[tl-append] / tl-append-test.c

/*
 * tl-append: time-logger appending shell
 * Copyright (C) 2023  Scott Worley <scottworley@scottworley.com>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#define _POSIX_C_SOURCE 2
#define _XOPEN_SOURCE
#define _GNU_SOURCE
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/file.h>
#include <time.h>
#include <unistd.h>

#include "common.h"

const size_t TIMESTAMP_LEN = 19;

typedef struct expectation {
  time_t a, b;
  const char *message;
} ex_t;

const ex_t END = {((time_t)-1), ((time_t)-1), NULL};
const ex_t CONSUMED = {((time_t)-2), ((time_t)-2), NULL};
static int is_end(ex_t exp) {
  return exp.a == END.a && exp.b == END.b && exp.message == END.message;
}
static void consume(ex_t *exp) {
  exp->a = CONSUMED.a;
  exp->b = CONSUMED.b;
}
static int is_consumed(ex_t exp) {
  return exp.a == CONSUMED.a && exp.b == CONSUMED.b;
}
static ex_t expectation(time_t a, time_t b, const char *message) {
  ex_t exp;
  exp.a = a;
  exp.b = b;
  exp.message = message;
  return exp;
}

static void remove_logfile() {
  if (remove(FILENAME) != 0) {
    if (errno != ENOENT) {
      die_err("Error removing log file");
    }
  }
}

static ex_t write_to_tl_append(const char *content) {
  FILE *p = popen("./tl-append", "w");
  if (p == NULL)
    die_err("Couldn't run tl-append");
  time_t start = time(NULL);
  if (fputs(content, p) == EOF)
    die("Couldn't write to pipe");
  int status = pclose(p);
  time_t end = time(NULL);
  if (status < 0)
    die_err("Error closing pipe");
  if (status != 0)
    die("tl-append exited abnormally");
  return expectation(start, end, content);
}

static char *timestamp_problem(const ex_t *ex, const char *line) {
  struct tm tm;

  /* localtime_r to set tm's timezone */
  time_t now_time = time(NULL);
  if (localtime_r(&now_time, &tm) == NULL)
    return "Can't unpack current time?";

  const char *strptime_result = strptime(line, "%Y %m %d %H %M %S", &tm);
  if (strptime_result == NULL || strptime_result != &line[TIMESTAMP_LEN])
    return "Wrong contents in log file: Couldn't parse timestamp";
  time_t t = mktime(&tm);
  int t_in_range = ex->a <= t && t <= ex->b;
  if (!t_in_range)
    return "Wrong contents in log file: Wrong time";
  return NULL;
}

static char *line_problem(const ex_t *ex, const char *line) {
  size_t line_len = strlen(line);
  if (line_len < TIMESTAMP_LEN + 1)
    return "Wrong contents in log file: Line too short";
  char *trouble = timestamp_problem(ex, line);
  if (trouble)
    return trouble;
  if (line[TIMESTAMP_LEN] != ' ')
    return "Wrong contents in log file: Bad format";
  if (strncmp(ex->message, &line[TIMESTAMP_LEN + 1], strlen(ex->message) + 1) !=
      0)
    return "Wrong contents in log file";
  return NULL;
}

static void verify_line(const ex_t *ex, const char *line) {
  char *trouble = line_problem(ex, line);
  if (trouble)
    die(trouble);
}

static void verify_log_contents(const ex_t exps[]) {
  FILE *f = fopen(FILENAME, "r");
  if (f == NULL)
    die_err("Error opening log file");
  for (size_t i = 0; !is_end(exps[i]); i++) {
    size_t len = TIMESTAMP_LEN + 1 + strlen(exps[i].message);
    if (len > INT_MAX - 1)
      die("message too long");
    char *buf = (char *)malloc(len + 2);
    if (fgets(buf, len + 1, f) == NULL)
      die("Error reading log file");
    if (ferror(f))
      die("Error reading log file");
    verify_line(&exps[i], buf);
    free(buf);
  }
  if (fclose(f) != 0)
    die_err("Error closing log file");
}

static void consume_expectation(ex_t exps[], const char *line) {
  for (size_t i = 0; !is_end(exps[i]); i++) {
    if (line_problem(&exps[i], line) == NULL) {
      consume(&exps[i]);
      return;
    }
  }
  die("Wrong contents in log file: Line didn't match any expectation");
}

