fd, buf);
+            if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         }
     }
     return RESULT_SILENCE;
@@ -913,7 +855,7 @@ static hresult helphandler(int fd, _U_ const char *key, _U_ const char *val){
     strpair *ptr = allcommands;
     while(ptr->key){
         snprintf(buf, 255, "%s - %s", ptr->key, ptr->help);
-        sendstrmessage(fd, buf);
+        if(!sendstrmessage(fd, buf)) return RESULT_DISCONNECTED;
         ++ptr;
     }
     return RESULT_SILENCE;
@@ -927,7 +869,10 @@ static int CAMbusy(){
     }
     return FALSE;
 }
-
+// check funtions
+static hresult chktrue(_U_ char *val){ // dummy check for `infohandler` (need to lock mutex anymore)
+    return RESULT_OK;
+}
 static hresult chkcam(char *val){
     if(val && CAMbusy()) return RESULT_BUSY;
     if(camera) return RESULT_OK;
@@ -944,7 +889,7 @@ static hresult chkfoc(char *val){
     return RESULT_FAIL;
 }
 static handleritem items[] = {
-    {NULL,   infohandler, CMD_INFO},
+    {chktrue,infohandler, CMD_INFO},
     {NULL,   helphandler, CMD_HELP},
     {NULL,   restarthandler, CMD_RESTART},
     {chkcam, camlisthandler, CMD_CAMLIST},
@@ -991,12 +936,12 @@ static handleritem items[] = {
 
 void server(int sock){
     // init everything
-    startCCD(&camdev);
-    camdevini(0);
     startFocuser(&focdev);
     focdevini(0);
     startWheel(&wheeldev);
     wheeldevini(0);
+    startCCD(&camdev);
+    camdevini(0);
     if(listen(sock, MAXCLIENTS) == -1){
         WARN("listen");
         LOGWARN("listen");
diff --git a/socket.c b/socket.c
index 170542e..833ca65 100644
--- a/socket.c
+++ b/socket.c
@@ -18,7 +18,6 @@
 
 #include <ctype.h> // isspace
 #include <netdb.h>
-#include <pthread.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/ioctl.h>
@@ -30,7 +29,7 @@
 #include "server.h"
 #include "socket.h"
 
-static pthread_mutex_t locmutex = PTHREAD_MUTEX_INITIALIZER; // mutex for wheel/camera/focuser functions
+pthread_mutex_t locmutex = PTHREAD_MUTEX_INITIALIZER; // mutex for wheel/camera/focuser functions
 
 /**
  * @brief start_socket - create socket and run client or server
@@ -82,26 +81,28 @@ int start_socket(int isserver, char *path, int isnet){
         if(isserver){
             int reuseaddr = 1;
             if(setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &reuseaddr, sizeof(int)) == -1){
-                LOGWARN("setsockopt()");
                 WARN("setsockopt()");
+                LOGWARN("setsockopt()");
                 close(sock); sock = -1;
                 continue;
             }
             if(bind(sock, p->ai_addr, p->ai_addrlen) == -1){
-                LOGWARN("bind()");
                 WARN("bind()");
+                LOGWARN("bind()");
                 close(sock); sock = -1;
                 continue;
             }
+            /*
             int enable = 1;
             if(ioctl(sock, FIONBIO, (void *)&enable) < 0){ // make socket nonblocking
-                LOGERR("Can't make socket nonblocking");
-                ERRX("ioctl()");
+                WARN("ioctl()");
+                LOGWARN("Can't make socket nonblocking");
             }
+            */
         }else{
             if(connect(sock, p->ai_addr, p->ai_addrlen) == -1){
-                LOGWARN("connect()");
                 WARN("connect()");
+                LOGWARN("connect()");
                 close(sock); sock = -1;
             }
         }
@@ -121,27 +122,34 @@ int start_socket(int isserver, char *path, int isnet){
 }
 
