initial commit

performance.h

@@ -0,0 +1,72 @@
+#include <unistd.h>
+#include <netdb.h>
+#include <errno.h>
+#include <sys/select.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <fcntl.h>
+
+/* handles select errors */
+int my_select(int fd, fd_set * fdread, fd_set * fdwrite, fd_set * fdex, long sec, long usec) {
+  int ret_val;
+  struct timeval stv;
+  fd_set *fdr2, *fdw2, *fde2;
+
+  do {
+    fdr2 = fdread;
+    fdw2 = fdwrite;
+    fde2 = fdex;
+    stv.tv_sec = sec;
+    stv.tv_usec = usec;
+    ret_val = select(fd, fdr2, fdw2, fde2, &stv);
+  /* XXX select() sometimes returns errno=EINTR (signal found) */
+  } while (ret_val == -1 && errno == EINTR);
+
+  return ret_val;
+}
+
+/*reads in a non-blocking way*/
+ssize_t read_safe(int fd, void *buffer, size_t len) {
+  int r = 0;
+  int total = 0;
+  int toread = len;
+  fd_set fr;
+  struct timeval tv;
+  int ret = 0;
+
+  fcntl(fd, F_SETFL, O_NONBLOCK);
+  do {
+    FD_ZERO(&fr);
+    FD_SET(fd, &fr);
+    tv.tv_sec = 0;
+    tv.tv_usec = 250000;
+    ret = select(fd + 1, &fr, 0, 0, &tv);
+  /* XXX select() sometimes return errno=EINTR (signal found) */
+  } while (ret == -1 && errno == EINTR);
+
+  if (ret < 0) {
+    if (debug) {
+      perror("select");
+      printf("df:%d\n", fd);
+    }
+    return -1;
+  }
+
+  if (ret > 0) {
+    while ((r = read(fd, (char*) ((char*)buffer + total), toread))) {
+      if (r == -1) {
+        if (errno == EAGAIN)
+          break;
+        return -1;
+      }
+      total += r;
+      toread -= r;
+      if (total == len)
+        return len;
+      if (r == 0)
+        return 0;
+    }
+  }
+
+  return total;
+}