1 //========================================================================
2 // GLFW 3.5 POSIX - www.glfw.org
3 //------------------------------------------------------------------------
4 // Copyright (c) 2022 Camilla Löwy <elmindreda@glfw.org>
5 //
6 // This software is provided 'as-is', without any express or implied
7 // warranty. In no event will the authors be held liable for any damages
8 // arising from the use of this software.
9 //
10 // Permission is granted to anyone to use this software for any purpose,
11 // including commercial applications, and to alter it and redistribute it
12 // freely, subject to the following restrictions:
13 //
14 // 1. The origin of this software must not be misrepresented; you must not
15 // claim that you wrote the original software. If you use this software
16 // in a product, an acknowledgment in the product documentation would
17 // be appreciated but is not required.
18 //
19 // 2. Altered source versions must be plainly marked as such, and must not
20 // be misrepresented as being the original software.
21 //
22 // 3. This notice may not be removed or altered from any source
23 // distribution.
24 //
25 //========================================================================
26
27 #if !defined(_GNU_SOURCE)
28 #define _GNU_SOURCE
29 #endif
30
31 #include "internal.h"
32
33 #if defined(GLFW_BUILD_POSIX_POLL)
34
35 #include <signal.h>
36 #include <time.h>
37 #include <errno.h>
38
_glfwPollPOSIX(struct pollfd * fds,nfds_t count,double * timeout)39 GLFWbool _glfwPollPOSIX(struct pollfd* fds, nfds_t count, double* timeout)
40 {
41 for (;;)
42 {
43 if (timeout)
44 {
45 const uint64_t base = _glfwPlatformGetTimerValue();
46
47 #if defined(__linux__) || defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__CYGWIN__)
48 const time_t seconds = (time_t) *timeout;
49 const long nanoseconds = (long) ((*timeout - seconds) * 1e9);
50 const struct timespec ts = { seconds, nanoseconds };
51 const int result = ppoll(fds, count, &ts, NULL);
52 #elif defined(__NetBSD__)
53 const time_t seconds = (time_t) *timeout;
54 const long nanoseconds = (long) ((*timeout - seconds) * 1e9);
55 const struct timespec ts = { seconds, nanoseconds };
56 const int result = pollts(fds, count, &ts, NULL);
57 #else
58 const int milliseconds = (int) (*timeout * 1e3);
59 const int result = poll(fds, count, milliseconds);
60 #endif
61 const int error = errno; // clock_gettime may overwrite our error
62
63 *timeout -= (_glfwPlatformGetTimerValue() - base) /
64 (double) _glfwPlatformGetTimerFrequency();
65
66 if (result > 0)
67 return GLFW_TRUE;
68 else if (result == -1 && error != EINTR && error != EAGAIN)
69 return GLFW_FALSE;
70 else if (*timeout <= 0.0)
71 return GLFW_FALSE;
72 }
73 else
74 {
75 const int result = poll(fds, count, -1);
76 if (result > 0)
77 return GLFW_TRUE;
78 else if (result == -1 && errno != EINTR && errno != EAGAIN)
79 return GLFW_FALSE;
80 }
81 }
82 }
83
84 #endif // GLFW_BUILD_POSIX_POLL
85
86