equal
deleted
inserted
replaced
95 * a child process linked to the parent in the same way, but it |
95 * a child process linked to the parent in the same way, but it |
96 * avoids the problem of duplicating the parent (VM) process |
96 * avoids the problem of duplicating the parent (VM) process |
97 * address space temporarily, before launching the target command. |
97 * address space temporarily, before launching the target command. |
98 * |
98 * |
99 * Based on the above analysis, we are currently using vfork() on |
99 * Based on the above analysis, we are currently using vfork() on |
100 * Linux and spawn() on other Unix systems, but the code to use clone() |
100 * Linux and posix_spawn() on other Unix systems. |
101 * and fork() remains. |
|
102 */ |
101 */ |
103 |
102 |
104 |
103 |
105 static void |
104 static void |
106 setSIGCHLDHandler(JNIEnv *env) |
105 setSIGCHLDHandler(JNIEnv *env) |
383 } |
382 } |
384 return offset+count; |
383 return offset+count; |
385 } |
384 } |
386 |
385 |
387 /** |
386 /** |
388 * We are unusually paranoid; use of clone/vfork is |
387 * We are unusually paranoid; use of vfork is |
389 * especially likely to tickle gcc/glibc bugs. |
388 * especially likely to tickle gcc/glibc bugs. |
390 */ |
389 */ |
391 #ifdef __attribute_noinline__ /* See: sys/cdefs.h */ |
390 #ifdef __attribute_noinline__ /* See: sys/cdefs.h */ |
392 __attribute_noinline__ |
391 __attribute_noinline__ |
393 #endif |
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394 |
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395 #define START_CHILD_USE_CLONE 0 /* clone() currently disabled; see above. */ |
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396 |
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397 #ifdef START_CHILD_USE_CLONE |
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398 static pid_t |
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399 cloneChild(ChildStuff *c) { |
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400 #ifdef __linux__ |
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401 #define START_CHILD_CLONE_STACK_SIZE (64 * 1024) |
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402 /* |
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403 * See clone(2). |
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404 * Instead of worrying about which direction the stack grows, just |
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405 * allocate twice as much and start the stack in the middle. |
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406 */ |
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407 if ((c->clone_stack = malloc(2 * START_CHILD_CLONE_STACK_SIZE)) == NULL) |
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408 /* errno will be set to ENOMEM */ |
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409 return -1; |
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410 return clone(childProcess, |
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411 c->clone_stack + START_CHILD_CLONE_STACK_SIZE, |
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412 CLONE_VFORK | CLONE_VM | SIGCHLD, c); |
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413 #else |
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414 /* not available on Solaris / Mac */ |
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415 assert(0); |
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416 return -1; |
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417 #endif |
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418 } |
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419 #endif |
392 #endif |
420 |
393 |
421 static pid_t |
394 static pid_t |
422 vforkChild(ChildStuff *c) { |
395 vforkChild(ChildStuff *c) { |
423 volatile pid_t resultPid; |
396 volatile pid_t resultPid; |
588 |
561 |
589 if ((c = NEW(ChildStuff, 1)) == NULL) return -1; |
562 if ((c = NEW(ChildStuff, 1)) == NULL) return -1; |
590 c->argv = NULL; |
563 c->argv = NULL; |
591 c->envv = NULL; |
564 c->envv = NULL; |
592 c->pdir = NULL; |
565 c->pdir = NULL; |
593 c->clone_stack = NULL; |
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594 |
566 |
595 /* Convert prog + argBlock into a char ** argv. |
567 /* Convert prog + argBlock into a char ** argv. |
596 * Add one word room for expansion of argv for use by |
568 * Add one word room for expansion of argv for use by |
597 * execve_as_traditional_shell_script. |
569 * execve_as_traditional_shell_script. |
598 * This word is also used when using spawn mode |
570 * This word is also used when using posix_spawn mode |
599 */ |
571 */ |
600 assert(prog != NULL && argBlock != NULL); |
572 assert(prog != NULL && argBlock != NULL); |
601 if ((phelperpath = getBytes(env, helperpath)) == NULL) goto Catch; |
573 if ((phelperpath = getBytes(env, helperpath)) == NULL) goto Catch; |
602 if ((pprog = getBytes(env, prog)) == NULL) goto Catch; |
574 if ((pprog = getBytes(env, prog)) == NULL) goto Catch; |
603 if ((pargBlock = getBytes(env, argBlock)) == NULL) goto Catch; |
575 if ((pargBlock = getBytes(env, argBlock)) == NULL) goto Catch; |
652 break; |
624 break; |
653 case MODE_FORK: |
625 case MODE_FORK: |
654 throwIOException(env, errno, "fork failed"); |
626 throwIOException(env, errno, "fork failed"); |
655 break; |
627 break; |
656 case MODE_POSIX_SPAWN: |
628 case MODE_POSIX_SPAWN: |
657 throwIOException(env, errno, "spawn failed"); |
629 throwIOException(env, errno, "posix_spawn failed"); |
658 break; |
630 break; |
659 } |
631 } |
660 goto Catch; |
632 goto Catch; |
661 } |
633 } |
662 close(fail[1]); fail[1] = -1; /* See: WhyCantJohnnyExec (childproc.c) */ |
634 close(fail[1]); fail[1] = -1; /* See: WhyCantJohnnyExec (childproc.c) */ |
675 fds[0] = (in [1] != -1) ? in [1] : -1; |
647 fds[0] = (in [1] != -1) ? in [1] : -1; |
676 fds[1] = (out[0] != -1) ? out[0] : -1; |
648 fds[1] = (out[0] != -1) ? out[0] : -1; |
677 fds[2] = (err[0] != -1) ? err[0] : -1; |
649 fds[2] = (err[0] != -1) ? err[0] : -1; |
678 |
650 |
679 Finally: |
651 Finally: |
680 free(c->clone_stack); |
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681 |
|
682 /* Always clean up the child's side of the pipes */ |
652 /* Always clean up the child's side of the pipes */ |
683 closeSafely(in [0]); |
653 closeSafely(in [0]); |
684 closeSafely(out[1]); |
654 closeSafely(out[1]); |
685 closeSafely(err[1]); |
655 closeSafely(err[1]); |
686 |
656 |