PostgreSQL Source Code  git master
parallel.c File Reference
#include "postgres_fe.h"
#include <sys/wait.h>
#include "pg_upgrade.h"
Include dependency graph for parallel.c:

Go to the source code of this file.

Functions

void parallel_exec_prog (const char *log_file, const char *opt_log_file, const char *fmt,...)
 
void parallel_transfer_all_new_dbs (DbInfoArr *old_db_arr, DbInfoArr *new_db_arr, char *old_pgdata, char *new_pgdata, char *old_tablespace)
 
bool reap_child (bool wait_for_child)
 

Variables

static int parallel_jobs
 

Function Documentation

◆ parallel_exec_prog()

void parallel_exec_prog ( const char *  log_file,
const char *  opt_log_file,
const char *  fmt,
  ... 
)

Definition at line 62 of file parallel.c.

64 {
65  va_list args;
66  char cmd[MAX_STRING];
67 
68 #ifndef WIN32
69  pid_t child;
70 #else
71  HANDLE child;
72  exec_thread_arg *new_arg;
73 #endif
74 
75  va_start(args, fmt);
76  vsnprintf(cmd, sizeof(cmd), fmt, args);
77  va_end(args);
78 
79  if (user_opts.jobs <= 1)
80  /* exit_on_error must be true to allow jobs */
81  exec_prog(log_file, opt_log_file, true, true, "%s", cmd);
82  else
83  {
84  /* parallel */
85 #ifdef WIN32
86  if (thread_handles == NULL)
87  thread_handles = pg_malloc(user_opts.jobs * sizeof(HANDLE));
88 
89  if (exec_thread_args == NULL)
90  {
91  int i;
92 
93  exec_thread_args = pg_malloc(user_opts.jobs * sizeof(exec_thread_arg *));
94 
95  /*
96  * For safety and performance, we keep the args allocated during
97  * the entire life of the process, and we don't free the args in a
98  * thread different from the one that allocated it.
99  */
100  for (i = 0; i < user_opts.jobs; i++)
101  exec_thread_args[i] = pg_malloc0(sizeof(exec_thread_arg));
102  }
103 
104  cur_thread_args = (void **) exec_thread_args;
105 #endif
106  /* harvest any dead children */
107  while (reap_child(false) == true)
108  ;
109 
110  /* must we wait for a dead child? */
112  reap_child(true);
113 
114  /* set this before we start the job */
115  parallel_jobs++;
116 
117  /* Ensure stdio state is quiesced before forking */
118  fflush(NULL);
119 
120 #ifndef WIN32
121  child = fork();
122  if (child == 0)
123  /* use _exit to skip atexit() functions */
124  _exit(!exec_prog(log_file, opt_log_file, true, true, "%s", cmd));
125  else if (child < 0)
126  /* fork failed */
127  pg_fatal("could not create worker process: %s", strerror(errno));
128 #else
129  /* empty array element are always at the end */
130  new_arg = exec_thread_args[parallel_jobs - 1];
131 
132  /* Can only pass one pointer into the function, so use a struct */
133  pg_free(new_arg->log_file);
134  new_arg->log_file = pg_strdup(log_file);
135  pg_free(new_arg->opt_log_file);
136  new_arg->opt_log_file = opt_log_file ? pg_strdup(opt_log_file) : NULL;
137  pg_free(new_arg->cmd);
138  new_arg->cmd = pg_strdup(cmd);
139 
140  child = (HANDLE) _beginthreadex(NULL, 0, (void *) win32_exec_prog,
141  new_arg, 0, NULL);
142  if (child == 0)
143  pg_fatal("could not create worker thread: %s", strerror(errno));
144 
145  thread_handles[parallel_jobs - 1] = child;
146 #endif
147  }
148 }
bool exec_prog(const char *log_filename, const char *opt_log_file, bool report_error, bool exit_on_error, const char *fmt,...)
Definition: exec.c:86
static int parallel_jobs
Definition: parallel.c:19
bool reap_child(bool wait_for_child)
Definition: parallel.c:278
void * pg_malloc0(size_t size)
Definition: fe_memutils.c:53
char * pg_strdup(const char *in)
Definition: fe_memutils.c:85
void pg_free(void *ptr)
Definition: fe_memutils.c:105
void * pg_malloc(size_t size)
Definition: fe_memutils.c:47
int i
Definition: isn.c:73
static void const char * fmt
static void const char fflush(stdout)
va_end(args)
va_start(args, fmt)
#define pg_fatal(...)
static char * log_file
Definition: pg_ctl.c:86
#define MAX_STRING
Definition: pg_upgrade.h:22
#define vsnprintf
Definition: port.h:237
#define strerror
Definition: port.h:251
UserOpts user_opts
Definition: option.c:29
int jobs
Definition: pg_upgrade.h:297

