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authorBjörn Gustavsson <[email protected]>2012-01-19 11:00:01 +0100
committerSverker Eriksson <[email protected]>2012-02-21 12:22:59 +0100
commitf81dd5da827e86af3bf6fedadeaaeb5fb3347c32 (patch)
treef05a3281b1eefcc68f1b0bd9513924b65360b6a2
parentdab78e34dac11579cda578ffc6cf9293394456e4 (diff)
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beam_ranges: Make ranges safe with multi-scheduling active
-rw-r--r--erts/emulator/beam/beam_load.c6
-rw-r--r--erts/emulator/beam/beam_ranges.c253
-rw-r--r--erts/emulator/beam/global.h4
3 files changed, 195 insertions, 68 deletions
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 873b94d175..6cabc6f558 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -5987,9 +5987,7 @@ void erts_start_loader_code_ix(void)
beam_catches_start_load();
export_start_load();
module_start_load();
- /*SVERK and more to come I guess...
- :
- */
+ erts_start_load_ranges();
CIX_TRACE("start");
}
@@ -5999,6 +5997,7 @@ void erts_commit_loader_code_ix(void)
beam_catches_end_load(1);
export_end_load(1);
module_end_load(1);
+ erts_end_load_ranges(1);
{
ErtsCodeIndex ix;
ix = erts_loader_code_ix();
@@ -6014,6 +6013,7 @@ void erts_abort_loader_code_ix(void)
beam_catches_end_load(0);
export_end_load(0);
module_end_load(0);
+ erts_end_load_ranges(0);
CIX_TRACE("abort");
}
diff --git a/erts/emulator/beam/beam_ranges.c b/erts/emulator/beam/beam_ranges.c
index 063b319f7a..ae701ea0c9 100644
--- a/erts/emulator/beam/beam_ranges.c
+++ b/erts/emulator/beam/beam_ranges.c
@@ -26,6 +26,7 @@
#include "global.h"
#include "beam_load.h"
+static Range* find_range(BeamInstr* pc);
static void lookup_loc(FunctionInfo* fi, BeamInstr* pc,
BeamInstr* modp, int idx);
@@ -34,67 +35,175 @@ static void lookup_loc(FunctionInfo* fi, BeamInstr* pc,
* each module. It allows us to quickly find a function given an
* instruction pointer.
*/
-static Range* modules = NULL; /* Sorted lists of module addresses. */
-static int num_loaded_modules; /* Number of loaded modules. */
-static int allocated_modules; /* Number of slots allocated. */
-static Range* mid_module = NULL; /* Cached search start point */
+struct ranges {
+ Range* modules; /* Sorted lists of module addresses. */
+ Sint n; /* Number of range entries. */
+ Sint allocated; /* Number of allocated entries. */
+ erts_smp_atomic_t mid; /* Cached search start point */
+};
+static struct ranges r[ERTS_NUM_CODE_IX];
+static erts_smp_atomic_t mem_used;
+
+#ifdef HARD_DEBUG
+static void check_consistency(struct ranges* p)
+{
+ int i;
+
+ ASSERT(p->n <= p->allocated);
+ ASSERT((Uint)(p->mid - p->modules) < p->n ||
+ (p->mid == p->modules && p->n == 0));
+ for (i = 0; i < p->n; i++) {
+ ASSERT(p->modules[i].start <= p->modules[i].end);
+ ASSERT(!i || p->modules[i-1].end < p->modules[i].start);
+ }
+}
+# define CHECK(r) check_consistency(r)
+#else
+# define CHECK(r)
+#endif /* HARD_DEBUG */
+
void
erts_init_ranges(void)
{
- allocated_modules = 128;
- modules = (Range *) erts_alloc(ERTS_ALC_T_MODULE_REFS,
- allocated_modules*sizeof(Range));
- mid_module = modules;
- num_loaded_modules = 0;
+ Sint i;
+
+ erts_smp_atomic_init_nob(&mem_used, 0);
