| 1 | /* |
| 2 | ashd - A Sane HTTP Daemon |
| 3 | Copyright (C) 2008 Fredrik Tolf <fredrik@dolda2000.com> |
| 4 | |
| 5 | This program is free software: you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation, either version 3 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | */ |
| 18 | |
| 19 | #include <stdlib.h> |
| 20 | #include <stdarg.h> |
| 21 | #include <string.h> |
| 22 | |
| 23 | #ifdef HAVE_CONFIG_H |
| 24 | #include <config.h> |
| 25 | #endif |
| 26 | #include <utils.h> |
| 27 | #include <mt.h> |
| 28 | #include <valgrind/memcheck.h> |
| 29 | |
| 30 | struct muth *current = NULL; |
| 31 | static ucontext_t mainctxt; |
| 32 | |
| 33 | static void freemt(struct muth *muth) |
| 34 | { |
| 35 | if(muth->running) |
| 36 | abort(); |
| 37 | #ifdef VALGRIND_STACK_DEREGISTER |
| 38 | VALGRIND_STACK_DEREGISTER(muth->vgid); |
| 39 | #endif |
| 40 | free(muth->stack); |
| 41 | free(muth); |
| 42 | } |
| 43 | |
| 44 | static void muboot(void) |
| 45 | { |
| 46 | struct muth *muth; |
| 47 | |
| 48 | muth = current; |
| 49 | muth->running = 1; |
| 50 | muth->entry(muth, *muth->arglist); |
| 51 | muth->running = 0; |
| 52 | swapcontext(&muth->ctxt, muth->last); |
| 53 | } |
| 54 | |
| 55 | struct muth *mustart(void (*fn)(struct muth *muth, va_list args), ...) |
| 56 | { |
| 57 | struct muth *muth, *last; |
| 58 | va_list args; |
| 59 | |
| 60 | omalloc(muth); |
| 61 | getcontext(&muth->ctxt); |
| 62 | muth->ctxt.uc_link = &mainctxt; |
| 63 | muth->ctxt.uc_stack.ss_size = 65536; |
| 64 | muth->ctxt.uc_stack.ss_sp = muth->stack = smalloc(muth->ctxt.uc_stack.ss_size); |
| 65 | #ifdef VALGRIND_STACK_REGISTER |
| 66 | muth->vgid = VALGRIND_STACK_REGISTER(muth->stack, muth->stack + 65536); |
| 67 | #endif |
| 68 | va_start(args, fn); |
| 69 | muth->entry = fn; |
| 70 | muth->arglist = &args; |
| 71 | makecontext(&muth->ctxt, muboot, 0); |
| 72 | if(current == NULL) |
| 73 | muth->last = &mainctxt; |
| 74 | else |
| 75 | muth->last = ¤t->ctxt; |
| 76 | last = current; |
| 77 | current = muth; |
| 78 | swapcontext(muth->last, &muth->ctxt); |
| 79 | current = last; |
| 80 | va_end(args); |
| 81 | if(!muth->running) |
| 82 | freemt(muth); |
| 83 | return(muth); |
| 84 | } |
| 85 | |
| 86 | int yield(void) |
| 87 | { |
| 88 | ucontext_t *ret; |
| 89 | |
| 90 | if((current == NULL) || (current->last == NULL)) |
| 91 | abort(); |
| 92 | ret = current->last; |
| 93 | current->last = NULL; |
| 94 | swapcontext(¤t->ctxt, ret); |
| 95 | return(current->yr); |
| 96 | } |
| 97 | |
| 98 | void resume(struct muth *muth, int ret) |
| 99 | { |
| 100 | struct muth *last; |
| 101 | |
| 102 | if(muth->last != NULL) |
| 103 | abort(); |
| 104 | if(current == NULL) |
| 105 | muth->last = &mainctxt; |
| 106 | else |
| 107 | muth->last = ¤t->ctxt; |
| 108 | last = current; |
| 109 | current = muth; |
| 110 | muth->yr = ret; |
| 111 | swapcontext(muth->last, ¤t->ctxt); |
| 112 | current = last; |
| 113 | if(!muth->running) |
| 114 | freemt(muth); |
| 115 | } |