Mon Oct 8 12:39:06 2012

Asterisk developer's documentation


timing.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 2008 - 2009, Digium, Inc.
00005  *
00006  * Kevin P. Fleming <kpfleming@digium.com>
00007  * Russell Bryant <russell@digium.com>
00008  *
00009  * See http://www.asterisk.org for more information about
00010  * the Asterisk project. Please do not directly contact
00011  * any of the maintainers of this project for assistance;
00012  * the project provides a web site, mailing lists and IRC
00013  * channels for your use.
00014  *
00015  * This program is free software, distributed under the terms of
00016  * the GNU General Public License Version 2. See the LICENSE file
00017  * at the top of the source tree.
00018  */
00019 
00020 /*! \file
00021  *
00022  * \brief Timing source management
00023  *
00024  * \author Kevin P. Fleming <kpfleming@digium.com>
00025  * \author Russell Bryant <russell@digium.com>
00026  */
00027 
00028 /*** MODULEINFO
00029    <support_level>core</support_level>
00030  ***/
00031 
00032 #include "asterisk.h"
00033 
00034 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 369001 $")
00035 
00036 #include "asterisk/_private.h"
00037 
00038 #include "asterisk/timing.h"
00039 #include "asterisk/lock.h"
00040 #include "asterisk/cli.h"
00041 #include "asterisk/utils.h"
00042 #include "asterisk/time.h"
00043 #include "asterisk/heap.h"
00044 #include "asterisk/module.h"
00045 #include "asterisk/poll-compat.h"
00046 
00047 struct timing_holder {
00048    /*! Do _not_ move this from the beginning of the struct. */
00049    ssize_t __heap_index;
00050    struct ast_module *mod;
00051    struct ast_timing_interface *iface;
00052 };
00053 
00054 static struct ast_heap *timing_interfaces;
00055 
00056 struct ast_timer {
00057    int fd;
00058    struct timing_holder *holder;
00059 };
00060 
00061 static int timing_holder_cmp(void *_h1, void *_h2)
00062 {
00063    struct timing_holder *h1 = _h1;
00064    struct timing_holder *h2 = _h2;
00065 
00066    if (h1->iface->priority > h2->iface->priority) {
00067       return 1;
00068    } else if (h1->iface->priority == h2->iface->priority) {
00069       return 0;
00070    } else {
00071       return -1;
00072    }
00073 }
00074 
00075 void *_ast_register_timing_interface(struct ast_timing_interface *funcs, 
00076                  struct ast_module *mod)
00077 {
00078    struct timing_holder *h;
00079 
00080    if (!funcs->timer_open ||
00081        !funcs->timer_close ||
00082        !funcs->timer_set_rate ||
00083        !funcs->timer_ack ||
00084        !funcs->timer_get_event ||
00085        !funcs->timer_get_max_rate ||
00086        !funcs->timer_enable_continuous ||
00087        !funcs->timer_disable_continuous) {
00088       return NULL;
00089    }
00090 
00091    if (!(h = ast_calloc(1, sizeof(*h)))) {
00092       return NULL;
00093    }
00094 
00095    h->iface = funcs;
00096    h->mod = mod;
00097 
00098    ast_heap_wrlock(timing_interfaces);
00099    ast_heap_push(timing_interfaces, h);
00100    ast_heap_unlock(timing_interfaces);
00101 
00102    return h;
00103 }
00104 
00105 int ast_unregister_timing_interface(void *handle)
00106 {
00107    struct timing_holder *h = handle;
00108    int res = -1;
00109 
00110    ast_heap_wrlock(timing_interfaces);
00111    h = ast_heap_remove(timing_interfaces, h);
00112    ast_heap_unlock(timing_interfaces);
00113 
00114    if (h) {
00115       ast_free(h);
00116       h = NULL;
00117       res = 0;
00118    }
00119 
00120    return res;
00121 }
00122 
00123 struct ast_timer *ast_timer_open(void)
00124 {
00125    int fd = -1;
00126    struct timing_holder *h;
00127    struct ast_timer *t = NULL;
00128 
00129    ast_heap_rdlock(timing_interfaces);
00130 
00131    if ((h = ast_heap_peek(timing_interfaces, 1))) {
00132       fd = h->iface->timer_open();
00133       ast_module_ref(h->mod);
00134    }
00135 
00136    if (fd != -1) {
00137       if (!(t = ast_calloc(1, sizeof(*t)))) {
00138          h->iface->timer_close(fd);
00139       } else {
00140          t->fd = fd;
00141          t->holder = h;
00142       }
00143    }
00144 
00145    ast_heap_unlock(timing_interfaces);
00146 
00147    return t;
00148 }
00149 
00150 void ast_timer_close(struct ast_timer *handle)
00151 {
00152    handle->holder->iface->timer_close(handle->fd);
00153    ast_module_unref(handle->holder->mod);