References generate_unaccent_rules::args, exec_prog(), fflush(), fmt, i, UserOpts::jobs, log_file, MAX_STRING, parallel_jobs, pg_fatal, pg_free(), pg_malloc(), pg_malloc0(), pg_strdup(), reap_child(), strerror, user_opts, va_end(), va_start(), and vsnprintf.

Referenced by create_new_objects(), and generate_old_dump().

◆ parallel_transfer_all_new_dbs()

void parallel_transfer_all_new_dbs ( DbInfoArr old_db_arr,
DbInfoArr new_db_arr,
char *  old_pgdata,
char *  new_pgdata,
char *  old_tablespace 
)

Definition at line 172 of file parallel.c.

175 {
176 #ifndef WIN32
177  pid_t child;
178 #else
179  HANDLE child;
180  transfer_thread_arg *new_arg;
181 #endif
182 
183  if (user_opts.jobs <= 1)
184  transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata, new_pgdata, NULL);
185  else
186  {
187  /* parallel */
188 #ifdef WIN32
189  if (thread_handles == NULL)
190  thread_handles = pg_malloc(user_opts.jobs * sizeof(HANDLE));
191 
192  if (transfer_thread_args == NULL)
193  {
194  int i;
195 
196  transfer_thread_args = pg_malloc(user_opts.jobs * sizeof(transfer_thread_arg *));
197 
198  /*
199  * For safety and performance, we keep the args allocated during
200  * the entire life of the process, and we don't free the args in a
201  * thread different from the one that allocated it.
202  */
203  for (i = 0; i < user_opts.jobs; i++)
204  transfer_thread_args[i] = pg_malloc0(sizeof(transfer_thread_arg));
205  }
206 
207  cur_thread_args = (void **) transfer_thread_args;
208 #endif
209  /* harvest any dead children */
210  while (reap_child(false) == true)
211  ;
212 
213  /* must we wait for a dead child? */
215  reap_child(true);
216 
217  /* set this before we start the job */
218  parallel_jobs++;
219 
220  /* Ensure stdio state is quiesced before forking */
221  fflush(NULL);
222 
223 #ifndef WIN32
224  child = fork();
225  if (child == 0)
226  {
227  transfer_all_new_dbs(old_db_arr, new_db_arr, old_pgdata, new_pgdata,
228  old_tablespace);
229  /* if we take another exit path, it will be non-zero */
230  /* use _exit to skip atexit() functions */
231  _exit(0);
232  }
233  else if (child < 0)
234  /* fork failed */
235  pg_fatal("could not create worker process: %s", strerror(errno));
236 #else
237  /* empty array element are always at the end */
238  new_arg = transfer_thread_args[parallel_jobs - 1];
239 
240  /* Can only pass one pointer into the function, so use a struct */
241  new_arg->old_db_arr = old_db_arr;
242  new_arg->new_db_arr = new_db_arr;
243  pg_free(new_arg->old_pgdata);
244  new_arg->old_pgdata = pg_strdup(old_pgdata);
245  pg_free(new_arg->new_pgdata);
246  new_arg->new_pgdata = pg_strdup(new_pgdata);
247  pg_free(new_arg->old_tablespace);
248  new_arg->old_tablespace = old_tablespace ? pg_strdup(old_tablespace) : NULL;
249 
250  child = (HANDLE) _beginthreadex(NULL, 0, (void *) win32_transfer_all_new_dbs,
251  new_arg, 0, NULL);
252  if (child == 0)
253  pg_fatal("could not create worker thread: %s", strerror(errno));
254 
255  thread_handles[parallel_jobs - 1] = child;
256 #endif
257  }
258 }
void transfer_all_new_dbs(DbInfoArr *old_db_arr, DbInfoArr *new_db_arr, char *old_pgdata, char *new_pgdata, char *old_tablespace)
Definition: relfilenumber.c:86