static void verify_log_contents_unordered(ex_t exps[]) {
  FILE *f = fopen(FILENAME, "r");
  if (f == NULL)
    die_err("Error opening log file");
  for (;;) {
    const int MAX_LEN = 9999;
    char buf[MAX_LEN];
    if (fgets(buf, MAX_LEN, f) == NULL) {
      if (feof(f))
        break;
      die("Error reading log file");
    }
    if (ferror(f))
      die("Error reading log file");
    consume_expectation(exps, buf);
  }
  if (fclose(f) != 0)
    die_err("Error closing log file");
  for (size_t i = 0; !is_end(exps[i]); i++) {
    if (!is_consumed(exps[i]))
      die("Wrong contents in log file: Unconsumed expectation");
  }
}

static void test_encode_time() {
  /* localtime_r to set tm's timezone */
  time_t now_time = time(NULL);
  struct tm tm;
  if (localtime_r(&now_time, &tm) == NULL)
    die_err("Can't unpack current time?");

  const char *strptime_result = strptime("2011-12-13 14:15:16", "%F %T", &tm);
  if (strptime_result == NULL || *strptime_result != '\0')
    die("Couldn't parse time?");
  time_t tt = mktime(&tm);
  if (tt == (time_t)-1)
    die_err("Can't pack time?");

  char *encoded = encode_time(tt);
  /* Loose check to allow for daylight savings time changes between the current
   * time and the target time.  :( */
  assert(encoded[0] == '2');
  assert(encoded[1] == '0');
  assert(encoded[2] == '1');
  assert(encoded[3] == '1');
  assert(encoded[4] == ' ');
  assert(encoded[5] == '1');
  assert(encoded[6] == '2');
  assert(encoded[7] == ' ');
  assert(encoded[8] == '1');
  assert(encoded[9] == '3');
  assert(encoded[10] == ' ');
  assert(encoded[11] == '1');
  assert(isdigit(encoded[12]));
  assert(encoded[13] == ' ');
  assert(isdigit(encoded[14]));
  assert(isdigit(encoded[15]));
  assert(encoded[16] == ' ');
  assert(encoded[17] == '1');
  assert(encoded[18] == '6');
  assert(encoded[19] == '\0');
  free(encoded);
}

static FILE *take_lock(FILE *f, char *lock_type) {
  int fd = fileno(f);
  if (fd == -1)
    die_err("Couldn't get file descriptor for locking");
  if (strcmp(lock_type, "fcntl") == 0) {
    if (fcntl(fd, F_SETLK,
              &(struct flock){.l_type = F_WRLCK,
                              .l_whence = SEEK_SET,
                              .l_start = 0,
                              .l_len = 0}) == -1)
      die_err("Couldn't take fcntl lock");
  } else if (strcmp(lock_type, "flock") == 0) {
    if (flock(fd, LOCK_EX) == -1)
      die_err("Couldn't take flock lock");
  } else {
    die("Bad lock type");
  }
  return f;
}

static void release_lock(FILE *f) {
  if (fclose(f) != 0)
    die_err("Error releasing lock");
}

static void *release_lock_after_delay(void *f) {
  sleep(1);
  release_lock((FILE *)f);
  return NULL;
}

static void *writer_thread(void *start_signal) {
  ex_t *ex = (ex_t *)malloc(sizeof(ex_t));
  if (ex == NULL)
    die_err("Couldn't allocate memory");
  char *message;
  if (asprintf(&message, "Hello from thread %lu\n", pthread_self()) == -1)
    die("Couldn't prepare message");
  pthread_rwlock_rdlock((pthread_rwlock_t *)start_signal);
  *ex = write_to_tl_append(message);
  return ex;
}

static void write_and_read_line() {
  remove_logfile();
  ex_t e = write_to_tl_append("foo\n");
  verify_log_contents((ex_t[]){e, END});
}

static void write_and_read_two_lines() {
  remove_logfile();
  ex_t e1 = write_to_tl_append("foo\n");
  ex_t e2 = write_to_tl_append("bar\n");
  verify_log_contents((ex_t[]){e1, e2, END});
}