 // simple wrapper over write: add missed newline and log data
-void sendmessage(int fd, const char *msg, int l){
-    if(fd < 1 || !msg || l < 1) return;
+int sendmessage(int fd, const char *msg, int l){
+    if(fd < 1 || !msg || l < 1) return TRUE; // empty message
+    static char *tmpbuf = NULL;
+    static int buflen = 0;
+    if(l + 1 > buflen){
+        buflen += 1024;
+        tmpbuf = realloc(tmpbuf, buflen);
+    }
     DBG("send to fd %d: %s [%d]", fd, msg, l);
-    char *tmpbuf = MALLOC(char, l+1);
     memcpy(tmpbuf, msg, l);
     if(msg[l-1] != '\n') tmpbuf[l++] = '\n';
-    if(l != write(fd, tmpbuf, l)){
-        LOGWARN("write()");
+    if(l != send(fd, tmpbuf, l, MSG_NOSIGNAL)){
         WARN("write()");
+        LOGWARN("write()");
+        return FALSE;
     }else{
+        DBG("success");
         if(globlog){ // logging turned ON
             tmpbuf[l-1] = 0; // remove trailing '\n' for logging
             LOGDBG("SEND '%s'", tmpbuf);
         }
     }
-    FREE(tmpbuf);
+    return TRUE;
 }
-void sendstrmessage(int fd, const char *msg){
-    if(fd < 1 || !msg) return;
+int sendstrmessage(int fd, const char *msg){
+    if(fd < 1 || !msg) return FALSE;
     int l = strlen(msg);
-    sendmessage(fd, msg, l);
+    return sendmessage(fd, msg, l);
 }
 
 // text messages for `hresult`
@@ -165,7 +173,7 @@ const char *hresult2str(hresult r){
  * @return `val`
  */
 char *get_keyval(char *keyval){
-    DBG("Got string %s", keyval);
+    //DBG("Got string %s", keyval);
     // remove starting spaces in key
     while(isspace(*keyval)) ++keyval;
     char *val = strchr(keyval, '=');
@@ -178,32 +186,49 @@ char *get_keyval(char *keyval){
     while(isspace(*e) && e > keyval) --e;
     e[1] = 0;
     // now we have key (`str`) and val (or NULL)
-    DBG("key=%s, val=%s", keyval, val);
+    //DBG("key=%s, val=%s", keyval, val);
     return val;
 }
 
 // parse string of data (command or key=val)
 // the CONTENT of buffer `str` WILL BE BROKEN!
-static void parsestring(int fd, handleritem *handlers, char *str){
-    if(fd < 1 || !handlers || !handlers->key || !str || !*str) return;
+// @return FALSE if client closed (nothing to read)
+static int parsestring(int fd, handleritem *handlers, char *str){
+    if(fd < 1 || !handlers || !handlers->key || !str || !*str) return FALSE;
     char *val = get_keyval(str);
-    if(val) LOGDBG("RECEIVE '%s=%s'", str, val);
-    else LOGDBG("RECEIVE '%s'", str);
+    if(val){
+        DBG("RECEIVE '%s=%s'", str, val);
+        LOGDBG("RECEIVE '%s=%s'", str, val);
+    }else{
+        DBG("RECEIVE '%s'", str);
+        LOGDBG("RECEIVE '%s'", str);
+    }
     for(handleritem *h = handlers; h->key; ++h){
         if(strcmp(str, h->key) == 0){ // found command
-            pthread_mutex_lock(&locmutex);
             hresult r = RESULT_OK;
-            if(h->chkfunction) r = h->chkfunction(val);
+            int l = 1;
+            if(h->chkfunction){
+                double t0 = dtime();
+                do{ l = pthread_mutex_trylock(&locmutex); }while(l && dtime() - t0 > BUSY_TIMEOUT);
+                if(l){
+                    DBG("Can't lock mutex");
+                    return RESULT_BUSY; // long blocking work
+                }
+                r = h->chkfunction(val);
+            } // else NULL instead of chkfuntion -> don't check and don't lock mutex
             if(r == RESULT_OK){ // no test function or it returns TRUE
                 if(h->handler) r = h->handler(fd, str, val);
                 else r = RESULT_FAIL;
             }
-            pthread_mutex_unlock(&locmutex);
-            sendstrmessage(fd, hresult2str(r));
-            return;
+            if(!l) pthread_mutex_unlock(&locmutex);
+            if(r == RESULT_DISCONNECTED){
+                DBG("handler return RESULT_DISCONNECTED");
+                return FALSE;
+            }
+            return sendstrmessage(fd, hresult2str(r));
         }
     }
-    sendstrmessage(fd, resmessages[RESULT_BADKEY]);
+    return sendstrmessage(fd, resmessages[RESULT_BADKEY]);
 }
 
