Fix use of INSN_GTOD so it works on 64-bit platforms.

A struct timeval is not the same size as a pair of lsampl_t's for 64-bit,
so can't point 'data' in a comedi_insn to a struct timeval and expect it
to work!

diff --git a/demo/insn.c b/demo/insn.c
index b842d046e2b541d2583b7c67bc6a186edf0534de..a67d4d01fe34b4fe5638328645faa30e69172bf4 100644 (file)
--- a/demo/insn.c
+++ b/demo/insn.c
@@ -34,6 +34,11 @@
  * This example does 3 instructions in one system call.  It does
  * a gettimeofday() call, then reads N_SAMPLES samples from an
  * analog input, and the another gettimeofday() call.
+ *
+ * (Note: The gettimeofday() value is obtained using an INSN_GTOD
+ * instruction, which places the seconds value in data[0] and the
+ * microseconds in data[1], so the seconds value is limited to
+ * 32-bits even on 64-bit systems.)
  */
 
 #define MAX_SAMPLES 128
@@ -45,7 +50,7 @@ int main(int argc, char *argv[])
        int ret,i;
        comedi_insn insn[3];
        comedi_insnlist il;
-       struct timeval t1,t2;
+       lsampl_t t1[2], t2[2];
        lsampl_t data[MAX_SAMPLES];
        struct parsed_options options;
 
@@ -77,7 +82,7 @@ int main(int argc, char *argv[])
        /* Instruction 0: perform a gettimeofday() */
        insn[0].insn=INSN_GTOD;
        insn[0].n=2;
-       insn[0].data=(void *)&t1;
+       insn[0].data=t1;
 
        /* Instruction 1: do 10 analog input reads */
        insn[1].insn=INSN_READ;
@@ -89,7 +94,7 @@ int main(int argc, char *argv[])
        /* Instruction 2: perform a gettimeofday() */
        insn[2].insn=INSN_GTOD;
        insn[2].n=2;
-       insn[2].data=(void *)&t2;
+       insn[2].data=t2;
 
        ret=comedi_do_insnlist(device,&il);
        if(ret<0){
@@ -97,14 +102,14 @@ int main(int argc, char *argv[])
                exit(-1);
        }
 
-       printf("initial time: %ld.%06ld\n", t1.tv_sec, t1.tv_usec);
+       printf("initial time: %d.%06d\n", t1[0], t1[1]);
        for(i = 0; i < options.n_scan; i++){
                printf("%d\n", data[i]);
        }
-       printf("final time: %ld.%06ld\n", t2.tv_sec, t2.tv_usec);
+       printf("final time: %d.%06d\n", t2[0], t2[1]);
 
-       printf("difference (us): %ld\n",(t2.tv_sec-t1.tv_sec) * 1000000 +
-                       (t2.tv_usec - t1.tv_usec));
+       printf("difference (us): %ld\n",(long)(t2[0]-t1[0]) * 1000000 +
+                       (t2[1] - t1[1]));
 
        return 0;
 }

diff --git a/doc/reference.sgml b/doc/reference.sgml
index 8584cc503357f20f631cd6438f285d945d97ea42..45e46c634357645a65154d09611ecaccab1295e2 100644 (file)
--- a/doc/reference.sgml
+++ b/doc/reference.sgml
@@ -518,7 +518,8 @@ INSN_GTOD
     </term>
     <listitem>
       <para>
-read a timestamp, identical to gettimeofday()
+read a timestamp, identical to gettimeofday() except the seconds
+and microseconds values are of type <link linkend="ref-type-lsampl-t">lsampl_t</link>.
       </para>
     </listitem>
   </varlistentry>

diff --git a/doc/tutorial.sgml b/doc/tutorial.sgml
index 9d37f28f6aa0bc9f26817950b582b70706899de8..a6934f644fc9cb34f583f92ab6e000b21b93aa02 100644 (file)
--- a/doc/tutorial.sgml
+++ b/doc/tutorial.sgml
@@ -306,6 +306,11 @@ function, the so-called <link linkend="instructions">instruction</link>.
  * This example does 3 instructions in one system call.  It does
  * a gettimeofday() call, then reads N_SAMPLES samples from an
  * analog input, and the another gettimeofday() call.
+ *
+ * (Note: The gettimeofday() value is obtained using an INSN_GTOD
+ * instruction, which places the seconds value in data[0] and the
+ * microseconds in data[1], so the seconds value is limited to
+ * 32-bits even on 64-bit systems.)
  */
 