static void write_to_locked_log(char *lock_types[]) {
  remove_logfile();
  ex_t e1 = write_to_tl_append("begin\n");
  FILE *f = fopen(FILENAME, "ae");
  if (f == NULL)
    die_err("Couldn't open file for locking");
  for (int i = 0; lock_types[i]; i++)
    take_lock(f, lock_types[0]);
  pthread_t unlock_thread;
  int create_ret =
      pthread_create(&unlock_thread, NULL, &release_lock_after_delay, f);
  if (create_ret != 0) {
    errno = create_ret;
    die_err("Couldn't start thread");
  }
  ex_t e2 = write_to_tl_append("delayed\n");
  int join_ret = pthread_join(unlock_thread, NULL);
  if (join_ret != 0) {
    errno = join_ret;
    die_err("Couldn't join thread");
  }
  verify_log_contents((ex_t[]){e1, e2, END});
}

static void write_concurrently() {
  remove_logfile();
  const int PARALLELISM = 250;
  pthread_t threads[PARALLELISM];
  pthread_rwlock_t start_signal;
  pthread_rwlock_init(&start_signal, NULL);
  for (int i = 0; i < PARALLELISM; i++) {
    int create_ret =
        pthread_create(&threads[i], NULL, &writer_thread, &start_signal);
    if (create_ret != 0) {
      errno = create_ret;
      die_err("Couldn't start thread");
    }
  }
  pthread_rwlock_unlock(&start_signal);
  ex_t results[PARALLELISM + 1];
  for (int i = 0; i < PARALLELISM; i++) {
    ex_t *ex;
    int join_ret = pthread_join(threads[i], (void **)&ex);
    if (join_ret != 0) {
      errno = join_ret;
      die_err("Couldn't join thread");
    }
    results[i] = *ex;
    free(ex);
  }
  results[PARALLELISM] = END;
  verify_log_contents_unordered(results);
  for (int i = 0; i < PARALLELISM; i++) {
    free((void *)results[i].message);
  }
}

