Overview
| Comment: | Started branch to replace C11 atomics with simpler (but hopefully lock-free) implementation |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | remove-c11-atomics |
| Files: | files | file ages | folders |
| SHA1: | c6f68257232a7086d58f36317f895a20107520d8 |
| User & Date: | rkeene on 2016-09-22 17:35:54 |
| Other Links: | manifest | tags |
Context
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2020-03-31
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| 13:41 | Merged in trunk check-in: 1c1d95a764 user: rkeene tags: remove-c11-atomics | |
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2016-09-22
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| 17:35 | Started branch to replace C11 atomics with simpler (but hopefully lock-free) implementation check-in: c6f6825723 user: rkeene tags: remove-c11-atomics | |
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2016-08-17
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| 16:23 | Post-release version increment check-in: 1233e63987 user: rkeene tags: trunk | |
Changes
Modified README from [8ec76224c9] to [280019e35b].
51 51 52 52 1. Logging (CFLAGS, -DFILED_DONT_LOG=1) 53 53 It is possible to disable ALL logging from filed. When logging is 54 54 completely disabled interlocks (mutexes) for the logging pointer are 55 55 not engaged and the logging functions are not compiled at all. 56 56 This results in a slightly smaller and faster binary 57 57 58 - 2. Kill idle connections (CFLAGS, -DFILED_DONT_TIMEOUT=1) 59 - Killing idle connections relies heavily upon C11 atomics. This 60 - requires a relatively new version of GCC (4.9+) or other C compiler 61 - that implements this aspect of C11 and so it can be disabled at 62 - compile time (which is the only time it makes sense). One day an 63 - alternate implementation might be present that uses a mutex instead 64 - of atomics at which point this documentation will be updated. 65 - 66 - 3. Debugging (CFLAGS, -DFILED_DEBUG=1) 58 + 2. Debugging (CFLAGS, -DFILED_DEBUG=1) 67 59 This is an internal option and should only be used during development. 68 60 69 - 4. Differing HTTP semantics (CFLAGS, -DFILED_NONBLOCK_HTTP=1) 61 + 3. Differing HTTP semantics (CFLAGS, -DFILED_NONBLOCK_HTTP=1) 70 62 It is possible that some HTTP clients may not process the HTTP stream 71 63 being delivered if they cannot write to the HTTP stream itself. This 72 64 has not been observed yet, but it is possible. If these semantics are 73 65 needed (and they should not be) then they can be enabled with this 74 66 flag at the cost of performance. 75 67 76 - 5. Differing chroot() semantics (CFLAGS, -DFILED_FAKE_CHROOT=1) 68 + 4. Differing chroot() semantics (CFLAGS, -DFILED_FAKE_CHROOT=1) 77 69 In some cases it is desirable to mangle paths with a path prefix 78 70 rather than call chroot() at startup. This is less secure and slower 79 71 and should be generally avoided -- however it may be necessary to do. 80 72 In these cases the executable may be compiled with the 81 73 FILED_FAKE_CHROOT C preprocessor macro defined and instead of calling 82 74 chroot() all HTTP requests will have the root suffix specified as the 83 75 argument to the "-r" or "--root" option prepended to them. 84 76 85 - 6. MIME Types (MIMETYPES) 77 + 5. MIME Types (MIMETYPES) 86 78 For single-file convenience "filed" compiles the mapping of file 87 79 extensions (the string in the filename following its last dot (".")) 88 80 into the executable. This mapping comes from a file in the format of 89 81 type1 type1_extension1 type1_extension2... 90 82 type2 type2_extension1 type2_extension2... 91 83 ... 92 84 However it may not be desirable to include this mapping, or it may be ................................................................................ 99 91 Because "filed" relies on chroot(2) and setuid(2), log files cannot reliably 100 92 be re-opened. If you need log rotation then a second process, which can close 101 93 and re-open log files, must be used. Any process may be used for writing logs 102 94 but if the process does not support log rotation then it will not provide that 103 95 benefit. For example, if you wish to write logs to syslogd(8) you can use 104 96 logger(1), such as: 105 97 # ./filed --root /www --user nobody --log '|logger -t filed' --daemon 106 - 107 -Troubleshooting 108 ---------------- 109 - 1. It won't compile, something about stdatomic.h not found or _Atomic not 110 - a valid type. 111 - 112 - => This is a bug in your compiler: 113 - https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58016 114 - 115 - GCC 4.7.x and 4.8.x define the macro indicating that they have C11 116 - support and do not define the macro that C11 requires to indicate 117 - that C11 atomics are not available. They should define that macro. 118 - 119 - You can disable the features in "filed" that require C11 atomics by 120 - defining FILED_DONT_TIMEOUT in the Makefile.
