1 files changed, 97 insertions, 0 deletions
diff --git a/semestr-5/so/lista5/so21_lista_5/prime.c b/semestr-5/so/lista5/so21_lista_5/prime.c
new file mode 100644
index 0000000..80ed3c6
--- /dev/null
+++ b/semestr-5/so/lista5/so21_lista_5/prime.c
@@ -0,0 +1,97 @@
+#include "csapp.h"
+
+typedef struct {
+  int read;
+  int write;
+} pipe_t;
+
+static inline pipe_t MakePipe(void) {
+  int fds[2];
+  Pipe(fds);
+  return (pipe_t){.read = fds[0], .write = fds[1]};
+}
+
+static inline void CloseReadEnd(pipe_t p) {
+  Close(p.read);
+}
+
+static inline void CloseWriteEnd(pipe_t p) {
+  Close(p.write);
+}
+
+static bool ReadNum(pipe_t p, long *valp) {
+  return Read(p.read, valp, sizeof(long)) == sizeof(long);
+}
+
+static bool WriteNum(pipe_t p, long val) {
+  return Write(p.write, &val, sizeof(long)) == sizeof(long);
+}
+
+static noreturn void generator(pipe_t out, long maxprime) {
+  for (long n = 2; n <= maxprime; n++)
+    WriteNum(out, n);
+  exit(EXIT_SUCCESS);
+}
+
+static void filter(pipe_t in, pipe_t out, long prime) {
+  long num;
+  while (ReadNum(in, &num)) {
+    if (num % prime != 0)
+      WriteNum(out, num);
+  }
+}
+
+static noreturn void filter_chain(pipe_t in) {
+  long prime;
+
+  /* TODO: Something is missing here! */
+  pipe_t out = MakePipe();
+  if (!ReadNum(in, &prime)) {
+    exit(EXIT_SUCCESS);
+  }
+  printf("%ld\n", prime);
+  if (Fork()) { /* parent */
+    close(out.read);
+    filter(in, out, prime);
+    close(out.write);
+    close(in.read);
+    Wait(NULL);
+  } else {  /* child */
+    close(out.write);
+    close(in.read);
+    filter_chain(out);
+  }
+
+  exit(EXIT_SUCCESS);
+}
+
+int main(int argc, char *argv[]) {
+  if (argc != 2)
+    app_error("Usage: %s [MAXPRIME]", argv[0]);
+
+  long maxprime = atol(argv[1]);
+
+  if (maxprime < 2 || maxprime > 10000)
+    app_error("Give maximum prime number in range from 2 to 10000!");
+
+  /* Spawn generator. */
+  pipe_t gen_pipe = MakePipe();
+  if (Fork()) { /* parent */
+    CloseWriteEnd(gen_pipe);
+  } else { /* child */
+    CloseReadEnd(gen_pipe);
+    generator(gen_pipe, maxprime);
+  }
+
+  /* Spawn filter chain. */
+  if (Fork()) { /* parent */
+    CloseReadEnd(gen_pipe);
+  } else { /* child */
+    filter_chain(gen_pipe);
+  }
+
+  for (int i = 0; i < 2; i++)
+    Wait(NULL);
+
+  return 0;
+}