int main() {
  test_encode_time();
  write_and_read_line();
  write_and_read_two_lines();
  write_to_locked_log((char *[]){NULL});
  write_to_locked_log((char *[]){"fcntl", NULL});
  write_to_locked_log((char *[]){"flock", NULL});
  write_to_locked_log((char *[]){"flock", "fcntl", NULL}); /* Deadlock risk! */
  write_to_locked_log((char *[]){"fcntl", "flock", NULL});
  write_concurrently();
}
Commit	Line	Data
ef591a4f SW	1	/*
	2	* tl-append: time-logger appending shell
	3	* Copyright (C) 2023 Scott Worley <scottworley@scottworley.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, version 3.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program. If not, see <https://www.gnu.org/licenses/>.
	16	*/
	17
b3d5ed96	18	#define _POSIX_C_SOURCE 2
bab98a3a	19	#define _XOPEN_SOURCE
8559ce11	20	#define _GNU_SOURCE
bab98a3a SW	21	#include <assert.h>
bab98a3a SW	22	#include <ctype.h>
27dfbfeb	23	#include <errno.h>
8559ce11	24	#include <fcntl.h>
90df84eb	25	#include <limits.h>
8559ce11	26	#include <pthread.h>
b3d5ed96 SW	27	#include <stdio.h>
	28	#include <stdlib.h>
	29	#include <string.h>
a1160bb5	30	#include <sys/file.h>
853b83c4	31	#include <time.h>
8559ce11	32	#include <unistd.h>
b3d5ed96	33
d522116b SW	34	#include "common.h"
d522116b SW	35
2998af81 SW	36	const size_t TIMESTAMP_LEN = 19;
2998af81 SW	37
71a7e5c5	38	typedef struct expectation {
853b83c4	39	time_t a, b;
eaaa0046	40	const char *message;
71a7e5c5	41	} ex_t;
eaaa0046	42
853b83c4	43	const ex_t END = {((time_t)-1), ((time_t)-1), NULL};
8559ce11	44	const ex_t CONSUMED = {((time_t)-2), ((time_t)-2), NULL};
853b83c4 SW	45	static int is_end(ex_t exp) {
	46	return exp.a == END.a && exp.b == END.b && exp.message == END.message;
	47	}
ee028f60 SW	48	static void consume(ex_t *exp) {
	49	exp->a = CONSUMED.a;
	50	exp->b = CONSUMED.b;
	51	}
8559ce11	52	static int is_consumed(ex_t exp) {
ee028f60	53	return exp.a == CONSUMED.a && exp.b == CONSUMED.b;
8559ce11	54	}
853b83c4	55	static ex_t expectation(time_t a, time_t b, const char *message) {
71a7e5c5	56	ex_t exp;
853b83c4 SW	57	exp.a = a;
853b83c4 SW	58	exp.b = b;
eaaa0046 SW	59	exp.message = message;
	60	return exp;
	61	}
	62
27dfbfeb	63	static void remove_logfile() {
d522116b	64	if (remove(FILENAME) != 0) {
27dfbfeb SW	65	if (errno != ENOENT) {
	66	die_err("Error removing log file");
	67	}
	68	}
	69	}
	70
71a7e5c5	71	static ex_t write_to_tl_append(const char *content) {
b3d5ed96 SW	72	FILE *p = popen("./tl-append", "w");
	73	if (p == NULL)
	74	die_err("Couldn't run tl-append");
d753115a	75	time_t start = time(NULL);
aacfb261	76	if (fputs(content, p) == EOF)
b3d5ed96 SW	77	die("Couldn't write to pipe");
b3d5ed96 SW	78	int status = pclose(p);
d753115a	79	time_t end = time(NULL);
b3d5ed96 SW	80	if (status < 0)
	81	die_err("Error closing pipe");
	82	if (status != 0)
	83	die("tl-append exited abnormally");
d753115a	84	return expectation(start, end, content);
aacfb261 SW	85	}
aacfb261 SW	86
8559ce11	87	static char timestamp_problem(const ex_t ex, const char *line) {
2998af81 SW	88	struct tm tm;
	89
	90	/* localtime_r to set tm's timezone */
	91	time_t now_time = time(NULL);
	92	if (localtime_r(&now_time, &tm) == NULL)
8559ce11	93	return "Can't unpack current time?";
2998af81 SW	94
	95	const char *strptime_result = strptime(line, "%Y %m %d %H %M %S", &tm);
	96	if (strptime_result == NULL \|\| strptime_result != &line[TIMESTAMP_LEN])
8559ce11	97	return "Wrong contents in log file: Couldn't parse timestamp";
2998af81 SW	98	time_t t = mktime(&tm);
	99	int t_in_range = ex->a <= t && t <= ex->b;
	100	if (!t_in_range)
8559ce11 SW	101	return "Wrong contents in log file: Wrong time";
8559ce11 SW	102	return NULL;
2998af81 SW	103	}
2998af81 SW	104
8559ce11	105	static char line_problem(const ex_t ex, const char *line) {
2998af81 SW	106	size_t line_len = strlen(line);
2998af81 SW	107	if (line_len < TIMESTAMP_LEN + 1)
8559ce11 SW	108	return "Wrong contents in log file: Line too short";
	109	char *trouble = timestamp_problem(ex, line);