References fflush(), i, UserOpts::jobs, parallel_jobs, pg_fatal, pg_free(), pg_malloc(), pg_malloc0(), pg_strdup(), reap_child(), strerror, transfer_all_new_dbs(), and user_opts.

Referenced by transfer_all_new_tablespaces().

◆ reap_child()

bool reap_child ( bool  wait_for_child)

Definition at line 278 of file parallel.c.

279 {
280 #ifndef WIN32
281  int work_status;
282  pid_t child;
283 #else
284  int thread_num;
285  DWORD res;
286 #endif
287 
288  if (user_opts.jobs <= 1 || parallel_jobs == 0)
289  return false;
290 
291 #ifndef WIN32
292  child = waitpid(-1, &work_status, wait_for_child ? 0 : WNOHANG);
293  if (child == (pid_t) -1)
294  pg_fatal("%s() failed: %s", "waitpid", strerror(errno));
295  if (child == 0)
296  return false; /* no children, or no dead children */
297  if (work_status != 0)
298  pg_fatal("child process exited abnormally: status %d", work_status);
299 #else
300  /* wait for one to finish */
301  thread_num = WaitForMultipleObjects(parallel_jobs, thread_handles,
302  false, wait_for_child ? INFINITE : 0);
303 
304  if (thread_num == WAIT_TIMEOUT || thread_num == WAIT_FAILED)
305  return false;
306 
307  /* compute thread index in active_threads */
308  thread_num -= WAIT_OBJECT_0;
309 
310  /* get the result */
311  GetExitCodeThread(thread_handles[thread_num], &res);
312  if (res != 0)
313  pg_fatal("child worker exited abnormally: %s", strerror(errno));
314 
315  /* dispose of handle to stop leaks */
316  CloseHandle(thread_handles[thread_num]);
317 
318  /* Move last slot into dead child's position */
319  if (thread_num != parallel_jobs - 1)
320  {
321  void *tmp_args;
322 
323  thread_handles[thread_num] = thread_handles[parallel_jobs - 1];
324 
325  /*
326  * Move last active thread arg struct into the now-dead slot, and the
327  * now-dead slot to the end for reuse by the next thread. Though the
328  * thread struct is in use by another thread, we can safely swap the
329  * struct pointers within the array.
330  */
331  tmp_args = cur_thread_args[thread_num];
332  cur_thread_args[thread_num] = cur_thread_args[parallel_jobs - 1];
333  cur_thread_args[parallel_jobs - 1] = tmp_args;
334  }
335 #endif
336 
337  /* do this after job has been removed */
338  parallel_jobs--;
339 
340  return true;
341 }

References UserOpts::jobs, parallel_jobs, pg_fatal, res, strerror, and user_opts.

Referenced by create_new_objects(), generate_old_dump(), parallel_exec_prog(), parallel_transfer_all_new_dbs(), and transfer_all_new_tablespaces().

Variable Documentation

◆ parallel_jobs

int parallel_jobs
static

Definition at line 19 of file parallel.c.

Referenced by parallel_exec_prog(), parallel_transfer_all_new_dbs(), and reap_child().