Tiny slowish pseudo random dd to debug partial writes implementation in mcastleech

2 files changed, 34 insertions, 1 deletions

diff --git a/mcastseed/src/Makefile.am b/mcastseed/src/Makefile.am
index 7ad2954..547d715 100644
--- a/mcastseed/src/Makefile.am
+++ b/mcastseed/src/Makefile.am
@@ -4,9 +4,10 @@ AM_CFLAGS =\
 	 -Wall \
 	 -g
 
-bin_PROGRAMS = mcastseed mcastleech
+bin_PROGRAMS = mcastseed mcastleech random_speed_dd
 
 mcastseed_SOURCES = mcastseed.c msock.c
 mcastleech_SOURCES = mcastleech.c msock.c dgrambuf.c
+random_speed_dd_SOURCES = random_speed_dd.c
 
 LDADD = @WSOCKLIB@
diff --git a/mcastseed/src/random_speed_dd.c b/mcastseed/src/random_speed_dd.c
new file mode 100644
index 0000000..0c11c05
--- /dev/null
+++ b/mcastseed/src/random_speed_dd.c
@@ -0,0 +1,32 @@
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+
+char buf[0xffff];
+
+int main() {
+	size_t nread, nwrite, remains;
+
+	srandom(1); // Always the same pseudo-random sequence
+
+	while ( (nread=read(0, buf, 0xf & rand())) >= 0 ) {
+		remains = nread;
+		while ( remains ) {
+			nwrite=write(1, buf, nread);
+			if ( nwrite < 0 )  {
+				if ( !(errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) ) {
+					perror("write");
+					return nwrite;
+				}
+			} else {
+				remains -= nwrite;
+			}
+		}
+		//fprintf(stderr, "nread==%zi, nwrite==%zi\n", nread, nwrite);
+		usleep( 0xfffff & rand() );
+	}
+
+	return 0;
+}
+