Modified filed.c from [73ad6aa47c] to [a92c173e7c].
39 39 #include <stdarg.h> 40 40 #include <fcntl.h> 41 41 #include <stdio.h> 42 42 #include <errno.h> 43 43 #include <time.h> 44 44 #include <pwd.h> 45 45 46 -/* 47 - * Determine if the C compiler supports C11 atomics 48 - */ 49 -#if __STDC_VERSION__ >= 201112L 50 -# ifndef __STDC_NO_ATOMICS__ 51 -# define FILED_FEATURE_C11_ATOMICS 1 52 -# endif 53 -#endif 54 - 55 -/* 56 - * If the C compiler does not support C11 atomics, disable TIMEOUT support 57 - * since it relies upon it 58 - */ 59 -#ifndef FILED_FEATURE_C11_ATOMICS 60 -# define FILED_DONT_TIMEOUT 1 61 -#endif 62 - 63 -/* 64 - * These headers are only required for TIMEOUT support 65 - */ 66 -#ifndef FILED_DONT_TIMEOUT 67 -#include <stdatomic.h> 68 -#include <stdbool.h> 69 -#endif 70 - 71 46 /* Compile time constants */ 72 47 #define FILED_VERSION "1.19" 73 48 #define FILED_SENDFILE_MAX 16777215 74 49 #define FILED_MAX_FAILURE_COUNT 30 75 50 #define FILED_DEFAULT_TYPE "application/octet-stream" 76 51 #define FILED_PATH_BUFFER_SIZE 1010 77 52 ................................................................................ 81 56 #define BIND_ADDR "::" 82 57 #define CACHE_SIZE 8209 83 58 #define LOG_FILE "-" 84 59 85 60 /* Fuzzing Test Code */ 86 61 #ifdef FILED_TEST_AFL 87 62 #define FILED_DONT_LOG 1 88 -#define FILED_DONT_TIMEOUT 1 89 63 #define pthread_create(a, x, y, z) afl_pthread_create(a, x, y, z) 90 64 #define bind(x, y, z) afl_bind(x, y, z) 91 65 #define socket(x, y, z) 8193 92 66 #define listen(x, y) 0 93 67 #define accept(x, y, z) afl_accept(x, y, z) 94 68 #define close(x) { if (strcmp(#x, "random_fd") == 0) { close(x); } else { exit(0); } } 95 69 #define fclose(x) exit(0) ................................................................................ 624 598 #define filed_sockettimeout_thread_init() 0 625 599 #define filed_sockettimeout_init() 0 626 600 #define filed_sockettimeout_accept(x) /**/ 627 601 #define filed_sockettimeout_processing_start(x) /**/ 628 602 #define filed_sockettimeout_processing_end(x) /**/ 629 603 #define filed_sockettimeout_close(x) /**/ 630 604 #else 631 -_Atomic time_t filed_sockettimeout_time; 605 +time_t filed_sockettimeout_time; 632 606 struct { 633 - _Atomic time_t expiration_time; 634 - _Atomic pthread_t thread_id; 635 - bool valid; 607 + time_t expiration_time; 608 + pthread_t thread_id; 609 + int valid; 636 610 }* filed_sockettimeout_sockstatus; 637 611 long filed_sockettimeout_sockstatus_length; 638 612 int filed_sockettimeout_devnull_fd; 639 613 640 614 static int filed_sockettimeout_sockfd_in_range(int sockfd) { 641 615 if (sockfd < 3) { 642 616 return(0); ................................................................................ 706 680 } 707 681 708 682 static void *filed_sockettimeout_thread(void *arg) { 709 683 time_t now, expiration_time; 710 684 pthread_t thread_id; 711 685 long idx; 712 686 int count; 713 - bool valid; 687 + int valid; 714 688 715 689 while (1) { 716 690 for (count = 0; count < 10; count++) { 717 691 usleep(30000000); 718 692 719 693 now = time(NULL); 720 694