00154    ast_free(handle);
00155 }
00156 
00157 int ast_timer_fd(const struct ast_timer *handle)
00158 {
00159    return handle->fd;
00160 }
00161 
00162 int ast_timer_set_rate(const struct ast_timer *handle, unsigned int rate)
00163 {
00164    int res = -1;
00165 
00166    res = handle->holder->iface->timer_set_rate(handle->fd, rate);
00167 
00168    return res;
00169 }
00170 
00171 void ast_timer_ack(const struct ast_timer *handle, unsigned int quantity)
00172 {
00173    handle->holder->iface->timer_ack(handle->fd, quantity);
00174 }
00175 
00176 int ast_timer_enable_continuous(const struct ast_timer *handle)
00177 {
00178    int res = -1;
00179 
00180    res = handle->holder->iface->timer_enable_continuous(handle->fd);
00181 
00182    return res;
00183 }
00184 
00185 int ast_timer_disable_continuous(const struct ast_timer *handle)
00186 {
00187    int res = -1;
00188 
00189    res = handle->holder->iface->timer_disable_continuous(handle->fd);
00190 
00191    return res;
00192 }
00193 
00194 enum ast_timer_event ast_timer_get_event(const struct ast_timer *handle)
00195 {
00196    enum ast_timer_event res = -1;
00197 
00198    res = handle->holder->iface->timer_get_event(handle->fd);
00199 
00200    return res;
00201 }
00202 
00203 unsigned int ast_timer_get_max_rate(const struct ast_timer *handle)
00204 {
00205    unsigned int res = 0;
00206 
00207    res = handle->holder->iface->timer_get_max_rate(handle->fd);
00208 
00209    return res;
00210 }
00211 
00212 const char *ast_timer_get_name(const struct ast_timer *handle)
00213 {
00214    return handle->holder->iface->name;
00215 }
00216 
00217 static char *timing_test(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00218 {
00219    struct ast_timer *timer;
00220    int count = 0;
00221    struct timeval start, end;
00222    unsigned int test_rate = 50;
00223 
00224    switch (cmd) {
00225    case CLI_INIT:
00226       e->command = "timing test";
00227       e->usage = "Usage: timing test <rate>\n"
00228                  "   Test a timer with a specified rate, 50/sec by default.\n"
00229                  "";
00230       return NULL;
00231    case CLI_GENERATE:
00232       return NULL;
00233    }
00234 
00235    if (a->argc != 2 && a->argc != 3) {
00236       return CLI_SHOWUSAGE;
00237    }
00238 
00239    if (a->argc == 3) {
00240       unsigned int rate;
00241       if (sscanf(a->argv[2], "%30u", &rate) == 1) {
00242          test_rate = rate;
00243       } else {
00244          ast_cli(a->fd, "Invalid rate '%s', using default of %u\n", a->argv[2], test_rate);  
00245       }
00246    }
00247 
00248    ast_cli(a->fd, "Attempting to test a timer with %u ticks per second.\n", test_rate);
00249 
00250    if (!(timer = ast_timer_open())) {
00251       ast_cli(a->fd, "Failed to open timing fd\n");
00252       return CLI_FAILURE;
00253    }
00254 
00255    ast_cli(a->fd, "Using the '%s' timing module for this test.\n", timer->holder->iface->name);
00256 
00257    start = ast_tvnow();
00258 
00259    ast_timer_set_rate(timer, test_rate);
00260 
00261    while (ast_tvdiff_ms((end = ast_tvnow()), start) < 1000) {
00262       int res;
00263       struct pollfd pfd = {
00264          .fd = ast_timer_fd(timer),
00265          .events = POLLIN | POLLPRI,
00266       };
00267 
00268       res = ast_poll(&pfd, 1, 100);
00269 
00270       if (res == 1) {
00271          count++;
00272          ast_timer_ack(timer, 1);
00273       } else if (!res) {
00274          ast_cli(a->fd, "poll() timed out!  This is bad.\n");
00275       } else if (errno != EAGAIN && errno != EINTR) {
00276          ast_cli(a->fd, "poll() returned error: %s\n", strerror(errno));
00277       }
00278    }
00279 
00280    ast_timer_close(timer);
00281 
00282    ast_cli(a->fd, "It has been %" PRIi64 " milliseconds, and we got %d timer ticks\n", 
00283       ast_tvdiff_ms(end, start), count);
00284 
00285    return CLI_SUCCESS;
00286 }
00287 
00288 static struct ast_cli_entry cli_timing[] = {
00289    AST_CLI_DEFINE(timing_test, "Run a timing test"),
00290 };
00291 
00292 int ast_timing_init(void)
00293 {
00294    if (!(timing_interfaces = ast_heap_create(2, timing_holder_cmp, 0))) {
00295       return -1;
00296    }
00297 
00298    return ast_cli_register_multiple(cli_timing, ARRAY_LEN(cli_timing));
00299 }

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