diff options
| -rw-r--r-- | lib/select.c | 109 |
1 files changed, 66 insertions, 43 deletions
diff --git a/lib/select.c b/lib/select.c index 597293c19..4e6c3046d 100644 --- a/lib/select.c +++ b/lib/select.c @@ -72,6 +72,16 @@ } while(0) #endif +/* Convenience local macros */ + +#define elapsed_ms (int)curlx_tvdiff(curlx_tvnow(), initial_tv) + +#ifdef CURL_ACKNOWLEDGE_EINTR +#define sockerrno_not_EINTR (SOCKERRNO != EINTR) +#else +#define sockerrno_not_EINTR (1) +#endif + /* * Internal function used for waiting a specific amount of ms * in Curl_select() and Curl_poll() when no file descriptor is @@ -80,27 +90,56 @@ * socket descriptor in a not null file descriptor set to work. * Waiting indefinitely with this function is not allowed, a * zero or negative timeout value will return immediately. + * Timeout resolution, accuracy, as well as maximum supported + * value is system dependant, neither factor is a citical issue + * for the intended use of this function in the library. + * On non-DOS and non-Winsock platforms, when compiled with + * CURL_ACKNOWLEDGE_EINTR defined, EINTR condition is honored + * and function might exit early without awaiting full timeout, + * otherwise EINTR will be ignored and full timeout will elapse. + * + * Return values: + * -1 = system call error, invalid timeout value, or interrupted + * 0 = specified timeout has elapsed */ -static void wait_ms(int timeout_ms) +static int wait_ms(int timeout_ms) { -#if !defined(__MSDOS__) && \ - !defined(USE_WINSOCK) && \ - !defined(HAVE_POLL_FINE) - struct timeval timeout; +#if !defined(__MSDOS__) && !defined(USE_WINSOCK) +#ifndef HAVE_POLL_FINE + struct timeval pending_tv; +#endif + struct timeval initial_tv; + int pending_ms; #endif - if (timeout_ms <= 0) - return; + int r = 0; + + if (!timeout_ms) + return 0; + if (timeout_ms < 0) { + SET_SOCKERRNO(EINVAL); + return -1; + } #if defined(__MSDOS__) delay(timeout_ms); #elif defined(USE_WINSOCK) Sleep(timeout_ms); -#elif defined(HAVE_POLL_FINE) - poll(NULL, 0, timeout_ms); #else - timeout.tv_sec = timeout_ms / 1000; - timeout.tv_usec = (timeout_ms % 1000) * 1000; - select(0, NULL, NULL, NULL, &timeout); -#endif + pending_ms = timeout_ms; + initial_tv = curlx_tvnow(); + do { +#if defined(HAVE_POLL_FINE) + r = poll(NULL, 0, pending_ms); +#else + pending_tv.tv_sec = pending_ms / 1000; + pending_tv.tv_usec = (pending_ms % 1000) * 1000; + r = select(0, NULL, NULL, NULL, &pending_tv); +#endif /* HAVE_POLL_FINE */ + } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR && + ((pending_ms = timeout_ms - elapsed_ms) > 0)); +#endif /* USE_WINSOCK */ + if (r) + r = -1; + return r; } /* @@ -113,7 +152,7 @@ static void wait_ms(int timeout_ms) * unles no valid file descriptor is given, when this happens the * negative timeout is ignored and the function times out immediately. * When compiled with CURL_ACKNOWLEDGE_EINTR defined, EINTR condition - * is honored and function will exit early without awaiting timeout, + * is honored and function might exit early without awaiting timeout, * otherwise EINTR will be ignored. * * Return values: @@ -140,8 +179,8 @@ int Curl_select(curl_socket_t readfd, curl_socket_t writefd, int timeout_ms) int ret; if((readfd == CURL_SOCKET_BAD) && (writefd == CURL_SOCKET_BAD)) { - wait_ms(timeout_ms); - return 0; + r = wait_ms(timeout_ms); + return r; } pending_ms = timeout_ms; @@ -167,12 +206,8 @@ int Curl_select(curl_socket_t readfd, curl_socket_t writefd, int timeout_ms) if (timeout_ms < 0) pending_ms = -1; r = poll(pfd, num, pending_ms); - } while ((r == -1) && (SOCKERRNO != EINVAL) && -#ifdef CURL_ACKNOWLEDGE_EINTR - (SOCKERRNO != EINTR) && -#endif - ((timeout_ms < 0) || - ((pending_ms = timeout_ms - (int)curlx_tvdiff(curlx_tvnow(), initial_tv)) > 0))); + } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR && + ((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0))); if (r < 0) return -1; @@ -234,12 +269,8 @@ int Curl_select(curl_socket_t readfd, curl_socket_t writefd, int timeout_ms) pending_tv.tv_usec = (pending_ms % 1000) * 1000; } r = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, ptimeout); - } while ((r == -1) && (SOCKERRNO != EINVAL) && -#ifdef CURL_ACKNOWLEDGE_EINTR - (SOCKERRNO != EINTR) && -#endif - ((timeout_ms < 0) || - ((pending_ms = timeout_ms - (int)curlx_tvdiff(curlx_tvnow(), initial_tv)) > 0))); + } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR && + ((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0))); if (r < 0) return -1; @@ -274,7 +305,7 @@ int Curl_select(curl_socket_t readfd, curl_socket_t writefd, int timeout_ms) * unles no valid file descriptor is given, when this happens the * negative timeout is ignored and the function times out immediately. * When compiled with CURL_ACKNOWLEDGE_EINTR defined, EINTR condition - * is honored and function will exit early without awaiting timeout, + * is honored and function might exit early without awaiting timeout, * otherwise EINTR will be ignored. * * Return values: @@ -307,8 +338,8 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms) } } if (fds_none) { - wait_ms(timeout_ms); - return 0; + r = wait_ms(timeout_ms); + return r; } pending_ms = timeout_ms; @@ -320,12 +351,8 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms) if (timeout_ms < 0) pending_ms = -1; r = poll(ufds, nfds, pending_ms); - } while ((r == -1) && (SOCKERRNO != EINVAL) && -#ifdef CURL_ACKNOWLEDGE_EINTR - (SOCKERRNO != EINTR) && -#endif - ((timeout_ms < 0) || - ((pending_ms = timeout_ms - (int)curlx_tvdiff(curlx_tvnow(), initial_tv)) > 0))); + } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR && + ((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0))); #else /* HAVE_POLL_FINE */ @@ -359,12 +386,8 @@ int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms) pending_tv.tv_usec = (pending_ms % 1000) * 1000; } r = select((int)maxfd + 1, &fds_read, &fds_write, &fds_err, ptimeout); - } while ((r == -1) && (SOCKERRNO != EINVAL) && -#ifdef CURL_ACKNOWLEDGE_EINTR - (SOCKERRNO != EINTR) && -#endif - ((timeout_ms < 0) || - ((pending_ms = timeout_ms - (int)curlx_tvdiff(curlx_tvnow(), initial_tv)) > 0))); + } while ((r == -1) && (SOCKERRNO != EINVAL) && sockerrno_not_EINTR && + ((timeout_ms < 0) || ((pending_ms = timeout_ms - elapsed_ms) > 0))); if (r < 0) return -1; |