+ for (i = 0; i < ERTS_NUM_CODE_IX; i++) {
+ r[i].modules = 0;
+ r[i].n = 0;
+ r[i].allocated = 0;
+ erts_smp_atomic_init_nob(&r[i].mid, 0);
+ }
}
void
-erts_update_ranges(BeamInstr* code, Uint size)
+erts_start_load_ranges(void)
{
- int i;
+ ErtsCodeIndex dst = erts_loader_code_ix();
- if (num_loaded_modules == allocated_modules) {
- allocated_modules *= 2;
- modules = (Range *) erts_realloc(ERTS_ALC_T_MODULE_REFS,
- (void *) modules,
- allocated_modules * sizeof(Range));
+ if (r[dst].modules) {
+ erts_smp_atomic_add_nob(&mem_used, -r[dst].allocated);
+ erts_free(ERTS_ALC_T_MODULE_REFS, r[dst].modules);
+ r[dst].modules = NULL;
}
- for (i = num_loaded_modules; i > 0; i--) {
- if (code > modules[i-1].start) {
- break;
+}
+
+void
+erts_end_load_ranges(int commit)
+{
+ ErtsCodeIndex dst = erts_loader_code_ix();
+
+ if (commit && r[dst].modules == NULL) {
+ Sint i;
+ Sint n;
+
+ /* No modules added, just clone src and remove purged code. */
+ ErtsCodeIndex src = erts_active_code_ix();
+
+ erts_smp_atomic_add_nob(&mem_used, r[src].n);
+ r[dst].modules = erts_alloc(ERTS_ALC_T_MODULE_REFS,
+ r[src].n * sizeof(Range));
+ r[dst].allocated = r[src].n;
+ n = 0;
+ for (i = 0; i < r[src].n; i++) {
+ Range* rp = r[src].modules+i;
+ if (rp->start < rp->end) {
+ /* Only insert a module that has not been purged. */
+ r[dst].modules[n] = *rp;
+ n++;
+ }
}
- modules[i] = modules[i-1];
+ r[dst].n = n;
+ erts_smp_atomic_set_nob(&r[dst].mid,
+ (erts_aint_t) (r[dst].modules + n / 2));
}
- modules[i].start = code;
- modules[i].end = (BeamInstr *) (((byte *)code) + size);
- num_loaded_modules++;
- mid_module = &modules[num_loaded_modules/2];
}
void
-erts_remove_from_ranges(BeamInstr* code)
+erts_update_ranges(BeamInstr* code, Uint size)
{
- int i;
+ ErtsCodeIndex dst = erts_loader_code_ix();
+ ErtsCodeIndex src = erts_active_code_ix();
+ Sint i;
+ Sint n;
+ Sint need;
- for (i = 0; i < num_loaded_modules; i++) {
- if (modules[i].start == code) {
- num_loaded_modules--;
- while (i < num_loaded_modules) {
- modules[i] = modules[i+1];
- i++;
- }
- mid_module = &modules[num_loaded_modules/2];
- return;
+ if (src == dst) {
+ ASSERT(!erts_initialized);
+
+ /*
+ * During start-up of system, the indices are the same.
+ * Handle this by faking a source area.
+ */
+ src = (src+1) % ERTS_NUM_CODE_IX;
+ if (r[src].modules) {
+ erts_smp_atomic_add_nob(&mem_used, -r[src].allocated);
+ erts_free(ERTS_ALC_T_MODULE_REFS, r[src].modules);
+ }
+ r[src] = r[dst];
+ r[dst].modules = 0;
+ }
+
+ CHECK(&r[src]);
+
+ ASSERT(r[dst].modules == NULL);
+ need = r[dst].allocated = r[src].n + 1;
+ erts_smp_atomic_add_nob(&mem_used, need);
+ r[dst].modules = (Range *) erts_alloc(ERTS_ALC_T_MODULE_REFS,
+ need * sizeof(Range));
+ n = 0;
+ for (i = 0; i < r[src].n; i++) {
+ Range* rp = r[src].modules+i;
+ if (code < rp->start) {
+ r[dst].modules[n].start = code;
+ r[dst].modules[n].end = (BeamInstr *) (((byte *)code) + size);
+ n++;
+ break;
+ }
+ if (rp->start < rp->end) {
+ /* Only insert a module that has not been purged. */
+ r[dst].modules[n] = *rp;
+ n++;
}
}
- ASSERT(0); /* Not found? */
+
+ while (i < r[src].n) {
+ Range* rp = r[src].modules+i;
+ if (rp->start < rp->end) {