	110	if (trouble)
	111	return trouble;
2998af81	112	if (line[TIMESTAMP_LEN] != ' ')
8559ce11	113	return "Wrong contents in log file: Bad format";
2998af81 SW	114	if (strncmp(ex->message, &line[TIMESTAMP_LEN + 1], strlen(ex->message) + 1) !=
2998af81 SW	115	0)
8559ce11 SW	116	return "Wrong contents in log file";
8559ce11 SW	117	return NULL;
83acbf7e SW	118	}
83acbf7e SW	119
8559ce11 SW	120	static void verify_line(const ex_t ex, const char line) {
	121	char *trouble = line_problem(ex, line);
	122	if (trouble)
	123	die(trouble);
	124	}
b3d5ed96	125
8559ce11	126	static void verify_log_contents(const ex_t exps[]) {
d522116b	127	FILE *f = fopen(FILENAME, "r");
b3d5ed96 SW	128	if (f == NULL)
b3d5ed96 SW	129	die_err("Error opening log file");
71a7e5c5	130	for (size_t i = 0; !is_end(exps[i]); i++) {
2998af81	131	size_t len = TIMESTAMP_LEN + 1 + strlen(exps[i].message);
90df84eb SW	132	if (len > INT_MAX - 1)
90df84eb SW	133	die("message too long");
71a7e5c5 SW	134	char buf = (char )malloc(len + 2);
	135	if (fgets(buf, len + 1, f) == NULL)
	136	die("Error reading log file");
	137	if (ferror(f))
	138	die("Error reading log file");
83acbf7e	139	verify_line(&exps[i], buf);
71a7e5c5 SW	140	free(buf);
71a7e5c5 SW	141	}
b3d5ed96 SW	142	if (fclose(f) != 0)
	143	die_err("Error closing log file");
	144	}
	145
8559ce11 SW	146	static void consume_expectation(ex_t exps[], const char *line) {
	147	for (size_t i = 0; !is_end(exps[i]); i++) {
	148	if (line_problem(&exps[i], line) == NULL) {
ee028f60	149	consume(&exps[i]);
8559ce11 SW	150	return;
	151	}
	152	}
	153	die("Wrong contents in log file: Line didn't match any expectation");
	154	}
	155
	156	static void verify_log_contents_unordered(ex_t exps[]) {
	157	FILE *f = fopen(FILENAME, "r");
	158	if (f == NULL)
	159	die_err("Error opening log file");
	160	for (;;) {
	161	const int MAX_LEN = 9999;
	162	char buf[MAX_LEN];
	163	if (fgets(buf, MAX_LEN, f) == NULL) {
	164	if (feof(f))
	165	break;
	166	die("Error reading log file");
	167	}
	168	if (ferror(f))
	169	die("Error reading log file");
	170	consume_expectation(exps, buf);
	171	}
	172	if (fclose(f) != 0)
	173	die_err("Error closing log file");
	174	for (size_t i = 0; !is_end(exps[i]); i++) {
	175	if (!is_consumed(exps[i]))
	176	die("Wrong contents in log file: Unconsumed expectation");
	177	}
	178	}
	179
bab98a3a SW	180	static void test_encode_time() {
	181	/* localtime_r to set tm's timezone */
	182	time_t now_time = time(NULL);
	183	struct tm tm;
	184	if (localtime_r(&now_time, &tm) == NULL)
	185	die_err("Can't unpack current time?");
	186
	187	const char *strptime_result = strptime("2011-12-13 14:15:16", "%F %T", &tm);
	188	if (strptime_result == NULL \|\| *strptime_result != '\0')
	189	die("Couldn't parse time?");
	190	time_t tt = mktime(&tm);
	191	if (tt == (time_t)-1)
	192	die_err("Can't pack time?");
	193
9b76e9d2	194	char *encoded = encode_time(tt);
bab98a3a SW	195	/* Loose check to allow for daylight savings time changes between the current
	196	* time and the target time. :( */
	197	assert(encoded[0] == '2');
	198	assert(encoded[1] == '0');
	199	assert(encoded[2] == '1');
	200	assert(encoded[3] == '1');
	201	assert(encoded[4] == ' ');
	202	assert(encoded[5] == '1');
	203	assert(encoded[6] == '2');
	204	assert(encoded[7] == ' ');
	205	assert(encoded[8] == '1');
	206	assert(encoded[9] == '3');
	207	assert(encoded[10] == ' ');
	208	assert(encoded[11] == '1');
	209	assert(isdigit(encoded[12]));
	210	assert(encoded[13] == ' ');
	211	assert(isdigit(encoded[14]));
	212	assert(isdigit(encoded[15]));
	213	assert(encoded[16] == ' ');
	214	assert(encoded[17] == '1');
	215	assert(encoded[18] == '6');
	216	assert(encoded[19] == '\0');
9b76e9d2	217	free(encoded);
bab98a3a SW	218	}
bab98a3a SW	219
a1160bb5	220	static FILE take_lock(FILE f, char *lock_type) {
8559ce11 SW	221	int fd = fileno(f);
	222	if (fd == -1)
	223	die_err("Couldn't get file descriptor for locking");
a1160bb5 SW	224	if (strcmp(lock_type, "fcntl") == 0) {
