ruby-changes:53102
From: normal <ko1@a...>
Date: Tue, 23 Oct 2018 12:47:51 +0900 (JST)
Subject: [ruby-changes:53102] normal:r65316 (trunk): Revert "vm_trace: implement postponed_jobs as st_table"
normal 2018-10-23 12:47:45 +0900 (Tue, 23 Oct 2018) New Revision: 65316 https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=65316 Log: Revert "vm_trace: implement postponed_jobs as st_table" This reverts commit 5a1dfb04bc2b09fcf8f3427cac72d0ce52a45eb2 (r63451) And mark the functions as async-signal-safe while we're at it to prevent future developers from making the same mistake as I did :x Modified files: trunk/include/ruby/debug.h trunk/vm_core.h trunk/vm_trace.c Index: include/ruby/debug.h =================================================================== --- include/ruby/debug.h (revision 65315) +++ include/ruby/debug.h (revision 65316) @@ -83,7 +83,11 @@ VALUE rb_tracearg_return_value(rb_trace_ https://github.com/ruby/ruby/blob/trunk/include/ruby/debug.h#L83 VALUE rb_tracearg_raised_exception(rb_trace_arg_t *trace_arg); VALUE rb_tracearg_object(rb_trace_arg_t *trace_arg); -/* Postponed Job API */ +/* + * Postponed Job API + * rb_postponed_job_register and rb_postponed_job_register_one are + * async-signal-safe and used via SIGPROF by the "stackprof" RubyGem + */ typedef void (*rb_postponed_job_func_t)(void *arg); int rb_postponed_job_register(unsigned int flags, rb_postponed_job_func_t func, void *data); int rb_postponed_job_register_one(unsigned int flags, rb_postponed_job_func_t func, void *data); Index: vm_core.h =================================================================== --- vm_core.h (revision 65315) +++ vm_core.h (revision 65316) @@ -630,7 +630,8 @@ typedef struct rb_vm_struct { https://github.com/ruby/ruby/blob/trunk/vm_core.h#L630 struct st_table *ensure_rollback_table; /* postponed_job */ - struct st_table *postponed_jobs; + struct rb_postponed_job_struct *postponed_job_buffer; + int postponed_job_index; int src_encoding_index; Index: vm_trace.c =================================================================== --- vm_trace.c (revision 65315) +++ vm_trace.c (revision 65316) @@ -1572,6 +1572,11 @@ Init_vm_trace(void) https://github.com/ruby/ruby/blob/trunk/vm_trace.c#L1572 Init_postponed_job(); } +typedef struct rb_postponed_job_struct { + rb_postponed_job_func_t func; + void *data; +} rb_postponed_job_t; + #define MAX_POSTPONED_JOB 1000 #define MAX_POSTPONED_JOB_SPECIAL_ADDITION 24 @@ -1579,56 +1584,85 @@ static void https://github.com/ruby/ruby/blob/trunk/vm_trace.c#L1584 Init_postponed_job(void) { rb_vm_t *vm = GET_VM(); - vm->postponed_jobs = st_init_numtable(); + vm->postponed_job_buffer = ALLOC_N(rb_postponed_job_t, MAX_POSTPONED_JOB); + vm->postponed_job_index = 0; } enum postponed_job_register_result { PJRR_SUCCESS = 0, - PJRR_FULL = 1 + PJRR_FULL = 1, + PJRR_INTERRUPTED = 2 }; +/* Async-signal-safe */ static enum postponed_job_register_result postponed_job_register(rb_execution_context_t *ec, rb_vm_t *vm, - unsigned int flags, rb_postponed_job_func_t func, void *data, size_t max) + unsigned int flags, rb_postponed_job_func_t func, void *data, int max, int expected_index) { - if (vm->postponed_jobs->num_entries >= max) return PJRR_FULL; + rb_postponed_job_t *pjob; + + if (expected_index >= max) return PJRR_FULL; /* failed */ + + if (ATOMIC_CAS(vm->postponed_job_index, expected_index, expected_index+1) == expected_index) { + pjob = &vm->postponed_job_buffer[expected_index]; + } + else { + return PJRR_INTERRUPTED; + } - st_add_direct(vm->postponed_jobs, (st_index_t)func, (st_data_t)data); + /* unused: pjob->flags = flags; */ + pjob->func = func; + pjob->data = data; RUBY_VM_SET_POSTPONED_JOB_INTERRUPT(ec); return PJRR_SUCCESS; } - -/* return 0 if job buffer is full */ +/* + * return 0 if job buffer is full + * Async-signal-safe + */ int rb_postponed_job_register(unsigned int flags, rb_postponed_job_func_t func, void *data) { rb_execution_context_t *ec = GET_EC(); rb_vm_t *vm = rb_ec_vm_ptr(ec); - switch (postponed_job_register(ec, vm, flags, func, data, MAX_POSTPONED_JOB )) { + begin: + switch (postponed_job_register(ec, vm, flags, func, data, MAX_POSTPONED_JOB, vm->postponed_job_index)) { case PJRR_SUCCESS : return 1; case PJRR_FULL : return 0; + case PJRR_INTERRUPTED: goto begin; default: rb_bug("unreachable\n"); } } -/* return 0 if job buffer is full */ +/* + * return 0 if job buffer is full + * Async-signal-safe + */ int rb_postponed_job_register_one(unsigned int flags, rb_postponed_job_func_t func, void *data) { rb_execution_context_t *ec = GET_EC(); rb_vm_t *vm = rb_ec_vm_ptr(ec); + rb_postponed_job_t *pjob; + int i, index; - if (st_lookup(vm->postponed_jobs, (st_data_t)func, 0)) { - RUBY_VM_SET_POSTPONED_JOB_INTERRUPT(ec); - return 2; + begin: + index = vm->postponed_job_index; + for (i=0; i<index; i++) { + pjob = &vm->postponed_job_buffer[i]; + if (pjob->func == func) { + RUBY_VM_SET_POSTPONED_JOB_INTERRUPT(ec); + return 2; + } } - switch (postponed_job_register(ec, vm, flags, func, data, MAX_POSTPONED_JOB + MAX_POSTPONED_JOB_SPECIAL_ADDITION)) { + switch (postponed_job_register(ec, vm, flags, func, data, MAX_POSTPONED_JOB + MAX_POSTPONED_JOB_SPECIAL_ADDITION, index)) { case PJRR_SUCCESS : return 1; case PJRR_FULL : return 0; + case PJRR_INTERRUPTED: goto begin; default: rb_bug("unreachable\n"); } } @@ -1647,12 +1681,12 @@ rb_postponed_job_flush(rb_vm_t *vm) https://github.com/ruby/ruby/blob/trunk/vm_trace.c#L1681 { EC_PUSH_TAG(ec); if (EC_EXEC_TAG() == TAG_NONE) { - st_data_t k, v; - while (st_shift(vm->postponed_jobs, &k, &v)) { - rb_postponed_job_func_t func = (rb_postponed_job_func_t)k; - void *arg = (void *)v; - - func(arg); + int index; + while ((index = vm->postponed_job_index) > 0) { + if (ATOMIC_CAS(vm->postponed_job_index, index, index-1) == index) { + rb_postponed_job_t *pjob = &vm->postponed_job_buffer[index-1]; + (*pjob->func)(pjob->data); + } } } EC_POP_TAG(); -- ML: ruby-changes@q... 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