+ /* Only insert a module that has not been purged. */
+ r[dst].modules[n] = *rp;
+ n++;
+ }
+ i++;
+ }
+
+ if (n == 0 || code > r[dst].modules[n-1].start) {
+ r[dst].modules[n].start = code;
+ r[dst].modules[n].end = (BeamInstr *) (((byte *)code) + size);
+ n++;
+ }
+
+ ASSERT(n <= r[src].n+1);
+ r[dst].n = n;
+ erts_smp_atomic_set_nob(&r[dst].mid,
+ (erts_aint_t) (r[dst].modules + n / 2));
+
+ CHECK(&r[dst]);
+ CHECK(&r[src]);
+}
+
+void
+erts_remove_from_ranges(BeamInstr* code)
+{
+ Range* rp = find_range(code);
+ rp->end = rp->start;
}
-Uint
+UWord
erts_ranges_sz(void)
{
- return allocated_modules*sizeof(Range);
+ return erts_smp_atomic_read_nob(&mem_used) * sizeof(Range);
}
/*
@@ -108,45 +217,61 @@ erts_ranges_sz(void)
void
erts_lookup_function_info(FunctionInfo* fi, BeamInstr* pc, int full_info)
{
- Range* low = modules;
- Range* high = low + num_loaded_modules;
- Range* mid = mid_module;
+ BeamInstr** low;
+ BeamInstr** high;
+ BeamInstr** mid;
+ Range* rp;
fi->current = NULL;
fi->needed = 5;
fi->loc = LINE_INVALID_LOCATION;
+ rp = find_range(pc);
+ if (rp == 0) {
+ return;
+ }
+
+ low = (BeamInstr **) (rp->start + MI_FUNCTIONS);
+ high = low + rp->start[MI_NUM_FUNCTIONS];
+ while (low < high) {
+ mid = low + (high-low) / 2;
+ if (pc < mid[0]) {
+ high = mid;
+ } else if (pc < mid[1]) {
+ fi->current = mid[0]+2;
+ if (full_info) {
+ BeamInstr** fp = (BeamInstr **) (rp->start +
+ MI_FUNCTIONS);
+ int idx = mid - fp;
+ lookup_loc(fi, pc, rp->start, idx);
+ }
+ return;
+ } else {
+ low = mid + 1;
+ }
+ }
+}
+
+static Range*
+find_range(BeamInstr* pc)
+{
+ ErtsCodeIndex active = erts_active_code_ix();
+ Range* low = r[active].modules;
+ Range* high = low + r[active].n;
+ Range* mid = (Range *) erts_smp_atomic_read_nob(&r[active].mid);
+
+ CHECK(&r[active]);
while (low < high) {
if (pc < mid->start) {
high = mid;
} else if (pc > mid->end) {
low = mid + 1;
} else {
- BeamInstr** low1 = (BeamInstr **) (mid->start + MI_FUNCTIONS);
- BeamInstr** high1 = low1 + mid->start[MI_NUM_FUNCTIONS];
- BeamInstr** mid1;
-
- while (low1 < high1) {
- mid1 = low1 + (high1-low1) / 2;
- if (pc < mid1[0]) {
- high1 = mid1;
- } else if (pc < mid1[1]) {
- mid_module = mid;
- fi->current = mid1[0]+2;
- if (full_info) {
- BeamInstr** fp = (BeamInstr **) (mid->start +
- MI_FUNCTIONS);
- int idx = mid1 - fp;
- lookup_loc(fi, pc, mid->start, idx);
- }
- return;
- } else {
- low1 = mid1 + 1;
- }
- }
- return;
+ erts_smp_atomic_set_nob(&r[active].mid, (erts_aint_t) mid);
+ return mid;
}
mid = low + (high-low) / 2;
}
+ return 0;
}
static void
diff --git a/erts/emulator/beam/global.h b/erts/emulator/beam/global.h
index 05517ac9e8..e6ff9d8577 100644
--- a/erts/emulator/beam/global.h
+++ b/erts/emulator/beam/global.h
@@ -891,9 +891,11 @@ Eterm erts_make_stub_module(Process* p, Eterm Mod, Eterm Beam, Eterm Info);
/* beam_ranges.c */
void erts_init_ranges(void);
+void erts_start_load_ranges(void);
+void erts_end_load_ranges(int commit);
void erts_update_ranges(BeamInstr* code, Uint size);
void erts_remove_from_ranges(BeamInstr* code);
-Uint erts_ranges_sz(void);
+UWord erts_ranges_sz(void);
void erts_lookup_function_info(FunctionInfo* fi, BeamInstr* pc, int full_info);
/* break.c */