From 349bdf95e3743abad0b160a36bf01f540ea5f36c Mon Sep 17 00:00:00 2001 From: Steve Hoelzer Date: Mon, 19 Dec 2016 11:10:09 -0600 Subject: [PATCH 1/2] poll: Use GetTickCount64 to avoid wraparound issues From Visual Studio 2015 Code Analysis: Warning C28159 Consider using 'GetTickCount64' instead of 'GetTickCount'. Reason: GetTickCount overflows roughly every 49 days. Code that does not take that into account can loop indefinitely. GetTickCount64 operates on 64 bit values and does not have that problem. Signed-off-by: Steve Hoelzer --- compat/poll/poll.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/compat/poll/poll.c b/compat/poll/poll.c index 7ed3fbbea1..8ccaeabcf7 100644 --- a/compat/poll/poll.c +++ b/compat/poll/poll.c @@ -449,7 +449,8 @@ poll (struct pollfd *pfd, nfds_t nfd, int timeout) static HANDLE hEvent; WSANETWORKEVENTS ev; HANDLE h, handle_array[FD_SETSIZE + 2]; - DWORD ret, wait_timeout, nhandles, start = 0, elapsed, orig_timeout = 0; + DWORD ret, wait_timeout, nhandles, elapsed, orig_timeout = 0; + ULONGLONG start = 0; fd_set rfds, wfds, xfds; BOOL poll_again; MSG msg; @@ -465,7 +466,7 @@ poll (struct pollfd *pfd, nfds_t nfd, int timeout) if (timeout != INFTIM) { orig_timeout = timeout; - start = GetTickCount(); + start = GetTickCount64(); } if (!hEvent) @@ -614,7 +615,7 @@ restart: if (!rc && orig_timeout && timeout != INFTIM) { - elapsed = GetTickCount() - start; + elapsed = (DWORD)(GetTickCount64() - start); timeout = elapsed >= orig_timeout ? 0 : orig_timeout - elapsed; } From f3b190ffb0fdce737cc2b5b568b4b60a77955fed Mon Sep 17 00:00:00 2001 From: Johannes Schindelin Date: Tue, 20 Dec 2016 17:18:05 +0100 Subject: [PATCH 2/2] poll: lazy-load GetTickCount64() This fixes the compilation, actually, as we still did not make the jump to post-Windows XP completely: we still compile with _WIN32_WINNT set to 0x0502 (which corresponds to Windows Server 2003 and is technically greater than Windows XP's 0x0501). However, GetTickCount64() is only available starting with Windows Vista/Windows Server 2008. Let's just lazy-load the function, which should also help Git for Windows contributors who want to reinstate Windows XP support. Signed-off-by: Johannes Schindelin --- compat/poll/poll.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/compat/poll/poll.c b/compat/poll/poll.c index 8ccaeabcf7..88f5c19c55 100644 --- a/compat/poll/poll.c +++ b/compat/poll/poll.c @@ -266,6 +266,20 @@ win32_compute_revents_socket (SOCKET h, int sought, long lNetworkEvents) return happened; } +#include +#include "compat/win32/lazyload.h" + +static ULONGLONG CompatGetTickCount64(void) +{ + DECLARE_PROC_ADDR(kernel32.dll, ULONGLONG, GetTickCount64, void); + + if (!INIT_PROC_ADDR(GetTickCount64)) + return (ULONGLONG)GetTickCount(); + + return GetTickCount64(); +} +#define GetTickCount64 CompatGetTickCount64 + #else /* !MinGW */ /* Convert select(2) returned fd_sets into poll(2) revents values. */