	225	if (fcntl(fd, F_SETLK,
	226	&(struct flock){.l_type = F_WRLCK,
	227	.l_whence = SEEK_SET,
	228	.l_start = 0,
	229	.l_len = 0}) == -1)
	230	die_err("Couldn't take fcntl lock");
	231	} else if (strcmp(lock_type, "flock") == 0) {
	232	if (flock(fd, LOCK_EX) == -1)
	233	die_err("Couldn't take flock lock");
	234	} else {
	235	die("Bad lock type");
	236	}
8559ce11 SW	237	return f;
	238	}
	239
	240	static void release_lock(FILE *f) {
	241	if (fclose(f) != 0)
	242	die_err("Error releasing lock");
	243	}
	244
	245	static void release_lock_after_delay(void f) {
a1160bb5	246	sleep(1);
8559ce11 SW	247	release_lock((FILE *)f);
	248	return NULL;
	249	}
	250
	251	static void writer_thread(void start_signal) {
	252	ex_t ex = (ex_t )malloc(sizeof(ex_t));
	253	if (ex == NULL)
	254	die_err("Couldn't allocate memory");
	255	char *message;
	256	if (asprintf(&message, "Hello from thread %lu\n", pthread_self()) == -1)
	257	die("Couldn't prepare message");
	258	pthread_rwlock_rdlock((pthread_rwlock_t *)start_signal);
	259	*ex = write_to_tl_append(message);
	260	return ex;
	261	}
	262
aacfb261	263	static void write_and_read_line() {
27dfbfeb	264	remove_logfile();
71a7e5c5 SW	265	ex_t e = write_to_tl_append("foo\n");
71a7e5c5 SW	266	verify_log_contents((ex_t[]){e, END});
aacfb261 SW	267	}
aacfb261 SW	268
27dfbfeb SW	269	static void write_and_read_two_lines() {
27dfbfeb SW	270	remove_logfile();
71a7e5c5 SW	271	ex_t e1 = write_to_tl_append("foo\n");
	272	ex_t e2 = write_to_tl_append("bar\n");
	273	verify_log_contents((ex_t[]){e1, e2, END});
27dfbfeb SW	274	}
27dfbfeb SW	275
a1160bb5	276	static void write_to_locked_log(char *lock_types[]) {
8559ce11 SW	277	remove_logfile();
8559ce11 SW	278	ex_t e1 = write_to_tl_append("begin\n");
d212cd99	279	FILE *f = fopen(FILENAME, "ae");
a1160bb5 SW	280	if (f == NULL)
	281	die_err("Couldn't open file for locking");
	282	for (int i = 0; lock_types[i]; i++)
	283	take_lock(f, lock_types[0]);
8559ce11 SW	284	pthread_t unlock_thread;
8559ce11 SW	285	int create_ret =
a1160bb5	286	pthread_create(&unlock_thread, NULL, &release_lock_after_delay, f);
8559ce11 SW	287	if (create_ret != 0) {
	288	errno = create_ret;
	289	die_err("Couldn't start thread");
	290	}
	291	ex_t e2 = write_to_tl_append("delayed\n");
	292	int join_ret = pthread_join(unlock_thread, NULL);
	293	if (join_ret != 0) {
	294	errno = join_ret;
	295	die_err("Couldn't join thread");
	296	}
	297	verify_log_contents((ex_t[]){e1, e2, END});
	298	}
	299
	300	static void write_concurrently() {
	301	remove_logfile();
	302	const int PARALLELISM = 250;
	303	pthread_t threads[PARALLELISM];
	304	pthread_rwlock_t start_signal;
	305	pthread_rwlock_init(&start_signal, NULL);
	306	for (int i = 0; i < PARALLELISM; i++) {
	307	int create_ret =
	308	pthread_create(&threads[i], NULL, &writer_thread, &start_signal);
	309	if (create_ret != 0) {
	310	errno = create_ret;
	311	die_err("Couldn't start thread");
	312	}
	313	}
	314	pthread_rwlock_unlock(&start_signal);
	315	ex_t results[PARALLELISM + 1];
	316	for (int i = 0; i < PARALLELISM; i++) {
	317	ex_t *ex;
	318	int join_ret = pthread_join(threads[i], (void **)&ex);
	319	if (join_ret != 0) {
	320	errno = join_ret;
	321	die_err("Couldn't join thread");
	322	}
	323	results[i] = *ex;
	324	free(ex);
	325	}
	326	results[PARALLELISM] = END;
	327	verify_log_contents_unordered(results);
ee028f60 SW	328	for (int i = 0; i < PARALLELISM; i++) {
	329	free((void *)results[i].message);
	330	}
8559ce11 SW	331	}
8559ce11 SW	332
27dfbfeb	333	int main() {
bab98a3a	334	test_encode_time();
27dfbfeb SW	335	write_and_read_line();
27dfbfeb SW	336	write_and_read_two_lines();
a1160bb5 SW	337	write_to_locked_log((char *[]){NULL});
	338	write_to_locked_log((char *[]){"fcntl", NULL});
	339	write_to_locked_log((char *[]){"flock", NULL});
d212cd99	340	write_to_locked_log((char []){"flock", "fcntl", NULL}); / Deadlock risk! */
a1160bb5	341	write_to_locked_log((char *[]){"fcntl", "flock", NULL});
8559ce11	342	write_concurrently();
27dfbfeb	343	}