 #define MAX_SAMPLES 128
@@ -317,7 +322,7 @@ int main(int argc, char *argv[])
   int ret,i;
   <link linkend="ref-type-comedi-insn">comedi_insn</link> insn[3];
   <link linkend="ref-type-comedi-insnlist">comedi_insnlist</link> il;
-  struct timeval t1,t2;
+  <link linkend="ref-type-lsampl-t">lsampl_t</link> t1[2], t2[2];
   <link linkend="ref-type-lsampl-t">lsampl_t</link> data[MAX_SAMPLES];
 
   parse_options(argc,argv);
@@ -343,7 +348,7 @@ int main(int argc, char *argv[])
   /* Instruction 0: perform a gettimeofday() */
   insn[0].insn=<link linkend="insn-gtod">INSN_GTOD</link>;
   insn[0].n=2;
-  insn[0].data=(void *)&amp;t1;
+  insn[0].data=t1;
 
   /* Instruction 1: do 10 analog input reads */
   insn[1].insn=<link linkend="insn-read">INSN_READ</link>;
@@ -355,7 +360,7 @@ int main(int argc, char *argv[])
   /* Instruction 2: perform a gettimeofday() */
   insn[2].insn=<link linkend="insn-gtod">INSN_GTOD</link>;
   insn[2].n=2;
-  insn[2].data=(void *)&amp;t2;
+  insn[2].data=t2;
 
   ret=<link linkend="func-ref-comedi-do-insnlist">comedi_do_insnlist</link>(device,&amp;il);
   if(ret<![CDATA[<]]>0){
@@ -363,14 +368,13 @@ int main(int argc, char *argv[])
     exit(0);
   }
 
-  printf("initial time: %ld.%06ld\n",t1.tv_sec,t1.tv_usec);
+  printf("initial time: %d.%06d\n",t1[0],t1[1]);
   for(i=0;i<![CDATA[<]]>n_scan;i++){
     printf("%d\n",data[i]);
   }
-  printf("final time: %ld.%06ld\n",t2.tv_sec,t2.tv_usec);
+  printf("final time: %d.%06d\n",t2[0],t2[1]);
 
-  printf("difference (us): %ld\n",(t2.tv_sec-t1.tv_sec)*1000000+
-      (t2.tv_usec-t1.tv_usec));
+  printf("difference (us): %ld\n",(long)(t2[0]-t1[0])*1000000+(t2[1]-t1[1]));
 
   return 0;
 }

diff --git a/testing/insn_read_time.c b/testing/insn_read_time.c
index 5f202b5e0b87937d27a052caafa22a10b51c8ae1..cd6b0c5c721724ef5964c47c9079e290af42fe3a 100644 (file)
--- a/testing/insn_read_time.c
+++ b/testing/insn_read_time.c
@@ -17,7 +17,7 @@ int test_insn_read_time(void)
 {
        comedi_insn insn[3];
        comedi_insnlist il;
-       struct timeval t1,t2;
+       lsampl_t t1[2],t2[2];
        lsampl_t data;
        int save_errno;
        int ret;
@@ -37,7 +37,7 @@ int test_insn_read_time(void)
 
        insn[0].insn = INSN_GTOD;
        insn[0].n=2;
-       insn[0].data = (void *)&t1;
+       insn[0].data = t1;
 
        insn[1].subdev = subdevice;
        insn[1].insn = INSN_READ;
@@ -47,7 +47,7 @@ int test_insn_read_time(void)
 
        insn[2].insn = INSN_GTOD;
        insn[2].n=2;
-       insn[2].data = (void *)&t2;
+       insn[2].data = t2;
 
        ret = comedi_do_insnlist(device,&il);
        save_errno = errno;
@@ -61,7 +61,7 @@ int test_insn_read_time(void)
        }
 
        printf("read time: %ld us\n",
-               (t2.tv_sec-t1.tv_sec)*1000000+(t2.tv_usec-t1.tv_usec));
+               (long)(t2[0]-t1[0])*1000000+(t2[1]-t1[1]));
 
 
        return 0;