 /**
@@ -218,17 +243,20 @@ int processData(int fd, handleritem *handlers, char *buf, int buflen){
     int curlen = strlen(buf);
     if(curlen == buflen-1) curlen = 0; // buffer overflow - clear old content
     ssize_t rd = read(fd, buf + curlen, buflen-1 - curlen);
-    if(rd <= 0) return FALSE;
-    DBG("got %s[%zd] from %d", buf, rd, fd);
+    if(rd <= 0){
+        //DBG("read %zd bytes from client", rd);
+        return FALSE;
+    }
+    //DBG("got %s[%zd] from %d", buf, rd, fd);
     char *restofdata = buf, *eptr = buf + curlen + rd;
     *eptr = 0;
     do{
         char *nl = strchr(restofdata, '\n');
         if(!nl) break;
         *nl++ = 0;
-        parsestring(fd, handlers, restofdata);
+        if(!parsestring(fd, handlers, restofdata)) return FALSE; // client disconnected
         restofdata = nl;
-        DBG("rest of data: %s", restofdata);
+        //DBG("rest of data: %s", restofdata);
     }while(1);
     if(restofdata != buf) memmove(buf, restofdata, eptr - restofdata + 1);
     return TRUE;
diff --git a/socket.h b/socket.h
index 5212aee..51e0201 100644
--- a/socket.h
+++ b/socket.h
@@ -20,6 +20,8 @@
 #ifndef SERSOCK_H__
 #define SERSOCK_H__
 
+#include <pthread.h>
+
 // max & min TCP socket port number
 #define PORTN_MAX   (65535)
 #define PORTN_MIN   (1024)
@@ -28,6 +30,17 @@
 // Max amount of connections
 #define MAXCLIENTS  (30)
 
+// wait for mutex locking
+#define BUSY_TIMEOUT    (0.3)
+// waiting for answer timeout
+#define ANSWER_TIMEOUT  (1.0)
+// wait for exposition ends (between subsequent check calls)
+#define WAIT_TIMEOUT    (2.0)
+// client will disconnect after this time from last server message
+#define CLIENT_TIMEOUT  (10.0)
+
+extern pthread_mutex_t locmutex;
+
 typedef enum{
     RESULT_OK,      // all OK
     RESULT_BUSY,    // camera busy and no setters can be done
@@ -35,6 +48,7 @@ typedef enum{
     RESULT_BADVAL,  // bad key's value
     RESULT_BADKEY,  // bad key
     RESULT_SILENCE, // send nothing to client
+    RESULT_DISCONNECTED,// client disconnected
     RESULT_NUM
 } hresult;
 
@@ -50,8 +64,8 @@ typedef struct{
 } handleritem;
 
 int start_socket(int server, char *path, int isnet);
-void sendmessage(int fd, const char *msg, int l);
-void sendstrmessage(int fd, const char *msg);
+int sendmessage(int fd, const char *msg, int l);
+int sendstrmessage(int fd, const char *msg);
 char *get_keyval(char *keyval);
 
 int processData(int fd, handleritem *handlers, char *buf, int buflen);